The GreenBook
Contents
1. DCV for Standard compliance since the uncertainty of this DCV technique is extreme and not generally understood by most users In many cases CO based DCV will under or over venti late by more than 50 Another method uses the ACO level between the supply air and zone This differential is generally very small and sensor error becomes a significant factor To minimize sensor error a single sensor with sampling capabili ties should be used to sample both the supply and space CO This method uses the steady state or transient state model and the supply airflow rate to the space to estimate the popu lation Direct Occupancy Count DCV Direct occupancy counting systems such as electro mechanical turnstiles thermal and video imaging sensors and other IR devices are a much more reliable method for DCV than its CO based counterpart On sin gle zone systems the breathing zone outdoor air is calculated by adding a fixed floor component to the variable occupancy component Following VRP procedures the corresponding outdoor air setpoint can be easily cal culated and reset Scheduling DCV The use of occupancy time schedules can be an effective method for DCV On single zone systems the breath ing zone outside air is calculated by adding a fixed floor component to the scheduled occupancy component Following VRP procedures the cor responding outdoor air setpoints can be easily calculated and reset using a2. spaces The airflow measurement de vice should be capable of generating an alarm when the airflow values vary by more than 10 from the design values This requirement can easily be achieved by using any EBTRON duct or plenum probe GTx116 P HTx104 P Proper model selection is based on the size of the intake budget constraints and the desired installed accuracy of the system High Occupant Density Spaces greater than or equal to 25 people per 1 000 sq ft Monitor CO levels within all high occupant density spaces Changes to ASHRAE Standard 62 1 in 2004 resulted in variable ventila tion rates per person with changes in occupancy As a result a single CO setpoint can no longer meet the Standard since CO levels at best can estimate the amount of outdoor air entering a space per person CO must be combined with direct outdoor airflow measurement on all systems and accurate zone airflow measure ment on multi zone systems to assure compliance with the Standard IEQ Credit 2 Increased Ventilation TEQ Credit 2 is designed to improve IAQ by providing at least 30 more breathing zone outdoor air than re quired by ASHRAE Standard 62 1 2007 Breathing zone outdoor air is directly related to occupant productivity and health When the cost of operating a facility takes into account the cost of employee salaries it becomes obvi ous that productivity and health are important criteria when evaluating t
3. time schedule Binary occupied unoccupied DCV Binary detection of occupancy is ben eficial when spaces operate at near design occupancy levels 70 or greater when occupied In most cas es a simple IR or combination R ul trasonic detector is used to determine occupancy On single zone systems this technique will set the outside air intake setpoint to fully occupied con ditions This technique should be avoided if the space will be occupied frequently by a one or two people dur ing unoccupied periods example a teacher stays in a classroom much of the day when the students are not present Multi zone high occupant density There is also often justification to re duce the outside airflow rate below design occupancy conditions on mul tiple zone systems However meet ing ASHRAE Standard 62 1 speci fied ventilation rates is not as straight forward since the fraction of outdoor air in the supply air required to sat isfy each zone will differ from space to space In all cases install a permanently mounted EBTRON duct or plenum AMD in the minimum outdoor air intake to control minimum outdoor airflow rates CO2 Based DCV Multi zone conditions complicate CO DCV application Many either ignore the multi zone requirements of ASHRAE 62 1 2007 and treat multi ple zones as a large single zone or use a zone CO sensor to reset zone sup ply airflow rates and provide reheat Treating multiple zones
4. 12 EEEF pressure and humidity control As a result the following airflow rates should be monitored and controlled m Outdoor air intakes Intake flow rates will change with changes in supply air volume if not monitored and controlled as a result of chang ing pressures in the mixing box Uncontrolled intake flow rates can result in the inability of the system to maintain space temperature and humidity as a result of too much outside air insufficient capacity to handle the latent load or too little outside air uncontrolled infiltra tion of high dew point outside air through the building envelope m Supply air Supply airflow rates affect a system s ability to provide proper temperature and humidity control Systems that allow oc cupant control of supply airflow rates to modify space temperature should at a minimum include sup ply airflow measurement high and low limit alarms m Return or exhaust air If supply airflow rates are varied building pressurization could be affected since the supply return or supply exhaust differential flow rate is directly related to building space pressure When combined with supply airflow measurement return or exhaust airflow measurement can be used for airflow tracking to assure proper building pressure control a prerequisite for proper space temperature and humidity control m Zone air Supply registers only operate effectively over a specified range of airflow rates EB
5. a prerequisite for acceptable indoor air quality IAQ Outside air for the dilution of con taminants requires precise monitoring and control of outside airflow rates into the building at each air handling unit Proper pressurization through control of airflow rates is essential to limit moisture development within the building envelope and for tem perature and humidity control EBTRON has been a leader producing thermal dispersion airflow measure ment products since 1984 Our trained application specialists combined with an extensive local representative network assure your designs meet the performance requirements demanded for today s 21st Century buildings AIRFLOW MEASUREMENT PRODUCTS EBTRON airflow measuring devices AMD are the result of the Compa ny s more than 25 years of experience manufacturing high performance thermal dispersion instruments AMDs are available to measure in ducts or plenums fan inlets and a range of specialty applications and can interface with any building auto mation system BAS EBTRON s thermal dispersion tech nology relates the velocity of the air to the power and rise in temperature of a heated element in a moving air stream EBTRON uses a precision bead in glass self heated thermis tor as the heated element and another precision thermistor to measure the ambient air temperature Multiple sensing points are used to produce an average velocity for true volumetric airflow C
