English

Surveys existing studies of natural ventilation which are of two types; full scale studies of small domestic buildings and analogue studies, mainly electronic digital analogues. Gives simple nomograms, deduced from the analogue studies which are useful for estimating gross building infiltration rates underextreme meteorological conditions. States that none of the analogue studies have been carried out in conJunction with simultaneous full scale or model scale studies in order to check their performance.

Describes a research project undertaken at the Building Research Station to measure wind pressures on the G.P.O. tower, London, and dynamic strains in the tower shaft. The development of a suitable pressure transducer which used strain gauges as sensors is described, together with the installation at the tower. some othe problems of strain gauging large civil engineering structures are outlined. NOTE Final results of this project are given in "Wind pressure and strain measurements at the Post Office Tower" Newberry C.W. Eaton K.J. Mayne J.R. abstract no.229. B.R.E. C.P. 30/73

Describes a computer program written in 1900 fortran which is suitable for computing natural ventilation rates in multi-storey buildings. Lists the assumptions made, the data requirements and output available. Gives a print-out of the program.

Describes research to study movement of air through fully or partially open doorways with and without influence of temperature, and to ascertain amount of supply air required toprevent this movement. Studies door openings of 0.10 to 104 m. wide and temperature differential of 0 to 12 deg.C. States that from these results critical areas in hospitals may be designed more effectively to given requirements.

Describes laboratory test performed on four steel swing windows and one steel double-hung window to determine leakage rates at different values of pressure and humidity. Concludes there is a wide variation in leakage rates of well constructed windows. Test results depend on the method of closing and latching windows, leakage for steel swing windows is found to differ when determined with ascending and descending pressure differences because the window is closed more tightly after completion of the ascending pressure difference.

Full scale measurements were made of wind pressures on the 177m high post office tower, London. The variation of pressure with height was studied from recordings made at nine different levels between 49m and 168m above ground level. It is suggested that wind speeds of greater magnitude than those at the top of the tower sometimes occurred at lower levels.

Reports results of studies conducted in Switzerland in small apartment buildings. Air change rates were measured in ten different apartment buildings using N2O as a tracer gas. Measurements were taken for various wind conditions andtemperature differences and with the windows partly open. Finds that ventilation rate increased by a factor of 4 when the windows on one facade were opened by only a few centimetres.

BSTRACT Describes test made to determine air flow through entrances to a multi-storey building. Temperature and pressure differences across entrances and outside wind speed were recorded and flow through doors studied using laboratory scale models. 

Analyses theoretically the natural ventilation of buildings. Derives fundamental formula for the amount of ventilation due to temperature difference from Bernouilli's theorem considering buoyancy. Explains physical meaning of friction loss and theneutral zone, derives pressure distribution due to wind from the shape of buildings and the location of openings. Obtains total expression for amount of ventilation due to both temperature difference and wind.

States direct observations of wind effects on real buildings are necessary for the development of reliable information for wind load estimation. Their essential role is to provide data for the guidance of systematic wind-tunnel investigations. Briefly reviews instrumentation used in a particular tall building and the methods employed to interpret the measurements. The review illustrates the potential, as well as some of the problems of field measurements in providing practical information about wind loading phenomena. Summarizes results and discusses their implications for design.