According to experts in the design and construction of energy-saving housing, for a window, the heat loss of the house is mainly through the window frame conduction, glass radiation, the gap convection between the window page and the door frame, and so on. Therefore, the hollow glass comes into being. In fact, hollow glass is not "empty". According to the technical requirements, the spacing between two layers of hollow glass is generally 8mm. The test proves that if the spacing of 8mm is completely vacuum, the atmospheric pressure will crush the glass. Therefore qualified insulating glass. The interlayer, an 8mm thick space, must be filled with the inert gases argon and krypton. After filling, the test shows that its K value (the limit value of heat transfer coefficient) can decrease by 5% compared with that under vacuum condition, which means better insulation performance.

In other words, if the sandwich of hollow glass purchased is really "empty", it undoubtedly means that its thermal insulation or thermal insulation and cold insulation performance is at best double glass, and the effect of thermal insulation and energy saving will be poor. Scientific testing has proved that qualified insulating glass can reduce the limit k value of general window glass heat transfer coefficient from the original 3.5 to 2.8. A decline in heat transfer makes it harder for the house to lose heat. The fake hollow glass on the market is mostly just two pieces of glass simply fixed together, and its heat insulation performance is no doubt lip service.

Don't mistake hollow glass for double glazing! Double-layer glass with poor heat insulation performance often fogs up in the sandwich due to the entry of air and water vapor, and even develops mildew spots. Therefore, some enterprises often adopt the "processing" technique of sandwicking aluminum strips with holes between two pieces of glass and placing granular desiccants in the pores of the aluminum strips. In fact, it only plays a temporary role in masking the public, and does not improve any insulation performance of double-layer glass. After a long time of desiccant failure, or will reveal.