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Modelling Study of Energy Use on a Construction Site by Adolphe

1. Table17 Energy delivered if the U value of double glazing window is 2 75 W mK Window External Double Total energy delivered wall glazing kWh year U value U value W m k W m k 0 27 29009 66 0 35 31864 65 2 75 0 76 39079 65 1 21 43846 4 Due to the insulation materials that tend to delay or stop heat transmission the coefficient of transmittance U value decreases and therefore the total energy consumed decreases As it is shown on the table17 the greater the U value of external wall the greater the total energy is delivered Also a minimal level of heating is required in cabins insulated to current regulation standards The maximum allowable elemental U values for external walls are 0 35W m K in England and Wales and 0 30 or 0 27W m K in Scotland Scottish regulations in 2002 required lower elemental U values for external walls than the equivalent regulations in England and Wales This because technical standards required in Scotland are different to those using a system of approved documents in England and Wales The revised 2002 England and Wales regulations have tried to simplify the situation Rather than having a separate method the elemental method now includes a higher degree of flexibility The external insulation is more effective because it eliminates thermal bridges reduces air wind and moisture penetration through the building envelope and therefore
2. is promulgated by management Responsibility for formulating and implementing energy policy lies with the energy management committee which is accountable to the main board This committee will be made up of representatives from each of the energy consuming sections within the industry The energy manager is responsible for coordinating energy management activities He she makes a monthly report to his her line manager providing separate accounts of expenditure on energy consumption and energy management activities 15 Through the line manager he she will make a quarterly report to the energy management committee which will report regularly and make an annual presentation to the main board on energy consumption and on energy management activities undertaken to reduce such consumption Formal communication on matters related to the control of energy consumption and energy management activities will be directed through the energy manager who will 14 bring it to the attention of his her line manager other senior managers and to the energy management committee All energy management activities will be subject to periodic review The energy manager will establish progress towards meeting objectives and the value for money of individual activities wherever possible An annual audit of these activities will be prepared on behalf of the energy management committee and presented to the main board 15 III Energy efficie
3. Figure2 Artificial lighting and daylighting combination 28 lamps off one lamp on both lamps on total illumination electric light contribution daylight contribution Form figure2 it is clear that the portion of the office near the windows is lit mainly by daylight the rear of the office is mainly lit by the artificial light The system of combined daylighting and artificial lighting contribute to the illumination of the central portion of the office The curves show relative light levels from both daylight and electric light As the daylight level falls off with distance from window the electric lighting makes up the difference so that total illumination is evenly maintained at design levels throughout the office So one can save electrical energy by controlling the artificial lighting with the photo electric cells which senses changing daylight levels and switch lights on and off as necessary HI 2 2 Artificial lighting III 2 2 1 Introduction Electric lighting system is typically composed of lamps circuitry switches lighting controls and luminaires When considering the efficiency of the lighting system the characteristics of all of these components must be included The quantity of the light of a certain surface is usually the primary consideration in the design of a lighting system This quantity is specified by the density of luminous flux or illuminance and measured in lumens m 21 Lighting syst
4. In this part of the thesis design changes options such as insulation and glazing types were modelled in order to see their technical performance in term of energy usage and identify the right alternative methods to save energy Different U values for insulated external wall and double glazing window were used in the model and these parameters were chosen because they may affect the total energy consumption For example window glazing can be used to affect heating requirements and occupants comfort by controlling the type and the amount of light that passes through windows And well insulated external wall has the benefits to improve the thermal performance of the building Insulation and glazing materials are well qualified to lower heat loss and gain they make an important contribution to energy conservation and to the sizing of heating equipment They also offer practical means for reducing heating loads without affecting the basic system design or without making demands to the users to change their living patterns The best way of reducing the internal surface temperature of windows and walls and therefore increase the dry bulb temperature is to combine improved insulation of walls and windows with reduced surface emissivity VI 5 2 Insulation materials The aim of an insulation material is to reduce heat transfer so it is worthwhile to examine the performance of different insulation materials to see whether the applications might p
5. It is calculated as follow CapitalCost AnnualSavings Payback period VII 2 3 Life Cycle Costing The life cycle costing is an analysis of the total cost of owning operating and maintaining a planned project over its useful life This analysis insists on the identification of all costs associated with the systems It can be used also to determine whether a specific project is cost effective or to compare the economic consequences of alternatives solutions When comparing the alternative solutions to a particular problem the system showing the lowest life cycle cost will usually be the first choice On NATS construction site the lighting system is provided by T8 58W fluorescent tubes throughout the cabins However it is suggested to replace this type of lights with its equivalent called T5 49W which is more energy efficient than T8 type In this study the two lighting systems T8 58W and T5 49W were compared and the total lighting electricity savings and energy costs savings were quantified 94 Table22 Total savings on lighting system when replacing T8 58W to T5 49W fluorescent tubes Lamp type T5 fluorescent tube T8 fluorescent tube Lamp wattage 49W 58W Luminous efficacy 1021m W Rated luminous flux 50001m 37001m per lamp Lamp life time 20 000hours 15 000hours Installation costs 10 10 luminaires gears Lamp costs 19 38 15 Electricity cost kwh 0 08 kWh 0 08 kWh
6. It is now possible to have an excellent daylight at a table or some other workplane and yet to be unable to see the sky because daylighting depends largely on light reflected by exterior surfaces and by interior surfaces Daylighting can provide the opportunity for both energy savings and improved visual comfort The level of its integration into the design can have a profound influence on the energy consumption To be effective daylighting must meet the same visual performance criteria as artificial lighting in providing adequate levels and quality of task illumination HI 2 1 1 Daylight factor The amount of daylight inside a room can be measured by comparing it with the total daylight available outside the room Their ratio called daylight factor remains constant for a particular situation because the two parts of the ratio vary in the same manner as the sky changes The daylight factor is defined as the ratio of the illuminance on a given horizontal plane in a room to the illuminance received at the same time on a horizontal plane exposed to 19 unobstructed sky It can be derived theoretically from the solid geometry of the building and its surroundings and the optical properties of the glass and the reflecting surfaces The daylight factor is partly due to the light received through the window directly from the sky and partly due to the light reflected from building opposite from the ground outside and from the intern
7. 44 I 3 1 2 3 Heat pumps II 3 1 2 3 1 Introduction Many modern buildings require simultaneously heating and cooling for prolonged periods during occupancy However the rising cost of energy is having an inflationary effect on energy cost consumption One obvious way to reduce energy costs is to use energy efficient equipments wherever possible and to recycle heat wherever possible The heat pump is well suitable for such applications and frequently shows a considerable saving in operating cost over other heating equipments Innovative use of heat pump principles may give considerable energy savings and more satisfactory human comfort than other systems I 3 1 2 3 2 Definition and heat pump s function A heat pump is an electrical device that extracts heat from a low temperature source and transfers it to a higher temperature so that it may be used for space or water heating Heat pumps transfer heat by circulating a substance called refrigerant through a cycle of evaporation and condensation A compressor pumps the refrigerant between two heat exchangers coils In one coil the refrigerant is evaporated at low pressure and absorbs heat from its surroundings The refrigerant is then compressed en route to the other coil where it condenses at high pressure At this point it releases the heat it absorbed earlier in the cycle The low temperature heat source may be from water air or soil which surrounds the evaporator The hea
8. Number of installations 140 3700 140units DEE 1 04units required in cabins at 5000 NATS Total installation costs 10 104 1040 10 140 1400 Burning hours over 3 years 3 48 7 20hours 20160hrs 3 48 7 20hours 20160hrs Time each lamp is 20160hrs 20160hrs E 1 344 teplaced in 3years 20000hrs 15000hrs Replacement costs 19 38 1 104 2016 15 1 344 140 2822 Electrical energy use 49 58 for each lamp kW 20160h 988kWh 1000 kW 20160h 1169kWh 1000 Total electricity use 988kWh 104 102752kWh 1169kWh 140 163699kWh Electricity costs 0 08 102752 8220 0 08 163699 13096 Running costs replacement electricity costs 2016 8220 10236 2822 13096 15918 Total costs over 3years installation costs running costs 1040 10236 11276 1400 15918 17318 Total saving over 3years 17318 11276 6042 The total savings on lighting systems year when replacing T8 58W to T5 49W 6042 fluorescent lamps SE 2014 year If NATS lighting system is controlled by switching off lights anytime they are not in use and the existing lights 58W T8 are removed and replaced by the T5 49W significant amount of money could be saved and the CO2 emissions could be reduced as it is shown below 95 VII 2 4 Rep
9. U value 1 7 O Window U value 2 75 88 Replacing non efficient glazing with advanced insulating glazing leads to the energy savings and consequently to the CO emissions reduction VI 6 Impact of windows and doors opening on total energy delivered Windows can represent a major source of unwanted heat loss and discomfort if they are left open unnecessarily In winter for example wind blows a large volume of outdoor cold air into indoor spaces through the opening paths And the energy required for heating indoor spaces is associated with air infiltration If the air infiltration rate increases the total energy delivered increase as well Windows are often left opened on NATS cabins even when there are unoccupied for significant periods of the days In this situation it is obvious that the air infiltration becomes very high because the opening windows produce a boost in ventilation rate The increases of air infiltration within cabins have significant effects on total energy consumption as it is shown in the table below Table20 Impact of air changes variation on total energy delivered at NATS cabins Double External Minimum Total energy glazing wall air delivered window U value changes kWh U value W mK rate W mK ac h 0 5 31864 65 me 1 5 47846 67 2 75 0 5 39079 25 0 76 1 5 52907 71 1 5 51820 52 0 67 2 60327 85 From the above table we can see th
10. then the air will flow in to replace the extracted air So the supply rate will match the extract rate although the source of the supply may need to be considered in the ventilation design Ventilation process extracts before it is generally widespread water vapour and or pollutants from areas where there are produced in significant quantities The design of ventilation systems needs to take into account of volume of air movement and distribution of the air infiltration temperature and humidity change energy conservation and control The common systems used to control some or all of these factors can be considered as two broad types natural ventilation and mechanical ventilation III 3 3 3 1 Natural ventilation Natural ventilation is the traditional method that allows fresh outdoor air to replace indoor air It is uncontrolled air movement into a building through cracks and infiltration and through vents such as window and doors This system operates without the use of a fan or other mechanical systems Natural ventilation is provided by two broad mechanisms such as air pressure differences as caused by the wind direction or air movement over and around the building and stacks effect caused by natural convection of warm air rising within the building However natural infiltration in building is unfortunately unpredictable and uncontrollable because it depends on the building s air tightness outdoor temperatures wind and
11. 84 Perlite Loose 0 92 1 08 Polystyrene Rigid 1 44 2 12 Polyurethane Rigid 2 24 3 08 Building regulations deal with design standards or fabric heat loss and have historically set minimum insulation levels in terms of elemental U values Each element of the building envelope roof walls floor windows and doors is assigned a maximum heat loss rate The following tables show some e lemental U values of each element of the building envelope required by the building regulations Table13 Maximum U values in 2002 Building Regulations Part L2 England and Wales 23 Element U value W mK Pitched roof with insulation between rafters 0 2 Pitched roof with integral insulation 0 25 Pitched roof with insulation between joists 0 16 Flat roof 0 25 Walls including basement walls 0 35 Floors including ground and basement 0 25 floors Windows doors and rooflights area 2 2 weighted average glazing in metal frames Windows doors and rooflights glazing in 2 0 wood PVC frames 57 Table A Maximum U values in 2002 Building Regulations Scotland 21 Element A B W m K W mK Pitched roof with insulation between rafters 0 2 0 18 Pitched roof with insulation between joists 0 16 0 16 Flat roof 0 25 0 22 Walls including basement walls 0 30 0 27 Floors including ground and basement 0 25 0 22 floors Windows
12. 88 VII Economic aspects on heating and lighting systems VII Economic aspects on heating SyYSteEMS sssessssrsssstnssrirrertrtnrtrn netna rernnn nenn nnen nnne 91 VII 2 Economic aspects On lighting swvsiems tasenn netrn nernnn nenn nnnn ennnen 92 VIND Ts ATO Le e RN 92 MIIP2225 PAybdEk PE A EE 93 VIE Lite CY Cle COSTING ed a A E a eee ee Med ete 93 VII 2 4 Replacing T8 58W with T5 49W fluorescent lamps and switching on off as MOGESSONY EE 95 VII 2 4 1 Conclusions ANd recommendoionms sesssseesssresertntertttnrttnnettnnernnn nenn nnne nennen 97 VII Conclusions and Recommendations for future work 98 VIL REEERENG ES ia ieie 2encdeces eensdeenseewste exe deen Seenacdenstecnsddaasts casdeaue devetdeashs aed eae erat 100 APPENDIX Simulation results for Zone 1 RestaurantG Te SEOMEIY ENG Ke le EE 102 2 SummMary description for the zone AEN 103 3 ZONS CONSIMUCTION STIS TE 104 4 Zone operation notes Ale ee Ee We S TEE 106 4 2 SCHEQUIEG GIG le 107 5 Zone db T figures 5 1 Plot of zone dry bulb temperature for the period Tue14 02 to Mon20 02 107 5 2 Frequency distribution of hours when the zone dry bulb temperature is in a specific elle 108 6 Comfort assessment for the zone ON DAY 14402 108 7 OUTPUT ZONS GETIMMON EE 109 8 Zone Casual gains distribution KWHMS ce ccececeseeceeeeeeeeeeeeeceeeeeseeeeeeeeceeeeeeteeeieesees 109 Ke re Ve e le 110 TO ZONG TUK setts setae sso asec
13. Infiltration air load in cabins 1 3 5 7 9 11 13 15 17 19 21 23 25 27 zones DI winter RB summer The figure8 shows fairly winter and summer conditions within NATS cabin accommodations The total heat losses depend upon both the area of external surfaces and the periods of the year On this figure8 it appears that the total heat loss is higher in winter periods than in summer periods for the same zone This result is to be expected because the total volume of air passing through the cabins structure in winter is much greater than that passing through the fabric envelope in summer periods Heat is therefore lost through NATS cabins structure and air infiltration causes a net heat loss more in winter than in summer 75 Figure8 Comparison of heat losses for a typical week in winter with that for a typical week in summer periods Total heat losses from cabins 1 3 5 7 9 141 13 15 17 19 21 23 25 27 zones DI winter RB summer 76 VI 2 Casual heat gains for National Air Traffic Service NATS cabins In this case casual heat gains take into account of the heat given off within the NATS cabins by various activities and equipment that are not primarily designed to give heat The major source of such heat are heat from people heat from lighting and other heat dissipating equipment such as computers water heating cookers refrigerators electrical applianc
14. Standard U value for construction partition is 0 25 Surf 6 1 72 15 0 0 150 700 0 1420 0 0 90 0 65 Plywood 2 D 50 0 0 000 0 0 0 0 air gap R 0 170 3 103 50 9 0 180 800 0 857 0 Perlite plasterboard 4 72 15 0 0 150 700 0 1420 0 Plywood 5 281 50 0 0 040 12 0 840 0 0 90 0 65 Glass Fibre Quilt Standard U value for construction extern_wall is 0 35 Surf 8 HN resrt Gr HN rest br rest neet Ir Rest_corriGre Rest Meer Rest docuctr Rest_off2al Rest_off2l rest_Corr_l Rest HE vw Rest_kitchl Rest_off1_l v2 201 W v2 225 103 Standard U 1 242 2 U A 242 Standard U 1 242 2 a 24 Standard U 1 i104 2 W A 66 d 5 ited Standard U 1 itd 2 A 66 4 W 5 LO4 Standard U 1 211 2 150 Standard U 1 211 2 150 Standard U 1 211 2 150 Standard U 1 21i z 150 Standard U 1 211 2 150 Standard U 1 211 2 150 Standard U 1 21i 2 150 Standard U 1 21i 2 150 Standard U Oo E w Ph e 50 0 150 0 50 0 19 0 6 0 100 0 Value 0 150 700 0 0 060 300 0 0 000 0 0 0 150 700 0 0 04 160 0 0 180 800 0 for construction 105 1420 0 0 90 0 65 1000 0 0 0 1420 0 1360 0 837 0 0 91 0 60 arnd_floor is 647 0 0 83 0 05 J Plywood Fibreboard air gap R 0 170 Plywood Wool felt underlay Perlite plasterboard 25 Plate glass 6 0 D ZO 2710 0 12 0 0 000 0 0 6 0 9 760 2710 0 value for construction 6 0 0 760 2710 0 12 0 0 000 0 0 6 0 D CDU 2710 0 Value for const
15. and force convection to transfer the heat produced They furnish directly warm air to the space in which they are installed and obtain themselves their heat from steam hot water electricity and also from direct combustion of gas or oil Permanent installed heaters whether fuel is supplied with a special electrical circuit a gas pipe or a supply of solid fuel must be sized correctly for the heat load Oil and gas heaters that receive heat from direct combustion require also the electricity for ignition and to operate a fan In that case oil or gas is piped to the heating element and this latter requires a flue or chimney to take away the combustion products especially to the outside the atmosphere The combustion products from natural gas are sometimes allowed to be released into the heated space if it is well ventilated III 3 1 2 Heat sources for central heating systems Heater installation in each room of a building is required for space heating However it is preferable to use a central heat source with a system of heat transfer to the rooms In central heating system heat generating equipment is used for air or water heating or for steam generation which is then conveys the heat to the various rooms and spaces throughout the building The heating system equipment using air as the primary distribution fluid is known as a furnace And if the fluid is a liquid or a steam the heating device is a boiler These terms
