Effects of residential floor-level thermal environment on task performance via psychophysiological responses using multilevel structural equation modeling

The rapid adoption of remote working has increased the importance of indoor environmental quality (IEQ) in residential environments. However, the relationship between residential environments and remote working productivity remains under discussion. Exposure to cold indoor environments during winter may contribute to decreased productivity because discomfort and thermal stress can impair cognitive performance. Many previous studies have examined the direct relationship between IEQ and productivity in thermal comfort research, overlooking the stepwise influence of physiological and psychological responses. However, IEQ probably affects productivity through the physiological and psychological responses of workers. Therefore, this study examines the effects of residential floor-level thermal environment on task performance through psychophysiological responses using multilevel SEM. A controlled experiment was conducted with participants performing work tasks in either a convective air-conditioned room or a radiant floor-heated room. Physiological (foot skin temperature), psychological (thermal comfort and concentration), and task performance measures were collected and analyzed. Multilevel SEM revealed that radiant floor heating significantly increases foot skin temperature, which improves thermal comfort and perceived concentration. In addition, no differences were observed among conditions for simple tasks, such as typing, whereas improved physiological and psychological states positively affected performance on cognitively demanding creative tasks. The results underscore the critical role of floor-level thermal environments in supporting work-from-home productivity. By integrating multilevel SEM, this study advances the understanding of hierarchical human–environment interactions. The results suggest that incorporating radiant floor heating into residential design can improve both comfort and cognitive performance, contributing to home workspaces that are more comfortable and productive.