Insulating glass is a glass deep-processed product that consists of two or more pieces of flat glass, separated by a spacer frame on the periphery, and sealed with a sealant, so that a dry gas space is formed between the glass layers. It should be reminded that the edge of the hollow glass is strictly sealed with sealant. The inner cavity of the hollow glass is filled with dry air or inert gas. This part of the gas is sealed in the cavity for a long time and cannot be convective with the outside air. Therefore, The heat on both sides of the hollow glass will not take away the heat due to the convection of the gas between the glass. On the other hand, air is a poor conductor of heat, and the two layers of glass separated by a sealing gas conduct little heat to each other, thus playing a good thermal insulation effect. In addition, when there is a large temperature difference between the two sides of the hollow glass, since a piece of glass only senses the temperature on one side, there will not be a large temperature difference between the two surfaces of the single piece of glass. Therefore, when the temperature difference between the inside and outside of the insulating glass is not particularly large (≥100°C), frosting and condensation will not occur.

In addition, it should be noted that insulating glass is not vacuum glass, and the pressure of the gas in the inner cavity of the insulating glass is basically the same as that of the outside, otherwise it is very easy to cause the glass to break. Through the above explanation, we can know that there is an essential difference between insulating glass and ordinary double-layer glass. The most essential difference between the two is that the former is sealed and the latter is not. It is because of the unsealed double glass that dust and water vapor can easily enter the inner cavity of the glass. The water vapor will frost when it is cold, and dew when it is heated. The dust attached to the inner surface of the glass can never be removed. It will cause the window to be installed and used soon. The glass was blurred and filthy. Of course, double-layer glass can also play a certain role in sound insulation and heat insulation to a certain extent, but its performance is far from that of insulating glass.