Effect of building insulation on cooling and heating load in different climate areas

Presents the three indexes—the cooling load to heating load gain ratio, the annual cooling and heating load variation ratio, and the cooding and heating weighted factor to assess the energy efficient performance of building insulation. Four zones with different orientations in one office building are used as an example to demonstrate the applications of these indexes in evaluating energy efficiency with different exterior wall insulation thicknesses in Beijing, Shanghai and Guangzhou. The results reveal that there are significant space for improvement in energy efficiency for zones facing all orientations in Beijing and with orientations excluding south in Shanghai, while for the south facing zones in Shanghai and all zones in Guangzhou there is little probability to reduce their total heating and cooling load. Considering variety of the cooling and heating weighted factor, increased exterior wall insulation thickness helps to reduce annual cooling and heating load in Beijing, but it quite depends on the orientation and cooling and heating load weighted factor in Shanghai and it would have no energy saving effect to increase exterior wall insulation thickness in Guangzhou.