Description

Displacement Ventilation (DV) is an air distribution method recognized to enhance indoor air quality, while having a potential for energy savings due to stratification, higher supply air temperature and opportunity of free cooling. Local discomfort such as draft or excessive temperature difference between head and ankle are common complaints associated with DV. In order to understand and prevent the local discomfort, complete assessment of the air velocity and temperature in the DV jet is required. In this experimental study, the air velocity and temperature fields produced by a wall-mounted DV air diffuser are measured in three perpendicular planes. Measurements are performed at heights of 0.02 m to 0.26 m (0.8 in to 10.2 in) above the floor, in the vertical longitudinal plan through the center of the diffuser, in the vertical transversal plan at 2.16 m (8.5 ft) from the diffuser, and in the horizontal plane at 0.05 m (2 in) above the floor. The supplied air temperature used, five degrees Celsius lower than the room temperature, is representative of supply conditions likely to be used in cold climates. The air velocity in the DV jet was found to vary significantly with the distance from the diffuser, with the distance from the central axis, and with the height inside the jet. The air temperature in the jet was found to vary significantly with the distance from the diffuser, and to a lesser extent with the distance from the central axis or with the height. Using vertical air temperature difference as an indicator of local discomfort, we found that indoor conditions are comfortable throughout the secondary zone.

Citation: ASHRAE Conference Papers, Montreal, QC

Product Details

Published:

2011

Number of Pages:

8

File Size:

1 file , 1.2 MB

Product Code(s):

D-ML-11-C025