Index of ventilation effectiveness regarding energy performance considering cooling effect of air movement: Equivalent Thermal Utilization Effectiveness

Indices of ventilation effectiveness regarding energy performance are required for the proper design and operation of ventilation systems. Regulations encourage ventilation systems to implement the cooling effect of air movement for energy-efficient provision of thermal comfort. However, existing energy performance indices of ventilation systems do not account for the cooling effect of air movement. This study proposes an index of ventilation effectiveness regarding energy performance, i.e., Equivalent Thermal Utilization Effectiveness (ETUE), to account for the cooling effect of air movement. The cooling effect of air movement is quantified based on the standard effective temperature and is equivalently transferred to the reduction in the air temperature of the occupied zone. The ETUE is obtained by combining the equivalent reduction in the air temperature of the occupied zone and the existing index of Thermal Utilization Effectiveness (TUE). Experiments on stratum ventilation, the representative of ventilation systems implementing the cooling effect of air movement, show that the proposed ETUE should be used instead of the existing TUE; otherwise, a low accuracy rate (0–38.5%) would occur for energy performance ranking. Moreover, the cooling effect of air movement contributes up to 86.8% to the energy performance of ventilation systems, which further demonstrates the indispensability of the proposed ETUE for accounting for the cooling effect of air movement. The proposed ETUE contributes to promoting the applications of ventilation systems with the cooling effect of air movement for the development of energy-efficient and thermally comfortable buildings.