Improving Buildings Thermal Comfort by Modifying HVAC Systems Terminal Units

This work presents numerical study using the computational fluid dynamics (CFD) simulations, employing the commercial ANSYS Fluent software. Aiming to improve the occupants’ thermal comfort in building environment by modifying heating, ventilation and air conditioning (HVAC) systems terminal units. Evaluating and comparing the airflow characteristics and occupant’s thermal comfort inside an office room, occupied by multi-cone ceiling air diffuser, which will be referred to CD. Then using the same air diffuser occupied with inclined undulated fins called inserted lobes, this diffuser is referred to LD. The thermal comfort was assessed in terms of percentage of dissatisfaction (PD) and draft rate (DR) indices. The optimal mesh density was selected after testing four different mesh densities. This numerical study was validated using SST k-w turbulent model. The results showed a reduction in air velocity and noticeable improvement in thermal comfort after inserting the inserted lobes by 20% and 5% in terms of PD and DR.