ventilation

Reviews the main mechanisms giving rise to natural ventilation of spaces with openings to outside air on one wall only. These are temperature difference, pressure fluctuation, mean pressure difference, turbulent diffusion and the "vane" effect. Derives expressions for the magnitude of the ventilation rates caused by each of these mechanisms. Reports wind tunnel studies of the ventilation rate in a small test chamber ventilated through one opening only. Air change rates were measured using a tracer gas.

Presents calculations of mean temperatures and relative humidities , shown graphically for three typical housing types assuming different heat and moisture inputs: 1) whole house uniformly heated with moisture from household activities uniformly distributed; 2) kitchen at constant temperature with high moisture emission rate; 3) unheated bedroom with two occupants assumed to be in thermalequilibrium with a room below at 15 c. Concludes that there is a certain critical amount of heat needed to give a relative humidity of less than 70% and thus avoid the danger of mould growth .