Effect of Velocity and Direction of Airflow on Thermal Comfort and Energy Consumption: Case of New Exclusive Cooling Systems

The application of personalized ventilation systems, particularly in the buildings, is one of the new topics that today presented to it, because of their proper performance in reducing energy consumption and creating better thermal comfort conditions. In the current study, the energy consumption of a personalized cooling system installed in a room, considering the constraint of thermal comfort, was evaluated and compared with a non-personalized cooling system. The dimensions of the room equal to 4×3×2.7 m3 and includes a return air outlet (for both personalized and non-personalized situations), a supply air inlet in a non-personalized situation, two air inlets for personalized ventilation, table, chair and an approximate model of a human. OpenFOAM numerical solver was used for the calculation and solving the governing equations. Results indicate that in the status of the use of the personalized cooling system, Predicted Mean Vote (PMV) changes in the presence of the person is much higher than the status of the use of the non-personalized cooling system. The local thermal discomfort parameter stemming from draught is within allowed range (less than %20) for a personalized cooling system, excluding of in velocity of 2 m/s and temperature of 21.1 °C. The other important result is that the energy consumption of the personalized cooling system reported much less than the non-personalized cooling system so that energy saving was achieved in about 50 percent. In personalized cooling mode, desired conditions of thermal comfort and minimum energy consumption obtained only at the velocity of 1 m/s and temperature of 20.5 °C among the cases investigated