English

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.

Air contaminants include all gases, vapours, liquid droplets and solids, including microogranisms of small size that can be dispersed in air and that are unwanted. Contaminants can be removed by dilution of the air, by deposition of particles on surfaces or by reaction with other materials in air or in space (such as furnishings).< This article discusses in general terms the reduction of contaminants and gives equations of concentrations of contaminants after time t. Discusses types of filters and their effectiveness.

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.

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.

Reports the results of three programmes of measurements of ventilation carried out in one-family houses, which in most cases were of the 'council house' type. The first programme measured ventilation rates using tracer gasin two houses room by room. Wind speed and direction were recorded but no general relation between ventilation and wind was found. The second measured ventilation rate in individual rooms in a house under six different wind conditions. The third measured ventilation rates in three identical homes.

Treats importance of keeping uncontrolled ventilation to a minimum in buildings equipped with balanced ventilation. Provides theoretical and experimental description of leakage of air past windows. Includes comparison between standards of different countries. Discusses effect on building ventilation of variations of wind and outdoor temperature. Considers in conclusion measurement of air flows between rooms in a building. Describes development of tracer gas method based on computer-assisted evaluation.