HI-85-40-4 -- Evaluation of a Simple Technique for Measuring Infiltration Rates in Large and Multicelled Buildings Using a Single Tracer Gas PDF

Large, multicelled, and naturally ventilated buildings pose many inherent difficulties for the measurement of overall infiltration rates using tracer gases. Considering a single tracer-gas decay technique, the most obvious of these are;

1. local variations in infiltration,
2. imperfect internal mixing of the air, and
3. practical difficulties in distributing (i.e ., seeding) the tracer gas and subsequently obtaining air samples.

A previous paper proposed a relatively simple technique to overcome these difficulties. By considering a multicell model, it showed that it was sufficient to seed part of a building with a single tracer gas in order to measure the overall infiltration rate to a good approximation.

The results from two preliminary field tests, designed to evaluate the "simple" technique, are presented here. The first test was carried out in a mechanically ventilated multicelled three-story office block and the second in a naturally ventilated large, single-cell building. The results obtained from these tests are encouraging and give confidence to proceed with the more extensive field tests required to fully validate this technique.

Units: SI