夏热冬冷地区外窗传热系数对建筑能耗的影响

使用清华大学开发的建筑能耗模拟软件DeST h，对宁波地区一幢典型居住建筑的能耗随各向窗户传热系数的变化规律进行了模拟分析。分析表明：各向外窗传热系数变化对采暖能耗有较大影响，对空调能耗影响不大，通过降低传热系数的方法很难减少夏季空调负荷；南向窗户传热系数对建筑能耗的影响最大，北向次之，东、西向最小；南、北向外窗传热系数从4.7降到3.2节能投资性价比最高。并且分析了外窗传热系数降低引起空调能耗增加的原因。研究结果对夏热冬冷地区其他城市也具有参考意义。

Effects of Heat Transfer Coefficient of External Window on Residential Buildings in Subtropical Areas

Using Designer's Simulation Toolkit DeST h developed by Tsinghua University, research was carried out on the energy consumption of a typical residential building in Ningbo, P. R. China, with a focus on the heat transfer coefficient of external windows facing every direction. Results show that variation of the heat transfer coefficient of external windows in all directions has a substantial effect on energy consumption for heating but little effect on energy consumption for cooling. It is difficult to decrease cooling energy consumption by decreasing the heat transfer coefficient of external windows in summer. The heat transfer coefficient of external windows facing south has a significant effect on building energy consumption, but the windows facing north have less effect, and those facing east and west have the least impact. Decreasing the heat transfer coefficient of external windows facing north and south from 4.7 to 3.2 produces the most favorable performance cost ratio for energy saving investments. Reasons for the decrease in the heat transfer coefficient of external windows leading to increased air conditioning energy consumption were discussed. The conclusions are useful for guiding energy efficient building design in other subtropical cities.