Study On The Thermal Parameters Of Exterior Enclosure Struture For Passive House In The Area With Hot Summer And Cold Winter

In recent years, domestic energy saving of residential building is continuously advancing toward high-level target. Although German passive house represents the highest standard of construction, it’s not applicable to the area with hot summer and cold winter. Promotion of passive house in the area with hot summer and cold winter should be determined after comprehensive analysis. Technical standard of German passive building can’t be directly used.In this paper, numerical simulation method is mainly used to study the problem of suitability of passive house in the area with hot summer and cold winter and the values of thermal parameters of enclosure structure of passive house. The accuracy of numerical simulation and calculation is validated by using experimental method. Passive house standard for the area with hot summer and cold winter has been presented in this paper, which means that heating and air conditioning load is minimized by improving the enclosure structure of thermal system (excluding fresh air and domestic hot water).Nanjing is selected as the example of the area with hot summer and cold winter. Typical residential building in Nanjing region is selected and simulation software DeST-h for building energy consumption is used for modeling to analyze its annual energy consumption caused by heating for air conditioning. The energy consumption of residential building is related to application mode of heating and air conditioning.In general, residential buildings are intermittently used. However, continuous use is used as the basis of calculation for energy saving standard of China’s residential building. Correspondingly, continuous mode is still used as the basis of calculation in the paper. All of the rooms are simultaneously involved in heating and air conditioning.The following conclusions can be obtained through the study in this paper:(1) Because German passive house adapts to the climate of cold region, technical standards of German passive house can’t be directly applied for promoting passive house in the area with hot summer and cold winter.(2) The standard of passive house for hot summer and cold winter should minimize heating and air conditioning load (excluding fresh air and domestic hot water) of the residential building by improving the thermal system of enclosure structure. At this time, the corresponding thermal system of enclosure structure can be used as the recommended standard of the passive house for the area with hot summer and cold winter.(3) If ventilation isn’t conducted by opening the window, reduce heat transfer coefficient of exterior wall and outer window. The number of days when indoor temperature exceeds 29℃ will greatly increase and additional air conditioning load in the transitional season will significant increase. During transitional season in the area with hot summer and cold winter, ventilation by properly opening the window can effectively reduce the time when indoor temperature is exceeded.(4) When air exchange frequency is 0.1h-1 under continuous operation mode, heat transfer coefficient of window is 1.5 and that of wall is 0.4. Heating and air conditioning load has stabilized and this parameter can be used as the recommended value of the passive house for the area with hot summer and cold winter. Because there should be virtually one indoor air exchange, indoor fresh air ventilation system should also be set. Air tightness of window can be just maintained at Level 6. If intermittent operation mode is used for heating and air conditioning system, above thermal parameters need to be adjusted.