Coupled thermal comfort control of thermal condition profile of air distribution and thermal preferences

Air distribution is widely used for thermal comfort. Air distribution is inevitably non-uniform with some subzones in the occupied zone cooler than the others, and the thermal preferences of occupants are differentiated. Non-uniform air distribution may deteriorate thermal comfort because occupants with warmer thermal preferences might sit in cooler subzones. This study proposes to utilize the non-uniformity of air distribution to improve the satisfaction of thermal preferences by coupling the thermal condition profile of air distribution and thermal preferences. Firstly, the thermal condition profile is characterized by ranking the thermal conditions of the subzones from cool to warm using possibility analysis. Secondly, the thermal condition profile and thermal preferences are coupled sequentially, and the thermal conditions of the subzones are controlled to be as close to the respective thermal preferences as possible. The sequential coupling of the thermal condition profile and thermal preferences takes advantage of the non-uniformity of air distribution and the active role of occupants in improving thermal comfort. Thus, with the proposed method, the occupants with warmer thermal preferences sit in the warmer subzones, and their differentiated thermal preferences are maximally satisfied by the non-uniformity in air distribution. Based on the experiments in a classroom served by stratum ventilation, the proposed method is validated by 100,000 cases with different cooling loads and thermal preferences. Compared with the previous method which ignores the matching between the thermal condition profile and thermal preferences, the proposed method improves the satisfaction of thermal preferences by 40.1% on average.