Effect of opening diffuser and return vent location on air quality, thermal comfort and energy saving in desk displacement ventilation (DDV) system

Recently, many investigations have been performed on return vent height; showing that the height of ۱.۳ m from the floor is the best height for this vent. In this article, the effect of distance between opening diffuser and return vent was investigated on air quality, thermal comfort and energy saving. The results showed, by increasing the distance between opening and return vent up to ۵ m, the return vent could be placed near the floor at height of ۰.۶ m without any unacceptable result in indices. Therefore in this case, energy saving of ۱۵.۸% could be achieved rather than ۸%, ۱۰.۹% and ۱۵.۲% in other cases. But, the air quality was lower than other cases. The case which brought better air quality and more thermal comfort with acceptable energy saving of ۱۵.۲%, was when the opening and return vent were relocated at maximum distance between them (۵ meters) and return vent was placed at the suggested height of ۱.۳ m from the floor, which was the optimum case in this research.

Keywords:

Displacement ventilation , Air quality , Thermal comfort , Energy saving , Desk Displacement Ventilation