Describes portable apparatus used to measure the air leakage of houses. A fan is used to exhaust air from the house and the air flow rate is measured. The air flow rate and corresponding pressure difference across the building can then be used to evaluate the relative air tightness to the house. The fan pressurization test equipment is portable, inexpensive and simple to operate. Describes test procedure and gives a few examples of house characteristic curves.
Reports wind pressure measurements being made on a four-storey building at Gaithersburg. Describes instrumentation and techniques for data acquisition, reduction and analysis. Outlines tests to be made on data to analyse the statistical properties of records.
Gives a brief account of exploratory efforts to isolate the contributions of flow separation and reattachment to local surface pressure fluctuations. The study is restricted to tall buildings with sharp vertical edges. Pressure fluctuation measurements were made on small scale models of actual buildings placed in uniform flow of low turbulence level. Gives figures showing mean and root-mean-square pressure coefficients. Finds maximum instantaneous pressure fluctuation was four times the root-mean-square value. Describes characteristics of pressure fluctuations.
Reports measurements of wind pressure distributions on the surface of a rectangular cylinder model in a wind tunnel. Finds fluctuating character of pressure on roof surface is dependent on the turbulent structure of wind tunnel flow. Experiments were also made on box-shaped models with square section. Finds windpressure distribution on the roof became uniform with increasing height of the model. Gives diagrams of wind pressure coefficients.
Reports measurements of pressure distribution on square cylindrical models in wind tunnel. Vertical distribution of wind velocity was produced by grids of horizontal rods at varying spacing. Wind pressure distributions on model-scale buildings were obtained, varying the height, width, depth and winddirection. To compare results, a large-scale model 3.6 metreshigh 1.2 metres by 1.2 metres in plan was placed on the shore and pressure distribution measured during a strong wind. Gives diagrams of pressure distributions.
Presents results of a survey of natural infiltration rates in 2 identical modern homes-one gas fuelled and one electric-over aperiod of a year. Infiltration rates were determined by releasing tracer gas, usually ethane, into the main return duct and measuring concentration every half hour. Discusses results and dependence of infiltration rates on wind speed and direction. Gives preliminary result that wind probably exerts agreater effect on infiltration than any other variable.
Describes a probe, developed for sensing static pressure in two-dimensional air flow. It was designed as a sensor for the measurement of static pressure acting on the surface of a building but the design also permits it to be used in free-stream flow. Gives details of the construction of the probe, calibration procedure and the effects of Reynolds number and of the sensitivity of the probe to pitch.
Reports measurements of air pollutants inside and outside three pairs of structures for different seasons of the year. Four pollutants were measured, suspended particulate, soiling particulate, carbon monoxide and sulphur dioxide. Describes instrumentation and gives results. Concludes that in homes withgas heating and cooking, the heating system has no effect on CO levels but gas stoves had a significant effect.
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