who stole my high performance building - minnesota ashrae

WHO STOLE MY HIGHWHO STOLE MY HIGH--PERFORMANCE PERFORMANCE

BUILDING? BUILDING? –– Part 1Part 1For

2012 Region VI

Chapter Regional ConferenceByBy

Todd Rindlisbaker, PE, QCxP,

LEED AP, HPBDP, CPD .

Rindlisbaker Commissioning, Inc.

1

5/8/2012 2

Todd Rindlisbaker, P.E., LEEDTodd Rindlisbaker, P.E., LEEDTMTM AP, HPBDP, AP, HPBDP, QCxPQCxP, CPD, CPD

� 19 years in mechanical HVAC engineering and commissioning

– Large hydronic systems, central plants, campus proj ects.– Control Systems and control sequences.– Energy Analysis reports and modeling

� P.E.-Licensed Professional Mechanical Engineer� LEED™- Accredited Professional� HPBDP-ASHRAE certified High Performance

Building Design Professional� QCxP-Qualified Commissioning Process Provider� National Speakers Association Apprentice� Integrated Project Delivery Process Facilitator

Who Sabotaged My HighWho Sabotaged My High--Performance Building?Performance Building?

ASHRAE WASHRAE WILLILL GGIVEIVE

YYOUOU THETHE WWORLDORLD

This ASHRAE Distinguished Lecturer is

brought to you by the Society Chapter

Technology Transfer Committee

Complete the Distinguished Lecturer Complete the Distinguished Lecturer Event Summary CritiqueEvent Summary Critique

�� CTTC needs your feedback to continue to CTTC needs your feedback to continue to improve the DL Programimprove the DL Program�Distribute the DL Evaluation Form to all

attendees�Collect at the end of the meeting�Compile the attendee rating on the Event

Summary Critique�Send the completed Event Summary Critique

to your CTTC RVC and ASHRAE Headquarters

Forms are available at:Forms are available at:www.ashrae.org/distinguishedlecturers

BBECOMEECOME A FA FUTUREUTURE LLEADEREADER ININ ASHRAE ASHRAE –– WWRITERITE THETHE NNEXTEXTCCHAPTERHAPTER IINN YYOUROUR CCAREERAREER

YOU ARE NEEDED FOR:� Membership Promotion� Research Promotion� Student Activities� Chapter Technology

Transfer Technical Committees

Find your Place in ASHRAE! Visit Find your Place in ASHRAE! Visit www.ashrae.org

ASHRAE Members who attend their monthly chapter meetings become leaders and bring information and technology back to their job.

5/8/2012 6

ObjectivesObjectives

� Identify common reasons building fail to operate properly and efficiently

� Identify “Key” Design items that will;– Save 20-30% energy (above HE equip).– Or waste up to 50% if they are missed.

� Find control strategies that provide additional energy savings.


5/8/2012 7

Objectives (continued)Objectives (continued)

� Identify key coordination items that result in costly change orders.

� Strategies to communicate and specify tools used to verify functionality and energy performance.

� Two Items to include to make you a hero with the building operating staff.


2

5/8/2012 8


5/8/2012 9


($1.25/CFM)7

Envelope Leakage Costs Envelope Leakage Costs –– Case StudyCase Study

� Building Area: 210,000 sq. ft.� Four Stories� Originally installed regular dampers in

exhaust and relief openings� Test 1 Building Leakage – 58,500 CFM� Envelope Leakage Costs - $1.25/CFM� Cost of Energy Waste: $56,700/Year5/8/2012 10


Envelope Leakage Costs Envelope Leakage Costs –– Case StudyCase Study

5/8/2012 11


Envelope Leakage Costs Envelope Leakage Costs –– Cx ResultsCx Results

5/8/2012 12


HVAC System Envelope LeakageHVAC System Envelope Leakage

� ASHRAE 90.1

5/8/2012 13


3

Summary Envelope Leakage Summary Envelope Leakage –– HVACHVAC

Recommendations: � Use Motorized, Low-Leakage type dampers for

all Outside Air, Exhaust, and Relief Air Dampers:– ROI ≈ 0.3 Years– All dampers > 300 CFM in buildings >2 stories

required to be motorized anyway.*– Coordinate with electrical & detail.

