Thermal comfort assessment in chilled ceiling and displacement ventilation environments.

The use of air-conditioning is known to be an energy-intensive solution to the problem of providing thermally comfortable conditions in buildings. This has led to the adoption of new techniques, such as displacement ventilation and chilled ceiling systems as a means for providing the cooling requirements. In addition, benefits are gained in terms of indoor air quality and comfort. However, there is a lack of information about the effect that chilled ceiling has on displacement air flow, and the corresponding implications for occupant thermal comfort. The thermal comfort of 128 test subjects (64 male, 64 female) was then measured in a test room over a range of ceiling temperatures. Vertical radiant asymmetry was found to have an insignificant effect on thermal comfort of the seated occupants for ceiling temperatures ranges from 12 C to 22 C. However, ceiling temperature was found to have an effect on the freshness vote. Furthermore, the Fanger thermal comfort model is shown to be capable of predicting the PMV of subjects in such environments.