Natural ventilation of large hospital buildings.

Wind-tunnel tests of hospital scale models and a computer program to calculate internal air flows were used to produce aprediction technique to determine the rates of natural ventilation of large hospitals. Technique was applied to aharness hospital design and article reports that the ventilation generated by wind forces in for instance, ward areas would not be consistently adequate for the comfort and well-being of the occupants.

Wintertime infiltration rates in mobile homes.

Reports measurements of air infiltration made on two mobile homes, identical except that one was treated with sheathing board and the other caulked. Carbon monoxide was used as a tracer gas and wind speed and direction, solar radiation, andoutside and inside dry and wet bulb temperatures were recorded. Finds considerable scatter in the data and analyses the reasons for this. These include the considerable sensitivity of infiltration rate to wind and instrument drift.

Radon in swedish buildings.

Outlines problem of radon in buildings and current state of knowledge. Suggests reduction of radon by a) more efficient ventilation, b) use of diffusion resistant films to seal wall surfaces and c) elimination of certain active materials. A research project at the Swedish Council for Building Research is currently investigating the problem.

Avoidance of condensation in roofs.

Sets out in general terms the design principles for avoiding condensation in roofs, pitched and flat. Recommends providing arain shield permeable to water vapour, a vapour barrier on thewarm side of the structure and in roofs with air spaces to ventilate the air space or blow dry air into the roof space.Discusses application of these to particular types of roofs.

An exhaust fan apparatus for assessing the air leakage characteristics of houses.

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.

Techniques for measuring wind loads on full-scale buildings.

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.

Separation-induced pressure fluctuations on buildings.

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.

A wind tunnel test of pressure distributions on box-shaped models.

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.

Study of wind pressure with vertical distribution on model-scale buildings.

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.

Wind pressure measurements on bluff bodies in natural winds.

Presents results of measurements of fluctuating wind pressures on prisms of square and rectangular section mounted on the rooftop of a 4-storied building. Describes models and experimental methods. Finds pressure fluctuations of thewindward side are subject to the influence of wind turbulence. Negative pressure on leeward side is relatively stable exceptwhere strong vortices are being shed Very high negative pressures were observed intermittently along the edges of a top board.

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