Data has been obtained on the radon concentration in natural gas supplied to several metropolitan areas in the United States. The average value of 20pCi/l was selected to estimate the contribution of this source of natural radioactivity to doses from radon daughters received by individuals in homes. Radon daughter concentrations in the home atmosphere were calculated by use of computer programs for an 800 cu.ft. house in which 27 cu.ft. of gas per day was used for cooking in an unvented kitchen range.
Describes the use of mechanical ventilation coupled with heat recovery devices in residential buildings to maintain acceptable indoor air quality and conserve energy. Gives tables showing the energy saving possible with a heat exchanger.
Reports study to investigate the possibilities of purifying air from formaldehyde by using a filter that brings the air into contact with an adsorbent substance. Finds that the type of adsorbent substance that works satisfactorily is that which involves adsorption in combination with the oxidation breakdown of adsorbent substances. Compares costs for residential premises between a) an increase in ventilation and the use of a heat exchanger and b) the type of air purification and recirculation describes above.
Reviews current and past air infiltration research related to low-rise residential structures. Discusses measurement techniques, case studies, techniques for detecting and reducing air infiltration in new and existing houses, occupant effects on air change rates and indoor air quality. Two appendices give respectively over 100 references and a print-out of the Lawrence Berkeley Laboratory's air infiltration bibliography.
Describes sources of radon in materials and measures of exposure. Reviews measurements of radon in mines and dwellings. Describes measurements of the concentration of radon in a sealed chamber. Concludes that concentration of radon daughters can be reduced by removing dust from the air using an electrostatic precipitator or by using a very high ventilation rate combined with an efficient heat exchanger. Finds most significant sources of radon in dwellings are cracks and openings in the floor. Suggests reducing radon by covering bare surfaces and sealing the floor, or using a crawl space.
Presents method for estimating the heat requirements of buildings. The method is based on the ASHRAE degree day method with modifications to take into account a) solar radiation incident on a building surface, b) variation of solar energy gained through windows, c) variation of air infiltration withwind speed and inside-outside temperature difference and d) heat generated by inside activity, such as lights, people etc.< Gives sample calculation for a house and compares with calculation by ASHRAE method.
Reports environmental background radiation exposure measurements made in approximately 100 residences in the vicinity of Livermore, California showing variations in annual exposure from 52 to 130 mr. Measurements were made with CaF2:Dy (tld-200) dosimeters at quarterly intervals for a period of 1 year. Dwellings were typically wood-frame structures with stucco exteriors. Interior exposure rates were, on average, about 25% lower than those outdoors.
Describes air infiltration measurements made in three apartment houses in the Chicago area using SF6 as a tracer gas. Two were in tenement districts and one was suburban. Data were collected in selected apartments in each building, and these data were used to estimate the infiltration rate for the entire building.
Discusses mechanisms for radon liberation in dwellings. Mentions survey which found radon concentrations exceeding the maximum permissable concentration of 3 x 10^-12 curies in 13 of the 65 dwellings. Gives expressions for number of radon atoms in indoor air at time t and activity due to radon per unit volume. Discusses liberation of radon from walls and from soil and concludes that if the ventilation is poor or if there is a high emanation of radon, the indoor radon concentration may approach the maximum permissable level.
Users' manual and documentation connected with computer program ENCORE. Program is based on weighting factor method. Provides general description of input data, building location and shape, heating system and building use.Describes in more detail standard output, error messages and warnings. Provides examples concerning warm-air heated house and house with electric space heating system. supplied detailed documentation of subroutines.
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