Due to the complicated flow phenomenon in urban areas, the assessment of wind pressure forces as well as the rates of natural ventilation for groups of low rise buildings is complex. As a result, the current design methods for the prediction of these forces are oversimplified and lead to inaccurate estimates of wind forces and ventilation rates in buildings. A survey of previous studies regarding wind properties and their influence on pressure forces along with work related to natural ventilation, wind loading and air flow round buildings was carried out.
Describes standard tests for air leakage, water-tightness and mechanical tests to be carried out on windows. Describes apparatus and test method. Defines normal resistance to air leakage as air penetration of 12 to 60 m3/h/m2 of the surface at a pressure of 10mm. of water. At air penetration of less than 12 m|3/h/m|2 the windows have improved resistance to air penetration.
Reports wind tunnel investigation of the air flow around single houses and in passages between two single buildings. Wind velocity around the house was measured using thermistors and results converted to isovel maps, that is maps showing curves joining points of equal velocity. Gives diagrams showing isovels.
Describes a computer program used to calculate the air exchange in multi- storey buildings. An air network is drawn up for the building and arbitrary initial pressures are assigned. A system of equations is drawn up for all linearly independent loops andjunctions and the program solves this system of equations. States that comparison with the hydraulic analogy method gives a discrepancy, not greater than about 3%. NOTES translation available from B.S.R.I.A. price 1 pound
Examines the conditions that develop inside an enclosure subjected to wind pressures, by analogy with a rectangular box held motionless in a stream of water. Finds that internal static pressures may rise by as much as the value of the impinging air velocity pressure. Tight interior partitions result in a series of descending pressure zones from windward to leeward.
Describes main features of full-scale wind load tests made on Royex House, an 18-storey office block in London. Wind tunnel tests were made on a model of the building and the results compared. Concludes that wind load on building is almost entirely on the windward wall, short duration gusts are significant in loading the building. Finds reasonably close agreement between wind tunnel and full scale tests in the matter of overall drag coefficient, but an assessment of the pressure distribution on the surface of a building requires a model with permeable walls.
Describes the basis of operation of electron absorption detector and the nature and causes of the erroneous and anomalous responses it may generate. Suggests pulse sampling technique asan alternative method of analysis. This retains the sensitivity of the simple low potential ion chamber method, but is substantially free of errors and anomolous responses. Describes the basis of this improved method and gives an account of the technique for its use in quantitative and qualitative analysis.
A comprehensive manual describing theory and techniques of thermography as used to determine insulation defects in buildings. Describes operation of infrared camera and theory of interpretation of thermograms. Provides practical rules for field work and discusses possible sources of error. Concludes with 56 page catalogue containing over 700 typical thermograms, many in colour, illustrating four wall types built a) strictly according to specifications and b) with common structural and insulation defects.
Discusses the nature of stack effect, the distribution of air pressures across a building enclosure and its interior separations that stack action causes, and some of the implications of the resulting air flow patterns. Concludes that way in which stack effect is distributed across the building enclosure can be altered by design.