16. assumed that if the opening occurs for most of the time the minimum of air changes rate per hour within NATS cabin accommodations is 1 5ac h or 2ac h but if windows opening are well controlled the minimum air changes rate per hour is 0 5ac h 90 As it appears in figure16 if the air changes rate is higher the total energy consumption would be higher as well It is also the same situation for the figure following figure that shows the effect of increasing infiltration rate on total energy consumption year external wall U value 0 76W m K and double glazing window U value 2 75W m K Figurel7 Impacts of increasing infiltration rates on the total energy delivered year U value for ext wall 0 76W m K U value for double glazing window 2 75W m K Windows and doors opening effect on total energy consumption within NATS cabins e 10000 S 8000 2 S 6000 2 g 4000 gt 2000 kl E ui 1 2 3 4 5 6 7 8 9 10 11 12 Month m windows amp doors opening controlled windows amp doors left open unnecessarily If we compare the total energy delivered when the air infiltration rate is kept to a minimum 0 5ac h and the U value for both external wall and double glazing window to 0 27W m K and 1 7W m K respectively with the total energy delivered when the air infiltration is kept to the highest level 2ac h when the U value for both external wall and double glazing window respectivel
17. decision making at different levels and this can undermine the energy management process 15 12 II 2 Aims and objectives Energy management on a construction site aims to control energy consumption in order to avoid unnecessary expenditure and save money It improves cost effectiveness and working conditions protect the environment and prolong the useful life of equipments and fuels The long term objectives are to buy fuels at the most economic costs to burn and use them as efficient as is practicable to reduce the amount of pollution particularly carbon dioxide emissions caused by energy consumption In the short term energy management aims are to gain control over energy consumption by reviewing and improving the purchasing the operating and training practices to invest in an energy saving programme which will maximize returns on investment to safeguard the gains by establishing and maintaining the management information system designed to ensure that information is delivered to those who need it on time and in a form which supports their managerial decision making II 3 Energy policy in perspective Escalating energy costs are putting pressure on management budgets So a thorough energy management is a means to a particular end safeguarding an industrial business so that it can pursue its activities without hindering by disruptions to its energy supply or by having to bear unnecessary costs It is i
18. doors and rooflights area 2 2 2 0 weighted average glazing in metal frames Windows doors and rooflights glazing in 2 0 1 8 wood PVC frames Column A refers to a building with a heating system boiler efficiency above a certain standard Column B applies to all other dwellings The target U value method sets a requirement for the average U value which can be achieved trough any combination of insulation levels of individual elements and areas of windows doors and roofights The effect of the heating system and solar gains are also taken into account II1 3 3 1 4 Energy efficient window and glazing systems Energy efficient window glazing can admit the maximum light and solar gain in winter months with a minimum of heat loss It can affect both heating and electric requirements within a building and therefore reduce the energy use throughout the year One method of reducing heat gains or loss through windows is coating the glass with an invisible heat reflective material called low e glazing Low E coatings can be applied to double pane glass to minimize heat loss through window These glazing let solar heat in to offset winter heating system requirements and keep the warmth inside Thus low e coatings can reduce radiation heat transfer to the point that heat transfer by natural convection becomes dominant However this convection loss can also be reduced substantially by applying the technique of double glazing th
19. ee dees 110 Tie CONMOLGASSEN ee 111 I Introduction The energy consumed on a construction site varies continuously and generally increases as a project progress The usual practice of considering annual energy consumption is wholly inappropriate for the construction businesses because every project is different and projects run only for a short term period However as the annual energy consumed within cabins on a construction site is relatively constant it is possible to establish benchmarks for energy performance based on standards of cabins This could be achieved by using a thermal simulation program And the result would be used to compare similar cabins or using the current consumption figures against advanced cabins with higher levels of insulation and units which meet new building regulations The focus of this research was on total energy use within the National Air Traffic Service NATS cabins because it was found that the energy usage is not well controlled at present 17 and temporary accommodation has received relatively little attention to date Since some construction companies wish to become more sustainable the results of this study would help them to achieve their goals Energy saving opportunities through innovative approach and new technologies were identified and a specification for energy efficient prefabricated cabins was outlined This research focused mostly on the heating and lighting systems within
20. for their continuous support and encouragements Last but not least my parents to whom I dedicate this thesis deserve much more than simple thanks I am heavily indebted to them for providing an emotional strength that made my effort worthwhile Abstract The need for energy conservation is a real challenge worthy of everyone s attention Recently the energy crisis has led to an increased discussion by the public of the pros and cons of different kinds of energy This is because utility rates are continuing to climb natural gas rates are increasing and fuel oil prices are sharply rocketing On the same time limited fuel resources are being depleted and some countries are becoming increasingly dependent upon oil and gas importation So many companies are deeply concerned with this situation because their businesses are seriously affected The aim of this thesis is to perform a modelling study of energy use on a construction site to meet the heat and lighting requirements within a temporary accommodation The focus of this research was on temporary accommodation because it has received relatively little attention to date and it was found that the energy usage within temporary cabin accommodation is not well controlled at present Through literature review various energy efficient methods and technologies were studied and different energy savings opportunities were identified In the case study different technologies options
21. forced air furnace Standard indoor furnaces are generally made of cold rolled steel If furnace is exposed to clean air and the heat exchanger remains dry this material has a long life and does not easily corrode The air combustion contaminated by substances such as cleaning solvents and halogenated hydrocarbon refrigerants can cause problems of heat exchanger corrosion and failure Common corrosion resistant materials include aluminized steel ceramic coated cold rolled steel and stainless steel Furnace controls include an ignition device gas valve fan switch limit switch and other components specified by the manufacturer An air filter in a forced air furnace remove dust from the air that could reduce the effectiveness of the blower and heat exchangers 42 III 3 1 2 1 2 Electric furnaces A resistance type heating unit heats the circulating air directly or through a metal sheath enclosing the resistance element Although the efficiency of an electric furnace is high it can be more expensive long term heating option because the electricity is relatively expensive form of energy and due to heat losses through its ducts The operating cost may be reduced significantly by using a heat pump in place of a straight electric resistance furnace The building s air is delivered to the furnace through return ducts and heated air is delivered back to the room through supply ducts If these ducts run through unheated areas
22. gaps in construction This air change may be accidental infiltration There is usually some wastage of heat energy used for water heating and space heating and the design of the services can minimize or make use of this heat wastage The heat given off by the hot water storage cylinders and distribution pipes even well insulated ones should be used inside the building if possible rather than wasted outside III 3 3 3 Ventilation systems Ventilation in buildings is the process of changing air in enclosed space It exchanges indoor air with outdoor air by taking continuously new air from a clean source in order to provide comfort to the occupants The main objectives of ventilation systems in buildings are the following supply of oxygen removal of dioxide of carbon control of humidity and air velocity for human comfort removal for body odours micro organisms moisture heat particles such as smoke and dust removal of organic vapours such as cleaning solvents removal of 61 combustion products from heating and cooking removal of ozone gas from photocopiers and laser printers removal f methane gas and decay products from ground conditions Ventilation of a building helps to remove moist air which might otherwise condense if it is cooled inside and damage the building This system is capable of limiting the moisture accumulation within a building In simple case it is assumed that if air is actively extracted by a fan
23. operate mostly automatically such as sensors actuators switches indicators etc II 3 2 2 Automatic heating control equipments II 3 2 2 1 A timer or programmer It is a device that allows the time settings for space heating and hot water to be full independent Some models switch the central heating and domestic hot water on and off either at the same time or at different times A programmer set the on and off time periods to suit the lifestyle and can set the heating and hot water to run continuously to run under the chosen on and off heating periods or to be permanently off When the central heating is running continuously or the heating is left on all day the energy is being wasted In spring and autumn for example there is no need to keep the heating on all day 48 With a seven day timer it is possible to set a different heating pattern for weekdays and weekends Some timers allow different patterns for each day of the week this can be useful for those temporarily occupied rooms or offices such as conferences rooms III 3 2 2 2 A room thermostat A room thermostat measures the air temperature within the building and switches the heating system on and off as needed It senses the air temperature switches on the heating system when the air temperature falls bellow the thermostat setting and switches it off once this set temperature has been reached The room thermostat doesn t affect neither how quickly th
24. operates 10hours a day from Monday to Friday and uses 140 fluorescent lamps for lighting systems FigureS NATS cabin accommodations 66 IV 3 NATS cabins description and structure IV 3 1 Description The two types of cabin accommodations located at Prestwick Airport are shown in the figureS The old cabins are located on left side towards the north and the new cabins are located on the right side towards the south For the old cabins the windows sizes are 108cm wide by 82cm high each These old cabins have north facing windows 6 windows on lower floor and 6 windows on upper floor west facing windows one on lower floor and 3 windows on upper floor and East facing windows 2 windows on lower floor and 3 windows on upper floor The new cabins are also shown on the same figure and their windows sizes are 80cm high by 69cm wide each These windows are East facing with 1 7windows on upper floor and 16 windows on lower floor and West facing with 18 windows on upper floor and 18 windows on lower floor Both the old cabins and new cabins have doors of the same sizes 193cm high by 82cm wide and the whole building has a corridor on both lower and upper floors with approximately 90cm wide and 36m long running through the centre of the cabins IV 3 2 Structure As stated previously Laing O Rourke is the main contractor on the third phase of construction which includes cladding roofing building services and i
25. other factors 62 If these natural forces are not present the building may lack sufficient ventilation for pollutants removal it may sometimes be necessary to use mechanical ventilation Buildings with high infiltration rates may experience high energy costs The high infiltration may allow contaminant air to enter from polluted areas So the building should be tightly sealed to reduce infiltration and a mechanical ventilation system should be installed to provide fresh air and remove pollutants when and where needed in a controlled manner that does not negatively impact indoor air quality or heating and cooling bills III 3 3 3 2 Mechanical ventilation Buildings need to have an indoor outdoor exchange of air to replenish oxygen used by the occupants and to remove pollutants generated by breathing different activities within the building and emissions from building materials and furnishings The decision to use mechanical ventilation systems is typically motivated by concern that natural ventilation is not providing adequate air quality The use of mechanical ventilation makes it possible to use spaces such as deep within the buildings that could not be easily ventilated by natural means Mechanical ventilation uses a fan or fans to create air change and movement Unlike natural ventilation the system can be designed to provide a positive air change and air movement However it costs more to install operate and to maintain Th
26. they lose some of their heat through air leakage as well as heat radiation and convection from the duct s surface A fan is used to maintain the flow and in most installations the air is filtered before passing over the hot surfaces of the furnace The furnace may be controlled manually or by a thermostat located in the return air path In an electric furnace blower large fan move air over a group of electric resistance coils The furnace s heating elements activate in stages to avoid overloading the building electrical system If a dirty filter is blocking air flow or if the blower fails a built in thermostat also called limit controller may b used to shut the furnace off as well as to prevent a overheating III 3 1 2 2 Boilers A boiler is a central heating device which use water in the form of liquid or steam as a primary distribution fluid in central heating system It is a pressure vessel heat exchanger made in cast iron steel or copper and designed with fuel burning devices and other equipments to burn fossil fuels It also transfers heat from electrical resistance elements to the fluid or by a direct action of electrodes on the fluid 43 The combustion space of some boilers is called furnace and the area of fluid backed surface exposed to the combustion products or to the fire side surface is the boiler heating surface However in the case of electric boilers electrodes are immersed in boiler water and the heating su
27. 0 25 0 30 Glasswool 0 60 Ceiling mineral 0 25 0 30 0 60 0 25 0 30 0 60 0 25 0 30 0 60 0 25 0 30 0 60 0 25 0 30 0 60 0 25 0 30 0 60 0 25 0 30 0 60 0 25 Glagswool Ceiling mineral Glagswool Ceiling mineral Glasswool Ceiling mineral Glasswool Ceiling mineral Glasswool Ceiling mineral Glasswool Ceiling mineral Glasswool Ceiling mineral 106 Casual gains for RestaurantG Total sensible Equipt sensible Lights sensible Occupt sensible Weekday Saturday 2 ea CH wen ee em wm we He 0 0 10 0 20 0 0 0 10 0 20 0 0 0 Time hrs 5 Operation notes Notes could have 20 occupants during working hours has 21 fluorescent Number of bWeekday Sat Sun casual gainse 15 0 o Tay Gain Type Period Sensible Latent Radiant Ho labl Hours Hagn tW Magn Ch Frac Wkd 1 ccuptl i 7 1 0 D D 0 50 kd 2 Deeupth 7 6 60 0 30 0 0 50 ikd 3 Deeupth 8 49 180 0 30 0 0 50 Wkd d Occupthl Ee 360 0 180 0 0 50 Wkd 5 Occupth 12 i4 1800 0 300 0 0 50 Wkd Deep 14 17 360 0 1850 0 0 50 Wkd Oecupth 17 18 60 0 30 0 0 50 Wkd 8 Deep 18 24 D D 0 0 0 50 Wkd 9 Equipt 44 24 D H 0 0 0 50 Wkd 10 Equipthl i 12 D D 0 0 0 50 Wkd 11 Lightsll Oo 24 D H D D 0 50 Wkd 12 Equipt 12 14 E00 O D D 0 50 Wkd 13 Lightsll 9 17 1072 0 0 0 0 50 Convec Frac 0 50 0 50 D P 0 50 0 50 0 50 0 50 0 50 0 50 0 50 0 50 0 50 0 50 Total latent Equipt latent Lights latent Occupt latent S
28. 0 27 W m K Window External Total energy double wall Delivered per year glazing U value kWh U value W mK W mK 1 2 28101 48 2 75 0 27 29009 66 87 Table19 Total energy delivered if the U value of external wall is 0 35 W m K Window External Total energy double wall Delivered per year glazing U value kWh U value W mK W mK 1 2 29704 18 1 7 0 35 30187 18 2 75 31864 65 High performance energy efficient windows have an impact on total energy consumption They have lower heat loss and less air leakage and can improve comfort and minimize condensation On this study if we compare from the above 2 tables 18 and 19 the highest U value with the lowest U value we could find the total energy which could be saved year by only changing the U value of double glazing windows This latter is 2160 47kWh i e small effect compared to changing wall U value The following figure shows the impact of glazing systems on the total energy delivered Figurel5 Effects of glazing systems and their modifications on total energy consumed with U value of with external wall 0 35W m K 7000 6000 5000 4000 3000 2000 1000 energy delivered year Impact of double glazed windows on NATS cabins energy consumption U value of external walls 0 35 6 7 8 9 10 11 12 month D Window U value 1 2 B Window
29. 2 2 4 3 3 Lighting Control SWitCheS relOYS ccececceeeeececeeeeeceeeeeeeeceeaeeeeeeeaeeeseeeeeeeeeeaeeeees 35 II 2 2 5 Lighting design ANA Measurement ss ssssessssrsssrrertrnstttnstrtnerttnntntnnnt tnne nenn nnenne 35 Ill 2 2 5 1 Measurement of IIQHtiING 2 cccccececceeesceeeeeeeecececeeeeessceeceeeeceesedeceeesseeseneseeeesees 36 Ih22 5 2 LIQHtING Aesi gAs e e e e ep eee ee E aE 36 II 3 Heating systems in a temporary ACCOMMOCATION 0 eeeeeceeeeeeeeeeeeeeeteeeetneeeeeeettaeees 39 Ill 3 1 Space heating ecuiprments AAA 39 UE Tole UIT AS EE EE 39 1 3 1 2 Heat sources for central NEATING SYSTEMS eeecceeeeeceeeeeceeeeeeeeeeeeeaeeeeteeeetseerenaes 39 i3121 FUAC EE 40 ER KC E Ee le V re ee n inn le LEE 41 WMS D Electric TUNATE E 42 W322 BOIS S A tie Ree eet eave yee eee sed et a E a E 42 3 12 35 HE Gt PUMPS EE 44 1 3 2 HEATING control IN DUICINGS erarnan iieiea 47 let tee HE iesse deer e e deeg ea reegt Seengen Dei emu hla ee a 47 1 3 2 2 Automatic heating Control swstemg trne eenn nnennnt 47 11 3 3 Building design for rational energy use ON heating SYSTEM eeceeeeeeeceeeeeeeeeetees 51 33 1 Building ENV GlO EE 51 IEN EI AMUN lge MES 52 333 7322 Moisture COntOl c2ecnv ie eee eed ee el eee lee eee 54 WSS E le Uer EE 55 111 3 3 1 4 Energy efficient window and double glazing SYSTEMS ccecceceeteeeeeeeteeeeees 57 INSES DEASEGT GGINS POSSE S ahos et ceeds aed eth aetna te ete ages Been he
30. 2 9 48 6 107 1 77 28 0 procu_ 36 5 24 3 68 1 77 71 V 1 3 Internal gains and schedules On NATS construction site cabins are occupied from Monday to Friday 8h to 18h lights are on and off during this period and some electrical devices are used on this period In order to define the essential characteristics of what goes on in cabins casual sensible and latent heat gains for people lights and small power has been considered this provides schedules for the different casual gains on Weekdays Saturdays and Sundays This model was run for 40 persons working on site on weekday period from 8h00 till 18h00 and it is assumed that one person doing the office work produces 90W sensible and 45W latent heat gain V 1 4 Ventilation The air flows infiltration and or ventilation rates have been defined on basis of air changes per hour This latter vary with the occupancy level and the activity undertaken within cabins For the reasons of indoor air quality it is recommended that the fresh air supply shouldn t be less than 0 5ac h even if there is no one in the room So in this model we considered a permanent infiltration of 0 5ac h when the cabins are not occupied night times and weekends During the weekdays the infiltration rate could be high more than 0 5ac h due to the doors and windows opening and the number of occupants 72 V 1 5 Heating control In NATS cabin accommodations the inside environmental temp