6. as a single zone does not meet the requirements of Standard 62 1 and zone reset will result in wasted reheat 1M M WThe EBTRON Green Book 15 One method uses zone CO levels and airflow measurement to estimate the population of each zone or at least of critical zones Once the population is known for each space the ventila tion rates specified by the Standard for mutli zone recirculating systems can be established and the correct out door air setpoint be maintained based on zone occupancy zone floor area and zone supply airflow rates As with all methods relying on CO lev els there is considerable uncertainty in the population estimates as a result of steady state assumptions CO pro duction level and CO measurement error As with high occupant density single zone systems the differential CO ACO level between the supply air and zone could also be used to esti mate the occupancy of each zone us ing a single sampling sensor Direct Occupancy Count DCV Direct occupancy counting systems is perhaps the best method for DVC Once the population is known for each space the ventilation rates speci fied by the Standard for mutli zone re circulating systems can be established and the correct outdoor air setpoint be maintained based on zone occupancy zone floor area and zone supply air flow rates The EBTRON GreenBook 16 Scheduling DCV The use of occupancy time schedules can be an effective method
7. being EBTRON has developed an ASHRAE 62 1 BACnet DCV Calculator that can calculate the setpoint required for compliance with any of the DCV methods indicated below thus elimi nating overhead required making the cumbersome calculations by the host control system In all cases install a permanently mounted EBTRON duct or plenum AMD in the minimum outdoor air intake to control minimum outdoor airflow rates CO Based DCV Changes implemented in 2003 to the VRP by addendum n redefined how CO DCV could be used for compli ance CO2 levels do not directly in dicate population as many incorrectly assume At best CO levels indicate the rate that outdoor air is entering a space per person OA cfm person One method to use CO is to monitor the differential CO ACO level be tween the outside and interior space Assuming steady state and the default CO production rate typically that for office work the ACO level has a cor responding outside airflow rate for a given population a transient state model can also be applied Reset the outdoor air setpoint to the calcu lated setpoint between minimum and design maximum population values By resetting the outdoor air setpoint in this manner the control system can adjust to changes in population This method can be simplified using the straight line approximation sug gested by Stanke Regardless of the method used one should exercise ex treme caution in relying on CO
8. for DCV The ventilation rates specified by the Standard for mutli zone recirculat ing systems can be estimated and the correct outdoor air setpoint be main tained based on scheduled zone occu pancy zone floor area and zone sup ply airflow rates Binary occupied unoccupied DCV Binary detection of occupancy is beneficial when spaces operate at near design occupancy levels 70 or greater when occupied In most cases a simple IR motion detector or combination IR ultrasonic detec tor is used to determine occupancy The ventilation rates specified by the Standard for mutli zone recirculat ing systems can be established and an approximate outdoor air setpoint be maintained based on maximum zone occupancy zone floor area and zone supply airflow rates This technique LOW RISK BINARY OCCUPANCY DETECTION DCV can be modified to use a ventilation matrix based on design occupancy and load if the space will be occupied frequently by a one or two people dur ing unoccupied periods see previ ous page The setpoint matrix below was established using ASHRAE 62 1 2007 guidelines on a three room classroom based on all occupancy combinations of either full occupancy 35 or zero occupancy Binary sensors placed in each classroom would set the outside airflow rate to the outside air setpoint listed in the table bottom left The actual outside air required for a given set of population and load conditions is listed in the tabl
9. the green initiative EBTRON products can help in obtaining a number of LEED points either directly or in directly and are an essential compo nent of any green high performance building Measurement for monitoring and or control is a prerequisite for the effec tive and efficient operation of today s high performance buildings Failure to provide measurement devices for monitoring and control of critical building systems can result in reduced energy efficiency occupant health and building longevity EBTRON products can make a differ ence in a building s performance EA Prerequisite 1 Fundamental Commissioning Prerequisite 1 in Energy and Atmo sphere EA requires that a building has a commissioning authority and plan That plan shall provide a means to verify the installation and perfor mance of the systems to be commis sioned The HVAC system is one of the pri mary energy related systems that re quire commissioning A number of parameters verifying the performance of this system can be documented us ing EBTRON products EBTRON CAN HELP YOU ACHIEVE LEED CERTIFICATION Airflow measurement can be invaluable when designing for LEED certifica tion A single AMD can have a cascading effect on multiple LEED points One credit in particular IEQ Credit 1 provides one point for measuring out side air intake flow rates to all low occupant density spaces Credits that can be impacted by the use of EBTRON AMDs i
10. FM or L s Each sensing point is individually calibrated at up to sixteen points to NIST traceable airflow standards Most models in clude a temperature output signal Unlike differential pressure flow rings or crosses that have very little sensitivity at low air velocities and use percent of full scale accuracy pressure transducers the sensitivity to airflow increases as the flow rate decreases As a result accuracy is percent of reading Greater sensi tivity results in better accuracy espe cially with turn down compared to differential pressure based devices and vortex shedders As a result the technology is ideal for the measure ment of the relatively low airflow rates typically found in most HVAC applications Long term stability is assured by the selection of high qual ity thermistors and signal processing components Unlike pressure based devices and vortex shedders that fre quently require field calibration and auto zeroing EBTRON does not rec ommend periodic calibration of its airflow measuring devices In fact there is no auto zero function in any EBTRON airflow measuring device It simply is not required IEEE The EBTRON Green Book 3 The EBTRON GreenBook 4 BEEF EBTRON prides itself on manufac turing only the highest quality prod ucts Our no compromise philoso phy is evident throughout all of our product lines The Advantage product line was originally comprised of two distinc
