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.
Describes in detail a multi-cell model for predicting ventilating airflows. Gives equations for flow through cracks, wind and stack effect. States that comparisons between prediction and measurements indicate that the method is capable of giving relatively high accuracy for a wide range of ventilation conditions. Discusses advantages and disadvantages of multi-cell and single-cell methods. Argues that multi-cell approach is potentially more accurate and more useful.
Describes investigation of the effects of five hour exposure of sixteen young people to different concentrations of formaldehyde. Physiological parameters, subjective discomfort and performance were monitored. Discusses setting of exposure standards for formaldehyde and suggests standard of 0.15 mg/m^3 for continuous exposure.< Discussion includes an account by R.Baars of developments in the Netherlands and measures taken to reduce formaldehyde concentrations in dwellings.
An air to air heat exchanger is only of value if one can control the movement of air into and out of the house. Suggests measures for reducing air leakage. describes construction of an air to air heat exchanger. Finds that heat exchanger can be used to control humidity in houses. Suggests use of a solar collector to preheat the cold outside air entering the heat exchanger.
Reviews literature on radioactivity in construction material. Finds that radioactivity in building materials used in the United States has received very little attention and that except for studies to find construction materials of very low background, there are no reports of radiological surveys of any U.S. building materials used for general construction purposes. Discusses surveys made outside the U.S.A. and summarized the gamma exposure rates found inside buildings (table 2). Gives bibliography of approximately 270 references.
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.
The Swedish building regulations give recommended tightness values for buildings of 3 air changes per hour for single houses, 2 air changes per hour for other housing with not more than two stories and 1 air change per hour fortaller buildings.
Reports wind tunnel tests of wind velocity, RMS velocity fluctuations and energy spectra for the streamwise velocity component in the lee of model fences of permeability 0% 20%, 34% and 50%. Compares results with existing field and wind-tunnel data. Turbulence measurements define the leeward flow regions which are dominated respectively by the bleed flow and by thedisplacement flow. Gives separate empirical relationships between mean velocity and turbulence intensity for these two regions.
Describes a sampling programme which measured simultaneously the indoor and outdoor concentrations of pollutants at three sites in Zurich during summer and winter. Gives brief summary of results showing concentrations of CO, NO, NO2 and HCHO and discusses sources of the different pollutants.
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