Reports measurements of the wake flows behind solid and porous fences, made with a pulsed wire anemometer (PWA) and a hot-wire anemometer (HWA). Discusses results which show the superiority of PWA in correctly measuring the highly turbulent and sometimes re-circulating wake flows. Gives empirical formula for profile of the velocity defect and shear stress perturbations. Concludes that porosity, and not the form of construction of thefence, determines the structure of the wake flow. States that in general it is difficult to say which value of porosity provides the best shelter.
Reports study of the aerodynamics of wind breaks in a boundary layer wind tunnel. Describes flow patterns and shelter effects in the lee of different fences and discusses efficiency of shelters in relation to pedestrian comfort. Gives results downstream in horizontal planes by nets of isocurves showing mean speed and turbulence. Discusses the influence of permeability, shape, size and wake ventilation and suggests new designs: for example two wind breaks in series.
Discusses in detail a general ventilation model, which relates indoor pollutant concentrations to those outside. When the time interval associated with changes in the outdoor concentration islong compared to that required either to change the air within the building or to remove the pollutant by internal means, the indoor concentration of pollutant can be related to the outdoor concentration by means of a simple expression. Finds good agreement between theory and experiment. Suggests method for reducing indoor ozone levels in California.
Reports study of indoor climate-primarily air quality-and energy consumption in a number of detached houses in a group housing area. All the houses were pressure-tested over three years; 1977-1980 and a relatively larger increase in air leakage was measured after the houses had been occupied for approximately one year. Suggests this is due to the drying out of timber, producing cracks. Two types of houses, a and b were investigated when studying indoor climate. both were mechanically ventilated.
Gives preliminary report of a study of natural ventilation and energy consumption in low-cost housing. The study includes the measurement of infiltration rates using tracer gas, pressure differences across outside walls, indoor and outdoor temperatures, air tightness of external walls and the position of windows and doors. Outlines future studies and gives preliminary conclusion that making houses more air tight can save energy.
Considers the rate of natural ventilation required in a room to maintain a healthy concentration of oxygen given the efficient sealing of windows against draughts. Includes a nomogram toassist the calculation of a rate of air introduction according to the height of the building, wind loads, and type of window construction.
Reports on a project to assess the air infiltration performance of new residential windows and compare field test results with anticipated performance. Supporting tests and techniques included air leakage tests of windows in the factory, leakage testing of the window/wall installation crack and infrared thermography of test conditions. Tests were also run to determine performance of new windows during cold weather, the possible change in performance over time, the performance of fixed sash and of old and retrofit windows. Presents results of pilot study.
Gives instructions for constructing a super-insulated house. Describes installing insulation, vapour barriers, shutters and an air-to-air heat exchangers. Outlines ways in which heat islost from a house and the problems of conventional structures.
Gives regulations and performance guidelines for the ventilation of buildings. Includes guidelines for air quality and gives recommended supply and return air volumes for different rooms of a building.
Examines the influence of air movement on the thermal performance of the building envelope by identifying and discussing the mechanisms of 8 distinctive air movement paths. These are; convection from interior air to interior surface ; convecti
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