Thermal comfort performance and energy-efficiency evaluation of six personal heating/cooling devices

Personal Comfort Systems (PCS) have the potential to improve individual thermal satisfaction and reduce energy consumption in buildings, but guidance on their application is still lacking. This study aims to evaluate and compare the thermal comfort effectiveness and energy consumption of six different personal heating/cooling devices (including warm air blower, electric radiant heater, heated cushion, desk fan, floor fan, and ventilated cushion). Twenty-eight college students were recruited to use the heating/cooling devices under cold (18 °C) and hot (32 °C) conditions, respectively. The results showed that all three heating devices improved subjects' average thermal sensation from cool (−1.96) to neutral (−0.18 – 0.09) under cold condition, while their energy efficiency varied greatly. The warm air blower (420.0 W) and electric radiant heater (630.1 W) consumed significantly more energy than the heated cushion (43.0 W). 67.8% of the subjects chose the heated cushion as their most preferred heating device. Under hot condition, the desk fan and floor fan increased subjects’ thermal acceptability to more than 80%, while ventilated cushion with a maximum airflow rate of 16.5 L/s cannot correct human thermal comfort. All cooling devices based on fans were available with small electric power (3.3–29.9 W). Most subjects (60.7%) preferred the floor fan among the three cooling devices. The advantages and disadvantages of each device perceived by the subjects were also investigated through interviews. This work can help researchers further understand the differences between different PCS devices, and guide the optimization and application of PCS devices.