� Discourage return air plenum returns (increase building leakage, since return air plenums are always negative, grow mold in moist areas)

� Encourage Building Envelope Commissioning

5/8/2012 14


Proper Building Proper Building Pressurization Measurement Pressurization Measurement

5/8/2012 15Recommended method for measuring building static pressure with BMS from ASTM E779-03


Proper Building Proper Building Pressurization Measurement Pressurization Measurement

5/8/2012 16Recommended method for measuring building static pressure with BMS from ASTM E779-03


Energy Usage Energy Usage –– UnderstandingUnderstandingWhere it goesWhere it goes

5/8/2012 17Energy Consumption Characteristics of Commercial Building HVAC Systems Volume II: Page 5-25


Design LoadDesign Load Operating LoadOperating Load

5/8/2012 18De Bullet - Chiller Plant Fundamentals and Optimization

Annual Energy Usage Annual Operating Usage


Cooling System Energy UsageCooling System Energy Usage



4

5/8/2012 20

>50%


Commercial HVAC Commercial HVAC Parasitic Energy UseParasitic Energy Use



Fan Energy: First Step, Run only as neededFan Energy: First Step, Run only as needed� Many exhaust fans are constant speed.

– Review schedule and required use. – Operate only when needed. Many fans run

unnecessarily.– Consider Occupancy sensors where appropriate

- (with run-on delays)� HVAC Systems:

– Separate 24/7 and equipment loads from comfort cooling loads:

• Provide standalone units for areas such as data roo ms, equipment rooms, etc.

• Where not separated size for max temp. reset StPt.– Shut off air handlers at night.

5/8/2012 22


Fan Energy UsageFan Energy Usage

5/8/2012 23


Fan Energy Fan Energy –– Fan CurveFan Curve

5/8/2012 24

SYSTEM EFFECTS?


Fan Energy Fan Energy –– System EffectsSystem Effects

5/8/2012 25


5

Fan Energy – System Effects

5/8/2012 26ASHRAE Fundamentals Chapter 35 – Duct Fitting Coefficients


5/8/2012 27

Fan Energy – System Effects

ASHRAE Fundamentals Chapter 35 – Duct Fitting Coefficients


5/8/2012 28

Fan Energy Fan Energy –– System EffectsSystem Effects



Fan Energy Fan Energy ––System Effects ExampleSystem Effects Example

� Results:� ∆P – 2.4

in. wg

5/8/2012 29


Fan Energy Fan Energy ––Air Handler ConnectionsAir Handler Connections

� Entrances & Exits - Specify

5/8/2012 30ASHRAE Fundamentals Chapter 35 – Duct Fitting Coefficients


r = 0.1 (in)r= 0.16 (in) r= 0.2 (in) D (in)

2 3.2 4 20

2.5 4 5 25

3 4.8 6 30

3.5 5.6 7 35

4 6.4 8 40

5 8 10 50

Building Energy Usage Building Energy Usage –– Fan SelectionFan Selection

� Air foil fans, slightly oversized offer up to 20% higher efficiencies (Energy Consumption Characteristics of Commercial HVAC Systems Vol. III pgs A-8 to A-11)

5/8/2012 31


6

Fan Energy Fan Energy –– Fan Wheel SelectionFan Wheel Selection

5/8/2012 32(Energy Consumption Characteristics of Commercial HVAC Systems Vol. III pgs A-8 to A-11)



5/8/2012 33(Energy Consumption Characteristics of Commercial HVAC Systems Vol. III pgs A-8 to A-11)



� Benefits of One to Two Sizes Larger Fan Wheel:– Up to 20% more efficient– Lower Sound Levels– Longer Bearing Life, Less Maintenance

� Caution:– Make sure system curve is still good

match to the fan curve (stay away from the surge line)

5/8/2012 34


Fan Energy Fan Energy ––Air Handler SizingAir Handler Sizing

� Parameters:– Optimized for First Costs, 5 Yr & 10Yr ROI– Operating Hours 3160 and 8760– Single Zone Constant Volume, 30,000 CFM Draw-

through unit.

� Results:– 5 Yr ROI ≈ 415 FPM AHU, 600 FPM OA Louver– 10 Yr ROI ≈ 315 FPM AHU, 600 FPM OA Louver

5/8/2012 35

� ASHRAE Journal – February 2009Air Handler Design for Energy Conservation – Arthur B Wheeler


Fan Energy Fan Energy ––Air Handler SizingAir Handler Sizing

5/8/2012 36

314

416


Fan Energy Fan Energy –– Air Handler SizingAir Handler Sizing

Comments regarding slides 35 & 36.� This study was for a constant volume

system.� Study shows that the filters and coil

selections are two of the most critical components regarding energy savings.

