In this research an evaluation of windows to realize the optimal heat balance according to the regional climatic characteristics and bearings was performed, focusing on the heating load of PVC windows in cold regions. In order to carry out this investigation the Taguchi method for trial calculations was used while studying appendage of windows, the thermal transmittance of windows, the solar heat gain coefficients of windows and the air permeability of windows, and examining their influence on heating load of windows, as well as demonstrating the reduced configuration of heating load of windows.
