skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Spot cooling. Part 1: Human responses to cooling with air jets

Conference ·
OSTI ID:33269
; ; ;  [1]
  1. Technical Univ. of Denmark, Lyngby (Denmark). Lab. of Heating and Air Conditioning

Eight standing male subjects and a thermal manikin were studied for thermal, physiological, and subjective responses to cooling with an air jet at room temperatures of 28 C, 33 C, and 38 C and a constant relative humidity of 50%. The subjects wore a standard uniform and performed light work. A vertical jet and a horizontal jet were employed The target area of the jet, i.e., the cross section of the jet where it first met the subject, had a diameter of 0.4 m and was located 0.5 m from the outlet. Experiments were performed at average temperatures at the jet target area of 20 C, 24 C, and 28 C. Each experiment lasted 190 minutes and was performed with three average velocities at the target area: 1 and 2 m/s and the preferred velocity selected by the subjects. The impact of the relative humidity of the room air, the jet`s turbulence intensity, and the use of a helmet on the physiological and subjective responses of the eight subjects was also studied The responses of the eight subjects were compared with the responses of a group of 29 subjects. The spot cooling improved the thermal conditions of the occupants. The average general thermal sensation for the eight subjects was linearly correlated to the average mean skin temperature and the average sweat rate. An average mean skin temperature of 33 C and an average sweat rate of 33 g{center_dot}h{sup {minus}1} m{sup {minus}2} were found to correspond to a neutral thermal sensation. The local thermal sensation at the neck and at the arm exposed to the cooling jet was found to be a function of the room air temperature and the local air velocity and temperature of the jet. The turbulence intensity of the cooling jet and the humidity of the room air had no impact on the subjects` physiological and subjective responses. Large individual differences were observed in the evaluation of the environment and in the air velocity preferred by the subjects.

OSTI ID:
33269
Report Number(s):
CONF-9406105-; TRN: IM9518%%90
Resource Relation:
Conference: 1994 American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) annual meeting, Orlando, FL (United States), 25-29 Jun 1994; Other Information: PBD: 1994; Related Information: Is Part Of ASHRAE transactions 1994: Technical and symposium papers. Volume 100, Part 2; PB: 1372 p.
Country of Publication:
United States
Language:
English