The impact of draught related to air velocity, air temperature and workload

This experimental study was designed to test the hypotheses that the effect s of draught increase with higher air velocity, with lower air temperature, and with lower workload. Thirty healthy young males were exposed to horizo ntal draught during 55 min while they operated an arm ergometer in a standi ng posture. Air velocity, air temperature, and workload were varied in 3 st eps each, between 11 and 23 degreesC, 0.1 and 0.3 m/s, and 104 to 156 W/m(2 ), respectively. The 27 combinations were distributed over subjects in a fr actional factorial 3(3)-design. The participants were clothed for thermal n eutrality. Workload was measured at the end of the sessions by respirometry . Draught-induced annoyance was determined every 5 min, separately for 10 b ody sites. Corresponding skin temperature was also recorded. The hypotheses were verified for the influence of air velocity and air temp erature. Regarding workload, local heat production is probably decisive, me aning that draft-induced local annoyance is inversely related to workload i n active but independent from workload in non-active body areas. To improve the situation for the workers concerned it is suggested to apply protectiv e gloves that cover an as great area of the forearms as possible and to lim it airflows to mean velocities of less than 0.2m/s (with turbulence intensi ties of 50 %). (C) 2001 Elsevier Science Ltd. All rights reserved.