Measuring Air Leakage Characteristics with Flexible Double Air Chambers

Abstract

The fan pressurization method for measuring air leakage through the building envelope relies on the assumption that the extraneous air leakage (EAL) through paths other than those through the specimen being tested is negligible. When EAL does exist, the calibration procedure by ASTM Standard E-283 is used to measure EAL values by covering the specimen or guarded chambers are used to equalize the pressure differences across these unintended paths. A new testing method, the flexible double-chamber method, is presented in this paper for large specimens where the above two approaches are difficult to implement and where flexible chambers are more easily applied. The experimental procedure and data processing routine are presented for the case of a full-size metal curtain wall specimen. The EAL is estimated by regression analysis in data processing. Inference analysis, multivariate error analysis, and the Monte Carlo simulation technique are also presented to examine the estimation errors.