Effect of Exposure Time on Thermal Behaviour: A Psychophysiological Approach

Abstract

This paper presents the findings of a 6-week long, five-participant experiment in a controlled climate chamber. The experiment was designed to understand the effect of time on thermal behaviour, electrodermal activity (EDA) and the adaptive behavior of occupants in response to a thermal non-uniform indoor environment were continuously logged. The results of the 150 h-long longitudinal study suggested a significant difference in tonic EDA levels between “morning” and “afternoon” clusters although the environmental parameters were the same, suggesting a change in the human body’s thermal reception over time. The correlation of the EDA and temperature was greater for the afternoon cluster (r = 0.449, p < 0.001) in relation to the morning cluster (r = 0.332, p < 0.001). These findings showed a strong temporal dependency of the skin conductance level of the EDA to the operative temperature, following the person’s circadian rhythm. Even further, based on the person’s chronotype, the beginning of the “afternoon” cluster was observed to have shifted according to the person’s circadian rhythm. Furthermore, the study is able to show how the body reacts differently under the same PMV values, both within and between subjects; pointing to the lack of temporal parameter in the PMV model.

Mitigating climate change through healthy discomfort

“…[28] While it is nearly impossible to quantify thermal comfort as it is an abstract concept of various parameters, it is possible to objectively measure and compare the ANS responses to environmental stressors. [29] As stress is a measure of how much the body is working it can also indicate its long-term wear and tear effects on the persons health. [30] While the relation between stress and health has been ongoing research for many decades in the fields of medicine, neurology, physiology, psychology, etc.…”

“…Or in other words, while too much stress is not so good for our health, neither is too much comfort. As this seems to be closely related to the temporal dimension of thermal stress, the physiological reaction of the body depends highly on the time of exposure as well as the time of the day [29]. As the human body follows a circadian rhythm, it will tend to react more strongly to heat in the afternoon as it will in the morning.…”

“…As the human body follows a circadian rhythm, it will tend to react more strongly to heat in the afternoon as it will in the morning. [29,35,36] Even though there is more research needed to understand the boundary conditions of such healthy temperature fluctuations, it is vital to address the accompanying standards. Kramer et al (2016) were able to calculate a 63% reduction of a museum's total energy demand with an increase of ± 1°C temperature fluctuation compared to the current uniform conditioning.…”

Towards a multivariate time-series approach with biosignal datasets for the global thermal comfort database

“…Together with this, it is plausible to assume that data collection periods will easily be much longer, considering the ease of it. An example from a recent work recorded climate and connected biosignal data from 5 participants, over 35 hours per subject (Kobas, Koth, Nkurikiyeyezu, et al, 2021). The resolution of environmental and behavioural data was matched to EDA data, sampled at 4 Hz.…”

“…With the availability of these devices, several researchers have gone in the direction of collecting physiological data, to find correlations between psychologically driven responses and physiological requirements. Several publications have already attempted to create models to correlate biosignal data to survey responses (Kobas, Koth, Nkurikiyeyezu, et al, 2021;Lu et al, 2019;Nkurikiyeyezu et al, 2018;Wang et al, 2019). As a principle, the data collection in thermal comfortrelated studies includes data from the following domains: 1.…”