Heat and moisture transfer of building envelopes under dynamic and steady-state operation mode of indoor air conditioning

Abstract

Realizing dynamic thermal comfort can help improve building performance. The heat and moisture transfer of the envelope is an important part of building performance. Therefore, this paper takes a typical room in Shanghai as an example and uses simulation software WUFI-PLUS and DELPHIN to study the influence of dynamic/steady-state operation mode of indoor air conditioning on the heat and moisture transfer of the envelope structure. The results show that based on the same thermal comfort, the energy consumption of the full heat load in dynamic operation mode is 73.69% lower than that in steady-state operation mode at 0ACH night ventilation, and it is 65.10% lower at 5ACH night ventilation. And at the same night ventilation condition, the moisture flow through the wall in the dynamic operating mode is smaller than that in the steady-state operating mode. In the case of 0ACH, when the partial pressure difference of water vapor is positive, the moisture transfer capacity in the dynamic operation mode of the indoor thermal environment is 11.7% lower than that in the steady-state operation mode. Therefore, when the partial pressure difference of water vapor is positive, the dynamic change of the indoor thermal environment can reduce the latent heat load of the envelope under the same water vapor pressure difference.