11. TES 1 Modulate ERV OA fan to maintain duct static pressure w reset 2 Modulate OA dampers to maintain AHU OA at each zone 3 OA EX Q 4 NOT BEST METHOD Use air balance measurement or permanently mounted AMD to manually balance OA and EX at each AHU zone 5 Modulate ERV EX fan to maintain overall Q COMMENTS 1 Active control is required to compensate for filter loading wind stack and mixed air plenum pressure VAV effects on forced makeup or ERV fan system i M MThe LBTRON Green Book 33 CV VAV multiple AHU s or FCU s low or high rise Systems with single minimum OA ERV minimum OA mode NOTES 1 Modulate ERV OA and EX fans to maintain duct static w reset 2 Modulate OA dampers to maintain AHU OA at each zone 3 OA EX Q at each zone 4 BEST METHOD Modulate AHU EX dampers to maintain Q at each zone COMMENTS 1 This method compensates for all external and system pressure effects The EBTRON GreenBook 34 E E EE CV VAV multiple AHU s or FCU s low or high rise Systems with single bypass ERV modulating economizer Reset OA1 setpoint NOTES 1 Modulate ERV OA and EX fans to maintain duct static w reset 2 Modulate OA damper then cooling coil at each zone in sequence to reset zone OA setpoint to maintain supply air temperature 3 OA EX Q at each zone 4 Modulate AHU EX dampers to mainta
12. TRON AMDs can drastically improve zone flow performance and thermal comfort by limiting minimum and maximum supply flow rates and setting alarms when applicable IEQ Credit 7 7 1 and 7 2 Thermal Comfort Design Verification IEQ Credits 7 7 1 and 7 2 require that a high level of thermal comfort be provided for the occupants When it comes to thermal comfort proper control of airflow rates is an essential prerequisite Generally air flow rates cannot be properly main tained during operation without moni toring and feedback control The critical airflow rates that should be monitored and or controlled to as sure proper thermal comfort are as follows m Outdoor air intakes Uncontrolled intake flow rates can result in the inability for the system to maintain space temperature and humidity as a result of too much outside air insufficient capacity to handle the latent load or too little outside air uncontrolled infiltration of high dew point outside air through the building envelope m Supply air Improper airflow rates will result in poor coil performance and discharge air temperature hu midity control m Return air When combined with supply airflow measurement re turn airflow measurement can be used for airflow tracking to assure proper building pressure control a prerequisite for proper space tem perature and humidity control m Zone air Supply diffusers only operate effectively over a specified
13. Trur GreenBook dg i a your Building with Airflow Measurement Breathe Easier Specify Z5 TRS thermal dispersion airflow measurement technology on your high performance buildings Breathe easier by improving IAQ It s not only green but ensuring the comfort and well being of the occupants makes good business sense since the benefits realized from increased productivity can offset the total cost of energy to operate a building EBTRON can provide airflow measurement solutions that result in energy efficient building operation and improved IAQ EBTRON manufactures a full line of airflow measurement devices to meet any application requirement and budget Take advantage of our more than 25 years of experience in measurement and control Contact EBTRON or one of our 80 independent representatives today EBTRON will show you how to use airflow measurement devices to satisfy LEED credit requirements save energy and help green your building LEED is a registered trademark of the U S GREEN BUILDING COUNCIL Pa ats on oY OE Saas l X e7 Thermal Dispersion Airflow Measurement 1663 HWY 701 S Loris S C 29569 Toll Free 800 2EBTRON 232 8766 Fax 843 756 1838 Internet EBTRON com INTRODUCTION Control of HVAC system airflow rates is essential for the successful opera tion of high performance buildings Outside air and building pressure are fundamental to ASHRAE Standard 62 1 compliance
14. air intake flow rates or by as suring that air side energy recovery systems are properly balanced and op erating at maximum efficiency Mini mum outside air control improved air side economizer performance and increase energy efficiency on ERVs is discussed in the section for EA Pre requisite 2 and can be applied to EA Credit 1 Proper selection of AMDs at the zone level on VAV systems is another area where real world performance improvements can be realized EB TRON s ELF D thermal dispersion AMD and EBTRON s STA102 T thermal dispersion AMD for small ducts can allow for lower supply airflow rates hence lower duct stat ic pressures less fan horsepower Equally important improved sensor accuracy at maximum turndown can significantly reduce reheat when com pared to pneumatic flow technology that is typically used in VAV terminal boxes It is not improbable for tradi tional terminal box flow technology to result in 20 or more error with turndown when the uncertainty of the DDC pressure sensor is considered EA Credit 3 Enhanced Commissioning EA Credit 3 requires additional verifi cation after initial system verification required in EA Prerequisite 1 The permanently mounted sensors and monitors discussed in EA Pre requisite 1 Fundamental Commis sioning can also be used as part of a long term continuous commission ing plan EBTRON AMDs are designed with high quality components and are not s
15. airflow A rates and challenging placement conditions associated with outdoor air intakes EBTRON manufactures a full C line of airflow measurement devices to meet any application requirement and budget Take advantage of our more than 27 years of experience in measurement and control Contact EBTRON or one of our 80 independent representatives today EBTRON will show you how to use airflow measurement devices to satisfy LEED credit rs requirements save energy and help green your building LEED is a registered trademark of the U S GREEN BUILDING COUNCIL l DTAP pe Bza Fh Thermal Dispersion Airflow Measurement 1663 HWY 701 S Loris S C 29569 Toll Free 800 2EBTRON 232 8766 Fax 843 756 1838 Internet EBTRON com The Ebtron GreenBook R2A
