Application Evaluation And Optimization Of The Sunroom In Rural Residential Huoses In Southeast Shangdong

China has large rural areas and lots of rural population.With the living conditions greatly improved,the energy consumption per unit area of rural residential houses has increased rapidly.There is no clear energy-saving path in rural areas,and building energy-saving work is lagging behind.Exploring passive building energy-saving technologies suitable for rural areas in China is an important part of building a new socialist countryside.The energy consumption of rural residential houses includes heating and cooling,cooking and heating water,household appliances and lighting,among which heating energy accounts for the largest proportion.The sunroom,as one of the passive solar heating technologies,has significant advantages in energy-saving,environmental protection and other sustainable development.It is a powerful means to reduce the heating energy consumption of rural residential houses in China.Using a sunroom to collect heat for indoor heating has always been one of the adaptive heating methods for villagers in rural areas of Southeast Shandong to cope with the cold climate.Although sunroom has been applied in rural areas of Southeast Shandong for a long time,the construction of the sunroom in this area lacks scientific guidance,and there are problems such as low performance and material waste,which need to be further optimized.In this paper,the influence of sunroom on the indoor thermal environment are tested and studied.A comprehensive evaluation method based on the Design Builder and dynamic investment payback period analysis is adopted to evaluate the energy-saving rate and economy.Furthermore,the optimization of the sunroom is performed,and the impact of seven key structural factors of sunroom for the indoor thermal environment,energy-saving,and economy was analyzed and evaluated.The research results show that:(1)The indoor thermal environment of rural residential houses in the Southeast Shandong is poor in the coldest month,and it can be improved by applying the sunrooms.Among them,the additional sunroom has the best performance on improving the indoor thermal environment,but it does not completely meet the indoor heating demand;(2)In this area,the window-to-wall ratio of the south wall of the additional sunroom should be increased and the type of window on the south wall of the additional sunroom needs to be considered in combination with the solar heat gain coefficient and heat transfer coefficient,the height of the cavity of additional sunroom should be increased and the depth of the cavity should be reduced,the heavy wall with high heat collection efficiency should be selected as the common wall,the window-to-wall ratio of the common wall should be controlled at 20%-40%,and the glass with low heat transfer coefficient should be selected as the window of common wall;(3)The window-to-wall ratio of the south wall of the additional sunroom has a highly significant impact on the temperature and heat load in the living room and bedroom,the type of window of the south wall of the additional sunroom and the height and depth of cavity and the window-to-wall ratio of common wall have a significant impact on the temperature and heat load in the living room and bedroom,while the material of the common wall and the type of window of common wall have no significant impact on the temperature and heat load in the living room and bedroom;(4)Based on the results of numerical simulation and orthogonal experimental design and combined with the economy and the needs of the villagers,the comprehensive optimization plan is the window-to-wall ratio of the south wall of the additional sunroom(90%),the type of window of the south wall of the additional sunroom(Low-E single glass),the height of cavity(4.0m),the depth of cavity(1.5m),the material of the common wall(brick wall),the window-to-wall ratio of common wall(30%),the type of window of common wall(single glass).After comprehensive optimization,the average temperature in the living room and bedroom has increased by 2.8℃,the time between11-14℃and 14-26℃increases by 180h and 94h respectively,and the energy-saving rate is 43.8%.Its dynamic investment payback period is 2.31 space heating periods,and the cumulative net income in the 50th year is 2725.56 yuan/m~2.The conclusions will provide a theoretical basis for improving the indoor thermal environment and energy-saving of rural residential houses in Southeast Shandong and other areas in cold zones and the construction of rural residential houses with sunrooms.