A transient pressurization method for measurements of airtightness
Journal article, 2007

By measuring the pressure decline in a pressurized air volume from which air is leaking it is possible to determine the air leakage rate as a function of the pressure difference. The leakage rate is proportional to the time derivative of the pressure. The formula, which is quite simple, accounts for temperature change of the air and volume change of the chamber. The derivation of the equation relating air leakage to pressure drop is described. Initial tests of the method have been performed and the derived equation shows good agreement with air leakage rates obtained by theoretical as well as standard steady-state methods.

heated room surfaces

orifice flow

air leakage


fan pressurization


general gas law

air infiltration

transient pressurization measurements


Björn Mattsson

Chalmers, Civil and Environmental Engineering, Building Technology

Johan Claesson

Chalmers, Civil and Environmental Engineering, Building Technology

Journal of Building Physics

1744-2591 (ISSN)

Vol. 31 1 35-53

Subject Categories

Civil Engineering



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