Performance on heating human body of an optimised radiant-convective combined personal electric heater

Abstract

In this study, we developed an optimised radiant-convective combined personal electric heater, considering the limitations of traditional personal heaters that heat the human body through heat transfer of single convection or single radiation. Based on human participant experiments in simulated environments, the heating performance of the optimised personal heater on the human body was tested. The initial indoor air temperature in the experimental room was set to 14 °C. Twenty-four healthy young college students, including 12 males and females, were recruited as participants. They were required to experience three types of personal heaters in a sitting position: optimised combined personal heater (PHSR + C), convective personal heater (PHSC), and radiant personal heater (PHSR). During the 80-min-long experiment, their subjective ratings of thermal comfort, perceived air quality, sweating sensation, air movement sensation, and sick building syndrome were collected using questionnaires, and physiological parameters, such as skin temperature, tympanic temperature, and heart rate, were measured. The obtained results showed that, compared with PHSC and PHSR, PHSR + C increased the overall thermal sensation more rapidly (0.083 scale/min), and maintained the human body at a warmer condition. Moreover, when using PHSR + C, mean skin temperature and its change rate, and the thermal sensation vote of all local body parts were higher. The results indicate that the heating performance of this newly developed combined personal heater surpassed that of the two traditional types. Moreover, compared to using PHSC and PHSR, over 27% of the energy consumption was saved using PHSR + C.