Numerical Investigation of Sample Room Ventilation and Presenting Solution to Overcome Downdraught Effects Adjacent to the Large Windows

In this study, the effect of warm air blowers on suppressing of heat losses and also downdraught for the buildings with exterior large windows was analyzed and compared. The air ducts were mounted at different locations besides the window at floor plenum, ceiling plenum and side walls. The simulation of flow and temperature fields for a two-person office room was carried out through computation fluid dynamic method. The thermal performance of these systems and analysis of thermal comfort were simultaneously accomplished based on ISO 7730 and ASHRAE standards. The inlet air temperature ranged 22-26°C for the three systems and the results were compared. The results show that the comfort air temperature was almost uniformly distributed the entire room for the systems with air ducts at floor and ceiling plenum. Also, the values of PMV and PPD for this system were lower than 15% in the occupied region.