Thermal comfort study on vertical air temperature gradient with displacement ventilation system in the tropics

The aim of that study is to explore the influence of vertical air temperature gradient and room air temperature (at 0.6 m height) on overall and local thermal comfort of 30 tropically acclimatized subjects in a room served by Displacement Ventilation (DV) system.
The 30 subjects were exposed to 3 levels of vertical air temperature gradient, and 3 room air temperatures, at the height of 0.6 m. It appears that temperature gradient had different influence on thermal comfort at different room temperatures and that room temperature had greater influence on thermal comfort than temperature radient.