Energy efficiency and thermal comfort characteristics of convection–radiation combined cooling system in office buildings

In this study, the thermal comfort and energy consumption of two different terminal units when combined with three different water supply temperatures were studied. Results showed that convection–radiation combined cooling terminals can increase the water supply temperature under the same thermal comfort level compared with convection cooling terminals. When the water supply temperature was fixed at 11 °C, the energy consumption of convection–radiation combined cooling terminals was 9.1 % lower than that of convection cooling terminals. The higher the water supply temperature, the lower the energy consumption under convection–radiation combined cooling terminals. Furthermore, the energy consumption rates at a water supply temperature of 15 °C were 18.2 % and 8.8 % lower than those at 7 °C and 11 °C, respectively. Meanwhile, the comfort and system operation efficiency were optimal when the water supply temperature was 15 °C, and the energy consumption was lower when combined with the cooling of the dual terminals.