Discusses the factors affecting air change rates in multi-storey buildings and derives expressions for the air infiltration through walls, windows and doors; air flow through gravity ventilation ducts; pressure pattern on the outside walls of the building and the "chimney draught" in the staircase. Derives mathematical model for calculating the air balance for a building with gravity ventilation ducts. Concludes that chimney draught (stack effect) has a large effect and that proper design of the extraction gravity ventilation system is very important.
Reports measurements made of wind pressures on a multi-storey building in London. Autocorrelations and power spectra were computed for the 48 pressure transducers and showed noticeable fluctuations in the pressures on the windward face, Possibly caused by a cushioning effect in front of the building "leaking" away at regular intervals. Mentions effect of the permeability of building. Comparisons made with wind tunnel tests improved when surrounding buildings were taken into account. Recommends design gust durations for various sizes of building.
Reports wind tunnel tests made on model building. Wind pressures on the models were measured using several manometers in holes on the windward side and a single manometer on the leeward side atwind speeds of approximately 35 feet and 45 feet per second. Single models and single models with a shielding building at varying distances were tested, and pressure distribution found.Comparison with full-scale tests indicates the general form of pressure distribution is the same but pressure reduction on leeward side is greater in full-scale test.
Presents a general picture of the consequence of wind on high buildings. States that the air velocity in the lower 250-600m layer of the atmosphere is strongly affected by the shape of the earth's contours, and discusses the effect and size of eddies. Gives the range of wind pressure variations between windward side, leeward side and at corners and edges and outlines problems that can result in ventilating, from draught and other wind hindrance aspects. Brief tips are given to minimize serious mishaps from the result of wind near high rise buildings.
Analyses wind pressure records, taken during 5 different windstorms on 2 levels in a 400ft (122m) high office building in downtown Montreal March 1964 pressure fluctuations on an actual building. Preliminary work done to compare full-scale measurements with wind tunnel measurements indicates that simulation of basic statistical properties of wind pressure fluctuations can be successful when carried out in a boundary layer type of wind tunnel.
Wind pressure measurements made over a 4 years period on a 34-storey building in downtown Montreal were used to obtain data for checking and improving wind tunnel techniques of modelling flow characteristics of wind and aerodynamic behaviour of buildings. Specifies the major problems involved in making field measurements and in comparing them with wind tunnel measurements. Comparisons with model measurements are made. Examples have been found of excellent agreements, but for some wind directions the comparisons gave unsatisfactory correlation.
Discusses current knowledge concerning wind-induced ventilation in buildings. states major difficulty in estimating ventilation and infiltration rates in a building is ignorance of wind pressure distributions around structures. Examines properties of wind with special reference to mean velocity profiles, characteristics of turbulence and wind energy spectrum. Reviews internal and external pressure distributions on an isolated building. Studies effect of grouping of buildings on pressure distribution around a house by considering results of wind tunnel tests.
In a lecture held for T.V.V.L. members on 22nd November 1965, the influence of wind, direction of the wind and wind force on buildings were described showing the resulting pressure distribution around the building and the general effect of wind on buildings which are ventilated either naturally or mechanically. The influence of wind on a specific building can be determined by pressure measurements, for instance in a windtunnel. This is followed by measurements with an electric analogue in which light bulbs give an indication of the air movement.
States that high-rise buildings can cause problems to occupants particularly since wind velocity and pressure fluctuations will be more pronounced than at ground level. Outlines ways in which smoke from chimneys can cause difficulties and gives reasons for difficulties when ventilating or air conditioning high-rise buildings. Recommends testing a model of the building in a windtunnel; lists points to be investigated; discusses rules for scaling giving formulae and outlines the testing procedure.
Treats 4 mechanisms of building heat exchange with the environment and their effect on overall energy consumption: 1) air infiltration and exfiltration, pressure distributions and gradients and resulting mass transfer at building surfaces; 2) influence on surface heat transmission of turbulent mixing of air close to building surface and mechanisms causing this mixing; 3) how air circulation around buildings strongly affects air conditioning cooling towers and how incorrect location of ventilation inlets and exhausts can reduce thermal efficiencies of cooling equipment and increase fan power