31. Modelling Study of Energy Use on a Construction Site by Adolphe NDAYIRAGIJE Reg No 200494711 A thesis submitted in fulfilment of the requirements for the degree of MSc in Energy Systems and the Environment Supervisor Dr Paul STRACHAN Strathclyde University Department of Mechanical Engineering September 2006 Copyright statement The copyright of this thesis belongs to the author under the term of UK copyrights acts as qualified by the University of Strathclyde regulation 3 49 Due acknowledgement must always be made of the use of any material contained in or derived from this thesis Acknowledgements I am extremely grateful to the many people who contributed directly or indirectly to the preparation of this thesis First my thanks go to my supervisor Dr Paul Strachan his valuable comments suggestions and gentle encouragements have always prompt and pertinent Next my thanks go to those who helped and guided me at one stage or another of this thesis especially Dr Steven Thomson Laing O Rourke resource strategist and Mr Georgios Kokogiannakis ESRU at Strathclyde University These people were extremely generous with their time and hospitality in providing useful information every time I asked I wish also to express my deep gratitude for the assistance and support provided by Bridges Project I am very please to thank Maggie Lennon Bridges Project director and extend special thank to my family and friends
32. acceptable ke eee TOON H o t E SN T zl OO M zl COD D Whe GO OH OPP Coe eo PR ZC 0 o o A A A G HA nd 109 Output zone definition Libs NNATS_cabins rest Results for NNATS_cabins Period Tue 14 Feb 00hS0 tot Mon 20 Feb 23ha0 Yeart2006 t simi 60m output 60m fone total sensible and latent plant used klbrs fone Sensible heating Sensible cooling Humidification Dehumidification id name Energy No of Energy No of Energy No of Energy No of ikihrs He rad kbesi Hre rgd Ckulhes He rgd klbrsi He rod 1 RestaurantG 234 57 50 0 0 00 o 0 O00 0 0 D 00 0 0 All 234 57 0 00 O00 0 00 Libs NNATS_cabins rest Results for NNATS_cabins Period Tue 14 Feb 0Qh40 tot Mon 20 Feb 23ha0 Yeart20Q06 7 simi 60m output 60m Casual gains distribution kllhrs for RestaurantG CL Gains Total Convectivel Radiative Radiant by connection type tupe ContRad part fairdl on surf external internal ground Oecupt 40 30 15 15 14 88 Bopa 2 76 7 29 4 54 0 2 Btrn 0 27 0 00 0 00 Lights 42 00 21 44 21 05 Gopq 4 91 10 30 6 84 0 39 trn 0 39 0 00 0 00 Equipt 6 00 3 00 2 95 Bopq 0 55 1 44 0 96 0 05 Btrn 0 05 0 00 0 00 Totals 79 18 39 55 39 55 7 93 15 02 12 64 Number of hours occupiedt Bo 00 Number of hours with lightest 45 00 Number of hours with small powers 15 00 Number of hours with ctld gains 0 00 Gopq amp Btrn associated with opaque or transparent surfaces Libs NNATS_ca
33. ains w inter m transp heat losses w inter O transp heat gains summer O transp heat losses summer 80 As it appears on the figure11 the transparent heat gains losses depend not only on the type of the transparent material but also on its size For example zone RestaurantG and zone 18 Open_plan_U are where transparent heat gains losses are higher than other zones for NATS cabins In zones 12 and 13 there is no transparent gains losses because these are corridors and they have no transparent areas In winter periods transparent heat gains are lower than they are in summer periods However the opposite appears for transparent heat losses for both seasons This may results on solar heat gains that are more important in summer than in winter periods VI 4 Heating requirements for NATS cabin accommodations The energy requirement within cabins at any particular time depends on the state of heat losses and heat gains at that time To maintain the required indoor conditions heat casual gains given off by lighting people and small equipment make an important contribution to the energy conservation and to the sizing of heating equipment It can be used for space heating rather than to be wasted to the outside and the energy delivered by a heating device could be reduced and therefore saving energy When casual heat gains and solar heat gains are used efficiently for space heating the size of the heating equipment and th
34. al surfaces of the buildings It can be used with any exterior daylight illuminance and indeed this is one of its advantages II 2 1 2 Combined daylight and electric light Lighting should be planned according to the task performance needs The task to be performed in each area of the building should be identified in order to coordinate the illumination requirements the orientation of the tasks and the location of the lighting equipment All lighting whether electric or daylighting costs energy so an energy conscious design dictates the use of only the amount of lighting required Working by natural light is most preferable However it is often difficult to provide adequate levels of natural illumination to all parts of the interior In this case daylight factor decreases rapidly with the depth of the office And it would not be economical to increase the ceiling height merely for the purpose of extending the use of daylight The best solution to the above is to utilize daylight as far as possible in that part of office that is close to the windows and use permanent supplementary artificial light for the interior However a high illuminance level wastes energy and a low illuminance level may cause glare from the windows In the case of low illuminance additional electric lights are provided during daylight hours at the rear of the office to overcome the glare and these are switched off at night time This is shown in figure2 20
35. ance results by improving external wall insulation from the conventional U value 0 67W m K to the external wall U value 0 35W m K recommended by the UK new building regulations 23 and saved 2277 05 year on heating systems and on the same time reduced 12 24 tonnes of CO2 emissions year from the environment If the existing lighting fluorescent tubes T8 58W is replaced with the most energy efficient fluorescent tubes T5 49W and lighting control is improved 27tonnes of CO2 emissions year could be reduced and 540 1 year could be saved There is still great potential to go further in reducing energy costs by using new energy efficient technologies with good management At present the lack of automatic controls of heating and lighting systems in some areas and the improper energy management such as leaving a room with heaters and lights switched on and opening windows unnecessarily results in significant energy wastage on NATS construction site Briefly improving thermal insulation and glazing systems reducing ventilation air quantities and lowering lighting levels can make an important contribution to energy savings in temporary accommodation Added to this designing an accommodation for the economically optimum level of thermal self efficiency will not only minimize annual energy costs but in most cases will also stabilize the interior surface temperature of the envelope resulting in more uniform interior conditions and g
36. apour is kept away from cold surfaces on which it might condense to liquid water It decreases then the possibility of moisture vapour to condense to water within the structure A vapour retarder is a vapour resistant membrane attached to insulation materials batt or roll in order to resist the movement of the moisture vapour to cold surfaces where it could condense to liquid water Vapour barriers are always installed toward the heated space so that they are placed between the heated room and the insulation They protect insulation from moisture produced in heating building While most moisture enters walls either through fluid capillary action or as water vapour through air leaks they retard moisture due to diffusion 55 III 3 3 1 3 Insulation Heat is lost from a building through the fabric envelope roofs walls floor windows and doors and through infiltration of cold air via any holes and gaps The heat transmission that would normally be accomplished through natural air movement can be slowed down by insulation materials which performance is a function of the nature of the material used the thickness and a number of other factors Insulation material is available in three basic types bans as it is shown in the following table Tablel 1 Insulation types 26 Type Description Batt or blanket insulation This type is made of mineral wool or fibreglass and is available faced with or without a vapour barrier It i
37. at the total energy delivered in NATS cabins is affected by the variation of air infiltration rate If the infiltration rate increases the total energy consumption will increase as well For example in the above table the U value of 89 double glazing window is taken to be 2 75W m K and that for external wall to be 0 35W m K and the ventilation is kept to a minimum when cabins are not occupied because it can not be eliminated completely If the air change rate is kept to a minimum of 0 5ac h on one hand and to 1 5ac h on the other hand the difference of total energy consumed within cabins is 15982 02kWh This result reflects the impact air infiltration that has on the heating requirement Figure16 shows the effect of the increased infiltration rate on total energy consumption year external wall U value 0 35W m K and double glazing windows U value 2 75W m K Figurel6 Impacts of increasing infiltration rates on the total energy delivered year U value for ext wall 0 35W m K U value for double glazing window 2 75W m K windows and doors opening effects on NATS cabins energy consumption year 10000 8000 gt gt S amp P 6000 o G 3 4000 S 2000 O Month E windows amp doors opening controlled windows amp doors left open unnecessarily On NATS cabins windows were often left opened unnecessarily This situation leads to the energy wastage In this study it is
38. at creates an air space 58 between the panes of the glass The air space created between the panes could be filled with an inert gas argon krypton to further improve thermal resistance Also the advantage of having an inert gas between the panes of glass is that the gas transfers less heat than air does because it has a lower U value and is denser than the air so it conducts less heat Thus a double panes window unit with argon or krypton gas loses less heat than a double panes window filled with air The table below shows U values of different types of low e double glazing windows Table15 U values in W mK for PVC U or timber windows with various glazing combinations 22 Gap between panes Double glazing air filled 6mm 12mm 16mm more Double glazing low E en 0 2 air filled 3 1 2 8 2 7 Double glazing low E en 0 15 air filled 2 7 2 3 2 1 Double glazing low E en 0 1 air filled 2 7 2 2 2 0 Double glazing low E en 0 05 air filled 2 6 2 1 1 9 Double glazing argon filled 2 6 2 0 1 8 Double glazing low E en 0 2 argon filled 29 CH 2 6 Double glazing low E en 0 15 argon filled 2 5 2 1 2 0 Double glazing low E en 0 1 argon filled 2 3 1 9 1 8 Double glazing low E en 0 05 argon filled 2 3 1 8 1 7 en is the emissivity of low E glass 59 II 3 3 2 Heat gains losses II1 3 3 2 1 Heat gains The flow of heat through a structure is dependent not o
39. at start Economical life time 80 tum flux from initial 100h value h 9000 CCC inductive 16000 ECG pre heat start II 2 2 3 3 Comparison of the Efficiency for T5 system and T8 system II 2 2 3 3 1 Relationship between relative luminous flux and ambient temperature The figure below figure4 shows a relationship between relative luminous flux and ambient temperature for T5 28W and T8 36W tubes The relative luminous flux and ambient temperature C are located respectively on y axis and x axis of the figure It is also indicated that the T5 tube was smaller in diameter 16mm than the T8 tube 26mm On the figure4 it appears that TS fluorescent tube produces a relative higher luminous flux than the T8 fluorescent tube at an ambient temperature exceeding 30 C Figure4 Relative Luminous flux 20 The above figure figure4 also shows how the luminous output increases for T5 28W and for T8 36W from an ambient temperature of 25 C to 35 C where the two fluorescent lamps emit their maximum luminous output with ballasts reference 26 Table3 Comparison of luminance between T5 and T8 fluorescent tubes 14 Type of Lamp Average lamp luminance T8 36W 11000 cd m T8 58W 14000 cd m T5 28W 17000 cd m T5 49W 23000 cd m T5 80W 37000 cd m The T5 tube produces higher luminance than the T8 tube as it is shown in the table3 and this has to be considered in designing a n
40. ater eet 59 3323s Ventilation Systems eer EES EEEEEEEEEEEEE EEN 60 UC Tewes E te e e EE 61 I 3 3 3 2 Mechonicolvenhlohton 62 Part II Laing O Rourke Group Case study IV Laing O Rourke Group IV 1 The Company s bockotrounmd ee 64 IV 2 The National Air Traffic Service NATS Centre cccceecceseeceeeeeceeeeeeeeceeeeeeeeaeeneenatens 65 IV 3 NATS cabin accommodations description AN StrUCtTUIe eeeeeeeeeeeseeeeeteteeeeeees 66 Wi Le eer eege eieiei iepel Bets MLN Sots Leta tate ut aes A 66 IV 3 2 e EE 66 V ESP r modelling and methodology Vs due 01018 VE 68 Vile Ta GeOOMe tty EE 68 K Lee EE 69 V 1 3 Internal gains ANd schedules c2cccceccccecececececec ences ceceeeeeeeecesseeeeeseeceeeeseneeeeeseneeess 71 KE le WE wait an ean eine ei aaa ane deri ae 71 VANS Ee une ene EE 72 V2 SIMUIOTION SATE E 72 VI Results analysis VI Infiltration air load within NATS CODIN sancon 73 V1 2 Casual heat gains for NATS coin 76 VI 3 Heat gains losses through fabric envelope of NATS CODINS cccccccceescesstteeeeeeees 78 V1 4 Heating requirements for NATS cabin ACCOMMOCATIONS ccceeeeseecceeeeesssteeeeeeeees 80 VI 5 Effects of insulation and glazing materials on NATS Cobams 82 VIS INSUIOTONUMOTSNGIS siecle ae Bele is ethene eee eee Ee 82 V1 5 2 Double GIAZING WINDOWS sensere eaa edasadee Senet a a EA 85 VI 6 Impact of windows and doors opening on the total energy delivered
41. ature of water inside the cylinder switching on the water heating when the temperature falls below the thermostat setting and off when this temperature set has been reached The water heating up depends on the heating system design For example it depends on the size of the boiler and the heat exchanger inside the cylinder The cylinder thermostat has a temperature scale marked on it and should be set at temperature between 60 C and 65 C This range of temperature is high enough to kill harmful bacteria in water Further raising temperature of the stored hot water in cylinder may result in energy wastage II 3 2 2 5 Thermostatic radiator valves TRV A thermostatic radiator valve TRV has an air temperature sensor which is used to control the heat output from the radiator by adjusting the water flow It may be fixed to each heat emitter and operates when the correct air temperature is reached by expanding and closing the valves These control valves provide individual room control of heat output and windows no longer need to be left open to maintain comfort in overheated rooms Thermostatic radiator valves switch individual radiators on and off depending on how warm the room they are located in is These devices sense the air temperature around them and provide good local temperature control in individual rooms by regulating the flow of water through the radiator where they are fitted to They are added to the heating system in or
42. ay dividends In fact the amount of insulation that should be applied to a surface is usually based on an economic trade off between savings and insulation costs One option for reducing the amount of energy consumed in warming a space is to increase the thermal resistance of the building envelope This is done by increasing insulation levels of the structure and therefore heat can not escape easily from an interior zone to the exterior zone 83 Figure13 Effects of insulating external walls on total energy consumed within NATS cabins Insulation effects of external walls on total energy delivered year 10000 S 8000 6000 xe S 4000 2 2000 LL 0 1 2 3 4 5 6 7 8 9 10 11 Month E ext wall U value 0 27 B ext wall U value 0 35 o ext wall U value 0 76 O ex wall U value 1 21 12 In figure13 it is assumed that NATS cabins have double glazing windows with a constant U value of 2 75W m K So on this case we are evaluating the impact of external walls insulation on the total energy delivered at NATS cabin accommodations By insulating the external walls their coefficients of transmittance U values decrease or increase depending on the type of insulation or the insulation level of the structure Then energy delivered can vary with the variation of the U value of external walls depending to the type of insulation materials installed This is shown in the table below 84
43. bins rest Results for NNATS_cabins Period Tue 14 Feb 00hS0 tot Mon 20 Feb 23ha0 Year t2006 t simi 60m outputl 60m Causal energy breakdown kilhrs at air point for zone 1 RestaurantG Infiltr ventila Oecupt Lights Equipt Opaque Opaque Transp Transp Convec Totals ation air load tion air load casual gains cazual gains casual gains MLE convect MLC convec MLE convect ect MLE convect int portion of plant ext int Gain 0 C0 0 000 15 150 21 440 4 000 4 137 39 709 0 000 0 000 244 569 317 005 Loss 290 550 0 000 0 000 0 000 0 000 10 875 39 356 10 253 0 000 0 000 450 824 110 Libs NNATS_cabins rest Results for NNATS_cabins Period Tue 14 Feb 00QhS0 tot Mon 20 Feb 23ha0 Yeart2006 t simi 60m output Dun Sensible heating load tkil Description Maximum Minimum Hean Standard value occurrence value occurrence value deviation Restaurant 10 50 i4 Febigl 2h 0 0 00 14 Febloghsd 1 40 2 57 All 10 50 14 Feblishso 0 00 14 Feb Lib NNATS_cabins res Results for NNATS_cabins Period Tue 14 Feb 00ha0 to Mon 20 Feb 2sh30 Yeart2006 sim 60m output 60m Infiltration NI Description Maximum Minimum Hean Standard value Occurrence Walle Occurrence Value deviation Restaurant 267 26 20 Feblitehao 12257 3532 17 FeblLahad 1728 16 2546 15 All 267 26 12257 5 1728 16 Libs NNATS_cabins rest Results for NNATS_cabins Period Tue 14 Feb 00ha0 to Mon 20 Feb 2sh30 Yeart2006 sim 60m outpu
44. c 2006 with 3 periods Per Start l Sensing lActuating Control law Data 1 0 00 db temp gt flux free floating 2 8 00 db temp gt flux basic control 10500 0 0 0 0 0 0 0 21 0 100 0 0 0 318 00 db temp gt flux free floating The sensor for function 1 senses the temperature of the current zone The actuator for function 1 is air point of the current zone Saturday control is valid Sun 1 Jan to Sun 31 Dec 2006 with 1 periods Fer Start l Sensing lActuating Control law Data 1 0 00 db temp gt flux free floating The sensor for function 1 senses the temperature of the current zone The actuator for function 1 is air point of the current zone Sunday control is valid Sun 1 Jan to Sun 31 Dec 2006 with 1 periods Per Start Sensing lAetuating Control law Data 1 0 00 db temp gt flux free Floating
45. cabin accommodation and it is broken into two main parts within it are grouped different chapters The organisation is presented as follow 10 Part I This part covers two major chapters The first concerns energy policy and considers the organisation structure and lines of communication The second chapter concerns energy efficient technology in a temporary accommodation This latter is divided into two main sub chapters The first provides detailed information on lighting systems This includes natural lighting artificial lighting lighting controls and lighting design and measurement The second sub chapter is about the heating systems in a temporary accommodation It describes briefly space heating equipment the heating controls in a temporary accommodation and building design for rational energy use on heating systems Part II This part concerns a case study It is broken into four chapters The first one describes the company s background and one of its construction sites National Air Traffic Service NATS centre and contains details related to the NATS cabins description and structure The second chapter describes the methodology followed to run a simulation program and gives details on simulation strategies The third chapter concerns the results analysis It illustrates the results obtained from the simulations analysis performed on heating systems including details on the effects of some design changes such as increas
