Describes a method for the investigation of ventilation rate in mechanically ventilated closed rooms. The room air is labelled with a radioactive isotope and the ventilation rate inferred from the reduction in radioactivity found by repeated sampling at different locations . Notes the results apply only when the room air is well mixed. Defines a parameter, the "ventilation factor" which describes the variation in ventilation rate. Gives examples of the use of this method.
Describes methods of measuring the air tightness of whole buildings. Outlines three tracer gas methods; constant concentration; decreasing concentration and constant emission. Describes pressurisation method. Describes measuring equipment and test procedure and discusses calculation of ventilation rateand error magnitudes. Gives brief summary of measured results and an appendix contains a print-out of data on the airtightness of houses.
Describes the importance and purpose of measurements of air infiltration. Discusses methods of measuring air-change-rate and the range of measurements. Describes test method and gives preliminary results of practical tests made in living rooms during the winter of 1975/76. Results indicate that more detailed and comprehensive tests are necessary to obtain valid data for heat loss due to air infiltration in rooms and buildings and dependence of air-change-rates on year of construction and type of building.
Natural ventilation of inhabited rooms is studied with regard to its dependence on wind velocity and temperature difference between the interior of buildings and outside air. On the basis of simultaneous aerosol and carbon dioxide measurements an attempt has been made to separate the two components of air exchange: ventilation through walls and ventilation through clefts and chinks.
Reports measurements of air change rates made on approximately 250 dwellings, occupied by low income households in 14 cities, in all major climatic zones of the United States. Two types of measurements were used : a tracer-gas decay technique using air sample bags and a fan depressurization test that measures induced air exchange rates. Shows that for this group of dwellings natural air infiltration rates have an approximate lognormal distribution.
Outlines the problem of assessing the rate of heat loss from dwellings due to ventilation. Discusses the mechanisms and pathways of ventilation and ways of controlling air infiltration. Reviews methods of measuring ventilation using tracer gases. Discusses qualities of ideal tracer gas and three automated measuring systems. Reviews some experimental results obtained from the SEGAS test house. Describes house and measurement method. Finds sealing house reduced ventilation rates by between 30 and 45 per cent.
Describes method for measuring the direction and volume of air flows in a building with several rooms. The method uses carbon dioxide as a tracer gas produced from dry ice in each room. Over a period of 2-3 hours the concentration of gas in each room is measured every ten minutes. Gives equations for calculating air flows between rooms and some results of tests made on a flat.
Discusses the use of a tracer to measure the dispersal of air pollutants. Suggest use of Freon-12 or sulphur hexafluoride as tracer. Describes release of tracer, collection of samples in bottles, concentration of sample and analysis in gas chromatograph. Gives results of field trial and concludes that test method is very promising for studying local air movements.
Describes method of estimating ventilation rate using organic vapours as tracer gases and ultra-violet absorption to measure concentration. Gives table of absorption of different vapours. Suggests estimation using a test paper. This method is less precise but requires a minimum of apparatus.
Briefly reviews methods of estimating infiltration rates in dwellings. Describes tracer gas method using methane. Gives results of measurements of air change rate made in houses in Minneapolis, Kansas and Denver. Concludes that technique works well for measuring residential infiltration.
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