Describes tests in Exeter University library of method of determining ventilation rate by measuring the amount that the atmospheric carbon dioxide concentration in an occupied space is raised above the outside ambient level. Compares rate obtained with that expected from the fan rating. Demonstrates that in addition to the ventilation rate, the average rate of production of carbon dioxide produced by the occupants could in principle have been estimated from the data.
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 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.
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.
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 measurements of suspended particulate matter, carbon monoxide and droplet nuclei in a climate chamber of 50m3 as indicators of the particulate and gaseous phase of cigarette smoke. Various combinations of smoking intensities andventilation rates between 1 and 16 air changes per hour were investigated partly by a standardized smoking machine procedure and by individual smoking by a panel of four persons.
Reports first report from committee, "Preliminary proposals for measures against radiation risks in dwellings". Notes that prime source of radiation, alum-based lightweight concrete, has been banned in new buildings in Sweden, but is still present in 10%of pre-1975 houses. Provisional limits for gamma radiation for undeveloped sites: 30-100 micro.r/h (site should only be built on subject to other conditions), more than 100 micro.r/h (building inadvisable). suggests that geological radiation maps be charted. Notes reduction in radon content through house ventilation.
Investigation has shown connection between radon content in mines and lung cancer in miners. Radon is also present in building structures. Presents measurements carried out inNorwegian houses and discusses consequences of radiation doses absorbed in human lungs as well as biological effects of background radiation. Diagram illustrates concentration of radon in concrete, brick and wood. Analyses factors which affect radon content, particularly barometric pressure and ventilation rates.
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