Describes a predictive model for air infiltration in residential structures. Uses wind speed and outdoor temperature data, along with selected building and site parameters to predict average infiltration. Presents long-term field validation results obtained in a portable test structure, together with long-term data from 3 unoccupied test houses at the Owens-Corning Technical Centre. Finds that the ratio between predicted and measured infiltration peaks near one in all comparisons. The estimated standard deviation of the ratios decreases with longer averaging times.
States that one of the major difficulties in estimating air infiltration rates in buildings is lack of full scale data on pressure distribution on various structural shapes located in different types of surface roughness category. Tries to fill this gap by studying two building structures of different shapes and situated in different environments, registering the mean pressure distribution and calculating the rate of air leakage due to openings. The first house is of old type construction and in a `semi-urban' environment.
Describes the methods and considerations employed in the development of a detailed monitoring and evaluation programme for passive solar residences. Data analysis is performed by determining the hourly heat transfer of all critical energy transfer components, using an on-site microprocessor based data acquisition system. Discusses air infiltration as one of the components, and describes measurement methods, including pressurisation and tracer gas techniques.
Describes the application of a model that relates infiltration to a quantity called the effective leakage area. This quantity scales the infiltration to local weather conditions and major design features of the house. The model isused to calculate the ratio of infiltration to leakage area averaged over the heating season, for a large number of sites in the US. It provides an effective tool for builders and designers who need a rational basis for assessing compliance with construction quality standards in ventilation.
Proposes a simple equation derived using a more complex theoretical model for use in the prediction of the infiltration performances of houses over a range of meteorological conditions. Initial comparisons have been made with the results from field measurements in a range of typical modern UK house types.
The results of a prediction method for calculating ventilation rates in a detached house are compared with experimental measurements described in aprevious paper. The method is capable of giving good agreement for a wide range of ventilation conditions. The need is demonstrated for further work in two important areas - the spatial distribution of background areas and the effect of turbulence.
Gives a brief survey of aspects of research into air infiltration. Discusses methods of measurement of ventilation rates and of building leakiness, covering the infrasonic and pressurisation methods of leakage testing, and thermography and tracer gas methods of measuring ventilation rates. Describes the available techniques for predicting leakiness and infiltration rates, and discusses their ease of application and accuracy. Concludes that the achievements of research to date are sound methods of measuring leakiness and infiltration rates.
This parameter study with the IMG calculation model for ventilation is an attempt at forming some background for decisions relating to the preparation of a standard in the Netherlands. From the results one can see that air tightness and the heat loss caused by infiltration cannot be considered as a simple linear relationship .
Describes LBL's Mobile Infiltration Test Unit (MITU) which spent the 1980-1981 winter in the field collecting the data required for infiltration modelling. Data included measured infiltration rates, surface pressures, wind velocities, indoor and outdoor temperatures, leakage area and leakage distribution. Comparisons of measured infiltration rates with values calculated from surface pressures (using MITU) have shown no decrease in accuracy when a square-root flow model is used instead of the general power-fit model of leakage.
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