Describes automated instrumentation using sulphur hexafluoride as a tracer gas in residential housing to determine rates of air infiltration in houses. Discusses in detail the principles of operation, necessary calibration procedures and early field data. Concentration levels of SF6 are maintained at the partsper million level in the buildings and are measured by sensitive electron capture detectors in conJunction with a gas chromatograph.
Discusses toxic and flammable gases and vapours that lead to hazards in buildings. Examines trends in accidental deaths in the home in England and Wales from gas poisoning. Discusses influence of buoyancy on the dilution by ventilation air of accidental leaks of toxic and flammable gases and shows where buoyancy dominates layers can readily form. Presents theoretical results for controlling gas hazards in buildings by ventilation for a wide range of practical situations.
States that to obtain accurate estimates of wind induced natural ventilation of buildings the pressure distribution over the building is required. Reviews the available information for isolated buildings and groups of buildings. Gives the results of wind tunnel measurements made on a cuboid when surrounded by buildings of the same shape. Results are presented statistically and indicate that the pressure distribution on a building can be fairly accurately determined provided the density of the built form and the roughness fetch are known.
Presents results obtained from a digital analogue method of calculating infiltration rates in building. The results are compared with a set of full-scale observations carried out by G.T.Tamura and A.G. Wilson. (abstract no.192). Finds that calculated and full-scale results give good agreement in terms of the rate of change of air infiltration rate with wind speed and that both show that total infiltration rate is more sensitive to wind speed than wind direction.
Surveys existing studies of natural ventilation which are of two types; full scale studies of small domestic buildings and analogue studies, mainly electronic digital analogues. Gives simple nomograms, deduced from the analogue studies which are useful for estimating gross building infiltration rates underextreme meteorological conditions. States that none of the analogue studies have been carried out in conJunction with simultaneous full scale or model scale studies in order to check their performance.
BSTRACT Describes test made to determine air flow through entrances to a multi-storey building. Temperature and pressure differences across entrances and outside wind speed were recorded and flow through doors studied using laboratory scale models.
Describes pressure method for testing whole houses for air leakage. States main advantages compared to tracer gas technique are that equipment is inexpensive, easy to handle and so well adapted to routine tests. The house is pressurized using a powerful fan and the flow through the fan is equivalent to the leakage through the building envelope at given pressure. Summarizes measurements made on test houses. and shows use of thermography to detect leaks. suggests use of pressure test to estimate the natural ventilation of a house.
The significance of air tightness on building performance and the factors affecting the air leakage performance of the building enclosure are discussed. the ability of the ASTM standard air leakage test method to check the quality of design and manufacture of factory-assembled walls, windows and doors as well as the inability of the method to provide the building designer with quantitative air leakage data for calculating heating and cooling loads and designing smoke control means is also discussed.
Reports on the air leakage characteristics of the exterior walls of eight multi-storey office buildings in Ottawa. Results of the measurements taken are given and a method for calculating infiltration rates caused by stack action has been developed andis applied to heat loss calculations using the measured wall leakage values.
Describes portable air leakage apparatus capable of measuring the air infiltration of whole dwellings directly on site by the pressure method. Main assembly consists of a flow measurement duct and electric fan. Describes test procedure and gives air leakage curves for an ordinary semi-detached house and an experimental house. Finds that doors and windows account for a surprisingly small proportion of total leakage.
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