Localized thermal control for global impact: A meta-analytical review of thermal comfort and energy performance of personal comfort systems

Personal Comfort Systems (PCS) offer individualized thermal control that enhances occupant comfort, while reducing energy consumption in buildings. By enabling localized environmental adjustments without affecting other people, PCS present a promising strategy for energy-efficient building operation. Despite growing evidence of their benefits, a comprehensive synthesis of PCS performance, particularly regarding thermal comfort and energy outcomes, remains limited, hindering broader implementation. This meta-analysis evaluates 64 peer-reviewed studies to quantify the effectiveness of PCS. Findings indicate that PCS improve thermal sensation and overall comfort by an average of one scale unit. They also shift comfort temperature thresholds by 2.2°C, lower in heating and higher in cooling modes, allowing for expanded Heating, Ventilation and Air Conditioning (HVAC) setpoint ranges and associated energy savings. PCS demonstrate stronger corrective effects on perceived ambient temperature under both high and low thermal conditions compared to those within the comfort zone, with an average corrective energy power of 42.6 W/°C. Among heat transfer methods, conduction and hybrid approaches outperform others in both heating and cooling, while convection is found particularly effective in cooling scenarios. The study develops the Coefficient of Comfort Temperature Shift (CCTS), a metric for evaluating the performance of PCS in modifying comfort temperature thresholds. This metric supports HVAC setpoint optimization and offers practical pathways for energy savings. Overall, the findings position PCS as a viable solution for enhancing occupant comfort and reducing energy demand through individualized thermal control. By enabling precise microclimate adjustments, PCS contribute to sustainable building practices and occupant well-being, supporting global efforts toward energy-efficient built environments.