Thermophysiological responses and thermal comfort of occupants in indoor spaces under different speaking and non-speaking conditions

Abstract

As speaking is one of the fundamental behaviours in human activities, understanding the thermal comfort of occupants during speaking is crucial to providing a satisfactory environment. To further strengthen this understanding and identify how occupant thermal responses change during speaking activities, this study performs an experiment to examine the thermophysiological parameters and thermal comfort of occupants across three different speaking and non-speaking conditions: (1) silent (i.e., non-speaking); (2) speech (i.e., continuous speaking); and (3) conversation (i.e., intermittent speaking). During the experiment, thermophysiological parameters, including skin temperature, electrodermal activity, and heart rate, were collected using smart wristbands from 30 subjects at three different temperature settings to represent three distinct thermal environmental conditions: (1) Cold: 20 °C; (2) Neutral: 24 °C; and (3) Hot: 28 °C. Subjects were also required to report their thermal comfort perceptions in terms of thermal sensation votes, thermal preference votes, and thermal satisfaction votes. Repeated measures ANOVA test and Friedman test were used to analyse the thermophysiological parameters and thermal comfort perceptions. The null hypothesis, which suggests no significant differences in thermal responses and comfort across the three speaking conditions, will be rejected at a significance level of 0.05 (two-tail). The results revealed significant differences in all three thermophysiological parameters between speaking conditions at all temperature settings, while the thermal comfort perception did not consistently show statistically significant differences between speaking conditions. The findings contribute to our understanding of the relationship between communication and thermal responses, highlighting the importance of contextual factors in designing comfortable environments for speaking-related activities.