16. ble Increased Efficiency of Exhaust Air Energy Recovery Ventilators ERV ERV energy performance and proper building pressure requires that in take and exhaust rates are properly balanced As with any outside air system flow rates are significantly influenced by wind and stack pres sures as well as mixed air plenum pressure variations on VAV systems Units are often oversized and require adjustment in the field On desiccant wheel ERVs filters load on the intake side faster than they do on the exhaust side The imbalance in filter loading results in decreased intake flow rates when compared to the exhaust EBT RON manufactures desiccant wheel ERV intake exhaust airflow measure ment stations designed to solve this problem EA Credit 1 Optimize Energy Performance EA Credit 1 provides up to 21 points for increasing the building s level of efficiency above the baseline prereq uisite The proper selection of AMDs for both monitoring and control can have a significant impact on the overall energy performance of a building compared to baseline values Un fortunately it is difficult to ascertain the actual performance of many of today s systems and sensors in real world installations As a result the benefit of using high performance AMDs is not always obvious to engi neers and owners HVAC energy efficiency can be sig nificantly improved by accurately monitoring key airflow rates such as outside
17. e spaces the minimum outdoor airflow rates should be set to maintain or ex ceed the minimum requirements spec ified by the VRP of ASHRAE Stan dard 62 1 for the maximum expected occupancy Note that the maximum expected occupancy for a space s cur rent use may be less than the design occupancy of the space Install a permanently mounted EB TRON duct or plenum AMD in the minimum outdoor air intake to moni tor and or control minimum outdoor airflow rates Multi zone low occupant density As is the case with low occupant den sity single zone systems there is little benefit of implementing DCV on this type of system 1M M The EBTRON Green Book 13 For low occupant density multi zone spaces the minimum outside airflow rates should be set to maintain or ex ceed the minimum requirements spec ified by the VRP of ASHRAE Stan dard 62 1 ASHRAE provides an easy to use Microsoft Excel spreadsheet for the determination of minimum ventilation rates with the ASHRAE 62 1 2007 User s Manual available for sale from ASHRAE On multi zone systems the percent age of outdoor air required from zone to zone will typically vary as a result of varying thermal loads between zones As a result there will be at least one zone that requires more out door air as a percentage of the supply air than the others This is known as the critical zone Critical zone fractions that are con siderably higher than surrounding zones can ha
18. e as OA Required bottom right The actual outside air delivered is listed as OA Provided Note that in all cases the classrooms were adequately ventilated Although the maximum demand controlled reductions was not achieved this technique would never have placed the students at risk our core goal as is possible with CO DCV techniques Setpoint Matrix Rm 1 Rm 2 Rm 3 OA Status Status Status Setpoint eee 1410 INOCC UNOCC Actual Conditions pe 3 ene ned JMNM WThe EBTRON Green Book 17 CV VAV Supply fan only minimum OA mode VeUOD EID OA NOTES 1 Modulate OA and RA dampers in sequence to maintain min OA 2 OA Q COMMENTS 1 If OA is greater than desired Q system requires exhaust or relief 2 Not recommended for DCV since building pressure will vary consid erably with changes in OA The EBTRON GreenBook 18 EEEF CV VAV Supply fan with constant exhaust or relief fan minimum OA mode EX VeOD VED OA NOTES n Modulate OA and RA dampers in sequence to maintain min OA 2 Use air balance measurement or permanently mounted AMD for con stant volume exhausts i e toilets 3 OA EX Q 4 Not recommended for DCV since building pressure will vary con siderably with changes in OA and here is no provision for exhaust airflow reset 1M M MThe EBTRON Green Book 19 CV VAV Supply fan with variable exhaust or relief fan min
19. eals and partitions IEQ Prerequisite 1 Minimum IAQ Performance Prerequisite 1 in Indoor Environmen tal Quality IEQ requires that build ings meet the minimum requirements of the Ventilation Rate Procedure VRP of ASHRAE Standard 62 1 2007 The VRP is very clear it specifies breathing zone outside air VENTILA TION RATES based on space type occupancy and area Low occupant density spaces such as offices or other spaces having an occupant density less than 25 people per 1 000 square feet have minimal changes in the specified outside air ventilation rate with typical changes in occupancy Low occupant den sity spaces should have a duct or plenum AMD installed in each out side air intake Minimum ventilation rates should be calculated using the guidelines of the ASHRAE 62 1 Us ers Manual and maintained during occupied periods LEED provides for an additional credit for the direct measurement of outside air intake flow rates in IEQ Credit 1 Outdoor Air Delivery Monitoring Demand controlled ventilation DCV meth ods using CO based reset should BE AVOIDED on low occupant density spaces The uncertainty associated with CO DCV especially at low oc cupant densities cannot assure com pliance with the Standard and in most 1888 The EBTRON Green Book 9 cases will significantly under or over ventilate the space The industry trend on high occupant density spaces is to use CO based DCV Although the co
20. ef 2 Not recommended for DCV since building pressure will vary consid erably with changes in OA 1 M WThe EBTRON Green Book 25 CV VAV Supply Relief fan system minimum OA mode active relief at AHU Toilet EX PAD YID OA a RE OPEN NOTES 1 Modulate OA and RA dampers in sequence to maintain min OA 2 SA RA EX Q 3 Modulate RE fan to maintain Q 4 Caution should be exercised when applying DCV e Do not allow OA setpoint to fall below EX flow e Do not allow Q to over pressurize the building when DCV OA requirements are high The EBTRON GreenBook 26 E E E F CV VAV Supply Relief fan system modulating economizer Toilet EX Reset OA setpoint OA RE OPEN NOTES 1 Modulate OA and RA dampers then cooling coil in sequence to reset OA setpoint to maintain supply air temperature 2 OA setpoint must not fall below minimum required for IAQ 3 SA RA EX Q 4 Modulate RE fan to maintain Q 5 Caution should be exercised when applying DCV e Do not allow OA setpoint to fall below lowest EX flow e Do not allow Q to over pressurize the building when DCV re quirements are high i1 M MThe EBTRON Green Book 27 CV VAV Single Supply Return serving multi floor system minimum OA mode no relief at AHU Toilet EX 1 Modulate SA and RA fans to maintain duct static w reset 2 Modulate OA and RA dampers in sequence to main
