Effect of inlet/outlet on thermal performance of naturally ventilated building

Abstract

Abstract Ventilation is a way of improving the air quality of rooms by circulation. The position of the inlet and outlet greatly influences the thermal comfort. This attempt proposes to analyse the effect of the position of window openings for a room building with natural ventilation and the air flow and temperature distribution numerically using a commercial computational fluid dynamics (CFD) code. This proposed study consists of (i) approving the numerical model against experimental data gathered in an environment similar to the one used in simulations and (ii) applying the CFD model to explore the results of four varying configurations of ventilator on the natural ventilation system and thermal comfort. For the varying arrangements, the wind speed is 0.2 m⋅s−1 perpendicular to the openings for a wind, (iii) evaluating the comfort level utilizing the Air Diffusion Performance Index (ADPI) on the basis of ASHRAE 55-210 criteria. The obtained results show that the positions of outlet and inlet openings highly affect the performance in the thermal comfort while they have a trivial effect on the occupied zone mean velocity. The computational results showed that the two cases (a) and (b) present results very close to each other with a slight difference at the center of the chamber. Most of the calculated values (effective draft temperature, EDT) are between (−1.7 and 1.1). Then ADPI is over 70% for case (a) and over 75% for case (b), so all points they are located in the comfort zone. The results affirmed also that configuration with inlet openings set at 1.022 m above ground and an outlet opening set at 0.52 m brings about the most applicable solution ventilation efficiency and give the best EDT that fulfills the criteria of ASHRAE 55-210 with an ADPI of ~90%.