Refined assessment and comparison of airtightness measurement of indoor chambers using the blower door and Pulse methods

Previous studies have compared the airtightness measurement of test enclosures utilising both the novel Pulse technique and the conventional blower door method.  Discrepancies between results of the two test methods were observed and it was concluded that differences either caused by wind or blower door installation integrity would have had an impact upon the results.   This study, as a continued investigation as well as validation process for product development, reports on an experimental investigation that assesses the airtightness of an indoor chamber using both the blower door and Pulse methods with the envelope difference and wind impact being minimized. This was achieved by utilising two door-sized rigid panels to replace the existing door of an indoor chamber in the setup of the blower door and Pulse units.  The blower door fan was located within one of these solid panels, which then negated any impact of leakage that would have otherwise been incurred around the frame of the blower door.  A wooden plate with multiple openings was utilised and mounted in the chamber envelope to provide various leakage levels and characteristics for testing by taping up different number of openings, in which airtightness tests were performed using both methods in an overlapped pressure range. This allowed both methods to be compared directly with minimum difference in testing conditions. Tests were also carried out in a house-sized indoor chamber to assess the repeatability of the Pulse unit and its agreement with the blower door test. The initial results showed that in most of the testing scenarios a good agreement (up to 7.4%) was observed between the leakage results given by both methods; however a larger discrepancy was seen in the case where the largest opening was present.  Strong repeatability was observed in the Pulse testing with an overall measurement uncertainty of ±5%; with a similar spread also presented by the blower door test method as part of the chamber testing.