Describes a test using four fan pressurization devices with three different operators to conduct round-robin tests on four different houses according to accepted test standards. The test results were analysed for significant trends using a standard procedure for interlaboratory test programs. The results that the extrapolation of test results to a house pressure of 4 Pa produced a 95% reproducibility interval of plus or minus 23.5% when averaged for all four test houses. At that condition, the impact of the operators was less than plus or minus 5%. At 50 Pa house pressure, these figures were plus or minus 7.5% and plus or minus 2%, respectively. The large interval at 4 Pa is largely a function of the statistical relationships when extrapolating far beyond the experimental measurements, as well as an effect of the less accurate low-pressure measurements being given greater weighting in the least-squares method.

KEYWORDS: fans, pressurization, air infiltration, buildings, measuring, testing, housing