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.
Errors resulting from treating a house as an enclosure surrounding a single, well-mixed volume of air are explored in detail for a ranch house with abasement. A fairly typical ventilation pattern is assumed and three quantities, the air exchange rate, the indoor pollutant concentration from a given emission, and the energy required to heat infiltrating air, are calculated and compared using both the one and two zone models for this house.In general, the errors were around 10-20% if the basement was included in the one zone models and 30-40% if the basement was neglected.
Reduction in air leakage rates due to weatherization of homes can be determined by fan pressurization and tracer gas techniques, but only the latter gives the results under normal occupancy conditions. Assessment of such rates measured before and after weatherization must consider their dependence on wind speeds and inside-outside temperature differences.
A two-part experimental study was conducted to identify antecedents of complaints from office workers in a sealed, air conditioned building. Building illness was documented as increased incidence of absenteeism and complaints among office workers in the study group compared to control subjects in a non-sealed building of a similar age. The second part monitored complaints and symptoms from subgroups when lighting was changed and when fresh air was introduced. Complaints and symptoms decreased with changes in air and lighting and increased again when previous conditions were established.
The manufacturing procedures and performance of a building air infiltration kit consisting of miniature passive perfluorocarbon tracer permeation sources and passive adsorption tube samplers are described.
The Brookhaven air infiltration measurement system (BNL/AIMS) uses a family of four passive perfluorocarbon tracer sources and miniature passive adsorbent samplers to inexpensively but very effectively tag individual zones within multizone buildings with uniquely discernible tracer vapors.
This is the third item in a series on methods for predicting condensation risks within structures. It answers criticisms made of the method described in NO 1729, on the basis that the method does not give the same answers, nor does it take account of the effect of the occurrence of condensation on the vapour pressure gradient within the structure, as does the graphical method described in NO 1728.
Describes in detail a computer-based technique for predicting the risk of condensation occurring in building structures. The technique not only indicates the position at which condensation is likely to occur, but also puts a figure on the risk of decay in timber within the structure. In the case of ventilated roofs or walls it gives the minimum sizes for ventilation openings.
Sets out the mathematical techniques for determining 1 the most likely position of the condensation plane, 2 the limiting humidity at a given room temperature, below which condensation will not accumulate within the structure, 3 the rate at which condensate is likely to accumulate at the plane if the relative humidity within the structure persistently exceeds the limiting humidity. The technique is a graphical one and assumes that the conditions chosen for the purpose of the analysis remain constant indefinitely, a condition known as "steady state".
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