Which side is more suitable for the Low - E film layer of aluminum alloy doors and windows?
As shown in the above figure, when we usually refer to which side the film layer is on, it is the order of the glass surface of aluminum alloy doors and windows counted from the outdoor side to the indoor side. For double - glazed and one - cavity insulating glass, there are 1 - 4 sides, for triple - glazed and two - cavity insulating glass, there are 1 - 6 sides, and for quadruple - glazed and three - cavity insulating glass, there are 1 - 8 sides.
When the Low - E film layer is inside the insulating cavity, that is, at the 2# and 3# positions, the heat transfer coefficient K value of the doors and windows remains unchanged. In other words, the position of the Low - E film layer has no impact on the K value of the insulating glass.
When the Low - E film layer is on the 2# side, the SHGC value is the smallest, and when it is on the 3# side, the SHGC value is the largest. That is to say, the position of the Low - E film layer has a significant impact on the SHGC value.
Different climate zones in China have different requirements for heat preservation and shading, and the heating and air - conditioning conditions are also different. Specific analysis is needed according to specific climatic conditions. In severe cold and cold zone A, it is recommended that the film layer be at the position with a larger SHGC value, and in other regions, it is recommended that the film layer be at the position with a smaller SHGC value.
Apart from the thermal performance, in most regions, it is recommended that the Low - E glass be placed on the 2# side. Another factor is that the "appearance value" of the Low - E glass can be utilized to fully reflect the architect's design intention for the building's appearance.
During the actual use process, we also need to pay attention not to install the single - piece Low - E insulating glass in the reversed indoor and outdoor positions; otherwise, the doors and windows or curtain walls will have an unsightly appearance.
