Air flows between predominantly naturally ventilated rooms through partly open doors

Abstract

Flows around doors in partly open positions are measured in full-scale laboratory chambers and in site tests. Flows which are primarily temperature driven are measured using tracer gas techniques. Also investigated are the superimposed effects of mechanical ventilation in the laboratory tests and of wind and stack effects in the site tests. At small door opening positions, conventional buoyancy theory can be applied to estimate the two-way flow generated by temperature difference. Combined temperature and pressure driven flows can be analysed within ±20% by superimposing the respective theories. Room air movement plays an important part, giving rise to relatively high superimposed flows. For this reason, back-flow is almost inevitable when the door is not properly closed.