Experimental Assessment of Temperature Distribution and Draught Discomfort for a Personalized CJV System

Thermal comfort and indoor air quality in the built environments are important issues that affect the occupants’ health and performance. Confluent Jets Ventilation (CJV) system is a new HVAC system that can reduce the energy consumption by performing a high indoor air quality for the occupants. This paper presents an experimental evaluation of an indoor environment that provides fresh air and thermal comfort for the occupants through a confluent jets ventilation system. The design of the nozzles for this system plays an important role in providing thermal comfort. In order to achieve more thermal satisfaction, two arrangements of nozzles were studied. In one case, a confluent jet with 4 rows of nozzles was experimentally investigated, and in the other case, the same system with 6 rows of nozzles was considered. Air temperature and velocity were measured at different horizontal distances from the mentioned system. The turbulence intensity and the draught rate were investigated at measured distances. At the distances of 0.54 m and further from the confluent jet, the air velocities were the same and about 0.4 m/s for both cases. Also, the turbulence intensity diagrams were similar and both had maximum points at the distance of 0.54 m, where the air velocities were decreased to the minimum value of 0.4 m/s. According to ASHRAE standards, the 6 rows confluent jets ventilation system provides more thermal satisfaction for the occupants as the draught rate is lower than 20% in the occupied zone, compared with the 4 rows system.

Keywords:

Confluent jets ventilation system , Turbulence intensity , Draught rate , Thermal comfort , Personalized ventilation system