Showering thermal sensation in residential bathrooms

Abstract

The thermal energy consumed by showering to the satisfaction of the showering subject, is largely dependent on the water temperature, shower duration, water flow rate, and bathroom air temperature. A research gap, between human thermal preferences and the smart use of thermal energy in high-rise urban residential bathroom environments, has been identified. This study examines the influence of a bathroom’s thermal environment on the showering subject’s thermal sensation. Of the 98 invited respondents, a total of 31 volunteers (12 females and 19 males) participated in the showering experiments, under three thermal conditions (control, colder, and warmer); their subjective thermal responses, including thermal sensation, thermal comfort, and thermal acceptability votes, were recorded. The results showed a non-linear trend of thermal sensation vote (TSV) against the bathroom air temperature. The predicted dissatisfied (PD) was asymmetrical, and the showering subjects preferred a slightly warm environment. Although the female TSV values were more sensitive than the male ones, in both the colder and warmer experiments, there were no significant gender differences. The findings of this study—including the expressions derived from the shower-water and bathroom air temperatures for the thermal comfort zone in a bathroom environment—can be used as a reference to enhance our understanding of thermal energy consumption in environmental design, and to help optimize the thermal environment in bathrooms.