Experimental Investigation of the Effects of Non-Uniform Clothing Ensembles on the Occupants’ Thermal Perceptions under a Local Ventilation System

This paper presents an experimental study that evaluated the effects of three different non-uniform types of clothing ensembles (Type A: short-sleeve shirt, T-shirt underwear, men’s briefs, straight trousers, socks, shoes; Type B: long-sleeve shirt, T-shirt underwear, men’s briefs, straight trousers; and Type C: long-sleeve shirt, men’s briefs, straight trousers, thick socks, shoes) with almost the same thermal insulation (about 0.52 clo) on the subjects’ local and overall thermal sensation and air movement preference under a desktop local ventilation system. The experiment was conducted in a test chamber with the mean air temperature of 2 4 ± 0 . 5 ∘ C and under three supply air temperatures of 1 6 ∘ C, 2 4 ∘ C, and 3 2 ∘ C from a desktop ventilation system. The results revealed that the body segments with the most critical thermal sensation were (i) forearms, hands and arms for the subjects with “A type” clothing ensemble, (ii) feet, hands and forearms for the subjects with “B type” clothing ensemble, and (iii) hands, arms, forearms and chest for the subjects that wore “C type” clothing ensemble. For the three clothing types of “A”, “B” and “C”, the values of overall thermal sensation changed from − 0.63, − 1.25, and − 1.13 at 1 6 ∘ C to − 0.31, − 0.31, and − 0.38 at 3 2 ∘ C inlet temperature, respectively. Also, the results indicated that upon elevation of the inlet air temperature from 1 6 ∘ C to 3 2 ∘ C, the percentages of the subjects who preferred less air movement dropped from 63%, 63%, and 50% to 38%, 25%, and 38%, respectively, for wearing “A”, “B” and “C” clothing ensembles.