Airtightness measurement of an outdoor chamber using the Pulse and blower door methods under various wind and leakage scenarios

Abstract

As a continued investigation following the previous testing of a house-sized chamber in a sheltered environment, this paper introduces an experimental study of airtightness measurement of an outdoor chamber using both the novel Pulse technique and the steady pressurisation method. The chamber has dimensions of approximately half that of a standard 20 ft long shipping container. The chamber's envelope was modified with multiple openings to provide a leakage level similar to that of an average UK house. Two sets of experimental tests were carried out independently at different times to investigate: a) How both methods compare on measuring the airtightness of an outdoor chamber at various leakage levels; and b) How the steady wind at various wind speed may affect the Pulse measurement of the chamber airtightness. Results show that the air permeability at 4 Pa measured by both methods has a percentage difference less than 16% in most testing scenarios, which is a slightly larger discrepancy than that found in the sheltered environment study. In steady wind tests, artificial wind at various speed levels was introduced in the Pulse tests by utilising a multi-gear portable trailer fan. Initial findings have shown that the impact of steady wind on the Pulse test is mostly insignificant when it is under 3.5 m/s. However, high wind speeds (4 m/s-9.5 m/s) decrease the value of air permeability at 4 Pa by 16%–24% in comparison to that measured under the fan-off condition in the steady wind tests.