Local body skin temperature-driven thermal sensation predictive model for the occupant's optimum productivity

This study aims to understand the comprehensive relationship between indoor temperature, physiological signals, thermal sensation, and cognitive performance and estimate thermal sensation for optimum productivity. A series of human experiments were conducted with 48 participants, and local skin temperatures and thermal sensation data were collected in 6 temperatures. The participants took two cognitive performance tests, OSPAN (Operation Span Task) and Vigilance test, to quantify their productivity. This study found that relatively high skin temperature of specific local body spots (Arm, wrist _(back), wrist _(In), back, and neck) were correlated negatively with the occupant's cognitive performance. Also, there were significant differences by gender in cognitive performances and physiological signals in the same indoor temperature. The mean skin temperature differences between males and females of most local body spots were more significant in the high-performing group than the low-performing group for the vigilance test. Local skin temperature differences by gender were more significant in the vigilance test (response time) than the OSPAN (working memory). Additionally, gender and two local skin temperatures (wrist (back) and neck) were accountable to estimate thermal sensation for optimum productivity by utilizing the J48 decision tree algorithm. This study provides new insights that the occupant's local body skin temperatures are correlated significantly with the occupant's cognitive performance (response time and working memory) in different indoor temperature conditions, and a single or combined local skin temperatures can be used as a variable to estimate individualized thermal comfort for the occupant's optimum productivity.