Discusses flow of air between two rooms through an open door. Considers 6 cases with and without mechanical ventilation and with a temperature difference between the two rooms. Gives examples of the calculation of air flow. Recommends that for hospitals where the transfer of bacteria should be avoided, doors should be kept shut as much as possible and that it is not economically justifiable to choose such a high ventilation rate that no undesirable back flow occurs with the doors open.
Four two-storey four-bedroom test houses were built in 1974 near Columbus, Ohio and have been instrumented and monitored by Ohio State University. All four houses are unoccupied. Air infiltration rates were measured in all four houses using sulphur hexafluoride as a tracer gas and two of the houses were pressure tested for air leakage. Discusses results and the correlation between infiltration, inside-outside temperature difference and wind velocity. Compares tracer gas results with pressurization tests.
In order to reduce heating energy consumption, single glazed windows are commonly replaced by double glazing and joints tightened in Danish dwellings. Reports investigation of the influence of such tightening of dwellings on the indoor climate. 25 tightened and 25 not-tightened identical flats were investigated. Finds an improvement in thermal climate and a significant reduction in heat consumption in the retrofitted flats. Finds absolute humidity of indoor air was significantly higher in improved flats, probably due to reduced ventilation.
An earlier paper gave the flow to be expected through an open door from theoretical considerations. Describes model tests designed to check these theoretical predictions. The model used was 6.3% of full size and water was used instead of air for the flow medium. Concludes there is reasonably good agreement between model and theory.
Discusses the tracer dilution method for measuring air change rates. The technique entails introducing small amounts of tracer gas into a building and measuring the rate of change in tracer concentration. Describes the method and compares different tracer gases. Outline ways of obtaining an estimate of the air infiltration from experimental data. An appendix discusses the errors in the procedure.
Notes that altering interior moisture content of a building can influence both energy use and other performance characteristics. Gives an assessment of the moisture interaction as related to health and comfort of the occupants, fire safety, durability and maintainability and design and construction of light-frame housing. Reviews published recommendations.
Reviews the state of the art in the measurement of ventilation and air infiltration. Considers tracer gas techniques and discusses some of the tracer gases used as well as some of the potential sources of error. Also discusses fan pressurization-evacuation procedures for measuring building tightness and compares fan and tracer measurements. Discusses the ASHRAE crack method.
Reports wind tunnel measurements of the wind-induced internal pressures of models of low-rise buildings of different geometry and internal volume. Three different uniform porosities (0.0 0.5 and 3.0% of the total surface area) have been examined in combination with openings in a wall ranging from 0 to 100% of that wall's area. Two terrain roughnesses were used corresponding to open country and suburban regions.< Finds that internal pressures are variable but generally lower than local external pressures.
Reports study of wind and rain over fifteen years and gives table of results. Reports measurements of wind pressure and driving rain on buildings. Discusses laboratory measurements of the tightness of facade elements under pressures of up to 50 Pa. and with temperature differences of -40 to +30 deg.C. across the facade. Describes pressurization of buildings and gives results of measurements in test dwellings. Discusses movement of joints in buildings and describes measurement of this movement.< Discusses permeability of both flat and sloping roofs.
Air velocities, air temperatures and dust and fluoride concentrations were measured in a burning shop of a pellet plant. The results show that there is a clear relationship between the air velocities, air temperatures and airpollution concentrations. The air flow pattern consists of an air current which rises above the burning machine as a result of convection and escapes through roof grates. Air is supplied through facade grates. The transport of air and polluting substances, especially in the cross direction of the hallindicates the influence of the wind.
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