Effects of climate change on cooling and heating energy consumption of buildings with different energy-saving levels in Tianjin

Based on the hourly data of ground meteorological observation in Tianjin from 1961 to 2017, the heating and cooling energy consumption (CEC) of office buildings, and the heating energy consumption (HEC) of residential buildings with different energy-saving levels were simulated by TRNSYS software.On this basis, the impacts of climate change on energy consumption of buildings with different energy-saving levels in Tianjin were quantitatively evaluated.The results show that temperature increases significantly and solar radiation decreases during the heating and cooling periods.As a result, the HEC and CEC of office and residential buildings decreases obviously and increases slightly during 1961 to 2017, respectively, indicating that the influence of climate change on the HEC is larger than on the CEC.With the improvement of energy-saving level of buildings, both the HEC and CEC show a decreasing trend, especially significant for the HEC.Compared with the one- to three-step residential buildings, the HEC of the four-stage energy saving buildings decreases 53.56%, 50.13% and 21.25%, respectively.Thus, the impact of energy-saving levels on energy consumption of buildings should be taken into account for new buildings and energy efficiency renovations of existing buildings, and upgrading and reconstruction should be conducted according to actual energy demand.In addition, the increasing of the energy-saving level in buildings will promote the variations of the HEC and CEC decreasing with warming, indicating that the sensitivity of building energy consumption to climate change is gradually weakening.Therefore, the increasing of energy-saving level in buildings can play a better role in dealing with climate change and reduce the building energy use in the future.