Cooling effect of air movement on heating performances of advanced air distribution

The cooling effect of air movement is widely recognized as an energy-efficient measure for thermal environment management under the cooling mode, but it is generally neglected under the heating mode. This study proposes that the cooling effect of air movement negatively impacts the energy efficiency of advanced air distribution and should be considered when modulating advanced air distribution under the heating mode. Advanced air distribution like stratum ventilation and wall attachment ventilation supplies warm and clean air into the occupied zone by employing supply air momentum to suppress thermal buoyancy. However, the supply air momentum elevates the air movement in the occupied zone and the cooling effect of air movement negatively impacts the energy efficiency of advanced air distribution under the heating mode. Based on numerical simulations validated by the experiments, the results show the cooling effect of air movement significantly impacts the optimal operation, particularly the optimal supply airflow rate of stratum ventilation and the optimal supply air temperature of wall attachment ventilation. Accounting for the cooling effect of air movement can improve the optimal overall performance of advanced air distribution, particularly when the preference for energy efficiency increases. Compared with the optimization ignoring the cooling effect of air movement, the optimization considering the cooling effect of air movement improves the overall performance by up to 38.7% for stratum ventilation and up to 67.6% for wall attachment ventilation. Therefore, the cooling effect of air movement should be considered for modulating advanced air distribution under the heating mode.