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.
Describes a photo-electric technique for instant determination of contaminant concentration in wind tunnel studies of stack gas dispersion. A roving sensor is used to measure the light scattered by the particles of oily aerosol representing theprototype stack effluent. The minature probe has a noise level of only one hundred thousandth of the full linear range of the output signal for a time constant of 5s. Device is also suitablefor measurement of fluctuating flow properties, such as turbulence, where a high frequency response is required.
Reports investigation of the relative effectiveness of wall gratings and flues as means of naturally ventilating unheated closed rooms. Ventilation rates of several rooms were measured using carbon dioxide as tracer gas and wind speed and direction were recorded. Presents results and finds for the flue, ventilation increased with wind speed irrespective of direction. For grating, ventilation rate increases slowly with size of grating and is dependent on both wind speed and direction. Concludes flue with base opening of 15 sq.ins. is as efficacious as grating having 50 sq.ins.
Describes the basis of operation of electron absorption detector and the nature and causes of the erroneous and anomalous responses it may generate. Suggests pulse sampling technique asan alternative method of analysis. This retains the sensitivity of the simple low potential ion chamber method, but is substantially free of errors and anomolous responses. Describes the basis of this improved method and gives an account of the technique for its use in quantitative and qualitative analysis.
Reports 312 measurements of ventilation rate in 31 rooms in old and new blocks of flats, 3 villa residences and a modern university building, made using coal gas as a tracer. Describes buildings and gives main results. Examines effect on air change rate of sealing flues and gratings, opening windows and weather conditions. Finds outside wind speed has most influence on ventilation rate. Discusses recommended standards of air supply.
Presents results of measurements of ventilation rate and window air leakage made in blocks of flats in Sweden. Describes measurement of ventilation rate using nitrous oxide as a tracer gas and pressurization tests on windows. Gives graphical results of tests. Finds that the majority of windows do not satisfy 1975swedish building code. Reports measurements of air leakage of windows before and after renewal of draught excluders. Concludes that old windows can be made relatively draught-free and that this is not expensive or time consuming.