Experimental investigation of effect of inlet direction and height on flow pattern and thermal comfort conditions under personalized confluent jets ventilation system

In this study, the flow pattern, temperature distribution and thermal comfort index have been experimentally investigated in a room with personalized confluent jets ventilation (CJV) system for different diffusers’ heights of 30 and 160cm from the floor and for two inlet temperatures of 16 and 24°C and three different inlet angles of 0, 22.5 and 45 degrees. The results showed that the above cases can be significantly affected by changing in location of inlet diffuser. So that by placing the inlet diffuser at a height of 160 cm, the occupants’ upper body is strongly affected by the flow and the maximum air velocity in this region, depending on the change of inlet flow angle from zero to 45 degrees, can respectively reach about 1.5 to 1 m/s and this causes the draught dissatisfaction in the occupants’ upper body. However, by placing the diffuser under the desk and at a height of 30cm, the most dissatisfaction caused by draught occurs in the legs and feet. Finally, it can be concluded that the draught dissatisfaction is the most important factor that can limit the use of personalized confluent jets ventilation system.