Applying large datasets to developing a better understanding of air leakage measurement in homes
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Air tightness is an important property of building envelopes. It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance. Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ. There are several methods for measuring air tightness that may result in different values and sometimes quite different uncertainties. The two main approaches trade off bias and precision errors and thus result indifferent outcomes for accuracy and repeatability. To interpret results from the two approaches, various questions need to be addressed, such as the need to measure the flow exponent, the need to make both pressurization and depressurization measurements and the role of wind in determining the accuracy and precision of the results. This article uses two large datasets of blower door measurements to reach the following conclusions. For most tests the pressure exponent should be measured but for wind speeds greater than 6 m/s a fixed pressure exponent reduces experimental error. The variability in reported pressure exponents is mostly due to changes in envelope leakage characteristics. Finally, it is preferable to test in both pressurization and depressurization modes due to significant differences between the results in these two modes.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- Environmental Energy Technologies Division; USDOE
- OSTI ID:
- 1341735
- Report Number(s):
- LBNL-1005795; ir:1005795
- Journal Information:
- International Journal of Ventilation, Vol. 11, Issue 4; ISSN 1473-3315
- Publisher:
- Taylor & FrancisCopyright Statement
- Country of Publication:
- United States
- Language:
- English
US residential building air exchange rates: new perspectives to improve decision making at vapor intrusion sites
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journal | January 2017 |
Effect of Airtightness on Thermal Loads in Legacy Low-Income Housing
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journal | May 2019 |
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