Compares wind pressures measured on a single-family dwelling with results obtained from a 1:50 scale model in a turbulent boundary layer. Shows that fluctuating components of surface pressures far exceeded mean or steady pressures and are well correlated over sizeable roof areas. Suggests that certain current provisions are marginal for tributary areas and excessive for localised area such as ridges, eaves and corners. Describes procedure for expressing loads on both localised and extended roof areas in terms of mean pressure coefficients and a peak factor.
Summarises research into air leakage. Describes field studies of air leakage of exterior walls, the heat loss caused by stack effect and smoke movement caused by wind and stack effect. Describes mathematical model for air leakage and flow patters of multi-storey buildings. Discusses implications of results on building design. NOTES general survey only.
A study made to confirm the values given in german standard DIN 4701. considers theoretical natures of air permeability and the k-value as they concern windows. Finds that infiltration through windows without weather-stripping depends to such an extent on the quality of manufacture and fitting that essential differences between single-glazed, double-glazed and double windows scarcely exist. Finds no real difference between woodenand metal frames when new, but after normal wear and tear an average value of 3m(3)/h for each metre of gap at 1mm pressure difference is acceptable.
Gives general data about windows in the experimental dwellings and the transport of air through small openings. Describes method for calculating the rate of air infiltration through windows as a function of the pressure difference between both sides of the construction. Presents results for each type of window graphically in several ways. Gives figures for cracks between movable construction parts.
Describes method for simulating natural wind boundary layer in a conventional, short working section, aeronautical wind tunnel. Boundary layers, which may be as thick as one-half of the working section height are generated by spires at the working section inlet. This approach is used to measure mean wind pressures and pressure spectra on a model of a tall building in downtown Montreal. Measurements are repeated using the long roughness fetch technique for boundary layer generation and results from the two methods compared.
States heat load on buildings due to wind is dependent on the shape of building, wind direction and wind speed. Gives theoretical calculation for the heat loss due to wind based ongerman standard DIN 4701. Discusses fundamentals of fluid dynamics and the practicalities of wind tunnel tests. Recounts tests made of a block of flats in Munich. Pressure distribution due to wind was determined by a wind tunnel test on a model, giving c-profiles for different wind directions.
Describes retrofitting a wood-frame residence, having only limited insulation in the attic, to reduce its energy requirements for heating and cooling. The three retrofit stages comprised : reducing air leaks ; adding storm windows : andinstalling insulation in the floor, ceiling and walls. The housewas extensively insulated to evaluate energy savings and other performance factors. an economic model was used to evaluate the cost effectiveness of the retrofit options.
Discusses reasons for making buildings air-tight and the requirements of the swedish building code. Gives examples of design solutions for detached houses and construction details for applying an internal vapour barrier consisting of a polythene sheet. Describes application to seven bungalows, resulting in air change per hour of 0.67 to 0.86. Subsequent measurements of ventilation and air velocity showed that in mechanically ventilated airtight houses the flow of ventilation air can be accurately controlled by the exhaust fan.
Describes the results of an investigation carried out to determine the rate of fresh air infiltration that is experienced during the winter in a modern air conditioned office building. Six different methods were employed to estimate the rate of infiltration through the building, four by direct measurement and two by calculation. The methods of direct measurement were,tracer gas decay, measured air flow through one floor, measured air flow through one air conditioning unit and measured change on power demand.
Reviews existing methods for the prediction of infiltration rates and the factors influencing the pressure difference across buildings. Describes experimental procedure used in tests conducted in wind tunnel. Discusses results and presents prediction technique which enables surface pressures acting on aparticular building situated within an array of similar low rise buildings to be estimated, procedure takes account of the geometrical form of the building spacing parameters describing the array, direction of the wind and the upstream fetch conditions.