Study On The Ventilation Technology For Residential Building In Guangzhou

Ventilation is an excellent strategy for passive cooling, improving the indoor thermalcomfort and air quality. The indoor air quality of residential building is poor because of no airchange rate in the air conditioning room, and it is impossible by the infiltration of buildingenvelop because of high energy saving requirement. Natural ventilation could be achieved byopening windows or doors, and its performance is depended on outdoor climate, as well asplan and construction of buildings. Outdoor air and noise pollution will have an impact on theindoor environment by natural ventilation. Therefore, the performance of natural ventilation isalways varied and out of control and cooling potential of outdoor climate might not be fullyutilized through naturally ventilation, furthermore indoor air quality will not be improved.Taking into account of these questions, the ventilation technology of residential building inGuangzhou has been studied in this paper, and main contributions of the research work are asfollows:First, the predictive equation of the optimal ventilation rate for cooling was achieved,that can be generally applied to residential buildings in Guangzhou. The design features ofbedrooms were investigated in typical Guangzhou residential areas, based on which a typicalmodel was built. The impacts of three factors and ventilation rate on cooling load wereanalyzed by orthogonal method and thermal simulations. Prediction models of annual coolingloads were obtained for bedrooms by multiple regression, which were tested to be statisticallyvalid. Finally, the predictive equation of optimal ventilation rate for cooling was achieved.For typical bedroom area10-21m~2, as low limit of change rate of ventilation contribution oncooling was5%, the optimal ventilation rates ranged from21.95to23h-1with energy savingrate of ventilation18-30%, and from11.95to13h-1with energy saving rate of ventilation35-55%as was low limit of10%.Second, the ventilation and air conditioning system integrated the air conditioning andmechanical ventilation was studied and achieved, including the system design, hardwareimplementation, control strategy and controller implementation, which contributed to energysaving, improving the indoor thermal comfort and air quality. The operating and noise of thesystem were tested through the experiment. The system was running in strictly accordancewith the control strategy and the parameters, and indoor temperature and relative humiditywere kept within the set range. The system was stable and reliable. The experiment wascarried out to study the energy saving effect and indoor thermal environment of the buildingwith ventilation and air conditioning system, air conditioning and natural ventilation. During the measurement, as indoor thermal environment of ventilation and air conditioning systemwas close to air conditioning, and compared to the air conditioning, the energy saving rate ofventilation and air conditioning system with indoor maximum air temperature27-29℃canreach20.93-61%per day during the night.Third, based on the indoor air temperature and cooling load calculated by DeST-h, theventilation period for cooling was achieved, and the fan electricity calculation software wasdeveloped to improve the comprehensive evaluation method of ventilation and airconditioning system energy consumption. Then the annual energy saving effect of ventilationand air conditioning system was quantitatively evaluated, that was54.51%when the indoorair temperature was26-29℃.Finally, indoor thermal environment of the ventilation and air conditioning system underdifferent equipment layouts was analyzed by the CFD software and reasonable layoutsuggestion was given, which will contribute to the application of ventilation control system inresidential building.