21. er pressurization between construction and occupied zones can be accom plished by using one of EBTRON s bleed airflow sensors These de vices can be used as either permanent monitors or be removed and used on subsequent projects IEQ Credit 3 2 Construction IAQ Management Plan Before Occupancy IEQ Credit 3 2 is designed to reduce indoor air quality problems resulting from the construction renovation pro cess prior to occupancy Option 1 Flush out Requires that a total air volume of 14 000 cu ft of outside air per sq ft while maintaining 60 F and rela tive humidity no higher than 60 of floor area is provided to flush out con taminants This volume of air can be provided prior to occupancy or during occupancy during a flush out pe riod as specified by the requirement By installing AMDs to meet the re quirements of IEQ Prerequisite 1 and IEQ Credit 1 you will already have provided the instrumentation required to meet this credit if the flush out will be accomplished using the existing HVAC system Simply use the out side air AMD to totalize the volume of air provided during the flush out periods until the required air volume is achieved IEQ Credit 5 Indoor Chemical amp Pollutant Source Control TEQ Credit 5 is designed to minimize the exposure of building occupants to hazardous particulates and chemical pollutants 18 M 8The LBTRON Green Book 11 In addition to proper
22. es Their versatile probe design allows them to be installed after the duct work is installed Fan Inlet Airflow Measurement F Sensor Probes Fan inlet stations are designed to be installed directly in the inlet of cen trifugal and vane axial fans without significantly affecting fan perfor mance This technology is generally applied when measurement in ducts or plenums is not feasible do to place ment limitations or excessive branch ducts at the AHU Application Specific Airflow Measurement EBTRON manufactures application specific AMDs for small ducts class room unit ventilators and desiccant wheel energy recovery ventilators The EBTRON Green Book 5 EA lt a Display Individual Sensor Airflow amp Tenperawre BAS Interface D Linear 0 10 VDC 4 20mA isolated from main circuit SS TLonwoiksFreeTopolowy inert Speci Funcions SSCS a Field Cal Wizard Linear 0 10 VDC 4 20mA isolated from 24 VAC Live or Coefficient Digital Offset Gain Adjustment P meaa Output Rate of Change Dampening Filter E e Variatie Oumar tme OOOO Tow LimtAirfow Cwo SSCS eloiy Weighed TempertreOuipa O O Paasnitr Creuitry and Couttracton S moea o O S SS a E E Switching Power Supply UL Listed The EBTRON GreenBook 6 LEED CERTIFICATION Based on LEED 2009 for New Con struction Schools and Core amp Shell Today s society is keenly interested in developing and supporting
23. filtration chemi cals and hazardous particulates must be contained within boundaries as a result of proper compartmentalized pressure control Compartmental ized pressure control is most effec tively accomplished by volumetric airflow control and or tracking using accurate AMDs Validation can be accomplished by monitoring pressure between critical pressure zones with bleed airflow sensors IEQ Credit 6 6 2 Controllability of Systems TEQ Credit 6 6 2 requires that a high level of thermal comfort control be provided to individual occupants or groups of occupants sharing spaces If local thermal comfort adjustments made by the occupants result in changes to the supply ventilation rates to the space a cascading effect on system performance will result with out proper monitoring and control On VAV systems this is generally understood although often ignored However many other systems will also have significant changes in sys tem performance Examples of such systems include under floor systems with manually adjusted floor diffus ers constant volume systems that al low for local changes in supply flow rates to adjust space temperature and cycling heat pump systems without a dedicated outside air system On these systems changes in the space temperature setpoint that change supply airflow rates will alter the breathing zone outdoor air It may also affect coil performance building The EBTRON GreenBook
24. floor COMMENTS 1 This method compensates stack effect on tight floor to floor construc tion and without vertical path for stack flow i e open stairwell atri um and some elevator shafts The EBTRON GreenBook 30 EEEF CV VAV Systems with minimum OA ERV minimum OA mode OA EX If there is no bypass on ERV se lect an EBTRON HTx104 E for OA EX measurement at the desic cant wheel NOTES 1 Modulate ERV OA fan to maintain min OA 2 OA EX Q 3 Modulate ERV EX fan to maintain Q COMMENTS 1 Active control is required to compensate for filter loading stack and mixed air plenum pressure VAV effects and to partially compensate for wind on forced makeup or ERV fan system 1M 8The EBTRON Green Book 31 CV multiple AHU s Systems with single minimum OA ERV minimum OA mode NOTES 1 Modulate ERV OA fan to maintain min OA 2 OA EX Q 3 Use air balance measurement or permanently mounted AMD to man ually balance OA and EX at each AHU zone 4 Modulate ERV EX fan to maintain Q COMMENTS 1 Active control is required to compensate for filter loading wind and stack pressure effects on forced makeup or ERV fan system 2 Do not use manual adjustment to AHU zones on cycling fan systems The EBTRON GreenBook 328888 VAV multiple AHU s low rise only Systems with single minimum OA ERV minimum OA mode NO
25. g ventilation rates of outside air required to pro vide acceptable IAQ The Standard has two procedures the VRP and the IAQ Procedure which engineers and building owners must select only one for compliance The IMC 2006 amp 2009 LEED and many local codes reference the VRP for compliance Both the VRP and IAQ Procedure specify ventilation rates for IAQ Because the IAQ Procedure has many subjective components the use of the VRP is typically recommended by EBTRON However the IAQ Pro cedure can be extremely useful when used in conjunction with the VRP on contaminants that are present and de tectable in buildings above threshold limits However when this is done the minimum ventilation rates speci fied by the VRP must be maintained The VRP specifies breathing zone outside air based on space use floor area and occupancy and the optimal design is dependent on whether the system is single or multi zone and low or high occupant density Single Zone low occupant density Low occupant density spaces typi cally have occupancy levels greater than 70 of the maximum expected occupancy For a typical office space a reduction in occupancy of approxi mately 30 will only result in a de crease in the required outside air of 10 The outside air reduction of 10 is well under the uncertainty of most DCV techniques therefore elim inating the application of DCV on this type application For low occupant density single zon