� Variable volume air handlers would benefit by selecting low pressure drop filters and coils. Suggested ranges are:– Filters: 0.3 in.wg (new)– HW coil < 0.2 in.wg– CHW coil < 0.4 in.wg

5/8/2012 37


7

Fan Energy Fan Energy ––Variable Volume ControlVariable Volume Control

5/8/2012 38


5/8/2012 39

Fan Energy Fan Energy ––Static Pressure Set PointStatic Pressure Set Point


Fan Energy Fan Energy ––Variable Volume ControlVariable Volume Control

5/8/2012 40


Fan Energy Fan Energy –– Variable Volume ControlVariable Volume Control

5/8/2012 41


Fan Energy Fan Energy –– Static Pressure ResetStatic Pressure Reset

� Since ASHRAE 90.1-1999

5/8/2012 42


5/8/2012 43


ASHRAE 90.1 User’s Manual


8


� Rules for Static Pressure Sensor Locations:– Static DP Sensor MUST be “Home Run”

to communicate directly to the air handler DDC controller. (Communication speed, reliability)

– If located downstream of major duct branches, each major branch must have sensor.

5/8/2012 44


Fan Energy Fan Energy ––Static Pressure Sensor LocationStatic Pressure Sensor Location

5/8/2012 45


Notes for Slide 45Notes for Slide 45

� Benefits of Static Pressure sensor at air handler d ischarge.– More reliable.– Sensor acts as an operational high static limit. (If a remote sensor cannot

meet static requirements, it increases fan speed wi thout knowing fan discharge pressure, some systems this is over the duct pressure rating, trips high limit).

– Less costly to install than remote sensor. Differe nce in cost can pay for additional sensors for informational purposes.

� Return fan control should be return plenum static p ressure (Static Pressure must be positive on building side of louve r to push relief air out).

� Outside air flow station is only reliable method of controlling outside air quantity.

� Provide system diagram and graphic requirements to contractor in design documents. Include operational and troub leshooting information.

� VAV airflows can be used to indicate supply fan air quantity within at least 5 – 10% accuracy. (Inexpensive way to provide information).

5/8/2012 46


Fan Energy Fan Energy ––Return/Relief Fan LocationReturn/Relief Fan Location

5/8/2012 47


Notes for Slide 47Notes for Slide 47

� Engineer’s building pressure relief sequence called for the relief air dampers to modulate open first and then to star t the relief fans and modulate them up to speed.

– Because the return air plenum is negative, outside air flowed backwards through the relief air louvers into the return air plenum. The relief air fans eventually turned on and ramped up to control the b uilding static, but there were long periods of time that the building static was out of control.

� Solution 1:– Add a static pressure sensor to the plenum between the relief fan and the

outside air louver.– Change sequence to turn on relief air fans maintain a plenum static

pressure set point.– Modulate the relief air dampers to maintain buildin g static pressure.

� Solution 2:– Change system configuration to have a return/relief fan as shown in slide

#44.– Benefits are: Smaller supply air fan requirements, more return air draw

from higher return air static pressure, and better building static pressure control.

5/8/2012 48


Fan Energy Fan Energy –– “Trim & Respond” Static “Trim & Respond” Static Pressure Set Point Reset @ Air HandlerPressure Set Point Reset @ Air Handler

5/8/2012 49

STATIC PRESSURE RESET SCHEDULE PROGRAMMING RESTRICTIONS

INITIAL START STATIC PRESSURE SET POINT . 0.5 in. wg. 0.2 - 1.0 in. wg.

MAXIMUM STATIC PRESSURE SET POINT . 2.5 in. wg.AS NOTED OR 0.5 LESS THAN

HIGH DUCT STATIC LIMIT

MINIMUM STATIC PRESSURE SET POINT . 0.2 in. wg. 0.1 - 0.5 in. wg.

UPPER MAXIMUM SYSTEM VAV DAMPER POSITION SET POINT . 95 % 90 - 98 %

UPPER MAX. SYSTEM VAV DAMPER SET POINT TIME DELAY . 5 MIN. 1 - 10 MIN.

