Investigation On Indoor Thermal Environment And Optimization Of Heating Method In Hot Summer And Cold Winter Zone In Winter Season

Indoor thermal environment has received more and more attentions in HVAC study and application fields with increasing in urbanization and industrialization in China. Some standards in hot summer and cold winter (HSCW) zone have been promulgated for guiding the HVAC and energy-efficiency design of residential buildings in these zones.In order to improve formidable indoor thermal environments in residential buildings in winter, conventional and novel heating facilities have been used for room heating in the zones mentioned above, such as gas-fired furnaces, electric heaters, oil stoves and panel heating membranes. For lack of scientific evaluating indexes and reasonable technical measuring methods, heating energy consumption is highly and difficult be estimated in winter in the HSCW zone. Considering the characteristics of indoor and outdoor climate variation in HSCW zone, high-efficient and high-comfort heating techniques and facilities should be employed to make effective energy consumption.A series of experiments have been done for investigating indoor thermal environment in HSCW zone in winter, three non-heated common rooms which adjacent to each other are selected in Shanghai city, the rooms have different building orientation and different air tightness, and indoor thermal environment are monitored continuously in almost three months in winter. The results show that the indoor thermal environment is awful and the features in such rooms are different from the non-heated rooms in Dalian city (which is located in cold zone). The orientation of buildings affects indoor thermal environment not so much in Shanghai city compared to that in north cities, so the influence of orientation of buildings in HSCW zone should be considered more in spring and summer seasons. Because the difference between indoor and outdoor air temperature is relatively small, air tightness is not the main factor affecting indoor thermal environment in HSCW zone.Probable room heating method is analyzed in theory according to the discussions and the characteristics of indoor and outdoor climate in Shanghai area. Mathematical models of a heating room are developed for different conventional heating methods, and finite difference technique is employed for solving the equations. By making use of the solutions, indoor thermal environments of radiant ceiling system and warm air system are estimated and analyzed, respectively. The comparison between computed results and measured data shows the model used in the present paper has high degree of accuracy, so it is reliable for evaluating indoor thermal environment heated by different methods.Indoor thermal environment of radiant ceiling system is compared with that of warm air system by the numerical results in HSCW Zone. The analysis indicates that radiant heating is not only comfort and energy-saving, but also economical and quickly warming. Thus it is an applicative and effective heating method for residential building in Hot Summer and Cold Winter Zone.