26. he overall performance of a building Typical employee costs including salaries and benefits are up to 50 times the cost of energy to operate a building A 2 increase in productiv ity on an individual having an annual salary of 50 000 would equate to a 1 000 benefit per year to an end user The 2 increase is conservative An increase in outdoor air at the breath ing zone from 17 cfm to 22 1 cfm based on the 30 increase required to meet IEQ Credit 2 and default val ues for office space in Standard 62 1 will cost the end user between 2 and 10 per year per person depending on the cost to condition the additional outside air Clearly there is a signifi cant benefit to all by fulfilling the re quirements of this credit Airflow measurement is a prerequi site for ensuring that ventilation rates specified by ASHRAE Standard 62 1 are delivered to the breathing zone in both low and high occupant density spaces TEQ Credit 3 3 1 Construction IAQ Management During Construction TEQ Credit 3 3 1 is designed to reduce IAQ problems resulting during the construction renovation processes Pathway interruption requires that the work area is negatively pressurized to minimize the migration of construc tion site contaminants Depending on the type s of systems used in the con struction and occupied zones the use of AMDs to provide compartmental ized pressure control is essential In addition verification of prop
27. imum OA mode EX NOTES 1 Modulate OA and RA dampers in sequence to maintain min OA 2 OA EX Q 3 Modulate EX fan to maintain Q 4 Caution should be exercised when applying DCV e Do not allow OA setpoint to fall below lowest EX flow e Do not allow Q to over pressurize the building when DCV OA requirements are high The EBTRON GreenBook 20 EEEF CV VAV Supply fan with variable exhaust or relief fan modulating economizer VAUD EYID OA NOTES jai Modulate OA RA dampers and then cooling coil in sequence to reset OA setpoint to maintain supply air temperature OA setpoint must not fall below minimum required for IAQ ventilation OA EX Q Modulate EX fan to maintain Q nA A W N Caution should be exercised when applying DCV e Do not allow OA setpoint to fall below lowest EX flow e Do not allow Q to over pressurize the building when DCV require ments are high 1M M WThe EBTRON Green Book 21 CV VAV Supply Return fan system minimum OA mode no relief at AHU Toilet EX OA NOTES 1 Modulate OA damper RA fan and RA damper in sequence to main tain minimum OA 2 OA EX Qp COMMENTS 1 If OA is greater than desired Qp system requires exhaust or relief 2 Not recommended for DCV since building pressure will vary consid erably with changes in OA The EBTRON GreenBook 220888 CV VAV Supply Return fan system minimum OA
28. in Q at each zone COMMENTS 1 This method compensates for all external and system pressure effects ALS IG Specify 57R2ZM for your high performance buildings on e Continuously verify system performance Improve economizer stability e Optimize outside airflow delivery e Balance energy recovery ventilators 4 e Maintain building pressure e Reduce fan energy gt e Improve thermal comfort e Minimize wasted reheat va EBTRON manufactures a full line of airflow measurement devices to meet any application requirement and budget Take advantage of our more than 25 years of experience in measurement and control Contact EBTRON amp or one of our 80 independent representatives today EBTRON will show you how to use airflow measurement devices to satisfy LEED credit requirements save energy and help green your building LEED is a registered trademark of the U S GREEN BUILDING COUNCIL cl TEL DTAP pe S 29 i AN Thermal Dispersion Airflow Measurement 1663 HWY 701 S Loris S C 29569 Toll Free 800 2EBTRON 232 8766 Fax 843 756 1838 Internet EBTRON com IEQ Credit 1 1 Point Outdoor Air Delivery Monitoring a n t Provide a direct outdoor airflow measurement device capable of x measuring the minimum outdoor air intake flow rate S LEED 2009 Rating System NC EB CS HC SC d EBTRON s thermal dispersion airflow measurement devices are ideal for the measurement of the lower
29. ion and reset to achieve the desired mixed air or supply air temperature setpoint Poor control results in lower energy effi ciency Economizer performance can be significantly improved by resetting the outside air intake setpoint between the minimum and maximum outside The EBTRON GreenBook 8 BEEF air intake flow rates This can be achieved on systems with full size or min max dampers using EBTRON s duct or plenum AMDs This strategy results in more stable temperature control while assuring that minimum intake rates are met and never ex ceeded Proper economizer tempera ture control is analogous to VAV box space temperature control on pressure independent systems that reset the flow setpoint rather than the damper position directly to improve space temperature control and assure mini mum and maximum ventilation rates Implementing this strategy allows for sequencing of dampers which results in lower pressure drop of AHU damp ers hence less fan energy The inte gral temperature output can be used for high limit shutoff control in areas where use of dry bulb temperature is acceptable When supply and return and or exhaust airflow measure ment is added net building pressure will also be maintained The velocity weighted temperature feature on all GOLD and HYBRID transmitters can improve supply or mixed air tempera ture measurement accuracy compared to traditional serpentine sensors and should be utilized whenever possi
30. mode active relief at AHU Toilet EX OA OPEN Optional NOTES 1 Modulate OA and RA dampers in sequence to maintain minimum OA 2 SA RA EX Q 3 Modulate RA fan to maintain Q 4 Caution should be exercised when applying DCV Do not allow OA setpoint to fall below EX flow e Do not allow Q to over pressurize the building when DCV OA requirements are high JNM WThe EBTRON Green Book 23 CV VAV Supply Return fan system modulating economizer Toilet EX Reset OA setpoint OA Assume ERV if present is totally bypassed on this system RE OPEN Optional NOTES ee Modulate OA RA dampers and then cooling coil in sequence to reset OA setpoint to maintain supply air temperature 2 OA setpoint must not fall below minimum required for IAQ 3 SA RA EX Q exercised when applying DCV 4 Modulate RA fan to maintain Q 5 Caution should be exercised when applying DCV e Do not allow OA setpoint to fall below lowest EX flow e Do not allow Q to building when DCV requirements are high The EBTRON GreenBook 24 E E E F CV VAV Supply Relief fan system minimum OA mode no relief at AHU Toilet EX Vaip EID OA CLOSED NOTES 1 Modulate OA damper RA fan and RA damper Relief fan and Recir culation damper in sequence to maintain minimum OA 2 OA EX Q COMMENTS 1 If OA is greater than desired Q system requires exhaust or reli
