The impact of personal environmental control on the performance of thermal systems: Building energy consumption, occupant thermal comfort, and productivity

Personal environmental control (PEC) is an energy-saving approach that empowers occupants with the freedom to regulate the indoor thermal environment, ensuring comfort while conserving energy by conditioning only the occupied space based on individual preferences. However, necessary information to support the practical application of PEC is still missing. Specifically, how the degree of freedom given to occupants changes the building energy efficiency, occupant thermal comfort, and productivity has not yet been investigated systematically. This research (i) investigates the application of PEC in existing thermal systems; (ii) examines the effects of PEC on the aforementioned three criteria for assessing the performance of thermal systems; and (iii) suggests an optimized thermal system incorporating the concept of PEC for a better performance of thermal systems. Primary data was collected by experimentation and observation among 21 participants under four different conditions in a field study in Hong Kong. Repeated measures ANOVA was applied in analyzing the thermal ratings, the energy consumption, and the productivity of participants. The outcome of this study shows that a higher PEC can only lead to marginal improvement of thermal comfort, but the building energy efficiency drops when they set the thermostat temperature themselves under a condition that they are given full control. No clear relationship is found in this study between the PEC and occupant productivity. As a pilot study to compare the performance of thermal systems under different PEC designs, this study contributes to the research field into a practical energy-efficient design of thermal systems by enhancing the occupants’ personal control of the thermal environment.