STATIC PRESSURE STEP UP INCREMENT . 0.1 in. wg. 0.02 - 0.2 in. wg.

LOWER MAXIMUM SYSTEM VAV DAMPER POSITION SET POINT . 85 % 80 - 88 %

LOWER MAX. SYSTEM VAV DAMPER SET POINT TIME DELAY . 5 MIN. 1 - 10 MIN.

STATIC PRESSURE STEP DOWN INCREMENT .0.05 in. wg. 0.02 - 0.2 in. wg.

CURRENT SYSTEM READINGS

MINIMUM SYSTEM VAV DAMPER POSITION . XX.X %

MAXIMUM SYSTEM VAV DAMPER POSITION . XX.X %

AVERAGE SYSTEM VAV DAMPER POSITION . XX.X %

STATIC PRESSURE SET POINT. X.XX in. wg.

ASHRAE Journal June 2007, Steve Taylor – Increasing VAV System Efficiency with Static Pressure Set Point Reset


9

Fan Energy Fan Energy –– “Trim & Respond” Static “Trim & Respond” Static Pressure Set Point Reset @ End of RunPressure Set Point Reset @ End of Run

5/8/2012 50

STATIC PRESSURE RESET SCHEDULE PROGRAMMING RESTRICTIONS

INITIAL START STATIC PRESSURE SET POINT . 0.5 in. wg. 0.2 - 1.0 in. wg.

MAXIMUM STATIC PRESSURE SET POINT . 1.2 in. wg.. Balancer may adjust lower.

MINIMUM STATIC PRESSURE SET POINT . 0.2 in. wg. 0.1 - 0.5 in. wg.

UPPER MAXIMUM SYSTEM VAV DAMPER POSITION SET POINT . 95 % 90 - 98 %

UPPER MAX. SYSTEM VAV DAMPER SET POINT TIME DELAY . 5 MIN. 1 - 10 MIN.

STATIC PRESSURE STEP UP INCREMENT . 0.1 in. wg. 0.02 - 0.2 in. wg.

LOWER MAXIMUM SYSTEM VAV DAMPER POSITION SET POINT . 85 % 80 - 88 %

LOWER MAX. SYSTEM VAV DAMPER SET POINT TIME DELAY . 5 MIN. 1 - 10 MIN.

STATIC PRESSURE STEP DOWN INCREMENT .0.05 in. wg. 0.02 - 0.2 in. wg.

CURRENT SYSTEM READINGS

MINIMUM SYSTEM VAV DAMPER POSITION . XX.X %

MAXIMUM SYSTEM VAV DAMPER POSITION . XX.X %

AVERAGE SYSTEM VAV DAMPER POSITION . XX.X %

STATIC PRESSURE SET POINT. X.XX in. wg.

ASHRAE Journal June 2007, Steve Taylor – Increasing VAV System Efficiency with Static Pressure Set Point Reset


Supply Speed Supply Speed ––Without & With SP ResetWithout & With SP Reset

5/8/2012 51

System Recovery Fan Speed System Mid-

Day Fan Speed


Supply Fan Power Supply Fan Power ––120 HP (115 BHP, 90 KW)120 HP (115 BHP, 90 KW)

5/8/2012 52

Heating Season System Recovery Fan Energy

System Mid-Day Fan Energy

System Idle Fan Energy

Cooling Season System Recovery Fan Energy


Fan Energy Fan Energy ––Static Pressure Initial St PtStatic Pressure Initial St Pt

5/8/2012 53

System Recovery Period 6:00 am – 11:00 am. (Mild Day)

System Mid-Day Fan Energy

Does Night Set-Back really save energy? … No!


Fan Energy: Duct LeakageFan Energy: Duct Leakage

� 10% Duct leakage ≈ 30% increase fan energy. (Avg. leakage 16%).– (110% Flow) 3 = Power increase– Conditioned air lost to plenum, etc.

