Insulating windows in building energy-saving design generally refer to the building transparent envelope structure with a certain thermal resistance. Its main thermal parameters are the value of heat transfer coefficient K (unit W/(m2.K)), which indicates that the temperature difference between the two sides of the envelope structure is 1K (Kelvin) under stable heat transfer, and the heat transferred through the envelope structure of unit area in unit time. The smaller the K value, the better the thermal resistance, that is, the better the thermal insulation effect, but it may affect the air tightness, leading to less indoor ventilation times, affecting indoor air quality.
Insulating windows in building energy-saving design generally refer to the building transparent envelope structure with a certain thermal resistance.
The main glass used for insulation windows are heat reflection glass, low-E glass and hollow/vacuum glass. The main window frames are wooden frames, whose heat transfer coefficient can be reduced to less than 2.0W/(m2.K); aluminium alloy and broken bridge aluminium alloy window frames, which have poor heat resistance, are seldom used in energy-saving design, and broken bridge aluminium alloy window frames have good heat resistance and high cost; PVC plastic window frames, commonly known as plastic steel windows, have good heat resistance, low cost, corrosion resistance, good air tightness and insulation. Sound property is widely used in building energy-saving design.