Are the energy conservation rates (RVRs) approximate in different cities for the same building with the same outer-wall thermal insulation measures?

Abstract

This paper chooses two cities with completely different hourly weather conditions as background, for example Chicago in USA and Shanghai in China. And then, the author makes hourly and classified analysis on the influence of the decrease of outer-wall heat transfer coefficient on the heating and cooling energy consumption and its RVRs. It is found that the reduction of outer-wall heat transfer coefficient U can significantly decrease the annual heating needs and classified heating needs both with and without solar radiation; It can also limitedly reduce the annual and classified cooling needs both with and without solar radiation. The degree of cooling reduction is obviously lower than that of heating. Despite of any climatic conditions, the proportion of the heating energy consumption without solar radiation in the total heating needs ( > 80%) is far higher than that with solar radiation ( < 20%) while the proportion of the cooling energy consumption with solar radiation in the total cooling needs ( > 90%) is far higher than that without solar radiation ( < 10%). Therefore, the reduction of outer-wall's U can greatly increase the energy conservation rates (RVRs) of heating and cooling (called the basic RVRs) when there is no solar radiation. In order to reach the best energy efficiency effect, solar radiation should be utilized to the limit in winter and controlled effectively in summer. The annual energy conservation rates of heating as well as cooling are both close in different cities under the same outer-wall U , that is taking the same outer-wall thermal insulation measures to identical building. This paper proves in all aspects that the energy efficiency rates of both heating and cooling are approximate under different climatic conditions (or in various cities) when taking the same energy efficiency measures to the same building.