This document discusses building airtightness testing that was conducted in Washington State on 31 buildings. It provides an overview of airtightness testing procedures and requirements under the 2009 and 2012 energy codes. Test results showed that while an airtightness of 0.4 cfm/ft2 is attainable, achieving it requires repetitive simple details, experienced teams, and coordination between designers, contractors and trades to minimize air leakage.

1. Building Enclosure Airtightness Testing In Washington State
LESSONS LEARNED ABOUT AIR BARRIER SYSTEMS
AND LARGE BUILDING TESTING PROCEDURES
JULY 1, 2014
PRESENTED BY DENALIJONES, RDH BUILDING SCIENCES, SEATTLE
ASHRAE 2014 Annual Conference
Seattle WA

2. Overview
Airtightness Testing
What is it?
Why test?
2009 vs. 2012 energy codes
Testing Procedures
ASTM E779 and USACE
Single-family vs. large building
Challenges with large tests
Test Results & Discussion
Different air barrier types
Common leakage areas
Summary & Conclusion

3. What is an Air Barrier?
A system of materials and components that resist the flow of air under a given air pressure difference
Code requirements:
Continuous
Components are joined and sealed in a flexible manner, allowing for relative movement
Withstands combined forces (negative and positive) without displacing adjacent materials
Materials: 0.004 cfm/ft2 @ 75Pa
Assemblies: 0.04 cfm/ft2 @ 75Pa
Whole building: 0.4 cfm/ft2 @ 75Pa

4. Primary Air Barrier Systems
Sealed Sheathing
Sheet-Applied
Liquid-Applied
Self-Adhered
Curtain Wall/Window Wall/Storefront

5. Forces On Air Barriers
Stack Effect
Wind
Mechanical Systems

6. Quantitative testing of air barrier system performance
Calibrated fans pressurize the building and measure flow
Flow in = flow out
Results in cfm/ft2of surface area
Whole-Building Airtightness Testing –What is it?

7. Simple answer: because the code says you have to.
To confirm air barrier performance
To identify air leakage pathways
To establish a number for future comparison
Whole-Building Airtightness Testing –Why Test?

8. 2009 Energy Codes
2009 Seattle Energy Code (SEC)
All nonresidential and multifamily family residential buildings must be tested.
Required* to achieve 0.4 cfm/ft2
2009 Washington State Energy Code (WSEC)
All nonresidential buildings > 5 stories must be tested.
Required* to achieve 0.4 cfm/ft2
*Requirement waived if air barrier has been inspected by a third party.
Nonresidentialair leakage testing requirements:

9. 2012 Energy Codes
All nonresidential buildings must be tested.
All buildings > 3 stories must be tested.
Required*to achieve 0.4 cfm/ft2or better. *If 0.4 is not achieved, then reasonable efforts must be made to seal all leaks and an additional report must be submitted to the code official.
WSEC and SEC nonresidentialair leakage testing requirements:

10. Testing Procedures –ASTM E 779 & USACE
Measure flow at multiple pressures (multipoint testing).

11. Test Procedures –Large Building Challenges
The concept is simple… but the execution…

12. Test Results -How airtight are these buildings?
Tested 31 buildings
All under 2009 code cycle
Air barrier type refers to walls

13. Test Results –How airtight are these buildings?

14. Takeaways -What it takes to get an airtight building
The Good
Repetitive, simple details
Few trade interfaces
Experienced design team, general contractor, and trades
Coordination of design team, contractor, and trades

15. Takeaways –What it takes to get an airtight building
The Bad
Owner/Contractor doesn’t perceive value in airtightness
Poor/incomplete detailing
Inexperienced trades
Difficult review conditions

16. What’s Next?
Code target of 0.4 cfm/ft2is attainable.
Better coordination between HVAC and envelope designers = better performance.
We know how airtight buildings are; size mechanical ventilation accordingly.

17. rdhbe.com
Discussion + Questions
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