Impact of Large Building Airtightness Requirements

Air leakage into and out of buildings affects building durability, occupant comfort, indoor air quality, and energy consumption. Recently, in response to increasing societal concern regarding the environment and rising energy costs, building enclosure airtightness is garnering more attention. Various jurisdictions in North America and worldwide have implemented or are considering implementing airtightness testing and/or quantitative airtightness performance requirements into building regulations. This paper summarizes select results from a study into the state of the industry with respect to the airtightness of large buildings in North America. As part of this study, airtightness test results from more than 500 buildings located primarily in North America were compiled into a one-of-a-kind database. The results are presented to demonstrate historical and current airtightness levels as well as to quantify the impact of whole building airtightness regulations on the measured airtightness of building enclosures. Additionally, the results of a survey that asked industry members working in a jurisdiction with mandatory whole-building airtightness testing to respond to questions regarding the impact of the regulations as well as their perception of the regulations are presented. Finally, the paper provides commentary on the difference between air leakage and airtightness and identifies where further research is required to allow for more accurate determination of large building air leakage rates. Overall, this paper provides the foundational information necessary to assess current airtightness performance and the impact of existing requirements so as to allow for evidence-based widespread adoption of whole-building airtightness regulations for large buildings.

Note: This article was published in Proceedings of Buildings XIII, 2016. Copyright 2016 ASHRAE. Reprinted by permission at rdh.com. This article may not be copied and/or distributed electronically or in paper form without permission of ASHRAE. For more information about the Buildings XIII Conference Proceedings, visit http://web.ornl.gov/sci/buildings/2016/proceedings/.