Discusses conditions that must be satisfied for a model in a wind-tunnel to give the same air-flow as a full-sized building. Reports two series of tests on interior and exterior air flow patterns, made on a full-sized building and a scale model of the building. Air flow patterns were observed using titanium tetrachloride smoke. Tests were also made to determine the limits by which the product of the height of the model by the air speed may vary without serious error.

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.

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.

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.

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.

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.