31. ms areas m Install a bleed airflow room pres sure monitor between the smoking room and adjacent area m Install an automatic door closer on the entry door to the smoking room m Control the exhaust fan speed using a variable frequency drive VFD and maintain at least 0 02 inches of water gauge negative pressure with respect to the adjacent area IEQ Prerequisite 3 Minimum Acoustical Performance Schools only IEQ Prerequisite 3 is designed to en sure that classrooms are sufficiently quiet to permit effective communica tion HVAC energy efficiency can be sig nificantly improved by accurately monitoring key airflow rates and improved efficiency can result in re duced fan speeds and size and there fore reduced noise IEQ Credit 1 Outdoor Air Delivery Monitoring IEQ Credit 1 is designed to provide ventilation system monitoring to help sustain occupant comfort and well being in accordance with the require ments of ASHRAE Standard 62 1 2007 Mechanically Ventilated Systems Low Occupant Density Spaces under 25 people per 1 000 sq ft IEQ Credit 1 awards 1 point for in stallation of a direct airflow measure ment device capable of measuring the minimum outdoor air intake flow with an accuracy of 15 of the design minimum outdoor air rate as defined by ASHRAE 62 1 2007 for all me chanical ventilation systems where 20 or more of the design supply airflow serves non densely occupied
32. ncept of re setting the ventilation rates based on CO levels is attractive the technique is prone to numerous errors that re sult from steady state assumptions and measurement error LEED pro vides a point for the use of standalone CO sensors in high occupant density spaces while requiring compliance with ASHRAE 62 1 2007 Unfortu nately CO DCV alone will not meet the requirements of 62 1 2007 Improved CO methods can estimate the population using AMDs installed in the outside air intake and at each zone mutlit zone systems However the uncertainties of CO based mea surement may not meet the intent of Standard 62 1 or LEED More accu rate methods to count the population will improve DCV performance and include turnstiles or electronic coun ters such as EBTRON s thermal oc cupancy counter IEQ Prerequisite 2 Environmental Tobacco Smoke Control Prerequisite 2 is designed to minimize exposure of the building occupants and its components to Environmental Tobacco Smoke ETS If Option 2 is chosen designated smoking rooms areas must have a dedicated exhaust system to maintain proper pressurization and isolation of ETS The EBTRON GreenBook 10 EEEF EBTRON generally does not recom mend direct pressure control of fans or dampers However in the interest of limiting overall costs EBTRON recommends that the following pres sure control method be used to main tain proper pressurization of smoking roo
33. nclude m EA Prerequisite 1 Fundamental Commissioning m EA Prerequisite 2 Minimum Energy Performance m EA Credit 1 Optimize Energy Performance m EA Credit 3 Enhanced Commissioning m EA Credit 5 5 1 5 2 Measurement Verification amp Submetering m EQ Prerequisite 1 Minimum IAQ Performance m EQ Prerequisite 2 Environmental Tobacco Smoke Control m IEQ Prerequisite 3 Minimum Acoustical Performance m IEQ Credit 1 Outdoor Air Delivery Monitoring m JEQ Credit 2 Increased Ventilation m IEQ Credit 3 3 1 3 2 Construction IAQ Management Plan Construction and Occupancy m JEQ Credit 5 Indoor Chemical amp Pollutant Source Control m IEQ Credit 6 6 2 Controllability of Systems Thermal Comfort m JEQ Credit 7 7 1 7 2 Thermal Comfort Design amp Verification m JEQ Credit 9 Enhance Acoustical Performance m JEQ Credit 10 Mold Prevention m ID Credit 1 Innovation in Design Permanently installed EBTRON airflow temperature monitors can verify that the building performance meets the Owners Project Require ments OPR and the Basis of Design BOD These techniques improve quality control by eliminating field measurement error while providing permanent documentation of critical parameters In addition permanently mounted AMDs can result in more cost effective monitoring faster more frequent intervals and can be used for additional functions such as control to improve building opera
34. of the minimum level of energy effi ciency for the buildings and systems to reduce the environmental and eco nomic impact of excessive energy use via Whole Building Energy Simula tion or the applicable ASHRAE Pre scriptive Compliance Path 1808 The EBTRON Green Book 7 Minimum Outside Air Control EBTRON s duct or plenum AMDs are essential for the control of mini mum outdoor air flow rates On most systems intake flow rates will vary dramatically as a result of damper hysteresis transient wind pressure stack effect and changes in mixed air plenum pressure VAV systems Simply resetting a damper or outside air fan to the same minimum position speed may not result in maintenance of the desired setpoint EBTRON testing has shown that the intake error associated with any one of these fac tors can result in intake fluctuations in excess of 30 Cumulative errors are even greater These uncertainties are not properly taken into account in most building energy models and as a result buildings may not perform as well as model predictions The uncertainties are real and significant benefits can be realized by monitoring and controlling minimum outside air intake levels on ALL systems regard less of model predictions Improved Air side Economizer Control ASHRAE 90 1 2007 requires modu lating air side economizers Con trol of air side economizers is often very poor since most strategies rely solely on damper posit
35. range of airflow rates On VAV systems measurement error drift low flow uncertainty from tradi tional pneumatic airflow measure ment devices cannot assure that the optimal range of flows are de livered thus resulting in very poor diffuser performance and thermal comfort EBTRON AMDs can drastically improve VAV zone flow performance As an added benefit accurate thermal dispersion zone airflow measurement can also re duce wasted reheat lower supply airflow rates at the box lower duct static pressure and improve DCV performance IEQ Credit 9 Enhanced Acoustical Performance Schools IEQ Credit 9 is designed to provide classrooms that are quiet to allow for effective communication HVAC energy efficiency can be sig nificantly improved by accurately monitoring key airflow rates and improved efficiency can result in re duced fan speeds and size and there fore reduced noise IEQ Credit 10 Mold Prevention Schools TEQ Credit 10 is designed to reduce the potential presence of mold in schools through preventative design and construction Accurately monitoring and control ling key airflow rates can result in proper building pressurization which could prevent the infiltration of mois ture into the building envelope there by reducing the potential for mold growth and water damage m ASHRAE STANDARD 62 1 2007 ASHRAE 62 1 2007 Ventilation for Acceptable Indoor air Quality is the industry standard definin
