Reports measurements of air change rates made on approximately 250 dwellings, occupied by low income households in 14 cities, in all major climatic zones of the United States. Two types of measurements were used : a tracer-gas decay technique using air sample bags and a fan depressurization test that measures induced air exchange rates. Shows that for this group of dwellings natural air infiltration rates have an approximate lognormal distribution.
Describes a general model for air infiltration which will accomodate wind pressures, stack effect and ventilation openings provided the vents are either all above or all below their respective neutral pressure levels. States that main innovation of this model is expressing the infiltration as a function of the shell leakage and of the neutral heights of each face.Describes experimental method for finding the neutral pressure level. Gives typical values of parameters for tight mid-westhouses for light and strong wind.
Describes detailed study of infiltration rates measured with a tracer gas and air leakage rates obtained from fan pressurization in small, 3 - bedroom California house as part of a larger study. Finds surface pressure measurements are an essential step in process of finding a correlation between natural air infiltration and air leakage by pressurization. Measurements also show significant duct leakage and air flow between attic, living space and crawl space.
Reports the investigation of the natural ventilation of three test houses. Describes the houses which were of standard design. Natural ventilation rates were measured using sulphur hexafluoride as a tracer gas. An energy audit was also performed using a fan to pressurize and depressurize the house and an infrared scanner to detect the leakage paths. The tracer gas measurements were converted to a format similar to thepressurization results by using a previously developed model. Gives results in the form of graphs.
Reports investigation to devise a simple method for measuring the airtightness of buildings which will provide clear results in conformity with a definite standard, swedish building regulations 1975. Consists of two parts; field measurements comprising overpressure and tracer gas methods using nitrous oxide, and a theoretical calculation of the infiltration of air into a building. Shows that a test method to measure the airtightness of buildings can be developed.
Developes mathematical model of air infiltration based on crack flow equations. Describes measurements made on test house. Shows that actual pressure distributions in walls deviate considerably from values in guidebooks. Finds background leakage area of house by pressurizing house with electric fan and measuring pressures. Suggests two distributions for leakage areas. Measures infiltration rate using helium tracer gas, recording temperature and pressure differences. Concludes that comparison between prediction and experimental results is encouraging.
Describes how in 1960-62 National Research Council of Canada conducted air infiltration measurements on 2 single-storey houses using helium as a tracer gas, followed in 1967-68 by measurement of air leakage characteristics using house pressurisation technique. Describes procedure developed from these tests for calculating infiltration rates. Gives equations for calculating infiltration due to stack effect and that due to wind action. Gives equation for combined effect.
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