Firstly, to achieve good sound insulation and thermal insulation effects, it is necessary to choose real insulated glass instead of ordinary double-layer glass. insulated glass refers to two pieces of glass that are sealed with a certain distance between them, usually with inert gas in between, which requires machine processing. Ordinary double-layer glass is simply hand glued together, and the interlayer will definitely leak air, resulting in a significant difference in performance.
Because handmade double-layer glass can leak air, there is a simple method, which is to observe whether there is frost between the two layers of glass in winter and whether there is fog before the two layers of glass in spring and summer.
In addition, real insulated glass will have an aluminum spacer between two pieces of glass, while double layered glass usually has a black sealing strip or sealant in the middle