Water vapour as a tracer gas for measuring air change rates in houses

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ConferenceProceedings, Building Science Conference "Design and Rehabilitation of Building Envelopes": 04 March 1982, London, Ont., Canada
Pages6883; # of pages: 16
Subjectair tightness; heat losses; air leakages; water vapor; Indoor air; Air flow/Wind pressure
AbstractThe values given by current methods of estimating air change rates in houses may be many times, more or less, the actual rate. Because the air change rate has such a great effect on the energy use pattern of houses, this uncertainty is particularly important to the field of energy auditing. Considering the various laboratory methods and specialized field techniques, it was hypothesized that a simple humidifier could be used to provide a steady concentration of tracer gas to measure the air change rates in existing houses. The method is based on the assumption that if the indoor humidity of a house is maintained at a constant level and if the only source of moisture is a humidifier, its total water output can be related to the amount of infiltration air. Several experiments using simple free- standing humidifiers were conducted in four unoccupied houses near Ottawa. During the experimental period the humidifier output was recorded and calculations made of the corresponding air change rates required to absorb that water. From the recorded data, it was discovered that another internal source of moisture had contributed to the moisture level of the indoor air. A method has been found to estimate this unknown quantity of water and its effect on the humidifier performance. It is now believed that the humidifier method can also be used in occupied houses. This paper presents the theory, outlines the major constraints and analyses the observed results from the experiments in which water vapour was used as a tracer gas to measure the air change rates in houses.
Publication date
AffiliationNRC Institute for Research in Construction; National Research Council Canada
Peer reviewedYes
NRC number21002
NPARC number20375892
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Record identifier8bc07ed3-7a8e-4fc1-9a40-44240d79137f
Record created2012-07-23
Record modified2016-05-09
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