A Comparative Study of Performance Between Two Combined Ventilation Systems and Their Effect On Indoor Air Quality and Thermal Comfort Inside Office Rooms

The most important problems that must be solved and improved in ventilation research are indoor air quality and thermal comfort. The Iraqi climate is characterized by being very hot and dry, so fresh cold air must be provided to the occupants of offices, factories, workshops and others to improve thermal comfort and increase their efficiency. This study focused on improving the quality of inhaled air by using two types of ventilation systems (mixing and displacement ventilation) in combined with a personal ventilation system. This study was a set of numerical tests that were conducted to predict the temperature distribution, air movement and speed inside a closed office room subject to the Iraqi climate in terms of weather conditions. This numerical study was carried out using (AIRPAK3.0.16) which is used to solve turbulence equations, Naiver stock, energy equations, and use of (FVM). A thermally isolated room was simulated with a personal ventilation system that supplies air at temperatures from 21 to 23 °C for case I (personal and mixing) and supplies air at a temperature from 18 to 20 °C for case II (personal and displacement) the air velocity for both cases was 0.6 m/s. It was found that there was a positive effect of the personal ventilation system in both cases, but its effect was more pronounced in the first case, through numerical calculations for each of the effectiveness of heat removal (εt) and air distribution performance index (ADPI), where (74.361) and (1.549) were found for the first case, and (68.321) and (1.71) for the second case.