Performance adaptability of heating terminals across varying heating loads: From an occupant-centric perspective

Occupant-centric part-time-local-space (PTLS) heating mode plays a critical role in reducing building energy consumption and enhancing comfort. However, the heating load significantly influences the dynamic environmental spatial distribution in PTLS mode, directly impacting occupant thermal comfort and energy utilization, yet quantitative analysis remains limited. Moreover, the performance adaptability of heating terminals also varies due to differences in heating mechanisms. Therefore, a comprehensive evaluation of terminal space heating alignment with occupant demand across multiple load conditions is essential for developing a clearer theoretical framework for PTLS heating. This study presented a comparative assessment of three representative terminals under varying load conditions from an occupant-centric perspective. An occupant-location-based evaluation method was employed to explore the temporal-spatial matching coefficients of indoor environment with occupant demand. Terminal heat consumption and entransy were analyzed to reflect both the heat quantity and quality dissipation for PTLS mode. Additionally, the impacts of convective and radiative features of terminals on mitigating the effects of load variations on heating performance were also examined. Results suggest that the increased heating load had a greater impact on the spatial matching coefficients of convective terminals with the heat consumption ratio rising by 38.5%, whereas it had a more pronounced increase in the heat source grade demand of radiative terminals (41.7%). The “convection first, then radiation” strategy with optimized airflow demonstrated effective potential for achieving demand-matched heating and maintaining consistent performance with load variations.