pressurization

Air exchange rates were measured in the National Archives Building under various combinations of temperature and wind speed. The average air exchange rate under normal operation of the HVAC system was 0.9 h-1 for an average temperature difference.

Several different ratings of building airtightness are used to report the results of fan pressurization tests. These are generally based on airflow rates at specific reference pressures, predicted by curve fits to the test data. The statistical

During the winters of 1982/83 and 1983/84, air infiltration measurements were made in 34 dwellings in 5 apartment blocks. In all 34 dwellings the air leakage of the building shell was measured by pressurization. In 5 dwellings tracer gas decay rate was used to measure the air change rate, both with andwithout mechanical ventilation. Results of these measurements are presented.

As part of a programme to develop measurement methods for determining the ventilation rates of large buildings, we performed two series of tests in a single-celled laboratory with a volume of 600m3. The first series utilised constant concentration, constant emission and rate of decay tracer gas techniques to determine the characteristics of the infiltration pattern in varying winds and external temperatures. We used both discrete and continuous injection and sampling methods.

The typical infiltration load for a residential building has been found to range from one-third to one-half of the total space conditioning load. However, most infiltration measurements have been made on single-family houses. 

Pacific Power and Light Company and Battelle PNW Laboratories have completed a project which investigated residential ventilation rates. The results presented in the report discuss evaluation of methods used to measure ventilation rates, the behavior of ventilation rates in residences and the comparison of ventilation rates among home construction types. The perfluorocarbon tracer gas decay technique for measuring ventilation rates was concluded to be the best method used during the testing.

This report presents the results of air leakage tests on polyethylene membranes installed in a frame wall. The results would be useful in evaluating the methods commonly used for installing such a component.

This paper discusses the measurement of air infiltration rates and reports on measurements relating indoor and outdoor aerosol size distributions in the 0.01 to 1 micron size range. 

Air tightness results for 40 New Zealand timber frame houses of varying age and construction detail are given. The steady pressure method was used at 6-9 indoor-outdoor pressure differences in the range 10-150 Pa. The data is presented in four ways: 1. air changes per hour at 50 Pa, 2. the coefficient and exponent of a generalized leakage function, 3. the leakage rate per unit shell area at 50 Pa, and 4. the equivalent leakage area at 50 Pa. Houses in the 0-5 and 6-20 year age groups were not significantly different in terms of air tightness.

Three different types of methods for estimating ventilation rates in residences have been presented and the results of each method discussed. Field measurement experiences have helped to identify the potential errors of these methods. To date, the best correlations obtained have been between theconstant emission tracer methods involving perfluorocarbon and tracer gases. It is expected that a better understanding of the parameters that affect all of the techniques, specifically mixing volume, will lead to improved accuracy.