Briefly reviews the study of wind flow around buildings. Shows that fundamental theoretical and experimental studies are beginning to produce simple descriptive and mathematical models of flows round buildings. These should enable designers to predict the general features of wind around a proposed building or group of buildings at an early stage in the design. Gives some examples of these models.
Derives analytical expressions for the exchange of air across doorways or similar apertures, in terms of the temperature difference between the spaces on both sides of the opening and the net volume of air flowing through this as a result of unbalanced air supply or extract.
Describes a technique developed for measuring air flows between internal spaces of houses. Involves using a portable gas chromatograph to monitor the concentrations of three tracer gases released in three distinct zones within the building envelope. Using the results of each measurement, which takes approximately two hours, the ventilation rate of each zone can be calculated along with the interconnecting air flow. Presents the tracer gas equations involved, and includes an account of the experimental method and the practical difficulties encountered.
Reports measurements on air transport through homes made by a committee working a Dutch Standard on Heating Load Calculation similar to DIN 4701, but taking account of air infiltration losses through joints and cracks between glazing, window-frame and facade construction. Describes the measuring method applied. Tables air leakage coefficients c and flow exponents, n ,of a number of flats and single family houses. Also tables c and n values of cracks according to type of construction and material, use of weather strips and measuring institute.
Describes methods of measuring the three-dimensional flow field using a three-sensor hot-wire probe, with emphasis on the techniques developed by the author's group at the Pennsylvania State University. The hot-wire equations, data processing procedure, calibration techniques, and a discussion of various errors in the measurement are included. Some typical data acquired by thisprobe is also included.
Discusses and analyses the characteristics of methods of determining local air flows through the building envelope, methods of determining the air leakage and ways of determining air changes in rooms. Summarises in a table methods of determining local air flows. Of the air leakage methods, treats static and non-static methods. Considers three commonly used tracer gas methods for air change measuring methods.
Reviews nature of air flow conditions, meteorology affecting building air flow, wind effects on systems operation, and physical modelling and full- scale measurements.
Lists the factors in a building (condensation, comfort, heat loss etc) which are affected by ventilation, mechanical or natural. Treats the driving forces of air exchange in buildings. Describes the four basic flow phenomena involved in air e
The method to calculate flow processes in multi-storey buildings having uniform storey arrangement(residential and office buildings) can be simplified to an extent enabling calculation by hand. Nomographs are given to calculate flows in sectional and central corridor buildings. The air flow rates depending on the action of wind, buoyancy and exhaust air plant operation can be derived from these nomographs for different combinations of flow resistances of the buildings. The latter factors may be included in thecalculation either individually or in any combination.
Reports an experiment to assess the magnitude of air flow through the brickwork of one of the ECRC test houses. Describes apparatus and method and gives results. Also describes smoke and tracer gas tests to detect air flow within the wall structure. Concludes that under average wind pressures ventilation through the wall is negligible but that air from outside may penetrate the building envelope and extract heat from the house without contributing to the ventilation. This heat loss could be as much as 50 to 100 Watts per day.
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