Evaluation of Natural Ventilation Performance in Providing Local Thermal Comfort and Indoor Air Quality in an Office Room

In this work, a natural ventilation system as an energy-efficient strategy is simulated to assess its performance in providing thermal comfort and indoor air quality in an office space. A three dimensional CFD model is implemented to predict temperature and velocity distribution in the space. Due to the presence of the openings and elevated air speed, a naturally ventilated space is considered as a non-uniform thermal environment. In such environments, the whole body thermal sensation is affected by local thermal sensation of different body parts. So, the CFD model is coupled with the standard thermal comfort model and the PMV and PPD indices are assessed at different heights according to ISO standard to evaluate the local thermal sensation of individual body parts. Afterward, the effects of outdoor air temperature as well as location and dimension of the openings are evaluated. The results show that in the outdoor temperature of ۲۴ ℃ and ۲۶ ℃, the PMV index is nearly between -۰.۷ and +۰.۷ and the PPD is less than ۱۵%, which are the recommended range considering the category C of ISO ۷۷۳۰. In addition, the best thermal comfort conditions are achieved by considering the openings with ۱۰% of the wall area.

کلیدواژه ها:

draught ، Indoor air quality ، natural ، Predicted mean votes ، Predicted percentage of dissatisfied ، Thermal sensation ، Ventilation