Study On The Effect Of Wind-Driven Rain On Hygrothermal Behavior Of Exterior Wall And Indoor Hygrothermal Environment And Energy Consumption Of Buildings In Hot Summer And Cold Winter Areas

Buildings are exposed to the subtropical monsoon climate with heavy rain in hot summer and cold winter zone(HSCW)of China.In this area,wind-driven rain(WDR)is one of the main moisture sources that cause water seepage of building exterior walls and deterioration of wall materials.The WDR may have a notable impact on the hygrothermal performance of the wall,the mould germination risks,indoor hygrothermal environment and building energy consumption simulation in this region.Therefore,the WDR should be analyzed as the boundary condition of the wall heat and moisture coupled model to make a more accurate assessment of the building performance.In this paper,four typical cities in HSCW zone including Chengdu,Shanghai,Changsha,and Shaoguan were taken as examples to study the effects of WDR on the hygrothermal performance and the mould germination risks of the wall.In addition,the influence of the WDR on indoor hygrothermal environment and building energy consumption were also analyzed.An experimental platform is established to validate the applicability and accuracy of the hygrothermal model of WUFI Plus’ s in HSCW zone of China.The temperature and humidity at different locations on the wall were measured.WDR was considered as the boundary condition.The hygrothermal model was successfully validated by comparing the simulated value solved by the model with the measured value.Hygrothermal simulations of three types of wall were performed with WUFI Plus in four typical cities in HSCW zone.The simulations were named according to the consideration(w WDR)or not of the WDR in the calculations(n WDR)to investigate the effect of WDR on the hygrothermal behavior and mould germination of building walls.The results indicate that WDR can cause a significant increase of the water content at different locations of the wall and the relative humidity as well as the moisture flux at different interfaces of the wall.In addition,WDR is responsible for increasing the heat flux at the interface and the inner surface of the wall.It is also proven that WDR loads can have a serious impact on mould germination risk.When ignoring WDR,the mould germination risk evaluation indexes of three typical walls in four cities are underestimated by 2.1-965.16 times.By considering WDR and not considering WDR,the indoor hygrothermal environmental parameters of four representative cities in in HSCW regions were calculated,and the sensitive factors affecting the indoor humidity environment were analyzed with considering WDR.It is found that WDR will increase the relative humidity in the room,which is not conducive to indoor thermal comfort.The use of air conditioners with humidity control or mechanical ventilation can reduce the proportion of indoor high humidity and increase indoor comfort.By considering WDR and not considering WDR,the building energy consumption of three types of walls in HSCW regions were calculated.The influence of WDR on the energy consumption of envelope structure,the building cooling energy consumption,the heating energy consumption,the latent heat energy consumption and annual total energy consumption were analyzed.Although WDR can reduce the heat flow value through the building envelope,it will significantly increase the building heating and indoor latent heat load.Ignoring WDR will cause the annual total energy consumption of buildings to be underestimated by-0.16%-12.41%.It can be seen that WDR has a greater impact on building energy consumption.WDR must be considered in the accurate calculation of building thermal comfort design and energy consumption in HSCW zone of China.