46. calculation of CO emissions is made as follows EnergySaved kWh FuelEmissionFactor kgCO kWh 1000 CO2 emissions tonnes 18 The total amount of CU emissions that could be saved by switching on off is 42334kWh 0 43kgCO kWh 1000 18 2tonnesOfCO emissions 96 By removing the existing T8 58W installed in cabin accommodations at NATS centre and replacing T5 49W fluorescent tubes Laing O Rourke Scotland could reduce the total energy consumption The total lighting electricity use is obtained by using the following formula TotalWatts BurningHours 1000 Total electricity use When the T8 58W are removed and the TS 49W tubes are replaced at NATS construction site the total electricity saved over three years is the difference between the electricity used by T8 58W tubes and that used by T5 49W over three years That difference is 163699kWh 102752kWh 60947kWh The total lighting electricity savings year when replacing T8 tubes to T5 tubes is 60947kWh 20316kWh The total amount of CO2 emissions that LORS could save when replacing the T5 49W 20316kWh 0 43 lamps is ee ERI 8 74tonnesOfCO Emissions By controlling the lighting systems at NATS cabin accommodations using the switch on off method as well as a high efficiency energy saver lamps T5 49W Laing O Rourke Scotland could reduce from the environment the total amount of 26 9tonnes of CO emissions And its total en
47. d energy results in savings that can be counted every year For example by improving external walls insulation and double glazing windows for NATS cabins while keeping the air infiltration rate at the recommended minimum level 0 5ac h Laing O Rourke could save energy and at the same time reduce CO emissions from the environment The total savings year on heating systems when the U value of external walls and double glazing windows for NATS cabins are reduced to the optimum level is calculated as follows 92 Annual savings on heating systems Unit cost kWh Energy saved year kWh 0 08 32226 37 2578 11 If Laing O Rourke reduces on NATS cabins the U value respectively to 0 27W m k for external walls and to 1 7W m K for windows it could save 2578 11 each year on heating systems The total amount of CU emissions that could be saved is calculated by using DEFRA guidelines which are based on the product of the total energy saved and the CO2 emissions factor And the following formula is used EnergySaved kWh FuelEmissionFactor kgCO kWh CO emissions tonnes 1000 18 32226 37kWh 0 43kgCO kWh 1000 13 86tonnesOfCO Emissions If the heating in the NATS cabins is well controlled by a central thermostat PIR sensors which control contactors on group of heaters in all heated spaces and central timer switches the CO emissions could be sensibly reduced Consequently sign
48. d to give satisfactory results For example energy consumption for illumination can be effectively reduced by 15 in most existing building by turning off lights when they are not needed in paying more attention to matching the amount of lighting used to do the job being done and by using lights that require less energy 1 Lights in unoccupied areas should be dimmed or shut off To do so a sufficient number of key switches should be installed where opportunities exist for their effective use so that all lights not needed for periods of time during the day can be turned off A careful analysis of all occupied rooms the number of occupants their activities in each space and the length of time each space is occupied will reveal many opportunities for reducing the intensity of illumination or shutting off lights completely Another method is to replace lamps with lamps of smaller wattage or lamps of greater efficiency However on this method removal of only one lamp from a two ballast circuit can affect ballast life seriously and can cause immediate failure If both lamps are removed from a two lamps ballast circuit a small amount of power is still consumed as the ballast draws magnetizing current In this case ballast should be disconnected when lamps are removed It is advisable when relamping to consider the existing windows that can be used to reduce electrical lighting requirements and to review existing lighting system taking int
49. der to provide extra benefits of individual room temperature control and greater energy savings The thermostatic radiator valves should be used with a room thermostat or a boiler energy control in domestic control to ensure boiler interlock However they shouldn t be installed in the same room as the room thermostat or a programmable room thermostat 50 When fitting several TRV it is essential to fit a bypass and a regulating valve to ensure that the flow rate through the boiler is maintained at a constant rate IHI 3 2 1 6 An automatic bypass valve This device controls water flow in accordance with the water pressure across it and is used to maintain a minimum flow rate through the boiler and to limit circulation pressure when alternative water paths are closed A bypass circuit must be installed if the boiler manufacturer specifies that a minimum flow rate has to be maintained while the boiler is firing The installed bypass circuit must then include an automatic bypass valve 51 HI 3 3 Building design for rational energy use on heating system IHI 3 3 1 Building envelope A building envelope includes everything that separates the interior of the building from the outdoor environment including windows walls foundation basement slab ceiling roof and insulation It can be analysed for its heat flow characteristics including its ability to control heat gain and heat loss by its construction orientation and the us
50. e external heat source can be reduced to maintain proper temperature within the building Then an analysis of internal loads and comfort temperatures is needed and appropriate scheduling of equipment operation during each season of the year can help to keep energy requirement to a minimum level When the outdoor air temperature drops significantly in winter for example there is a large difference between inside and outside temperatures of cabins which increases the rates of heat losses by conduction and ventilation Therefore the internal heat gains may be insufficient to meet the space conditioning requirements As the heat losses are greater than heat gains a certain level of heating is required for balancing losses and gains inside the building 81 Figurel2 Total energy required for space heating within NATS cabin for a typical week NATS cabins energy delivered winter and summer comparison 1 3 5 7 9 11 13 15 17 19 21 23 25 27 zones E Energy delivered winter Energy delivered summer The figurel12 shows the total energy to be supplied by a heating system within NATS cabin accommodations In summer casual and solar heat gains are sufficient to meet the heating requirements However in winter period the more heat is lost the more energy demand increases for maintaining the temperature comfort inside the cabin 82 VI 5 Thermal insulation and double glazing VI 5 1 Introduction
51. e of particular building materials The transmission of heat through the envelope glass walls roof and door is a function of conductive characteristics surface area and the difference in dry bulb temperature between inside and outside Today a wide variety of alternative materials is being used to construct buildings many of them have energy efficiency as well as environmental benefits To assess the envelope ability for controlling thermal transfer and regulating interior conditions for thermal comfort the following factors must be considered Heat losses by transmission through the fabric of the building Heat losses by air leakage around openings and through fabric Control systems for space heating and hot water Heat losses from vessels and pipes used for hot water Heat losses from hot water pipes and hot air ducts used for space heating Energy efficient lighting sources and switching for the building So by taking advantages of innovative technology and new design concepts perfects comfort conditions in buildings could be achieved at little or no additional cost One option for reducing the amount of energy consumed in space heating is to increase the thermal resistance of the envelope This barrier walls approach requires more material such as insulation in construction and the extra labor Once this approach is applied 52 the energy conservation required could be achieved without making demands on t
52. e room heats up nor cools down but the heating up depends on the design of the heating system for example the size of the boiler and radiators Turning a room thermostat to a lower setting results in the room being controlled at a lower temperature generally 18 C and saves energy Any further adjustment above this setting result in energy wastage and cost more money II 3 2 2 3 A programmable room thermostat A programmable room thermostat is a combined programmer and room thermostat which allows the user to set different periods with different target temperatures for space heating usually in a daily or weekly cycle This device lets users choose the time they want the heating to be on and to determine the target temperature to be reached while it is on It allows the user to select different temperatures in a particular building at different times of the day or days of the week to meet particular heating requirements One programmable room thermostat can be used to control the whole building if the heating system is carried by a boiler with radiators However if different temperatures in individual rooms are required the thermostatic radiator valves TRV should be installed on individual radiators 49 HI 3 2 2 4 A cylinder thermostat A cylinder thermostat measures the temperature of the hot water cylinder and switches on and off the heat supply from the boiler to the hot water cylinder It operates by sensing the temper
53. eference SRV13892 1 Carbon Trust Reference CNC75823 Date 11 04 2004 18 Environment KPIs Energy Use Construction process www defra gov uk environment climatechange trading pdf trading reporting pdf 19 http www esru strath ac uk for tutorials ESP r cook book user manual 20 http www saudilighting com techinfo 4 4 htm The T5 System Technical information 2002 2003 21 http www sbsa gov uk current_standards th html 2006 bsthd 92 htm The Scottish building standards Technical hand book Domestic 22 http www pge com pec Pacific Energy Center Factsheet Energy Efficient Window Glazing systems 23 http www bfrc org Technical publications European Building Regs 09 04 03 0 4 UK PDF Building Regulations Part L 25 http www thecarbontrust co uk carbontust low_carbon_tech 26 http www bpa gov n energy_Tips weatherization about htm R values per inch of some typical insulation materials 27 http www wbdg org design windows php Representative Glass Specifications 28 http www eca gov uk etl Lighting controls 29 http www advancedbuildings org main t lighting daylighting controls htm Sensors amp Controls 30 http www dti gov uk energy inform 31 http Awww idealboilers com system html 32 http www osram dk info t8 pdf 102 APPENDIX Simulation results for one of the 28 zones restaurantG 1 Geometry amp attributions for the zone 1 2 Summary d
54. em is an important area of energy conservation in buildings as high energy efficient types of lamps such as compact fluorescent lamps and high pressure discharge lamps can be installed in existing buildings as well as in new buildings The energy saved by a modernized lighting usually pays for the cost of installation within a shorter payback period It is desirable to replace existing unit with types that use a lower lamp lumen depreciation when relamping For example fluorescent lamps with better lamp lumen depreciation factors may cost more per unit but the investment can be recovered by lower expenditures for energy and maintenance TII 2 2 2 Luminaires Luminaires are the fixtures into which the lamps are placed they usually include a reflecting surface to direct the light toward the space to be lighted In the design of lighting installations the choice of lamp must be combined with the choice of luminaires as they usually absorb and redirect some of the luminous flux emitted by their associated lamps Luminaires may also serve a number of mechanical and electrical purposes such as positioning the lamps in space protecting the lamps and controlling the lamps gear Individual luminaires may be controlled by separate switches so that selected units can be independently turned on or off or dimmed as needed to vary the illumination in space Physical properties that may be relevant in the choice of the luminaire include its e
55. erature is controlled and maintained at 21 C for cabin offices at 19 C for corridors and 18 C for showers and toilets For the heating control 4 control loops were created and therefore connected to the 28 zones of the model This is to sense the temperature in each zone and to define a control strategy for periods and temperature set points For each day type control periods were defined 3 control periods for weekdays 0h00 8h00 and 18h00 and one control period on weekends These day types and periods allow the control to be switched off during the weekend days and the nights on weekdays On working time however the control is activated when the inside air temperature drops below or exceeds the heating set point As no cooling required on this model the cooling set point is 100 C which is an impracticable temperature So with this value no zone humidity control required V 2 Simulation strategies In this study simulations were run for both winter and summer periods and only one week was selected for each period in order to take into account of the construction heat storage For the winter period the typical week chosen was Tuesday 14Feb 06 00h30 to Monday 20Feb 06 23h30 and for summer period the typical week selected was Tuesday 15Aug 06 00h30 to Monday 21 Aug 06 23h30 These weeks are important because they give a real image of the average temperature conditions for each period winter or summer As said pre
56. ere is also a risk of noise from fans and ducts A significant part of the operating cost associated with a ventilation system is the electricity used to operate a fan Energy efficient fans should be used to reduce these costs Fans selected for ventilation systems should be manufactured for continuous operation and long life and installed in location that is easily accessible for regular maintenance Mechanical ventilation systems are also used to control interior pressure with respect to outside to maximize the building durability combustion safety and indoor air quality Since this system has costs associated with it such as the costs of electricity to run it and 63 the cost of heating the outdoor air that the system brings in mechanical ventilation system must operate only when needed and would do so automatically without the need for occupant intervention The costs of heating the outdoor air that the system brings in can be reduced by incorporating heat recovery capabilities in the system There are three main types of mechanical ventilation such as exhaust ventilation which forces inside air into the building supply ventilation which forces outside air into the building and balanced ventilation which forces equal quantities of air into and out of the building Exhaust ventilation systems works by reducing the inside air pressure below the outdoor air pressure They extract indoor air from the building while make up air inf
57. ergy costs savings per year when using this control system is 2014 3387 5401 year TotalInitialCosts 11276 The payback period 2 years EnergyCostSaving year 5401 Laing O Rourke Scotland will recover its spending on lighting system over two years when the energy consumption is properly controlled and will also contribute to the environmental protection by reducing the CU emissions to the surroundings areas 97 VII 2 4 2 Conclusions and recommendations It is worthwhile to remove the T8 58W and replace them with T5 49W fluorescent lamps powered by electronic ballasts and dimmed according to the amount of natural light inside the cabins It is also important to install a lighting control system equipped with time scheduling daylight and occupancy responsive devices and take into account the idea of localised lighting and other measures such as a regular maintenance plan the awareness of users sub contractors and the alternative of turning off the lighting systems By this way the lighting electricity savings would be 5401 year and the lighting quality improved Further to the lighting control system that can dim the lamp s output in response to the daylight availability it is also necessary to substitute the conventional high loss magnetic ballasts with the electronic ballasts because even for the same lamp wattage the inrush current of electronic ballasts is in principle higher than that of the conve
58. es etc Heat casual gains are additional heat loads which have a strong potential for reducing energy demand if it is used effectively In winter for example this heat can be used to advantage if it is distributed effectively where it is needed Another way to save energy from casual heat gains is to turn equipment on and off in accordance with occupancy schedules In summer heat casual gain is another component of heat that must be removed This is because the potential for solar heat gains may be high in summer and this situation will have an impact on occupant thermal comfort for some zones that experience high casual gains Casual internal heat gains from lights people and small equipment may contribute to summer time overheating and the potential heat output from casual heat gains is very large inside NATS cabins if we consider the present case Where the greatest emission of casual heat gains occurs special care must be taken to reduce casual heat gains and provide controllable ventilation For example extra fans are used in smokers canteen drying room and changing room for NATS cabins and it may be even necessary to install balanced mechanical systems locally to remove heat and to limit excessive casual gains The system would only operate when the zone temperature exceed the set point temperature and would only run for a preset period ay For NATS cabins the main determinants of heat gains from lights and a
59. escription for RestaurantG 103 Fone RestaurantG i 1 is composed of 17 surfaces and 31 vertices It encloses a volume of 374 m S of space with a total surface area of S98 m 2 amp approx floor area of 125 m 2 RestaurantG describes a A summary of the surfaces in RestaurantG 1 Sur l Area we 41 6 23 7 19 3 9 00 16 7 125 4 42 4 31 16 7 19 3 16 7 16 7 43 5 5 10 16 7 16 7 16 7 OO J OO OFT E A Po e 270 D 180 Du 180 a ara lAzimlElevl surface geometry Ideg Ideg name Itypellocl QO Surf 1 OPAL VERT 0 Surf 3 OPA VERT 0 Surf 4 0 Surf 5 QO Surf 6 OPAL VERT 90 Surf 8 OPA FLOR Q WrestE_Gr TRAN VERT 0 W_restO_Gr 10 coc CC oo Follows construction lenvironmert name extern wall extern wall OPAQ WERT partition OPAC WERT partition extern_wal 1 grnd_f loor dbl_glz TRAN VERT dbl_glz OU rest_meet_Gr OPAQ VERT partition Q Rest_corriGe OPAQ VERT partition 90 Rest Heer UI OPAQ CEIL ceiling DC a0 DC a0 a0 a0 Rest docuctr OPAQ CEIL Rest_off23ll OPAQ CEIL rest_Corre_U OPAQ CEIL Rest_M F_we OPAC CEIL Rest kirch OPAQ CEIL Rest_off1_U OPAQ CEIL ceiling ceiling ceiling ceiling ceiling ceiling lother side I lt external Il external Il Surf 22Kitchen_Gr Il Gurt ickitchen br IC external I lt ground profile 1 Il external I lt external Il Surf 4 Meeting_robr Il Surf 62Corrido_Gr Il Surf 6 Meetroom_l L
