The steady-state heat loss of a house can be expressed as the sum of the above-grade conduction loss, the below-grade conduction loss, and the infiltration loss, minus the solar gain. Each of these terms is the product of a weather related variable and a coefficient that describes a physical characteristic of the house. If the infiltration driving force is properly defined, the infiltration coefficient is the equivalent leakage area.
Reliable surface pressure and indoor wind speed data from model buildings in boundary layer wind tunnels can only be expected if appropriate modeling parameters are considered carefully. Modeling parameters to examine when planning boundary layer wind tunnel studies of indoor airflow and external surface pressures due to wind are identified, and criteria for assessment are suggested.
Two techniques for estimating natural wind airflow through buildings for comfort cooling utilizing data derived from boundary layer wind tunnel studies are presented. One method is based on pressure and discharge coefficients. The other uses wind speed coefficients determined from model studies in a boundary layer wind tunnel.
In the past several years measurements of radon and its daughters made in residential buildings in the USA indicate that in some situations the potential health hazard to the occupants of buildings from inhalation exposure can be significant.
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.
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