Contrastive analyses on annual energy consumption characteristics and the influence mechanism between new and old residential buildings in Shanghai, China, by the statistical methods

The purposes of this research are to contrast the energy use characteristics of old residential buildings and new residential buildings in Shanghai, China, to look into influence factors of residential energy consumption, and to further analyze the reasons which result in the differences of energy consumption quantities between high-energy use family group and low-energy use family group. 1610 families in Residential District A and 819 families in Residential District B were chosen to trace their monthly energy consumption data in the whole year of 2006. Buildings in District A were all constructed in the 1980s, while those in District B were built in the 2000s. 300 families in each district were further selected from all above investigated families to do questionnaires in the year of 2007, so as to understand building characteristics, the possession and utilization of space heating and cooling appliances, and energy-saving consciousness. Annual energy consumption of the two kinds of buildings is contrasted and energy consumption quantities of spacing cooling and heating are also calculated. Influencing factors of residential energy consumption are analyzed by Quantification Theory I. Quantification Theory III is used to classify all the families into different categories based on the differences in their energy consumption amounts, and to further find out the reasons leading to the different energy consumption between different groups. Conclusions are as follows: (1) the average annual energy consumption quantity is 23.27 GJ/household for new buildings and 14.40 GJ/household for old buildings. The ratio of space heating and cooling to total annual energy consumption is just 16% and 11.6% for new buildings and old buildings respectively; (2) energy consumption and its variance lie on the integration of many factors, such as the floor area, materials of window frames, the number of family members, operation months of space heaters in winter and air conditioners in summer, and energy-saving actions; (3) all the families in the two districts can be classified into two categories: Household Region M of much energy use, and Household Region N of little energy use. Adopting the aluminum window frames, large floor areas and the large number of family members (above 4 person) are the main reasons leading to more energy use in Household Region M, while the small number of family members (1–2 persons/household) and small floor areas are the main reasons resulting in the less energy use in Household Region N; the long period of space heating, using illumination as little as possible are also the reasons causing the differences in energy consumption quantities between the two categories, but their influences on the samples clustering are smaller than the main reasons above; (4) compared with the energy consumption in some developed countries, the ratio of space heating and cooling to total residential energy use is much smaller in Shanghai. Indoor thermal environment is very poor besides that. With the growth of economy and the improvement of living standard, people will have the higher requirement for good-quality indoor thermal environment, and hence space heaters and coolers will be used much more frequently, so the residential energy consumption in China will still continuously increase rapidly, if few energy-conservation strategies are adopted; (5) considering current little prevalence of energy-saving actions with low efficiency, more effective energy-saving actions should be fully adopted in China.