Energy consumption and efficiency analysis on exterior windows in heating residential buildings in Jinan

Based on a residential building of traditional brick masonry-concrete structure with exterior walls of 370mm thickness, this paper analyses heat loss through envelope in case of three typical windows. The results show that the ratio of heat loss through windows to heat loss through the total envelope ranges greatly from 49% to 27%, dependent on window types. In case of traditional metal-famed windows, the heat loss index of building q(H) is greater than the regulated maximum value, but when energy saving windows are employed, q(H) may meet requirement of energy conservation standard, especially for buildings with relatively big area ratio of windows to walls. Improving the heat insulation property of exterior windows is an effective measure to reduce heat loss of buildings.