60. ew luminaire Table4 Comparison between T5 and T8 mirror louvre fixture Type of luminaire T8 luminaire with HF T5 luminaire with HF ballast ballast 1x36W T8 1x28W T5 Light output ratio 61 76 System wattage 36 10 46W 28 2 5 30 5W Luminous flux lamp 3200 Im 2900 Im Luminous flux luminaire 1950 Im 2200 Im Luminous efficacy 54 Im W 72 Im W Energy saving 0 33 The above table shows that the luminous efficacy can increase from 541m W to 721m W or by about 35 for luminaires provided with the more effective reflector material which has been adapted for the new T5 fluorescent tube This improvement results to the lamp system contribution of a maximum of 7 for a HF ballast to the improved aluminium reflectors and louvres of 10 to the higher lamp luminous efficacy of 10 at 35 C and to the improved efficacy due to smaller lamp diameter from 26mm to 16mm Table5 Comparison between T5 and T8 mirror louvre fixture Type of Luminaire T8 Luminaire T8 Luminaire with T5 Luminaire with without HF ballast HF ballast HF ballast 1x36W T8 1x36W T8 1x28W T5 Light output ratio 60 61 76 System wattage 36 10 46W 32 4 36W 28 2 5 30 5W Luminous flux lamp 3350 Im 3200 Im 2900 Im Luminous flux 2010 Im 1950 Im 2200 Im luminaire Luminous efficacy 44 Im W 54 Im W 72 Im W Energy saving 0 23 64 27 Table5 compares the effect of luminous e
61. f basic formula is used However by understanding the basics of lighting design several ways to improve the efficiency of lighting systems become more apparent There are two common lighting methods that have been developed and are found to give satisfactory results These are the lumen method and the point by point method The point by point method calculates the lighting requirements for the task in question The lumen method is the most widely used approach to the determination of lighting layout that will provide a service illumination on the working plane from lamps overhead in a substantially regular pattern The lumen method uses the following formula E A ee eee CES Fey L L 37 Where N number of lamp fittings required E illumination required at working plane A areas of the room F lumens output per lamp found in manufacture s catalogue U coefficient of utilization can be found in manufacture s catalogue L lamp depreciation factor can be found in manufacture s catalogue L2 luminaire fixture dirt depreciation factor When considering the efficiency of the lighting system the characteristics of all of the components must be included HI 2 2 5 2 1 Lighting components characteristics The luminaire fixture dirt depreciation factor L2 takes into account the effect of dirt accumulation on a luminaire and varies with the type of luminaire and the atmosphere in which it is ope
62. fficacy of the equivalent T8 luminaire with or without HF ballasts and the luminaire which has been adapted for the T5 fluorescent tube The comparison between the T8 luminaire without HF ballast 44 Im W and the T5 luminaire 72 Im W shows an increase in luminous efficacy of 65 Equally changing the ballast used with the T8 fluorescent tube from conventional to HF produces an increase in luminous efficacy of about 25 14 Table6 Comparison between T5 and T8 with conventional ballast 14 Type of lamp Ballast losses Luminous flux Efficacy Increase in efficacy T8 36W 10W 3350 Im 89 Im W 0 T5 28W 2 5W 2900 Im 95 Im W 30 By comparing the T5 and T8 with conventional ballast the above table shows that T5 in itself emits around 30 more light than the T8 with conventional ballast Table7 Comparison between T5 and T8 with HF ballast 14 Type of lamp Ballast losses Luminous flux Efficacy Increase in efficacy T8 36W 4W 3200 Im 89 Im W 0 T5 28W 2 5W 2900 Im 95 lm W 7 The above table shows that the T5 system with the luminaire which has been adapted for the new T5 fluorescent tube emits only around 7 more light than the T8 with HF ballast 28 III 2 2 3 4 Benefits of using T5 fluorescent tubes on lighting systems The improved technology and reduced dimensions inherent in the T5 fluorescent tube can produce more lighting systems with luminaires whic
63. generally refer to the equipment using fuel or electricity as the energy source but are 40 sometimes used in reference to alternatives such as solar furnaces or heat recovery boilers The fuel for a furnace or a boiler for a central heating system can be oil gas solid fuel or electricity By using one of the heat transfer processes the heat source fuel transfers its thermal energy to the fluid increases the fluid temperature or changes its state from a liquid to a gas There is no need to use a central heating system with electric resistance heating because electricity can be easily conveyed directly to the space to be heated and can therefore be converted into heat by a wide variety of heaters Electric heating equipment usually requires less maintenance and offers the opportunity to eliminate the central heat generating stage so that heating with electrical energy can considerably reduce the first cost of the system Nonetheless using electrical heating is more expensive than that for other fuels due to the high cost of the electricity But a more economical use of electric energy is a heat pump III 3 1 2 1 Furnaces A furnace is a heating device which use air as the primary distribution fluid in central heating system It may be available in up flow down flow horizontal and in other heated air directions to the applications requirements The central heating appliances include generally warm air furnaces and steam
64. h cracks around windows and doors on windward side of the cabins Consequently the rate of air infiltration increases depending on the difference between the temperatures inside and outside the cabins Added to this the total volume of the air passing through the cabins structure in winter is much greater than that for summer periods due to inside and outside temperature difference Heat is therefore lost through the building structure and air infiltration causes a net heat loss more in winter than in summer The infiltration air load varies depending on the internal and the external air temperature difference and whether windows and doors are open or shut the amount of heat stored in the structure and the area of external surfaces 74 As appeared on the figure below the greater the area of the external surfaces the greater is the air infiltration load For example the infiltration air loads for the zone RestaurantG or zonel8 Open_plan_U is much greater than that for any manager office officel_U for example This is explained by the fact that some of important factors which affect the rate at which heat is lost include exposure to climate As the air flow from warmer area to the colder the rate of heat loss from the building depends also on the size of the surfaces exposed to the outside cold air Figure7 Comparison of the infiltration air load for a typical week in winter with that for a typical week in summer periods
65. h fit exactly into the standard ceiling grid without occupying additional adjacent space The T5 lamps are specially designed for high frequency operation with electronic ballasts for higher energy efficiency and longer economic time due to lower lumen depreciation Compared to T8 lamps their reduction in tube diameter and tube length give more luminaire design capabilities and they can easily fit into the common ceiling module systems Also the T5 fluorescent lamps are more environmentally friendly because they contain less mercury than the T8 fluorescent lamps Consequently less mercury is disposed off and emitted to the environment during their replacement The efficacy of the T5 luminaires depends on the type and design of luminaire And the luminaire efficacy depends on the ambient temperature within the luminaire and whether the luminaire is equipped with a reflector or a louvre The luminaire designed for the T5 fluorescent tubes is provided with a mirror reflector giving improved reflector quality and higher lighter output ratio The improved reflectors permit a more precise control of the light from the fluorescent tubes Although the T5 luminaire is more expensive the higher costs of the T5 luminaire could be easily compensated via enhanced performance such as high efficacy high utilisation factor long lamp life less heat dissipation reduced energy consumption and demand charge etc 29 III 2 2 4 Lighting contr
66. he users to change their living patterns While it is possible to implement energy conservation measures in new building by using correct construction methods at little or no additional cost there are major changes that can be made in existing building such as replacing windows with insulated walls or increasing the thickness and insulation of walls or roofs This also involves either a costly new exterior surface with changes in the frames of all openings or a new interior surface with changes at electrical outlets counters or fixtures adjacent to exterior walls and again at all windows and doors frames These modifications to existing building require an additional investment to achieve the desired results and the costs vary with the type of the building In most cases significant results in annual energy savings can be achieved Such savings should be considered in terms of their present value to determine their true worth and the payback periods over the life of the building III 3 3 1 1 Air infiltration Ventilation rate Air infiltration or air leakage is outside air that infiltrate into a building through various leakage paths such as dry lining masonry walls timber frame construction windows doors and roof lights in building fabric This outside air in form of infiltration and ventilation imposes a heating or cooling load on the conditioned space and on the mechanical systems that control the temperature and the humidit
67. ificant improvement on the environment protection would be achieved VII 2 Economic aspects on lighting systems VII 2 1 Introduction A wide range of energy efficient measures are available for the lighting system in buildings for which the financial and the environmental implications can vary considerably It is very important to determine whether replacing an existing system with a new one results to better cost benefits For example evaluate the economic and environmental impacts of replacing an existing inefficient lamp with an energy saver one With respect to the light sources comparative costs can most readily studied on basis of quantity of lumens produced since illumination also depends on fixture and the type of space these vary with each installation 93 The aim of this part is to determine the total savings at NATS cabin accommodation for the two lighting systems namely the T5 and the T8 fluorescent tubes On this point an economic assessment taking into account the total costs and the environmental benefits is to undertake in order to justify the selection of the best technology that minimize the pollution on one hand and in other hand which save energy and therefore money VII 2 2 Payback period The payback period is the length of time required to recover the capital investment out of the savings or earnings When the time value of money is not considered it is a ratio of the initial cost to the annual savings
68. iltrates through leaks in the building shell and through intentional passive vents The supply ventilation systems works by pressurizing the building By pressurizing the building they discourage the entry of pollutants from outside and allow outdoor air introduced into the building to be filtered to remove pollen and dust In winter they cause warm air interior to leak through random openings in the exterior wall and ceiling If the interior air is humid enough some moisture may condense in the attic or cold outer parts of the exterior walls where it can promote mould mildew and decay So this system has the potential to cause moisture problems in cold climates Balanced ventilation systems neither pressurize nor depressurize a building if properly designed and installed Rather they introduce and exhaust approximately equal quantities of fresh outside air and polluted inside air respectively They are appropriates for all climates 64 PART II LAING O Rourke Group Case study IV LAING O Rourke Group IV 1 The Company s background LAING O Rourke is an international construction industry specialising in the design procurement and delivery of major construction projects across a wide spectrum of global markets It has currently a total of 16000 employees around the world and 9000 in the UK In Scotland the business unit within this company is called Laing O Rourke Scotland Ltd LORS this unit focus on construct
69. ing surfaces and the nature of the building structure roof walls The rate at which heat from the sun falls on a surface varies throughout the day and the year During the winter periods the fabric solar heat gains through alls and roofs are considered negligible for masonry buildings For heavyweight construction little solar heat reaches the interior of the building because it delays the heat transmission until the direction of heat flow is reverse with the evening arrival 60 III 3 3 2 2 Heat losses Windows and the air infiltration are by far the largest contributors to the heat loss However the heat transmission through the materials of walls roofs and floors contributes also to the heat loss from a building This may occurs when a wind blows across the fabric the rate of heat transfer through the envelope increases Some important factors which affect the rate at which heat is lost are insulation of building area of the external shell temperature difference between inside and outside the building air change rate exposure to climate and the use of the building The greater the area of external surfaces the greater is the rate of heat loss from the buildings The temperature difference increases the rate of heat lost by conduction and ventilation As the air flow from the warmer area to the colder warm air leaving a building carries heat and is replaced by colder air The air flow occurs through windows doors and
70. ing wall insulation changing glazing types changing the heating controls and identifies impacts that building infiltration air flow can make to the total energy consumed within NATS cabins The fourth chapter addresses the economic aspects on heating and lighting systems And finally this thesis ends with conclusions and recommendations for future work 11 PART I Energy use on a construction site II Energy policy II 1 Introduction Within many organisations there is a general understanding of responsibilities and accountability for energy consumed but very few amongst them have a formal energy policy 15 Energy policy is the framework from which the operating principles of energy management are derived It is what needed to know in order to establish the doctrine for prudent management of the business Policy gives operations the discipline which permits managers to optimize decisions in order to maximize their profits And its establishment is the responsibility of the top management Responsibilities and accountability for energy consumption may be clearly written down by a committee or someone on the staff And it is also necessary to distribute it routinely to all relevant employees Without a written energy policy the commitment to saving energy is left to operate on an unofficial basis and then decisions are made randomly and generally by intuition Thus where commitment is absent or informal there is a lack of
71. ion activities and its annual turn over is of 100m covering a wide range of construction projects In this study our aims are limited to determine the total energy use by LORS on one of its construction sites National Air Traffic Service especially on lighting and heating systems And therefore quantifying the total energy costs savings at NATS National Air Traffic Services construction site The case study was chosen due to identified problems associated with energy usage within NATS cabin accommodations For example despite Action Energy posters awareness lights and heaters were generally left switched on and windows often left open in some rooms which are unoccupied for significant periods of the day There were also a lack of automatic control of heating and lighting which results in significant energy wastage on site 17 65 IV 2 The National Air Traffic Service Centre NATS Prestwick Airport Laing O Rourke is the main contractor on the construction of the new NATS centre which is located next to the existing NATS building near Prestwick Airport The construction contract started in November 2004 and is to be completed by October 2006 At the NATS construction site there are two types of cabin accommodation old cabin and the new cabin accommodations Each of them comprises a lower and an upper floor with offices kitchens canteens drying rooms for subcontractors clothes shower rooms and toilets The site
72. ir source heat pumps require a supplementary heating system such as electric resistance heaters or an oil or gas furnace In general using a heat pump alone to meet all heating systems may not be economical However if used in conjunction with a supplementary form of heating such as an oil gas or electric furnace a heat pump can provide reliable and economic heating in winter and cooling in summer If an oil or electric heating system already exists installing a heat pump may be an effective way to reduce the energy costs Water source systems usually use well water from depth up to 80m in the temperature range of 5 to 18 C and they do not have a frosting problem They typically have higher coefficient of performance COP but are more complex and require easy access to a large body of water such as under ground water 46 Ground source systems require the burial pipes deep in the ground where the soil temperature is relatively constant Those heat pumps are more expensive to install but more efficient than air source heat pumps III 3 1 2 3 3 Heat pump operating costs The operating costs of a heat pump can be lower than those of other heating systems particularly electric or oil heating systems However a number of factors affecting heating costs must be considered when running a heat pump These include the cost of electricity and other fuels the location of space heating and the severity of winter climate the type a
73. isible Transmittance Daylight U factor Winter Solar Heat Gain Coefficient SHGC Single Pane glass standard clear 6 89 1 09 0 81 Single White Laminated w Heat Rejecting Coating 73 1 06 0 46 Double Pane Insulated standard clear 79 0 48 0 70 Double Bronze Reflective Glass LOF Eclipse 21 0 48 0 35 Triple Pane Insulated Glass standard clear 74 0 36 0 67 Pyrolitic Low e Double Glass LOF clear Low e 75 0 33 0 71 Soft coat Low e Double Glass w Argon gas fill 73 0 26 0 57 High Efficiency Low e Solar screen 2000 VEI 2M 70 0 29 0 37 Suspended Coated Film 55 0 25 0 35 Suspended Coated Film w Argon gas fill 53 0 19 0 27 Glazing can use metallic layers of coating or tints to either absorb or reflect specific wavelengths in the solar spectrum In this manner desirable wavelengths in the visible spectrum that provide daylight are allowed to pass through the window while other 18 wavelengths such as infrared which provides heat and ultraviolet which can damage fabric are reflected as it is shown on the figurel below Figurel Characteristics of ideal window in hot weather 22 window reflected IR absorbed IR Thus excess heat and damaging ultraviolet light can be reduced while still retaining the benefits of natural light
74. keep the whole structure warm As the coefficient of transmission of external walls increases the heat loss from the building increases and therefore the total energy consumption increase as well In this case if we compare the total energy delivered from the highest U value 85 with that from the lowest U value the total energy which could be saved year by changing only the U value of external wall is 14836 74 kWh It is also important to recognise that increased thermal insulation reduce both the carbon dioxide emissions and the total energy consumption VI 5 3 Double glazing window Windows and the infiltration rate are by far the largest contributors to heat loss Further considerations should be given to the energy efficient windows to improving seals around the windows or to reducing their size Energy efficient windows are designed to keep heat inside the building in winter and outside the building in summer This reduces heating costs minimizes energy consumption and limits the size of heating equipment required for keeping the building comfortable One common method of reducing heat gain or heat loss through windows is by coating the glass with an invisible heat reflective material Low e coating can reduce radiation heat transfer and further heat reduction can also be substantially done by filling the air space between panes with a high molecular weight gas like argon or krypton Once the thermal resistance of a uni
