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C A L I F O R N I A E N E R G Y C O M M I S S I O N
2013 Building Energy Efficiency Standards Staff Workshop
David W. WareCalifornia Energy Commission
August 17, 2011
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C A L I F O R N I A E N E R G Y C O M M I S S I O N
Nonresidential Air Infiltration Standard
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• PurposeReduce infiltration & exfiltration through envelopeo Infiltration increases heating & cooling energyo Exfiltration increases fan, heating & cooling energy
• ResearchInfiltration contributes to >40% of office building heating loadsAverage air leakage rate of 203 sampled buildings was 1.55 cfm/ft2 @ 0.3” w.g.
C A L I F O R N I A E N E R G Y C O M M I S S I O N
Examples of Air Infiltration Standards
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• State & local jurisdiction adoptionsFL, WI, WA, MA, MN, Seattle
• National reference standards & codesASHRAE 90.1, ASHRAE 189IECCIgCCArmy Core of Engineers
C A L I F O R N I A E N E R G Y C O M M I S S I O N
National Air Infiltration Standard
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IECC Climate Zones
Air Barrier Requirements:CZs 4-6
C A L I F O R N I A E N E R G Y C O M M I S S I O N
National Air Infiltration Standard
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• IECC 2012, Section 502.4.1 air barrier requirement
Building infiltration target of ≤ 0.40 cfm/ft2 at a pressure differential of 0.3” w.g.o can be met through: (1) choice of materials, (2)
assembly testing, (3) building performance testing
IECC & ASHRAE air infiltration requirement not applicable to climate zones 1-3 (which encompass majority of CA climate zones)
C A L I F O R N I A E N E R G Y C O M M I S S I O N
Nonresidential Air Infiltration Analysis
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• How much is infiltration reduced when the HVAC system is running and pressurizing the space?
Benefits of reduced air leakage usually associated with heating loadsNACM presently assumes 100%2009 PNNL study suggests 75%o Drivers affecting air infiltration:
Building height (stack effect)Wind speed (pressure differences)Temperature
C A L I F O R N I A E N E R G Y C O M M I S S I O N
Nonresidential Air Infiltration Analysis
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• Stack effect to be modeled in accordance with ASHRAE Handbook - Fundamentals – 2009, Chapter 16, Equation 38
• 1, 3, and 12 story office buildings analyzed
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
‐50 0 50 100 150
Infil
trat
ion
(cfm
/ft²)
Outdoor Temperature (°F)
Stack Effect Infiltration by Floor - Baseline
1
1P
2
2P
3
3P
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
‐50 0 50 100 150
Infil
trat
ion
(cfm
/ft²)
Outdoor Temperature (°F)
Stack Effect Infiltration by Floor - Proposed
1
1P
2
2P
3
3P
C A L I F O R N I A E N E R G Y C O M M I S S I O N
Nonresidential Air Infiltration Analysis
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1. Run energy models to determine potential value of energy savings using 2013 LCC methodology
– 6 representative climate zones
2. Compare modeled energy savings to existing estimates of the cost to comply with: ≤ 0.40 cfm/ft2 at 0.3” w.g.
3. Conduct additional measure cost and feasibility research if necessary
C A L I F O R N I A E N E R G Y C O M M I S S I O N
Nonresidential Air Infiltration Analysis
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C A L I F O R N I A E N E R G Y C O M M I S S I O N
Nonresidential Air Infiltration Analysis
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-1.0%
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
6.0%
7.0%
3 7 9 13 14 16
Perc
ent T
DV
Sav
ings
Climate Zone
Air Leakage TDV Savings
LO
RT
WH
0.0%
0.5%
1.0%
1.5%
2.0%
2.5%
3.0%
LO RT WH
Perc
ent T
DV
Sav
ings
Building Type
Average Air Leakage TDV Savings
LO
RT
WH
C A L I F O R N I A E N E R G Y C O M M I S S I O N
Nonresidential Air Infiltration Requirement
• Refine analysis and cost effectiveness • Air infiltration/air barrier requirement may
be dependent on:– Climate zone– Building height– Building type
• Air barrier compliance alternatives– Materials– Assemblies– Building testing 11
C A L I F O R N I A E N E R G Y C O M M I S S I O N
Nonresidential Air Infiltration Requirement
• Limit air leakage by continuous air barrier• Air barrier compliance alternatives
– Materials: ASTM E2178 – Standard Test Method for Air Permeance of Building Materials
– Assemblies: ASTM E2357 – Standard Test Method for Determining Air Leakage of Air Barrier Assemblies
– Building testing: Air leakage ≤ 0.40 cfm/ft2 at a pressure differential of 0.3” w.g.
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C A L I F O R N I A E N E R G Y C O M M I S S I O N
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ASTM E2178 Product Materials Building Performance Testing
C A L I F O R N I A E N E R G Y C O M M I S S I O N
Nonresidential Air Infiltration Standard
• Questions?• Comments?
Contact: David W. [email protected]
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