36. t series the GOLD Series and the SILVER Series In 2008 the HY BRID Series combined key features of both All Advantage products are complete AMDs that include the sensor probes and transmitter As a result no additional transmitters or transducers are required to interface with your BAS This results in single source responsibility with improved accuracy and lower equipment first cost Transmitters are available with traditional analog output signals 0 10 VDC 4 20mA as well as RS 485 BACnet MS TB BACnet ARC NET Modbus RTU JCI N2 Bus Ethernet BACnet TCP IP Modbus or Lon all at no additional charge Which Series is best for you Series selection is based on the type of sensor probe application interface requirements and budget What sensor probe should you use AMD sensor probe selection is de pendent on your application Consult EBTRON or your local representa tive for application engineering and product selection support AMD sen sor probes are available for the fol lowing measurement applications Duct Plenum Airflow Measurement P Sensor Probes Duct plenum probes are ideal for ap plications requiring out of the box accuracy This type of AMD has the most predictable performance when installed in accordance to published placement guidelines Duct plenum mounted AMDs are ideal for sup ply return or exhaust airflow track ing and the direct measurement of outside air intake flow rat
37. tain total OA 3 SA RA EX Q at each zone 4 Modulate RA floor dampers to maintain Q for each floor COMMENTS 1 This method compensates stack effect on tight floor to floor construc tion and without vertical path for stack flow i e open stairwell atri um and some elevator shafts The EBTRON GreenBook 2830888 CV VAV Single Supply Return or Supply Relief serving multi floor system minimum OA mode active relief at AHU AMD OPEN Recommended Toilet EX MD i Pos Toilet EX RA1 NOTES 1 Modulate SA and RA or RE fans to maintain duct static w reset 2 Modulate OA and RA dampers in sequence to maintain total OA 3 SA RA EX Q at each zone 4 Modulate RA floor dampers to maintain Q for each floor COMMENTS 1 This method compensates stack effect on tight floor to floor construc tion and without vertical path for stack flow i e open stairwell atri um and some elevator shafts 1 M MThe LBTRON Green Book 29 CV VAV Single Supply Return or Supply Relief serving multi floor system modulating economizer Toilet EX Reset OA setpoint OPEN Recommended NOTES 1 Modulate OA and RA dampers then cooling coil in sequence to reset OA setpoint to maintain supply air temperature 2 Modulate SA and RA or RE fans to maintain duct static w reset 3 SA RA EX Q at each zone 4 Modulate RA floor dampers to maintain Q for each
38. tion and obtain additional LEED points Commissioning can be achieved us ing AMDs as follows 1 Balancing a Set fan sheaves to obtain design flow rates of fan systems b Set variable frequency drive maximum and minimum speeds c Balance energy recovery ventila tor intake and exhaust flow rates for proper ventilation and pres sure control d Set damper minimum maximum positions on modulating damp ers or set fixed damper positions on manual damper systems 2 Verification of equipment opera tion a Verify the operation of fans mo tors belts and variable frequen cy drives b Verify the operation of dampers and actuators 3 Verification of performance a Verify energy consumption us ing both the airflow rate and temperature from the AMD b Verify design supply airflow rates at each air handler floor and or zone c Verify design discharge air tem perature of heating cooling coils when AMDs are installed down stream of coils d Validate coil performance by in dicating the velocity and or tem perature profiles downstream of coils e Verify minimum and maxi mum outside airflow rates are achieved during operation f Verify pressurization at each specified pressure compartment i e building floor zone etc by monitoring airflow supply return or supply exhaust differ entials EA Prerequisite 2 Minimum Energy Performance Prerequisite 2 requires establishment
39. ubject to drift Interface flexibility allows for fast and accurate measure ment independent of the BAS EA Credit 5 5 1 5 2 Measurement Verification amp Submetering EA Credit 5 5 1 5 2 requires ongo ing accountability of building energy consumption over time The concept of installing measure ment equipment for monitoring pur poses is often overlooked In many buildings monitoring for control is only a subset of the sensors that should be installed so that the over all performance of the building can be monitored and maintained over time Some examples of where EBTRON monitoring devices could be benefi cial over time are as follows m Monitor outside airflow rates on fixed minimum and DCV sys tems with duct or plenum AMDs to make sure that minimum intake flow rates are maintained and DCV systems do not drive intake flow rates above design maximums i e fully occupied levels or below minimum levels affecting occupant health or building pressure Moni toring also provides a method to verify that damper actuators link age etc have not malfunctioned m Monitoring for tenant submetering provides a process for corrective action if energy savings are not be ing met m Monitor supply airflow rates to detect filter loading belt slippage breakage etc m Monitor bleed airflow across critical pressure zones with build ing room pressure monitors to verify the integrity of the building envelope s
40. ve a dramatic impact on minimum ventilation rate required This is especially true on multi zone mixed occupant density spaces hav ing small variable occupancy con ference rooms When one zone has a disproportionately high critical zone fraction consideration for increasing the supply flow rate providing recir culated plenum air or a installing a dedicated outdoor air system to the zone should be considered On some buildings calculating the minimum ventilation rate based on seasonal load changes may result in some savings on minimum ventila tion rates The EBTRON GreenBook 148 885 Install a permanently mounted EB TRON duct or plenum AMD in the minimum outdoor air intake to moni tor and or control minimum out air flow rates Single Zone high occupant density High occupant density spaces typi cally but not always have significant changes in occupancy throughout the day When an occupancy change re sults in a reduction of the required outdoor airflow rate by more than 10 there is motivation to use some type of DCV strategy to reduce en ergy consumption DCV is compelling but not always effective as a result of uncertain ties in the technique used to estimate changes in occupancy The following methods may be used for DCV Care should be taken when implementing any of these strategies and one should not forget that the core mission in providing outdoor air is to improve occupant satisfaction and well
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