On the temporal dimension of adaptive thermal comfort mechanisms in residential buildings

In response to the change of indoor thermal environment, building occupants constantly interact with the surrounding environment through various adaptive behaviours. The purpose of this study is to better understand the adaptive thermal comfort mechanisms by investigating the interrelationship between the expectation of the occupants (the psychological adaption), their behavioural adjustment (the physical adaption), and the indoor thermal environment in the context of residential buildings. Eleven households in South Korea participated in this longitudinal field study carried out between 2015 and 2017. The indoor thermal environmental parameters, the occupant subjective evaluations of thermal comfort, and their adaptive behaviour pattern were monitored. On average, 1,512 datasets from each household and a total of 16,632 datasets were collected and analyzed. Our analysis focused on understanding both the temporal dimension (i.e. duration of thermal discomfort episodes) and the intensity of stimuli (i.e. deviation from the comfort zone) both before-and after the participants' decision on the use of air-conditioners. The study proposes the constructs of 'discomfort capacity' and 'comfort restoration' as multi-dimensional indices to better understand the triggering mechanisms for household air-conditioner usage. Using these indices, the study quantified householders' tolerance of thermal discomfort events before they resort to air-conditioning.