75. l Surf 62Docu_control IC Surf B OF FSS I lt Surf 6sCorriz_U IC Surf 6sFem_mal_wel Il Surf Brkitchen_U Il Surf 6s0F Ficed_U 104 3 Multi layer constructions used fone construction details for PestaurantG CL Surface LayerIMatl Thick IConduc lDensity SpeciflIR Solel Description Idb fmm tivity lheat lemislabs Surf 1 1 72 15 0 1 150 200 0 1420 0 0 90 0 65 Plywood 2 D 50 0 0 000 0 0 0 0 air gap R 0 170 A 103 40 0 O 180 800 0 857 0 Perlite plasterboard 4 72 15 0 0 150 700 0 1420 0 Plywood 5 281 80 0 0 040 12 0 840 0 0 90 0 65 Glass Fibre Quilt Standard U value for construction extern_wall is 0 35 Surf 3 1 72 15 0 0 150 700 0 1420 0 0 90 0 65 Plywood 2 D 50 0 0 000 Uu H Uu H air gap R 0 170 3 108 50 0 0 180 500 0 8537 0 Perlite plasterboard 4 72 15 0 0 150 700 0 1420 0 Plywood 5 281 80 0 0 040 12 0 840 0 0 90 0 65 Glass Fibre Quilt Standard U value for construction extern_wall is 0 35 Surf 4 1 jd 13 0 0 420 1200 0 837 0 0 91 0 50 Gypsum plaster 2 D 50 0 0 000 0 0 0 0 air gap R 0 170 A 66 140 0 0 040 160 0 16868 0 Cork board 4 D 50 0 0 000 0 0 D H air gap R 0 170 5 itd 13 0 0 420 1200 0 837 0 0 91 0 50 Gypsum plaster Standard U value for construction partition is 0 25 Surf 5 1 104 13 0 0 420 1200 0 837 0 0 91 0 50 Gypsum plaster 2 D 50 0 0 000 9 9 air gap R 0 170 3 66 140 0 0 040 160 0 1658 0 Cork board 4 D 50 0 0 000 0 0 1 0 air gap R 0 170 5 104 13 0 0 420 1200 0 837 0 0 91 0 50 Gypsum plaster
76. lacing T8 58W to T5 49W fluorescent lamps and switching on off as necessary In NATS cabin accommodations there are in total 140lamps installed in offices canteen kitchen drying rooms toilets etc The lighting is often switched on unnecessarily in most areas which lead to the energy wastage It is assumed in the calculations that lights are on 20hours a day 7days per week and 48weeks year However it is suggested to reduce the amount of burning hours as much as possible in order to save energy and propose to switch on 10hours a day 5days a week and 48weeks per year 17 This could reduce considerably the energy consumption save money and protect the environment from greenhouse gases Then the total burning hours required over three years for NATS construction site to be illuminated without energy wastage is 3 48 7 1Ohours 7200hours By turning on lights for only 10hours a day over three years the total electricity use at NATS construction site is 102752kWh 20160h The lighting electricity saving over three years 163699kWh 36697kWh 127002kWh 7200h 36697kWh The electricity savings per year is 42334kWh The energy cost savings per year is 0 08 42334 3387 year Also LORS could reduce CO emissions from the environment by switching on off controls The method for measuring CO emissions from energy are based on the product of energy saved and CO emissions factor according to DEFRA method The
77. lectrical insulation moisture resistance appearance and durability 22 III 2 2 3 Energy efficient lamps III 2 2 3 1 Compact Fluorescent Lamps Fluorescent lamps are available in compact forms comparable in size to a traditional Tungsten filament lamp Some of them have an electronic control gear incorporated inside the lamp so that they can be installed in a conventional light fitting to directly replace a Tungsten filament lamp others have the control gear in the fitting Light is produced by a discharge arc passing through a gas in the tube Ultra violet rays are converted into visible light by interacting with a phosphor coating on the inside of the tube Ballast is required in the circuit to regulate the current and the starting voltage A compact fluorescent lamp can replace an incandescent light source in particular applications They are much more efficient than incandescent lamps and have up to 20 times longer life than some incandescent They are long life low cost high output and efficacy and are available in an extremely wide range of sizes colours brightness They also have a relative insensitivity to voltage fluctuation Three configurations are possible for the installation of the compact fluorescent lamps dedicated self ballasted and modular Dedicated compact fluorescent lamp systems are similar to full size fluorescent lighting systems in which ballast is hard wired to lamp holders within a laminaire Se
78. lf ballasted and modular compact fluorescent lamps products have screw bases designed for installation in medium screw base sockets they typically replace incandescent lamps A self ballasted CFL contains a lamp and ballast as an inseparable unit And a modular CFL product consists of screw base ballast with a replaceable lamp The lamp and ballast connect together using a socket and base design that ensures compatibility of lamps and ballasts 23 While most of modular types are operated in the preheat mode the electronic ballasted lamps particularly rapid start mode and in principle could be dimmed Operation of fluorescent lamps particularly rapid start tubes at frequencies more than 60Hz has many beneficial effects It increases lamp efficiency decreases ballast cost weight size and heat losses and lowers maintenance Operating fluorescent lamps at high frequency 20 to 30Hz with solid state ballasts are 10 to 15 more efficacious than 60Hz operation 3 All ballasts for indoor fixtures are required to be protected by an integral thermal sensing device that will disconnect the ballast in the event of overheating Overheating is caused by excessive voltage excessive ambient temperature or failure of a ballast component These devices are either thermostatic self resetting or fuse type self destructive III 2 2 3 2 The efficiency of the T5 system IHI 2 2 3 1 Technical data for the different T5 fluorescent lamps In an effort
79. lumination as incandescent lighting with less energy consumption It may be possible to reduce wattage of lamps to each fixture and in some cases the number of fixtures in services without a reduction in allowable illumination The quantity of lights on a certain surface is usually the primary consideration in the design of lighting system This quantity is specified by the density of luminous flux or 2 illuminance and a measured in lumens m 36 The type of lighting suitable for a particular building should be linked to other design decisions for the building such as the basic plane shape the type and extent of windows and the type of heating and cooling Light abatement can be included in the design to minimize the energy consumption by specifying the correct type of lighting HI 2 2 5 1 Measurement of lighting Light is one form of energy and could be measured by the standards units of energy But the effect of light on human environment depends upon the sensitivity of the eye and special set of units has therefore been developed for the measurement of light and its effects HI 2 2 5 2 Lighting design Illuminance is affected by the distance and the angles between the illuminated surface and the light source and by the reflectance of the surrounding surfaces In an interior building where there is many light sources and several reflecting surfaces the repeated combination of these effects makes calculations difficult i
80. me switch device to switch lighting on and or off at predetermined times or intervals Presence detector amp controller Automatic device detecting occupancy or movement in an area to switch lighting on and off in line with occupancy needs Daylight detection amp switching controller Device to monitor daylight availability in an area and control the switching of lighting on and off according to the occupants needs Daylight detection amp regulation controller Device to monitor daylight availability in an area and regulate the light output of the electric lighting to provide only sufficient artificial lighting to supplement the daylight component Generally used in conjunction with high frequency fluorescent luminaries equipped with dimmable ballasts Central control unit Control unit for an overall managed lighting control system utilising some or all of the types of control elements listed above The timer control method is applied by setting timers to switch off lighting for periods of known inactivity such as the end of the working day This system use clock sensors to regulate the illumination as a function of time The daylight control method use photocell sensors that measure the illumination level and switch lights on and off or dim lights according to the level of daylight detected in a room The occupation control method use personnel sensors to detect
81. mperative that management using all available resources be prepared to face problems of energy shortages and rising costs Saving energy should not be pursued without due attention to its effects on other aspects of the industry s operations e g staff morale fuel consumption and building related health risks Other issues such as the depletion of finite resources pollution and the environment degradation also need careful attention At present because the growing concern about environment issues energy policy is receiving increased attention 13 II 4 Organisation structure and lines of communication A formal written energy policy acts as a guidance of both management and the operating divisions of the industry It acts also as a public expression of the industry s commitment to energy consumption and the environment protection For the uniform guidance of the actions of those who must make decisions regarding energy savings policy must be formulated disseminated and discussed It is in the best interest of the industry that its framework for energy policy be expressed in formal written declaration of commitment accompanied by a set of stated objectives an action plan for achieving them and a clear specification of delegated responsibilities A thorough discussion of the policy while it is being developed and especially the feeling of participation by the people involved in will assist materially in its acceptance when it
82. nd the efficiency and the coefficient of performance By running a heat pump less gas or oil is used but more electricity is required If the electricity is very expensive the operating cost may be higher So a careful analysis based on relative costs of different energy sources is needed in order to determine the total savings and the payback period Heat pumps have a service life between 15 to 25 years depending on the heat pump type For example ground source heat pumps have life expectancy higher than that for air source heat pumps because the compressor of ground source heat pumps has less thermal and mechanical stress and it is protected from the environment 47 III 3 2 Heating controls III 3 2 1 Introduction Space heating or central heating systems can run efficiently by providing warm and comfortable building at a surprisingly low cost The overall effectiveness of a heating system depends on high efficiency heating equipment that ensures little potential heat is wasted and on good controls designed to ensure that the heating equipment is only working when required Installing new controls devices as well as making the heating system more flexible can save energy This because better controls let heating systems react to changes in temperature provide different levels of heat in different rooms and switch hot water on and off at whatever times are specified Good heating control require a variety of equipments that
83. ned to switch the artificial lighting on and off automatically as the daylight level falls and rises through a predetermined level However one problem with this control type is the frequency of the switching on and off particularly during unstable weather conditions when daylight levels are fluctuating around the switching illuminance This can annoy occupants and reduce lamp life There exist several variants to the on off control namely differential switching time delay and solar reset to reduce the number of switching operations A differential switching has two switching illuminance one at which the light should switched off and another at which the light are switched on A time delay means that there is no further switching until the lapse of a preset amount of time after the last switching or after reaching a preset target daylight illuminance value In solar reset switching the lighting can only be switched off at certain set times of the day Although an automatic dimming control system is adopted for daylight space lighting the logged brightness reading can be used to determine the number of switching operations and the energy saving of a standard on off control To reduce the annoying rapid switching on and off of lights differential switching should be required in a practical system III 2 2 5 Lighting design and measurement The lighting system design may specify newer types of fixtures that will give the same amount of il
84. ng items in a temporary accommodation In recent years there has been an increasing interest in incorporating daylight in the architectural and building designs to save building energy The accurate instruments optimum control cycles and a basic understanding of cause and effect applied to the system functions can save energy New technologies for example time switches and photoelectric controls have been developed to improve the efficient use of daylight Daylight responsive dimming systems consist of three major components photo sensor lighting controller and electronic dimming ballast It consists of maintaining target illuminance levels at the workplane regardless of the amount of daylight available in the interior space To satisfy such a purpose the electric light output is continuously adjusted based on the changes in available daylight measured by photo sensors This system is used to improve both the quantity and the quality of the visual environment and can reduce significantly electric lighting requirement where daylight can serve as a useful source of illumination 33 III 2 2 4 3 2 Sensors and control systems Lighting control can be achieved by different methods such as timer control daylight control occupation control and local switching control The table below shows eligible lighting control equipments Table Eligible lighting control equipments 29 Type Function Time controller Automatic ti
85. nly upon the thermal properties of the structure but also upon the heat exchanges between the surfaces and air The manner in which heat enters a space is typically indicated as solar radiation through fenestration heat conduction through envelope heat generated within the space by people lights electrical equipments or appliances or any other electrical mechanical or thermal process within the space Heat gain is the rate at which heat enters or is generated within a space at a given instant It is classified by the manner in which it enters the space and whether it is sensible or latent heat Heat can be generated within the building by various activities and equipments that are not primary designed to give heat The major sources of such heat are heat from people heat from lighting heat from cooking and water heating heat from machinery refrigerators electrical appliances etc For example all electrical power entering a lighting fixture ends up as heat in the space This heat dissipated by lighting fixtures will reduce air conditioning loads and can be used as a source of hot air Heat can also enters the building through walls floors ceiling windows doors and other openings in the building fabric The heat gained in a building by a radiation from sun depends upon various factors such as geographical latitude of the site the orientation of the building on site the local clouds conditions the angles between sun and the build
86. nnn 16 UE A DAYN SYSTE acd te cece e aa e eee ees opera eee coves sy e O Manan vee 16 ILA Daylight e Le te 18 1 2 1 2 Combined daylight and electric light ce ceececeeeeeceeeeeeeceeneeeeeeaeeeesceeeeeeeeeeeees 19 M22 AtitiGiall ebe ooh tees geet eege Sek deet Etec Ate e a Ear oaa at 20 UE Nu reie e e LEE 20 23222 lees UE 21 Ill 2 2 3 Energy efficient lIAMPS 2 sc cciieisseeh accede baste hohe acini ENEE 22 Ik22 3 1 Compact fluoressent lam PS e eegen Arete tenn Mee eae ee eee eee 22 IIl2 2 3 2 The T liQhting system csc seecsee eed a eee eee 23 II 2 2 3 2 1 Technical data for different T5 fluorescent IOMPS ceeeeceeeeeeeeeeeteeeeeeeees 23 122 3 2 2 Technical data for 18 L SSW irasra iienaa a a e 24 II 2 2 3 3 Comparison of the efficiency for T5 system and T8 system e ceeeeeeeeeeees 25 IIl 2 2 3 4 Benefits of using T5 fluorescent tubes on lighting systeMs cceeeeeeeees 28 IIl 2 2 4 Lighting controls methods ANd eoutpments 29 IRD A Wl e UE 29 II 2 2 4 2 Electric lighting control method 30 II 2 2 4 2 1 Control of lighting power CONSUMPTION ceecceeeeeceeeeeeeeeeeeeeetenteeeetseeeetaes 30 IIl 2 2 4 2 2 Maintenance and depreciation Of omps s sssessssrrsrrersserrnssrtnrrtnsrernnre nren 31 II1 2 2 4 3 Lighting control eoupments nenna eenne nennen 32 IEZ E Elte Le EI EE 32 II 2 2 4 3 2 Sensors ANA Control swvstems cece eeeeceeeeeseneecesaeeeeseeaeeeeteeeeesinaeeneas 33 IIl
87. nt technologies in temporary accommodation II 1 Introduction No one can deny that technological progress during these two past decades has had a profound effect on construction industry It has affected the energy consumption in dynamic ways and the industry s expenditure New technologies are being used to improve the conversion efficiency of devices used for services within buildings For example condensing boilers recover much of the latent heat from flue gas before they are released more efficient forms of electric lamps have been designed Heat pumps can make use of low temperature heat source such as waste air which have been ignored in the past Accurate instruments optimum controls cycles and a basic understanding of causes and effects applied to system function can save energy An energy manager must understand how to incorporate new efficient technologies into plant operations And plant engineers and managers are also expected to apply new technologies keep their plants competitive and achieve high operating efficiencies It is clear that applying proven energy efficiency technologies offer significant rewards A great deal should be said about plant operation and design of all types of buildings from the standpoint of how much glass insulation and lighting should be installed what type of mechanical system to use and what various ways to save energy etc For example better insulation less glazing and deeper plan s
88. nternal fittings with completion scheduled for October 2006 As this company doesn t have yet its own construction equipment on site it hired cabin accommodations which are occupied by around 40 office staff and management The external wall has a thermal transmittance U value of 0 35W m K and is insulated with 80cm mineral fibre quilt fitted in between vertical timber studding Its general finishes are composed by bark textured paint on plywood and a vapour barrier is fitted 67 directly onto internal side of the wall studs The internal lining is made with 12 7mm cream magnolia vinyl plasterboard fixed onto timber studding The floor insulation is composed by two layers of floortherm foil insulation over draped over joists and bagged to create minimum 25 air void between layers and the underside of timber deck The floor has a thermal transmittance U value of 0 25W m K The floor deck is made with 18mm WBP plywood glued and nailed to floor joists The flat roof structure has a thermal transmittance U value of 0 25W m K and its insulation is composed by 80mm expanded polystyrene fixed between joists with a layer of 80mm fibre glass insulation quilt above between the firings plus One layer of floortherm foil insulation and vapour barrier are laid at the ceiling level The internal lining is composed by 12 7mm white vinyl plasterboard fixed into ceiling joists External doors are covered with laminated glass pain
