Thermal sensation and occupancy-based cooperative control method for multi-zone VAV air-conditioning systems

Abstract

Most existing multi-zone variable air volume (VAV) air-conditioning systems rely on manual adjustment or a constant temperature set point, with no consideration for users' thermal sensation. VAV terminals operate regardless of whether there is a demand for cooling in the zone, rather than according to the actual occupancy situation between multiple zones, resulting in poor indoor thermal comfort and the high energy consumption of air-conditioning systems. This paper proposes a thermal sensation and occupancy-based cooperative control (TSOCC) method for multi-zone VAV air-conditioning systems in order to provide an indoor thermal environment more in line with the real-time needs of personnel, while also increasing cooperative control between multiple zones to ensure that VAV terminals do not operate unnecessarily when zones are unoccupied. To evaluate the control performance of this method, a simulation platform is built, case simulations with different zone occupancy rates are carried out and various comparisons and analyses are made with temperature set point-based control. The results show that the TSOCC method for multi-zone VAV air-conditioning systems can provide an indoor thermal environment more in line with the thermal comfort needs of the personnel and save 6–14% of daily system energy consumption compared with the temperature set point-based control strategy, while the system's energy-saving rate increases as the zone occupancy rate decreases, marking a change from whole zone-oriented cooling to zone-oriented cooling and providing more accurate air-conditioning services for indoor personnel.