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.
Describes use of a radioactive tracer for measuring ventilation rates. Finds krypton 85 is the most suitable gas although xenon 133 and argon 41 have been used. Mentions various studies using radioactive tracers made in both France and England. Suggests commercial sources for krypton 85.
Reports full-scale studies of wind pressures on a tall prismatic building under a strong wind. Discusses correlations of the wind and wind pressures, periodic changes which may be caused Karmon vortices and well correlated ranges of the wind pressure.
Reports study of the natural ventilation in elementary tall office buildings has been made using the analogy between the flow of air through a building and the passage of an electric current through a circuit of resistances. The prime motive forces, those of wind pressure and stack effect are detailed, and experimental values for these and other parameters related to the building are outlined.
Reports a series of experiments made in the U.S. Bureau of Mines radon test chamber to study the effects of condensation nuclei, humidity and turbulence on the rapid deposition or plateout of radon daughter activity on the chamber walls. Under low humidity conditions the presence of a small fan reduced the working level by 41%. The activity was not deposited on the walls by the turbulent flow from the fan but actually became attached to the fan blades. High relative humidity (>80%) totally inhibited this observed effect.
Reviews methods for the measurement of the activity concentrations of radon-222 daughters in air. Describes method which enables activity concentrations as low as 0.05 pc i/l of ra a to be measured with simple readily transportable equipment. The method presented here also measures RaB (214 Pb) and RaC (214Bi) activity concentrations and working levels with improved precision compared with established methods.
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 air leakage measurements made in a mobile home using sulphur hexafluoride as a tracer gas. The home was located in an environmental chamber where it was possible to measure and control the temperature outside the home. The effect on infiltration rate of inside-outside temperature difference, simulated wind, installation of storm windows, opening of doors and operation of the furnace for was investigated. Also reports pressurization measurements which showed that the installation of storm windows had little effect on air leakage.
Presents model of indoor pollution that assumes a linear relation between indoor pollutant levels and the air change rate. Discusses effect of heating system and cooking on pollutant levels and ventilation rate. The model predicts that when air change rate is reduced 4-fold, heating systems pollutant contributions can still rise up to 3-fold despite the saving in energy from reducing ventilation. Suggests precautions are necessary when tightening building envelope. Recommends that pilot lights be eliminated and effective kitchen ventilation systems installed.
Gives general discussion of sources of radon gas and its daughter products. Reviews measurements made of radon concentrations in air. Outlines control strategies for limiting radon in buildings.
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