� New ASHRAE 90.1 – 2007 addendum cqand ASHRAE 90.1 – 2010 6.4.4.2.1 – All ductwork … shall be constructed to

seal Class A. – Openings with rotating shafts sealed with

bushings.– All pressure class ratings designated in

design documents.5/8/2012 54


Fan Energy: Duct Leakage Fan Energy: Duct Leakage –– ASHRAE 90.1ASHRAE 90.1

5/8/2012 55


10

AIR HANDLING UNIT SYSTEM AIR HANDLING UNIT SYSTEM DESIGN SUMMARYDESIGN SUMMARY

� Minimize System Effects: Requires Detailing, Space

� Fan Selection: Over minimum size is a +� Constant Volume AHU Sizing: 5 Yr LCC ≈ 425

FPM.� Variable Volume AHU Sizing: Minimize filter &

coil pressure drop.� Static Pressure Set Point:

– “Trim & Respond” Set Point Reset Method– Minimize the Maximum Set Point.– Sensor location at air handler discharge.

� Return/Relief Fan Locations & Control� Duct Leakage5/8/2012 56


5/8/2012 57

Fittings Fittings –– Air handler, Air handler, Duct Shaft ConnectionsDuct Shaft Connections


5/8/2012 58

Fittings Fittings –– Air handler, Duct ShaftAir handler, Duct Shaft

– Goal #3



5/8/2012 59

Fittings, Duct Elbows, Flex Elbows, HVFittings, Duct Elbows, Flex Elbows, HV

� Goal #2



60

Spin In FittingsSpin In Fittings

5/8/2012 ASHRAE Fundamentals Chapter 35 – Duct Fitting Coefficients


61

High Efficiency TakeHigh Efficiency Take--Offs (HET’s)Offs (HET’s)

5/8/2012 ASHRAE Fundamentals Chapter 35 – Duct Fitting Coefficients


11

5/8/2012 62

Properly Detail InstallationProperly Detail Installation

Add system details, not just component details.


5/8/2012 63

Example of System EffectsExample of System Effects

Who Sabotaged My HighWho Sabotaged My High--Performance Building?Performance Building?Who Sabotaged My HighWho Sabotaged My High--Performance Building?Performance Building?

5/8/2012 64



5/8/2012 65



5/8/2012 66

Duct Fittings…Duct Fittings…


5/8/2012 67

Duct Fittings…Duct Fittings…

Significant pressure losses when air turns directions


12

5/8/2012 68

Proper Flex Duct InstallationProper Flex Duct Installation

No Flexible duct turns: Much quieter and less pressure drop.


Duct Construction SummaryDuct Construction Summary

�Proper Duct Layout and Coordination– Fittings– Sizing– Profile: < 3:1 w:h– Details: System Layout and Detail– Flex Duct: No turns, short runs.

5/8/2012 69


VAV Box VAV Box –– SelectionSelection

1. Pressure drop across the box2. First costs of VAV box, installation

& controls3. VAV box controller ability to

measure and control min. & max. Set Points

4. Noise Generation5. Space Constraints.

5/8/2012 70


VAV Box VAV Box –– Life Cycle CostingLife Cycle Costing

5/8/2012 71



� Calculate the ∆TP of the VAV box

5/8/2012 72

Sizing VAV Boxes – Steve Taylor, Jeff SteinASHRAE Journal, March 2004



5/8/2012 73Sizing VAV Boxes – Steve Taylor, Jeff SteinASHRAE Journal, March 2004


13

VAV Box Controller and Sensor SelectionVAV Box Controller and Sensor Selection

� Use Multi-Point Cross Flow Averaging Sensor – TypicalMagnification = 2.33

� 14 Bit Controller will allowSP readings of 0.004 in.wg.

� 10 Bit Controller will allow SP readings of 0.01 in. wg.

5/8/2012 74



VAV Box Controller and Sensor SelectionVAV Box Controller and Sensor Selection

5/8/2012 75

14 Bit, 0 – 1” Sensor 10 Bit, 0 – 1” Sensor



5/8/2012 76

VAV Box InstallationVAV Box Installation

Typical VAV box Manufacturer Installation Manual


VAV Terminal Unit SizingVAV Terminal Unit Sizing

� LCC Sizing: Select VAV boxes for 0.5 in wg TSP (SP + VP)

� Air Flow Sensors: Cross Flow MP Avg.

� Controller Quality: 14 Bit resolution

5/8/2012 77


Demand Control VentilationDemand Control Ventilation� Observed 20 – 30% heating design

loads used for reheat during mid-summer (it was not a dream).