89. ntional ballasts So no special provision is required for electronic ballasts to be made for inrush current at starting The energy savings could be improved on this case as well as the visual conditions of the users The lighting control systems could be different for outside and inside of the building Inside the buildings the occupancy and daylight responsive systems could be used while the outdoor lighting is geared with timers The lighting in the meeting rooms are continuously operating during the day unnecessarily Therefore occupancy sensors which could switch off the lighting when there is nobody in the rooms should be installed In brief by applying the lighting system equipped with new control devices such as occupancy sensors photo sensors timers with the tele control capabilities one could reduce considerably the yearly burning hours And so the lighting savings and energy costs savings will increase 98 VIII Conclusion and Recommendations for future work Applying proven energy efficient technologies with proper energy management offer significant rewards This helps to reduce or eliminate energy wastage to ensure whether the company s operations are more productive and improve the quality of its businesses and management and to prevent the environmental pollution Laing O Rourke has so far done some improvement in reducing energy consumption on NATS cabin accommodations It has achieved energy costs avoid
90. o account individual fixtures that can be fully disconnected or lamps that can be fully removed to reduce wattage of an individual fixture It is also required to select a light source that has the highest efficiency compatible with other systems requirements such as lower wattage life colour rendition etc 31 Individual luminares should be selected and controlled by separate switches so that selected units can be independently turned on or off or dimmed as needed to vary the illumination in the area HI 2 2 4 2 2 Maintenance and depreciation of lamps Lamps deteriorate as they get older They produce less light and eventually they fail Even if all lamps are installed at the same time they will fail at different time because the average life of lamp is influenced by the frequency of switching on and off by the ambient temperature by the adjustment of the control gear and by the type of ballast It is more economic for large offices to allow a few failed lamps in position and to replace all lamps together on regular schedule The loss of light can be appreciable if the lamps are not cleaned Dust accumulation is a special problem with lamps in indirect luminares that reflect the light upwards particularly for the fluorescent lamps that present long horizontal tubes to the dust particles 32 III 2 2 4 3 Lighting control equipments III 2 2 4 3 1 Introduction Artificial lighting is one of the major electricity consumi
91. ols methods and equipments IHI 2 2 4 1 Introduction The energy crisis has caused users to look for ways to reduce power consumption One method of controlling light output is to exploit daylight more efficiently Effective daylighting has a strong potential for reducing energy demand in non domestic building Daylighting approach allows a more flexible building fa ade design strategy and enhances a more energy efficient and greener building development Energy savings resulting from daylighting means not only low electric lighting and reduced peak electric lighting demands but also reduced cooling loads and potential for smaller heating ventilating and air conditioning HVAC plants Even with adequate daylight illumination electric lighting must usually be provided for times when the availability of natural light is not enough In order to save energy a control system is needed to switch off the artificial lighting when the daylighting is sufficient The control may be manual or automatic Manual controls are simpler and less expensive but not as reliable as automatic controls Automatic controls normally consist of photoelectric switches that automatically dim or turn off unnecessary electric lighting when daylighting is sufficient and then turn them back on when needed 30 HI 2 2 4 2 Electric lighting control methods III 2 2 4 2 1 Control of lighting power consumption Some simplified methods have been developed and are foun
92. omposition of surfaces the type of surface opaque or transparent and the environment conditions were defined Also the construction layers were defined from the outside to inside order Each zone was attributed a specific name which facilitates its recognition As it is shown in the table below Tablel6 NATS construction zones and their sizes 70 Zones Volume m Base Floor Opaque Transparent area m construction Construction m m 1 Restaurant 374 125 386 71 13 2 Kitchen_ 58 1 19 3 94 3 1 10 3 Meeting 50 33 3 83 5 1 10 4 Drying 99 9 66 6 134 2 21 5 Changing 99 9 66 6 134 2 21 6 Corridor 90 5 60 3 189 0 000 7 Canteen 99 9 66 6 134 2 21 8 Cnst amp saf_ 99 9 66 6 134 2 21 9 Meeting U 50 33 3 83 5 1 10 10 Doc contr 50 33 3 83 5 1 10 11 Off23_U 99 9 66 6 134 221 12 Corri 1U 8 10 5 40 28 8 0 000 13 Corri 2U 24 3 25 2 75 6 0 000 14 Recept U 50 33 3 83 5 1 10 15 Fe mal U 50 33 3 83 5 1 10 16 Kitchen U 50 33 3 83 5 1 10 17 Officl U 50 33 3 83 5 1 10 18 Open plan 540 327 511 11 0 19 0 Ext er 27 36 83 4 0 000 20 M_F_shwe 72 9 24 3 105 3 54 21 O_meet_gr 36 5 24 3 64 8 1 77 22 0 firstAid 36 5 24 3 64 8 1 77 23 O_male we 36 5 24 3 64 8 1 77 24 0 client g 36 5 24 3 64 8 1 77 25 O_off234 109 72 9 146 5 31 26 O ExtUpp 27 36 83 4 0 000 27 O_cntrOffl 7
93. or water boilers The warm air furnaces are of different types and depend on the force required to move the combustion products and on the force required to move supply and return air It also depends on the location in the building and the efficiency required 4 II1 3 1 2 1 1 Natural gas furnaces The natural gas is the most common fuel supplied for residential heating and the central system forced air furnace is the most common way of heating with natural gas This type of furnace is equipped with a blower to circulate air through the furnace enclosure over the heat exchanger and through the ductwork distribution system The main components of such a furnace are casing heat exchangers combustion system including burners and controls forced draft induced draft or draft hood circulating air blower and motor air filter and other accessories such as a humidifier electronic air cleaner air conditioning coil or a combination of these elements The force to move the combustion products can be supplied by the natural buoyancy of hot combustion products in a natural draft furnace by a blower in a forced draft or induced draft furnace or the thermal expansion forces in a pulse combustion furnace If the space to be heated is closed and or above the furnace the force to move heated and supply and return air can be supplied by the natural buoyancy of heated air in a gravity furnace That force can also be supplied by a blower in a
94. ors 0 5 Rooms with windows or exterior doors on 1 one side Rooms with windows or exterior doors on 1 5 two sides Rooms with windows or exterior doors on 2 three sides Entrance halls 2 The building regulations requires that air leakage through building envelope to be limited as far as is practicable by preventive measures such as sealing gaps with windows and doors sealing gaps at junctions with walls floors and ceilings complete sealing of vapour control membranes etc 54 III 3 3 1 2 Moisture control Occupants of buildings certain appliances and plumbing equipments generate moisture that is carried in air as vapour As moisture vapour moves from a warm interior through construction materials to a colder surface the moisture condense as water which could damage the building When moist air comes in contact with a cold surface some of the moisture may leave the air and become liquid or condense If it condenses inside a wall or in attic it can cause a number of problems If the moisture produced in building condense in the insulation of walls floors and ceilings the insulation become less effective This is because wet insulation is less effective in preventing heat loss or the additional weight could also cause structural damage by exceeding the weight bearing capacity of the ceiling By locating vapour retarders on the side of the insulation toward the warm area moisture v
95. ot escape into the 78 room So reducing the casual gains from lights and appliances will reduce the overheating in the areas where they are concentrated V1 3 Heat gains losses through building fabric of NATS cabins In summer periods when the external air temperature is higher than the internal air temperature windows opening will further increase the heat gains rather than remove heat The fabric transmission losses will reverse and heat gains through fabric will become possible From 15 08 06 to 21 08 06 the total heat gains through the opaque walls of NATS cabins is 440 6kWh while the total heat losses through the same opaque walls is 144 2kWh If the thermal mass of the fabric envelope is at a lower temperature than the incoming air it will absorb heat from both internal gains and the incoming ventilation air The heat absorbed will then be released to the outside area when the external air temperature becomes lower than that for the thermal mass temperature at night times for example On the typical week considered in summer the cooling system which could be done only by opening windows and doors is required for redressing the balance between heat gains and heat losses From 14 02 06 to 20 02 06 the total heat losses through opaque walls of NATS cabins is 417 6kWh while the total heat gains through the opaque walls of the cabins is 349 4kWh on the same period It shows that in winter periods the heating system is re
96. ppliances are the actions and choices of subcontractors themselves Their use of equipment and appliances and the way they use the cabins determine the magnitude and timing of the casual heat gains However there may be some scope for Laing O Rourke Scotland to influence the impact of these actions For example install high efficiency light provide efficient appliances and limit their number and their size High efficiency lighting can play an important part in the reduction of casual gains Figure9 Heat casual gains sources and conditions within NATS cabins NATS casual gains kWh E occupt casual gains lights casual gains O equit casual gains As stated previously heat casual gains depend on the occupancy levels and the use of lighting and small equipment within cabin accommodations For example as it appears on the above figure that 20 people using an open plan zone during weekdays produce more heat than 2 people working in a small office Further to this in the open plan more lighting and small equipment are required than in small office Therefore more lights casual gains and small equipment casual gains are produced within NATS cabins As seen on the figure9 most heat casual gains are generated from lighting system If high levels of electric lighting are provided it is often necessary to extract air through the lighting fittings so that the heat from them is removed and does n
97. quired for heat gains and heat losses balance Figure10 shows that heat loss through opaque walls of each of the 28 zones for the model is much greater in winter periods than it is in summer periods However heat gains through opaque walls of each of the 28 zones is lower in winter periods than it is in summer periods 79 In summer periods heat losses through opaque walls for each of the 28 zones is lower than heat gains through the same building fabric However in winter periods heat losses through opaque walls for each of the 28 zones are higher than heat gains through the same fabric Figurel0 Total heat gains losses through NATS opaque structure Opaque heat gains losses 1 3 5 7 9 11 13 15 17 19 21 23 25 27 zones E opaqu heat gains winter opaque heat loss winter O opaqu heat gains summer O opaqu heat loss summer The figure10 shows that heat gains in summer periods is high than it is in winter periods This may results to the potential for solar heat gains which is important in summer and very low in winter It also appears on the above figure that heat loss through opaque structure is higher in winter than in summer periods due to the inside and the outside temperature difference Figurel1 Transparent heat gains losses for NATS cabins Transp heat gains losses 123 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 zones E transp heat g
98. r speed 0 10 Default mean radiant temperature Time t air Lt rel GEI PV DW PPD Comfort assessment Chere deg 3 dea GI deal CG f Gi based on DW 16 0 16 4 40 18 6 1 10 0 98 25 cool unpleasant ERT 15 7 dd 17 5 1 32 1 22 36 cool unpleasant 13 8 15 1 d 17 0 1 43 1 354 42 cool unpleasant 13 6 14 6 db 16 7 1 48 1 40 45 cool unpleasant 13 1 14 2 468 16 5 1 55 1 48 50 cool unpleasant 12 8 14 9 SO 16 0 1 6 1 54 453 cool unpleasant 12 5 13 6 53 15 8 1 65 1 59 56 cool unpleasant 12 3 13 3 BS 15 6 1 68 1 63 58 cool unpleasant 16 6 13 8 43 16 0 1 20 1 10 30 cool unpleasant 21 0 15 6 24 20 9 0 64 0 51 10 slightly cool acceptable 21 0 17 3 35 21 5 0 51 0 57 H comfortable pleasant 21 0 17 9 35 21 8 0 46 0 51 7 comfortable pleasant 19 6 18 2 38 21 2 0 59 0 42 comfortable pleasant 16 9 16 4 39 20 9 0 66 0 48 10 comfortable pleasant 20 3 18 7 Ad 21 7 0 49 0 52 comfortable pleasant 21 0 16 9 34 22 1 0 41 0 25 confortable pleasant 21 0 19 1 35 22 2 0 59 0 22 confortable pleasant 21 4 19 2 32 22 4 0 34 0 16 comfortable pleasant 20 1 19 0 Ad 21 8 0 49 0 50 comfortable pleasant 18 8 18 6 36 21 0 0 65 0 47 10 comfortable pleasant 19 1 15 5 35 21 1 0 63 0 45 9 comfortable pleasant 19 0 15 5 35 21 0 0 65 0 47 10 comfortable pleasant 19 9 15 4 35 21 0 0 66 0 48 10 comfortable pleasant 18 8 18 4 35 20 9 0 68 0 50 10 slightly cool
99. rated The lamp depreciation factor L1 takes into account the deterioration of lamp output with time It is specified by the manufacturer on the basis of testing programs The coefficient of utilisation U indicates how efficiently the luminaire illuminates the working plane It is related to the room geometry and the reflectance as well as the characteristics of the luminaire The IES lighting handbook contains U values for various types of the luminaries and room characteristics The coefficient of performance is the ratio between the total flux in lumens reaching the working plane to the total flux in lumens generated by the lamp It takes into account of light absorbed or reflected by walls ceiling and the fixture itself The light loss factor LLF takes into account of deterioration of the lamp with time and accumulation of dirt It could be found from the manufacture s catalogue 38 LLF Illuminance provided at some given time Initial illuminance LLF lamp maintenance factor luminance maintenance factor room maintenance factor Maintenance factor M takes into account the light loss due to dirt accumulation on the fittings and room surfaces 39 III 3 Heating systems in a temporary accommodation III 3 1 Space heating equipments III 3 1 1 Unit heaters Heaters come in a wide variety of models they may be permanently installed or portable and they may employ a combination of radiation natural convection
100. rce s emitted at an luminous luminous ambient efficacy at an output emitted temperature of ambient T of at an ambient 25 C 35 C T of 35 C 14W 549 mm 1200 Im 96 lm W 1350 Im 21W 849 mm 1900 Im 100 lm W 2100 Im 28W 1149 mm 2600 Im 104 Im W 2900 Im 35W 1449 mm 3300 Im 104 Im W 3650 Im 24W 549 mm 1750 Im 83 Im W 2000 Im 39W 849 mm 3100 lm 90 lm W 3500 Im 54W 1149 mm 4450 Im 93 Im W 5000 Im 49W 1449 mm 4300 Im 100 Im W 4900 Im 80W 1449mm 6150 Im 88 Im W 7000 Im The above table compares the T5 fluorescent lamp s maximum luminous output at 35 C and the luminous output that applies at 25 C under the condition that the fluorescent lamp is powered with reference ballast II 2 2 3 2 2 Technical data for the T8 L 58W 32 Figure3 Physical dimensions of T8 L 58W PHYSICAL DIMENSIONS in mm Cap G13 1505 9 1 2 1 500 0 1514 2 25 0 1 5 25 Technical Data Frequency Hz 50 Hz Operation Lamp wattage W 58 Nominal current CCG operation uncompensated A 0 67 Lamp arc voltage UL after switch on 10 V 110 Resistance Impedance Z for CCG Q 165 System power CCG operation W depends on EEI class of CCG Pre heat current IEC 81 mA 1 000 Luminance cd cm 1 5 Compensation capacitor power factor 1 for CCG uF 7 0 Row capacitor for CCG duo wiring uF Vc 5 3 450 Average life time 50 failure rate h 15000 CCG_inductive 20000 ECG pre he
101. reater comfort For further improvement on energy savings the following are recommended 99 Ventilation systems should be scheduled so that the exhaust system operates only when it is required And the outdoor air supplied within cabins should be reduced to minimum local requirements and the exhaust requirements should be balanced to maintain a slight positive pressure retarding air infiltration and thereby reducing heat losses or heat gains The major fuel use on construction sites is diesel for construction plants where it is estimated that 75 to 80 of fuel use occurs The remaining fuel use is mostly electricity some from temporary main supplies but mostly from diesel generators When the number and types of plant equipment are taken into account these electrical consumption figures represent only 20 to 25 of the total energy consumed on construction site The major energy users on site are construction plants such as backhoe loaders dampers hydraulic excavators cranes etc 17 At present there is no method on LORS construction sites of logging diesel consumption on generators and no method of keeping an accurate log of energy consumption at NATS construction site This lack of any real knowledge of energy use prohibits any appraisal of the value of energy efficiency measures taken and to quantify the total energy used on construction site 17 Due to the lack of real figures related to the total fuel consumed in li
102. rface is the surface of electric elements The design of electric boilers is largely determined by the shape and the heat produced by electric heating units used A system of pipes connected to the boiler delivers heated fluid to the point of use and returns the cooled fluid to the boiler Boilers may be designed to burn various grades of fuel oil various types of fuel gas coal etc or to operate as electric boilers A boiler designed for one specific fuel type may not be convertible to another type of fuel Boilers selection should be based on the following parameters Net boiler output capacity Total heat transfer surface Water content Auxiliary power requirements Internal water flow patterns Cleaning provisions for all heat transfer surfaces Operational efficiency Space requirements and piping arrangement Water treatment requirements II 3 1 2 2 1 Energy efficient condensing boilers High efficient condensing boilers convert around 90 of their fuel into heat compared to 79 for conventional types They have a larger or sometimes an additional heat exchanger This heat exchanger captures much of the energy otherwise lost through the flue The flue gases are cooled to the point where water vapour produced during combustion condenses Hence the name Condensing Boiler If the right heating controls are installed with high efficiency condensing boilers 40 on the fuel bill could be saved 31
103. ruction 13 0 0 420 1200 0 50 0 0 000 0 0 140 0 o 040 160 0 50 0 0 000 0 0 13 0 O 420 1200 0 Value for construction 13 0 O 420 1200 0 50 0 0 000 D D 140 0 o 040 160 0 50 0 0 000 0 0 13 0 0 420 1200 0 Value for construction 140 0 0 04 250 0 10 0 o 040 290 0 Value for construction 140 0 D Dd0 250 0 10 0 o 040 290 0 Value for construction 140 0 D Dd0 250 0 10 0 o 290 0 Value for construction 140 0 o d40 250 0 10 0 o 030 290 0 Value for construction 140 0 O d40 250 0 10 0 o 040 290 0 Value for construction 140 0 O 040 250 0 10 0 o 040 290 0 value for construction 140 0 D Dd 250 0 10 0 o 040 290 0 Value for construction 140 0 o d40 250 0 10 0 0 030 290 0 Value for construction 0 0 BETEAN dbl_glz EETA 0 0 837 0 dbl_glz 837 0 0 0 1888 0 0 0 837 0 0 91 partition is 837 0 0 91 D D 1585 0 0 0 gar 0 0 91 partition is 940 0 0 90 20000 0 90 ceiling is 540 0 0 90 2000 D 0 90 ceiling is 840 0 0 90 2000 0 0 90 ceiling is 540 0 0 90 2000 0 0 90 ceiling is 840 0 0 90 2000 D 0 90 ceiling is 240 0 0 90 2000 0 0 90 ceiling is 540 0 0 90 2000 0 0 90 ceiling is 540 0 0 90 2000 0 0 90 ceiling is O53 is 0 53 0 85 is 0 91 air gap R 0 170 Plate glass Plate glass air gap R 0 170 Plate glass Gypsum plaster air gap R 0 170 Cork board air gap R 0 170 0 50 Gypsum plaster 0 25 0 50 Gypsum plaster air gap R 0 170 Cork board air gap R 0 170 0 50 Gypsum plaster
