A quantitative estimate of the accuracy of tracer gas methods for the determination of the ventilation flow rate in buildings

Abstract

The paper presents a quantitative estimate of the error of the decay and constant concentration method. A number of tests were carried out in an indoor test house located in the laboratory hall at the National Swedish Institute for Building Research. At the beginning of the paper the relevant meaning of the concept ‘air-exchange rate’ is discussed and an appropriate terminology is suggested. Then follows a presentation of the theoretical background, based on a multi-cell model, of the two tracer gas methods studied experimentally. Finally, the results obtained are given. Apart from the accuracy of the tracer gas methods, some results of studies of the effect on the infiltration rate due to different operation modes of mechanical ventilation systems are also presented.