The effects of retrofitting for building tightness, air-to-air heat exchangers, and HVAC circulation fans on radon and radon progeny levels were investigated using two matched test houses.
There are three general categories of techniques for the control of radon and radon progeny concentrations in indoor air - restriction of radon entry, reduction of indoor radon concentrations by ventilation or air cleaning, and removal of airborne radon progeny.
A new method for measuring interzonal air movement, using up to four different tracer gases simultaneously, has been developed at the Polytechnic of Central London and tested in a solar air-heated experimental house in Peterborough, UK.
Large, multicelled, and naturally ventilated buildings pose many inherent difficulties for the measurement of overall infiltration rates using tracer gases.
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.
This paper deals with a new computer program, MOVECOMP, which calculates the in- and exfiltration and the airflows between the rooms of a multicell building. The calculations are made due to wind and thermal forces and the characteristics of the leakage openings. MOVECOMP was developed to be user friendly: input data are limited and output data are very flexible. The userchooses which output he wants from a menu. The building is described with asystem of pressure nodes, connected to each other through flow-pressure difference functions.
Fan pressurization techniques are being employed by an increasingly large number of contractors and auditors to determine the leakage characteristics of structures. In this study, a large data base of flow exponents and flow coefficients are compiled to determine the degree of correlation that exists between flow parameters. The resulting empirical relationships are then used to determine the feasibility of predicting these flow parameters directly from a single pressure difference test. On the basis of these correlations, a new pressure independent tightness parameter is proposed.
Air leakage is the single most important quantity in the determination of air infiltration in residential structures. Air leakage is most commonly measured using the fan pressurization technique (ASTM standard E779): the data gathered with this method is often used to determine a leakage constant and a flow exponent. In this report, data gathered from measurements in the USA and Canada is compiled into a list of leakage constants and flow exponents, and the variability of these values over climate and housing types is examined.
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