104. s best use for crawl spaces or unfinished walls and can be used also in ceilings where little or no insulation is already installed Loose fill insulation This type is usually made of mineral fibre cellulose fibre vermiculite or perlite It is convenient insulation type to use in unfinished attics especially if some insulation is already installed On the application process it is poured or blown into the space to be installed Rigid board insulation This type is generally made of fibreglass polystyrene and polyurethane It is usually attached with adhesive mastic and is used for crawl space perimeters concrete walls and exposed beam ceilings There are a wide variety of insulation materials available and each of them has different properties Some of them trap air more effectively than others and produce the same insulation value with less material thickness For example 1mm of mineral wool insulation has the same heat resistance R value capabilities as 46mm for concrete insulation R values of standards insulating materials range from 0 84 to 3 08 per cm The table12 shows R values of some typical insulating materials Table12 Some typical insulating materials 56 26 Insulating material R value cm Mineral wool batts 1 4 Fibreglass batts 1 24 1 4 Mineral wool Loose fill 1 12 Cellulose Loose fill 1 24 1 48 Vermiculite loose 0 84 0
105. t 60m Total occupant gain UU Description Hax num Minimum Hean Standard value occurrence Value occurrence value deviation Restaurant 1800 00 14 Feb Shao 0 00 i4 Feb odhse 180 36 391 96 All 1800 00 0 00 180 36 Lib NNATS_cabins rest Results for NNATS_cabins Period Tue 14 Feb 00hS0 tot Mon 20 Feb 23ha0 Year t2006 t simi 60m output 60m Total lighting gain Chl Description Maximum Minimum Hean Standard Value occurrence Value occurrence Value deviation Restaurant 1072 00 14 FebBlohso 0 00 14 Febloohso 255 24 435 76 All 1072 00 0 00 255 24 Lib NNATS_cabins rest Results for MNATS_cabins Period Tue 14 Feb 00hS0 tot Mon 20 Feb 23hS0 Year t2006 t simi 60m output 60m Total small power gain hl Description Maximum Minimum Hean Standard value occurrence value occurrence value deviation RestaurantG 600 00 14 Feb ishso 0 00 14 Febltohsd 35 71 122 00 All 600 00 0 00 45 71 Lib NNATS_cabins rest Results for NNATS_cabins Period Tue 14 Feb 00ha0 to Mon 20 Feb 2Shs0 Yeart2006 siml 60m outputi 60m Total surf convection OU Description Maximum Minimum Hean Standard value occurrence value occurrence Value deviation Restaurant 726 46 16 Feb 2kh 0 4826 03 20 Febloghad 105 04 876 00 All 726 46 4826 03 105 04 111 Control description The sensor for function 1 senses the temperature of the current zone The actuator for function 1 is air point of the current zone Weekday control is valid Sun 1 Jan to Sun 31 De
106. t finish and have 838mm internal blonde oak door Windows are double glazed and have a thermal transmittance of 2 75W m K 68 V ESP r modelling and methodology The modelling was made in order to identify the effect of some design change such as increasing wall insulation changing glazing type introducing daylight control devices and changing the heating control regime And to determine the benefits that can be expected from energy efficient strategies V 1 Methodology V 1 1 Geometry To make the model less complex and more understandable the number of zones was reduced to a minimum by combining some windows for the same zone and the same side and the zones with the same occupancy level within it the same activities were undertaken on the same periods These zones were also created according to the volume and associated usage of each zone By using the above logic NATS cabins were divided into 28 zones which in reality represent the old cabin and new cabin accommodations The following figure figure6 shows the geometry of the two types of NATS cabin 69 Figure6 Geometry of the old cabin and new cabin accommodations of NATS Project Modelling study of energy use on NATS cabins accommodat i HL deFini tions zones networks et V 1 2 Constructions With the aid of some pre existing databases which contain construction profiles physical properties and surface boundaries were attributed to the zones The c
107. t has been improved with a low e coating and an inert gas newly developed spacers can considerably reduce heat loss A low e coating can reduce the U value of a double glazed window This latter indicates the rate of the heat flow due to conduction and radiation through a window as a result of a temperature difference between inside and the outside In figure14 it is assumed that the external walls of NATS cabin accommodations have a constant U value of 0 27W m K And the effects of glazing systems and their modifications on the total energy delivered at NATS cabin accommodations are examined 86 Figurel4 Effects of glazing systems and their modifications on total energy consumed with U value of with external wall 0 27W m K Impact of double glazed windows on NATS cabins energy consumption U value of external walls 0 27 6000 5000 4000 3000 2000 1000 energy delivered year month D Window U value 1 2 Window U value 1 7 As it appears in figure14 the energy loss through low e double glazing windows is reduced because the energy leaving the cabins through windows is less than energy coming into the cabins through windows And on the tables 18 an 19 the results show that the lower the U value of double glazing window the lower the heat loss and therefore the less heating is required Table18 Total energy delivered if the U value of external wall is
108. t pump always give out more energy than the energy used for driving it and it is a means of using electrical energy to it advantage The objective of a heat pump is to maintain a heated space at a high temperature This is accomplished by absorbing heat from a low temperature source such as a well or cold 45 outside air in winter and supply this heat to the high temperature medium such as a house The heat pump cycle is fully reversible and heat pumps can provide year round climate control for space heating in winter and cooling and dehumidifying in summer Since the ground and air outside always contain some heat a heat pump can supply heat to a building even on cold winter days In fact air at 18 C contains about 85 of heat it contained at 21 C The measure of performance of a heat pump is expressed in terms of the COPup defined as _ DesiredOutput Qy COPup Re quiredInput HE 1 It can also be expressed as COPpp Qn Oy Se QO t Q Qn Most existing heat pumps use cold outside air as heat source in winter However the major problem with air source system is frosting which occurs when the temperature falls to near or bellow the freezing point The frost accumulation on the evaporator coils is highly undesirable since it seriously disrupts heat transfer and therefore the efficiency drops significantly It is necessary to use a separate boost heaters to supplement the heat pumps in very cold weather Most a
109. to reduce lighting energy costs T8 fluorescent lamp with electronic ballast was the standard for fixtures and could be retrofit in commercial office buildings school and a substantial portion of industrial lighting However a new range of T5 fluorescent tubes was developed for higher system efficiency T5 lamps are specially designed for higher frequency operation with electronic ballasts for higher efficiency and longer life Their shorter length 50mm less than T8 and thinner diameter 16mm enable lighting fittings designed for these tubes to fit into the common ceiling module systems without occupying additional space Improved technology and reduced dimensions inherent in the T5 tube can produce more efficient external environmentally friendly lighting systems with luminaires which fit within the common European building modules leading to easier fixing and installation For the reasons stated above these two types of lighting T8 and T5 systems were the most interesting and were selected amongst many others This research focused on them in order to see their impact on total energy consumption within a temporary accommodation 24 Table2 Comparison of T5 fluorescent lamp s maximum luminous output at 35 C and the luminous output that applies at 25 C 20 T5 lamp Length Design lumen Luminous Max Luminous light source s Efficacy light Output light luminous flux source s max sou
110. tres of diesel the current study had to be limited to the total energy consumed within cabin accommodations So it is suggested that future work could identify the total fuel use and running hours for each item of plant equipment on the construction site analyse the fuel consumption variation for each plant over a period of a year and identify why exceptional fuel consumption has occurred From this one could establish whether the amount of energy use is normal and set targets for improvement 100 References 1 Smith T E Industrial Energy Management for cost reduction Thomas E Smith Edition ann arbor mich ann arbor science publisher c1979 2 McMullan R Environmental Science in Building 5 edition London McMullan 1983 3 McGuiness William J Mechanical and Electrical Equipment for Building ei edition William J McGuiness Benjamin Stein John S Reynolds 4 Thumann Albert Plant Engineers and Managers Guide to Energy conservation 6 edition Albert Thumann Lilburn GA Fairmont press Upper saddle River NJ Distributed by Prentice Hall PTR c1996 5 Conference papers EFCE publication series N 23 Energy Money Materials and Engineering Oxford Pergamon Dec 1982 6 Larry C Witte Industrial Energy Management and Utilization Larry C Witte Philips S Schmidt David R Brown Washington Hemisphere Pub corp c1988 7 Bradshaw Vaughn Building Control Systems Va
111. tructures contributes sensibly in reducing heating requirements 16 III 2 Lighting systems in a temporary accommodation HI 2 1 Daylighting system Daylight is a source of illumination that uses solar energy It provides contact with the natural environment outdoors and varies with the luminance of the sky The light from the sky varies with the time of the day with the season of the year and with the local weather The most prominent characteristic of the daylight is its variability system When daylight enters the structure through windows its continual variation provides a constantly changing pattern of space illumination This could create special problems of glare control direct sunlight control and heat gain limitation However the use of energy efficient technologies such as high performance windows provides comfort and adequate natural lighting for interior spaces It could admit maximum light and solar heat gain in winter months with minimum heat loss In hot weather it is possible to control heat gain by keeping solar energy from entering the interior space while allowing reasonable visible light transmittance views and daylighting Special glasses which prevent the transmission of most of heat radiation while admitting light transmission are now available Table shows representative glass specifications 17 Tablet Representative Glass Specifications 27 Glass Type product Glass Thickness mm V
112. ughn Bradshaw New York Wiley c1985 8 Cowan Henry J Environmental Systems Henry J Cowan Peter R Smith New York London Van Nostrand Reinhold c1983 9 Awbi H B Hazim B Ventilation of Buildings H B AWBI London New York Spon 1991 10 University of Strathclyde Energy Systems Research Unit ESRU Manual U05 1 the ESP r system for Building Energy Simulation User Guide 11 CIBSE guide 5 edition London Chartered Institution of Building Services Engineers 1986 12 London Metropolitan University ESP r Course notes for Masters in Architecture Energy and Sustainability European Masters in the Integration of Renewable Energy into Buildings Module AR52P 13 Strathclyde University ESP r Course notes for Masters in Energy Systems and the Environment Department of Mechanical Engineering 14 Tommy GOVEN Energy Savings Through Improved Lighting Design and Engineering RIGHT LIGHT 4 1997 Volumel GOVEN AB Fagerhult Asogatan 115 116 24 Stockholm Sweden 101 15 Eclipse Research Consultants Cambridge Energy Management Guide prepared for BRECSU General Information Report 7 January 1993 16 ASHRAE Handbook Heating ventilation and air conditioning applications Atlanta GA American Society of Heating Refrigerating and Air Conditioning Engineers c1991 17 David Palmer BSc MSc MIEMA The Campbell Palmer Partnership Report for Laing O Rourke Scotland Document R
113. unday 10 0 20 0 tubei 30 0 25 0 6 a 20 07 15 0 10 0 S i bi AS NS 5 0 0 0 107 Operation notest could have 20 occupants during working hourst has 21 fluorescent tubei Control no control of air flow Number of Weekday Sat Sun air change periods 6 1 1 Period Infiltration Ventilation From Source id Hours Rate ach m ss Rate ach ma s Zone Temp Wd 1 G 8 0 50 0 0519 0 00 O 0000 Q 0 00 Wd 2 8 9 0 80 0 0831 0 00 O 0000 Q 0 00 Wd 3 9 12 1 60 0 1662 0 00 O 0000 A 0 00 Wkd 4 12 14 8 00 0 8314 O 00 O 0000 0 0 00 Wd 5 14 1 1 60 0 1662 0 00 O 0000 Q 0 00 Wkd 6 1 24 2 50 0 0519 O 00 O 0000 0 0 00 Sat 1 0 24 0 50 0 05193 0 00 O 0000 Q 0 00 Sun 1 0 24 0 50 0 0519 0 00 O 0000 Q 0 00 Lib NNATS_cabins res Results for NNATS_cabins Period Tue 14 Feb 00h30 tot Mon 20 Feb 23h30 Yeart2006 sim 60m output 60m Zones RestaurantG 20 estaurantG db T 15 z 0 SO i 10 MUO Op E 0 D 12 24 36 48 60 72 84 96 108 120 132 144 156 168 Time Hrs 108 Lib NNATS_cabins rest Results for NNATS_cabins Period Tue 14 Feb 00h30 tot Mon 20 Feb 23h30 Yeart2006 sim 60m output 60m Zones RestaurantG Not filtered by occupancy 25 14 00 D i 20 12 00 t 10 00 i 15 b 8 00 u t 10 6 00 1 D n 4 00 5 2 00 0 0 00 9 11 13 15 1 19 21 Zone db temperature degC Bin width 0 5 Comfort assessment for RestaurantG on Day 14 of month 2 Activity level 90 00 Clothing level 0 70 Ai
114. viously our aim is to analyse the total energy delivered at NATS cabin accommodations the zone flux transfer gains losses on the cabins surfaces to see the effect of some design change and the casual gains occupant heat gains lights heat gains and small power heat gains 73 VI Results analysis VI 1 Infiltration air load within NATS cabins In summer periods most of the 28 zones defined previously can use natural ventilation and the opening and closing of doors and windows are manually sufficient to provide the required fresh air The openings are the main means of removing the excess and unwanted heat gains as well as the removing of body odours This is made according to the internal temperatures It is recommended that in absence of further information 8 I sec person should be taken as the minimum ventilation to control body odour levels in rooms with sedentary occupants In this study the control of ventilation systems is based to the occupancy variation and to the sources of contaminants And we considered that some controls over the air flow rate are achieved by opening or shutting windows During a large part of the year the temperature of the outside air is less than that for the inside of the cabins Therefore the cooling is associated with the air infiltration and the conduction part of the load due to windows is negative In winter periods for example winds blow cold outdoor air into indoor spaces throug
115. were modelled to determine their technical and economic performance and a feasibility study of heating and lighting requirements within cabin accommodation was undertaken The analysis made use the ESP r simulation program and considered the impact of the design changes options such as insulation glazing types etc not only on the energy usage but also in terms of other performance criteria particularly the thermal comfort The results of this study allowed some general conclusions to be reached and confirmed the benefits associated with these technologies Finally an analysis was carried out to determine the CO emissions savings that could be achieved with good management and best practice Contents TM St eege ee ke Set enna AM Ue 1 Declaration Of AUthorisation wo ie ee cccceeeeceececccecsesceeeeeececeeeeeeeeeeeeeeeeseseceeeeeuuuaaaueueeeeeeeeeueeaaaaeeeees 2 Acknowledgements ssssssssseesssrnsstnsertnttttttttttntt ttnn AEAE AEAEE EEEEE EEEE ESEAS EEEE EEEEEE EEEE AEAEE EERE EEEE 3 ADSIFO EE 4 elei eg ele 5 Elleng ele T L e DEE 9 Part I Energy use on a construction site II Energy policy Reutte Lee NEE 11 IZ Alms And objectives 222 12 I 3 Energy policy IN perspective AEN 12 I 4 Organisation Structure ANd lines of COMMUNICATIONS oo eeeeceseeceeeeesesstseeeeeeessesaes 13 III Energy efficient technologies on a temporary accommodation IET lege el Lee 15 IL 2 Lighting systems on a temporary OC ommocoion e
116. whether a space is 34 occupied by sensing the noise or the motion of the occupant The sensors turn lighting on when there is someone in the room and off again after a time delay if there is nobody in the room The local switching method is about switching on lights only in the part of the room which is being occupied To maintain target lighting levels at the workplane in response to the changes in the amount of available daylight a signal is first measured by photo sensors which should represent workplane illuminance values Photo sensors are used to measure the light intensity They can detect both the reflected electric light as well as daylight to provide a close loop control dimming system The lighting level received can be sent to a dimming controller which varies the light output of the fluorescent lamps accordingly via the dimmable electronic ballasts Other sensors can be used to record the transmitted daylight The digital electronic control gear enables the fluorescent lamps to be dimmed from to 100 of their luminous flux The brightness of the fluorescent fittings can be used to evaluate daylighting performance of the space lightened The zero brightness reading indicates savings of a standard on off while 100 shows the system under full operation Daylight linked automatic lighting control system can provide excellent energy savings 35 TII 2 2 4 3 3 Lighting control Switches relays An on off control is desig
117. y conditions Ventilation is a fresh air that enters a building in a controlled manner to exhaust excess moisture and reduce odours and stuffiness while air infiltration arises from controlled and uncontrolled leakage through cracks and openings The amount of fresh air needed to be supplied to a space depends with the occupancy level and the activities carried within 53 that space For example Table 9 shows the minimum recommended fresh air supply rates that should be used to control body odour levels in rooms with sedentary occupants Table9 Recommended fresh air supply rates for sedentary occupants 16 Conditions Recommended outdoor air supply rate With no smoking 8 l sec per person With some smoking 16 l sec per person With heavy smoking 24 l sec per person With very heavy smoking 32 l sec per person The infiltration rate is one of the most difficult quantities to accurately estimate The difficulty lies in the wide variation in type quality of construction shape and location of the building the type of heating system and the design variation in window and door construction However the rates of probable infiltration occurring under average conditions in residences are estimated according to CIBSE guide These are given in the table10 Table1l0 Air changes occurring under average conditions in residences 11 Kind of room Number of air changes h Rooms with no windows or exterior do
118. y is 0 67W m K and 2 75W m K we could find the total energy saving of 32226 37kWh year This result shows that by reducing air infiltration rate within cabins and by combining improved insulation with reduced emissivity one could save 54 of energy 91 VII Economic aspects VII 1 Economic aspects on heating systems For economic reasons Laing O Rourke has made some efforts to save energy on space heating by selecting and using energy efficient construction materials However there is still great potential to go further in reducing its expenditures on energy consumption In this research a simulation analysis was undertaken using insulation and glazing materials with different coefficients of transmittance The results show the best alternative and they are presented in the following table Table21 Impact of air changes variation on total savings year Double External Minimum Total energy Total glazing wall air delivered energy window U value changes kWh costs year U value W mK rate W mK ac h 0 5 31864 65 2549 17 ve 1 5 47846 67 3827 74 2 75 0 5 39079 25 3126 34 0 76 1 5 52907 71 4232 6 1 5 51820 52 4145 64 0 67 2 60327 85 4826 22 It is the responsibility for the company to select the option which is the most economical as well as consistent with the degree of safety and aesthetic value required As shown in the table21 the elimination of cost for waste

Modelling Study of Energy Use on a Construction Site by Adolphe

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