The Response of Human Thermal Sensation and Its Prediction to Temperature Step-Change (Cool-Neutral-Cool)

Abstract

This paper reports on studies of the effect of temperature step-change (between a cool and a neutral environment) on human thermal sensation and skin temperature. Experiments with three temperature conditions were carried out in a climate chamber during the period in winter. Twelve subjects participated in the experiments simulating moving inside and outside of rooms or cabins with air conditioning. Skin temperatures and thermal sensation were recorded. Results showed overshoot and asymmetry of TSV due to the step-change. Skin temperature changed immediately when subjects entered a new environment. When moving into a neutral environment from cool, dynamic thermal sensation was in the thermal comfort zone and overshoot was not obvious. Air-conditioning in a transitional area should be considered to limit temperature difference to not more than 5°C to decrease the unacceptability of temperature step-change. The linear relationship between thermal sensation and skin temperature or gradient of skin temperature does not apply in a step-change environment. There is a significant linear correlation between TSV and Qloss in the transient environment. Heat loss from the human skin surface can be used to predict dynamic thermal sensation instead of the heat transfer of the whole human body.

Real-Time Monitoring of Occupants’ Thermal Comfort through Infrared Imaging: A Preliminary Study

“…All subjects followed the schedule depicted in Figure 4. The observed temperature step-changes, which can be found in many tests for thermal sensation and/or comfort evaluation in the literature [10,13,19,23,24], allowed us to monitor the initial adaptation to the new thermal environment in order to have transient periods together with periods of constant temperature. As tests were performed in the warmer part of the year, the subjects were asked to spend some time in the "cold chamber" prior to the test starting until they felt thermally comfortable.…”

“…Commonly, when the skin temperature is used as a parameter for the human thermal sensation and comfort estimation, thermocouples [9,10,24], infrared cameras or thermometers are used [12,16,19]. However, thermocouples are an invasive approach for an everyday application.…”

Effect of Transient Changes of Air Temperature on Subjective Response of Office Worker in Tropical Country (Case Study: Jakarta, Indonesia)

“…Basically, thermal condition of Vt2 and Vt3 were relatively similar, but overshoot response on Vt3 were observed, especially on transient state participant of Office A. This non-uniform sensation is also observed in [11], explained that subjects who returned to the same cool room after exposed to comfortable temperature voted the more extreme response. As found in current study, thermal comfort would be lower than the response on before temperature step changes.…”

“…Du et al [11] suggested to control the air temperature difference between two environments not to exceed 5 ∘ C during winter. Our finding shows significant decrease on thermal perception and arousal level after exposure of 8.49 ∘ C difference of air temperature, but not significant on 4.50 ∘ C. However, we could not suggest the range of acceptable air temperature difference for thermal perception and arousal level since this study only examined two thermal conditions.…”

Effects of temperature steps on human health and thermal comfort

“…Zhang revealed that both skin temperature and its change rate over time had significant impact on thermal sensation [8]. Liu and Du implied heat loss from skin surface could be used as an index to predict thermal comfort after temperature step changes [9,10].…”