Thermal Performance Of Envelope In Rural Dwellings In Dry-hot And Dry-cold Regions

Building energy consumption is not only related to the thermal performance of the envelope structure,but also affected by building operation mode.Buildings in dry-hot and dry-cold regions must adapt to the harsh climate both in summer and winter.In present study,based on the investigations on climate responsive strategies and human adaptive behaviors in rural buildings in Turpan basin,the building operation mode combined passive strategies with active measures to satisfy indoor thermal comfort was summarized.Then,indoor thermal environment in typical buildings were simulated using WUFI PLUS software based on the building operation mode.The heat flux and temperature of interior surface of envelope were taken as indicators to evaluate the influence of insulation constructions,heat transfer coefficient and thermal inertia index.The main findings are as followed:(1)The exterior wall of rural dwellings in Turpan basin is conducive to saving energy when adopts internal insulation and self-insulation structure.External insulation and sandwich insulation can maintain inner surface temperature stable when the equipment is turned off under intermittent working conditions.(2)The smaller the heat transfer coefficient of exterior wall and roof is,the smaller the difference between the inner surface temperature and the air temperature is.It is also beneficial for energy saving.However,when the thermal inertia index is greater than 4,the change of the heat transfer coefficient has little effect on the inner surface temperature under non-heating conditions in winter.(3)The change of thermal inertia index has little effect on the energy saving of external thermal insulation walls and roofs.Small thermal inertia indexes are more energy saving.However,the difference between the inner surface temperature of the walls and roofs with high thermal inertia indexes and the air temperature is smaller,which is more conducive to indoor thermal comfort.The change of thermal inertia index has little effect on the heating energy consumption of the internal insulation wall,and has a certain impact on the cooling energy consumption.The thermal inertia index has different effects on the inner surface temperature of the envelope under different operation mode.Under continuous heating,non-heating,continuous air conditioning,and intermittent air conditioning conditions,regardless of whether the envelope using internal or external insulation,the greater the thermal inertia index is,the more beneficial for thermal comfort it is.It is recommended that the thermal inertia index of roof and external wall is 4.Under intermittent heating conditions,the thermal inertia index has little effect on the inner surface temperature of the external insulation wall.Under night ventilation conditions,if the room is used during the daytime or both daytime and nighttime,the thermal inertia index of the roof and the exterior wall should be high.If the room is used during nighttime,the thermal inertia index of the roof and the exterior wall should be low.(4)Rooms which are utilized during all the day under continuous heating,intermittent heating and night ventilation are recommended to adopt at least 400 mm raw soil wall with 100 mm EPS external insulation and roof with 200 mm overburden and 200 mm hay insulation.The room used only after the heating or cooling equipment turning on should adopt the internal insulation structure.