Effect of Window Characteristics on Indoor Air Quality in Residential Housing

With serious energy crisis and high demand for Indoor Air Quality (IAQ), natural ventilation has taken more and more attention, which is recognized to be an effective and economic method to decrease the risk of Sick Building Syndrome (SBS), as well as reducing air-conditioning opening time, and thus saving energy. In view of window´s characteristics having a great effect on ventilation, the paper discussed the influence of air inlet window type and area ratio of open window to floor on indoor steady-state contamination of CO₂ and steady-state time. In addition, for tilt, hopper or grille window, the larger opening angle, the better ventilation performance, yet once over 30deg, its influence on steady-state contamination became unobvious, so, the paper only discussed the situation with opening angle 30deg, inside. And to calculate more accurately and quickly, as well as conveniently and cost effectively, CFD model was used, which was firstly validated by experiment, good agreement in between, with absolute error in simulation 9.2%. Then, combined with the measured outdoor weather data in Tianjin, the results were obtained, push-pull window was the preferred window type, lower indoor average steady-state contamination of CO₂ and shorter steady-state time, 550 ppm and 6.5 min, with area ratio of open window to floor beta 5%. Moreover, on this basis, the optimal area ratio of open window to floor beta for push-pull window was studied, which was proposed to be or larger than 10%.