� Demand Control Ventilation –– 50% reduction in OA results in 25%

reduction in ventilation– 31% reduction Heating– 14% reduction Cooling

(Energy Consumption Characteristics of Commercial HVAC Systems Vol. III pgs Pgs A-83 to A-87)

5/8/2012 78


Demand Control VentilationDemand Control Ventilation� Consider demand control ventilation

in any space with expected occupancy load at or below 40 ft2/person. CO2 DEMAND RESET

CO2 900 (PPM) 1100 (PPM)

MIN StPt 132 (CFM) 452 (CFM)

- LOW MIN. StPt. = AREA VENTILATION RATE

- HIGH MIN. StPt. = AREA + PEOPLE VENTILATION RATE

1100 . SQ. FT. Children's Classroom

32 . PEOPLE

10 . CFM / PERSON PEOPLE VENTILATION RATE

320 . PEOPLE VENTILATION RATE

0.12 . CFM / SQ. FT. AREA VENTILATION RATE

132 . AREA VENTILATION RATE

5/8/201279

Consider additional criteria for final Minimum ventilation set point


14

Occupancy Sensors Occupancy Sensors ––VAV ControlVAV Control

� Consider occupancy sensors:– in any space with expected occupancy

load at or below 40 ft 2/person. (Classrooms, conference rooms, etc.)

– In all zones with dedicated units (office)– Intermittently used spaces

� Aux contacts for lighting control occupancy sensor or dedicated occupancy sensor.

� Set to “Standby” Mode i.e. Min = 0 CFM, Temperature StPts = Occupied.

5/8/201280


VAV BOX CONTROL W/ STANDBY MODE VAV BOX CONTROL W/ STANDBY MODE AND MINIMUM SETPOINT AIRFLOW RESETSAND MINIMUM SETPOINT AIRFLOW RESETS

5/8/2012 81


5/8/2012 82

Questions and AnswersQuestions and Answers

Todd RindlisbakerTodd Rindlisbaker

Rindlisbaker Commissioning, Inc.Rindlisbaker Commissioning, Inc.

[email protected]@me.com


YOU WANT MORE?YOU WANT MORE?

II –HYDRONICSIII - CONTROLS

5/8/2012 83


MORE INFORMATIONMORE INFORMATION

5/8/2012 84

Reference Documents� Energy Consumption Characteristics of Commercial Bu ilding HVAC Systems Volume II:

Thermal Distribution, Auxiliary Equipment, and Vent ilation� Energy Consumption Characteristics of Commercial Bu ilding HVAC Systems Volume III:

Energy Savings Potential� Advanced VAV System Design Guide – PEIR� HVAC Equations, Data, and Rules of Thumb – 2 nd Edition – Bell� ASTM E779-03 – Standard Test Method for Determining Air Leakage Rate by Fan

Pressurization� ASHRAE Fundamentals Chapter 35 – Duct Fitting Coeffi cients� ASHRAE Journal – February 2009 Air Handler Design fo r Energy Conservation – Arthur B

Wheeler� ASHRAE 90.1 and ASHRAE 90.1 User’s Manual� ASHRAE Journal June 2007,– Increasing VAV System Eff iciency with Static Pressure Set

Point Reset - Steve Taylor � ASHRAE Journal, March 2004 - Sizing VAV Boxes – Steve Taylor, Jeff Stein � ASHRAE - Guideline 4-1993 Preparation of Operating a nd Maintenance Documentation for

Building Systems� ASHRAE - Guideline 13-2007 Specifying Direct Digital Control Systems � ASHRAE - Guideline 14-2002 Measurement of Energy and Demand Savings� ASHRAE - Standard 55-2004 Thermal Conditions for Hum an Occupancy� ASHRAE - Standard 90.1-2004 Energy Standard for Buil dings Except Low-Rise

Residential Buildings� NIBS - Guideline 3-2005 Exterior Enclosure Technical Requirements for the

Commissioning Process� NIBS – Whole Building Design Guide, Building Commiss ioning


5/8/2012 85

Helpful WebsitesHelpful Websites� Total Building Commissioning Blog www.totalbuildingcommissioning.com� The Building Commissioning Association (BCA) www.bcxa.org� National Institute of Building Sciences (NIBS) www.nibs.org ,

www.wbdg.org/project/buildingcomm.php� American Society of Heating, Refrigeration and Air Conditioning Engineers

(ASHRAE) www.ashrae.org� U.S. Green Building Council (USGBC) www.usgbc.org� American Society of Plumbing Engineers (ASPE) www.aspe.org
