Experimental study on human comfort responses after simulated summer commutes with double transients of temperature and metabolic rate

摘要

? 2022 Elsevier LtdIn summer, when people arrive indoors after commuting, they will experience transients in metabolic rate and environment temperature. This makes the occupants who just arrive indoors feel too warm and uncomfortable at neutral temperatures. Therefore, it is necessary to study the thermal comfort requirements of human after commuting. Thirty subjects were asked to perform four levels of exercise (sedentary-SE, low speed-LS, medium speed-MS, high speed-HS) for 20 min at 25, 30 and 33 °C to simulate commuting activities, and then entered a temperature adjustable room to sit sedentary for 50 min. The physiological responses, human thermal responses, and environmental parameters corresponding to different experimental cases were studied to obtain the recovery time of the thermal neutral state and the optimal comfort temperature ranges. The results show that the average recovery time of physiological responses and human thermal responses was 38% lower than that in the room with the recommended temperature of 26 °C by subjects adjusting the indoor air temperature. Commuting activities significantly reduced the thermal neutral temperatures of subjects. For example, after exercising at 30 °C, the thermal neutral temperatures of SE, LS, MS, and HS were 24.6, 24.3, 23.8, and 22.8 °C, respectively. Within 50 min after exercising, the acceptable temperature range for 80% of the subjects in the states of SE, LS, MS, and HS was 24.6–27.3 °C, 24.3–27.1 °C, 23.8–26.0 °C, and 22.8–25.8 °C, respectively. This study provides references for enhancing occupants' satisfaction with thermal environments and optimizing the indoor environments.