Contrastive Research On Energy Conservation From The Application Of Green Roof And Cool Roof

Energy conservation has become the basic national policy of China, and the reduction of building energy consumption and carbon emissions is also one of the problems which are urgent to be solved in the current urbanization. As a part of the building envelope, roof receives the longest solar radiation, which has significant potential for energy saving and carbon reduction. Among many studies of roof, the saving energy and carbon reduction study of green roof and cool roof receives extensive attention, in which their saving energy and carbon reduction effect are related to the local climate. In order to study the energy saving and carbon reduction effect of green roof and cool roof in Guangzhou, comparative study of energy conservation on the application of green roof and cool roof is undertaken in a typical office building of Gungzhou.Firstly, the heat transfer process of roof and energy saving and carbon reduction mechanism of green roof and cool roof are analyzed based on the heat balance equation of roof. The impact of green roof and cool roof on the energy consumption of office building in Guangzhou is qualitatively analyzed combined with the characteristics of Guangzhou climate and office building energy consumption.Secondly, three rooms of a typical office building in Guangzhou are selected, with the same face, area, window and layout of indoor heat source. The roof of the three rooms are processed into green roof, black roof and cool roof separately, and the energy-saving measurement platform of green roof and cool roof is built. Then different parameters, such as indoor and outdoor air temperature, interior and exterior surface temperature of the roof, thermal conductive heat flux of the roof, outdoor solar irradiation, the weight of planting module and air-conditioning energy consumption of the three rooms with green roof, black roof and cool roof are tested in different conditions.Thirdly, energy-saving and carbon reduction effect of green roof and cool roof are analyzed by the statistical analysis method, with the data of different conditions which are air-conditioning and non-air-conditioning condition in summer, non-air-conditioning condition in transition season, air-conditioning and non-air-conditioning condition in winter.Finally, the benefits of energy saving, carbon reduction and economy of green roof and cool roof throughout the whole life cycle are calculated, which indicates that the benefits of energy saving, carbon reduction and economy of green roof are higher than coof’s. The study is expected to provoid theoretical and technical support for the future choice of green building technology.