Adaptability law of central heating environment under the effect of thermal history: A continuous field survey

Creating an optimal indoor thermal environment that meets the needs of diverse populations is a crucial aspect of building design. Given the escalating frequency of population migration and the widespread adoption of centralized heating systems, it is important to establish the effects of various prior thermal histories on human adaptability to centralized heating environments. In this study, 15 subjects with no prior experience of heating in hot summer and cold winter regions (HSCW) and 13 subjects with prior experience of heating in cold regions (C) were selected for a 40-day follow-up study at a university in Qingdao. In total, 992 valid responses were obtained from the questionnaires. The results indicated that prior thermal history had a notable influence on thermal perception in centrally heated environments, with those lacking heating experience reflecting a better initial perception of heat. Specifically, in a classroom environment, the differences between the two groups, in terms of thermal sensation, thermal acceptability (percentage of acceptance), and thermal expectation (percentage of desiring "warmer") decreased from 0.26, 12%, and 19% in the first cycle to 0.03, 2%, and 3% in the fourth cycle (25-32 days), respectively. The difference in thermal comfort also reduced from 0.23 in the second cycle (9-16 days) to 0.04. Similar trends were observed in the dormitory environment, indicating that the duration of the impact of heat experience on adaptation to the centrally heated environment was 32 days. The results of this study are useful for describing the dynamic thermal acclimatization of different populations in unfamiliar thermal environments and for providing indoor thermal environments that match the thermal preferences of residents with different thermal experiences.