CFD Analysis for The Effect of Personal Ventilation Combined with Mixing Ventilation on Performance Index (ADPI) and Thermal Human Comfort

Abstract

Good indoor air quality and ideal thermal comfort are very important indicators for the comfort of occupant’s space. The Iraqi climate is hot dry in summer, so the use of air conditioners is indispensable. This work focuses on solving the IAQ problems in office room environments, and it evaluated a new principle of ventilation which is combined personal and mixing ventilation systems. Personal and mixing ventilation system can provide individual control of indoor climate. The airflow motion and distribution of temperature investigated numerically with the best flow rate from combined system. CFD study is used for simulation the indoor airflow and temperature distribution by using (AIRPAK3.0.16) for solving the turbulence equations, Naiver-Stocks, energy equations, and using (FVM). The Renormalization Group RNG K-Ɛ turbulence model was used for simulation this study cases, the airflow rate from ATD was 5 l/s and 10 l/s. For mixing ventilation supply temperature of 17°C and The temperature of the supplied air from the personal ventilation system ranges from (17 to 23) °C, it was found that if using personal ventilation system at airflow rate of 10 l / s it would improve the quality of the inhaled air present in the breathing zone. The personal and mixing ventilation system provides good human thermal comfort based on the values of effectiveness temperature (Ɛt) and air distribution performance index (ADPI) which give (1.241) and (63.226%) respectively. The increased airflow rate from (ATD) leads to a decrease in the temperature in the breathing zone, this increases the human thermal comfort of the occupants inside the room.