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.

Calculations of the activity concentration of RaA (218 Po) in the air within living rooms and in the outside air were made at 87 dwellings in England and Scotland. From these measurements together with a determination of the ventilation rate existing in the room at the time of the measurements, the rate at which 222 Rn is emanating from room surfaces into room air in pci/l/h can be calculated.

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.

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.

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 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.

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.

Uses Turk's equation to obtain CO concentration v time curves in an office and a one-family house. Compares results with similar studies, current threshold limit values and ambient air quality standards for CO. Finds model is apparently valid for CO and probably for other gaseous contaminants not affected by absorption or deposition. Concludes that commercial environments should have at least 5 cfm fresh air per occupant and that a value of 50 cfmfresh air appears to be adequate for a one-family dwelling.

Describes a method for measuring the radon concentration of three litre samples of atmospheric air without pretreatment. Apparatus used consists of a 12 in. photomultiplier with 2ns (ag) phosphor and counting chamber. A measured efficiency of 38% when the phospor is negatively changed, is in good agreement with theory. The ultimate sensitivity is governed by the background which is equivalent to a concentration of 5 x 10|-4 c/l

Describes a model for calculating the energy losses caused by ventilation and uncontrolled leakage of air in buildings. Discusses leakage characteristics of building envelope and duct system, the effects of wind and stack effects. Gives general picture of the calculation model.