Comfort cooling by wind towers in the Australian residential context – Experimental wind tunnel study of comfort

Abstract

Comfort performance of a wind tower in a residential setting was evaluated in a series of wind tunnel experiments using a sealed, four storey apartment building model at 1:100 scale. This study was structured into three phases; first, the pressure distribution over the wind tower openings and the building fenestrations were measured in a boundary layer wind tunnel. From these data, internal bulk flow air change rates and mean indoor room air speeds were derived. Second, the pressure coefficient results of the first phase were applied to the Sydney Typical Meteorological Year (TMY) to assess the ventilation performance of the wind tower in terms of hourly indoor air speed. Wind tower results were benchmarked against through-window cross ventilation. In the third phase, increased indoor air speeds under wind tower ventilation were processed through the Standard Effective Temperature (SET*) comfort model to compute the additional comfort degree hours resulting from inclusion of a wind tower. Results indicate that the wind tower reduced indoor SET* values by an average 3.2 ​°C relative to conventional through-window cross-ventilation during Sydney’s summer when outdoor temperatures were warmer than neutral.