Thermal comfort benefits, energy efficiency, and occupant regulation behaviour in four types of personal heating within the built environment

Abstract

The conventional approach to creating a uniform and stable thermal environment cannot guarantee the required thermal satisfaction rate and consumes significant energy. Personal comfort systems (PCS) offer a promising solution for office buildings. However, practical guidelines for selecting and operating PCS based on current studies remain elusive. In this study, 28 male participants were exposed to three cold conditions (16, 18, and 20 °C) and separately used four personal heating devices (PHDs): a warm air blower (WB), heated table mat (HM), heated cushion (HC), and leg warmer (LW). Variations in the subjective perception, skin temperature, heating setting adjustments, and operating parameters were monitored. The best improvements in overall thermal sensation under 16, 18, and 20 °C were achieved by HC (ΔOTSV = 0.97), WB (ΔOTSV = 0.85), and HM (ΔOTSV = 0.57), respectively. The energy consumption required to achieve the same thermal comfort benefit differed among the four PHDs. The corrective energy and power of WB, LW, HM, and HC were 64.0 W/K, 42.0 W/K, 14.0 W/K, and 7.9 W/K at 16 °C, respectively. The relationships between the overall thermal benefits of four devices and operating parameters were established to obtain the lower thresholds and suggested values of the heating parameters under different cold conditions. Advice on the automatic control for PHDs was proposed, including the limited air temperature for activation authority, activation priority order in the multi-device scenario, and initial heating settings. Integrating automated PCS with existing building management systems can achieve microenvironmental management, enhancing comfort and energy conservation.