What is vacuum insulating glass？ - Synergy Energy Saving Glass (Tian jin) Co., Ltd

What is vacuum insulating glass?

The vacuum insulating glass is composed of two flat glass, one or two of which are Low-E glass. The glass plates are separated by a square array of pillars with a height of 0.1 ~ 0.2mm. The two pieces of glass are sealed with glass solder around. There is a exhaust port on one piece of glass and a getter is placed. After vacuum exhaust, the vacuum cavity is formed by sealing the exhaust port with a sealing piece. vacuum insulating glass has the characteristics of low heat transfer coefficient and good sound insulation performance, which can play the role of heat insulation, anti- condensation, energy saving, reducing noise and so on.

Heat transfer is realized by three ways: heat conduction, convection and heat radiation. There are almost no gas molecules in the vacuum insulating glass, so the heat transfer of heat conduction and convection is greatly reduced, Meanwhile, the Low-E glass has greatly improved the thermal radiation performance. Therefore, the vacuum insulating glass has better thermal insulation performance.

Three ways of heat transfer:

Thermal insulation

The thermal transmittance U of vacuum insulating glass can be as low as 0.38W/（m2·K）

Doors and windows are the weak link of building insulation. 50% of building energy consumption is lost through doors and windows, and glass accounts for more than 70% of the area of doors and windows. vacuum insulating glass significantly improves the thermal insulation performance of doors and windows, greatly insulates the exchange of cold and hot air, and enables the indoor to maintain a comfortable temperature.

Low-E vacuum insulating glass 0.42 W/(m2·K）
Low-E insulating glass1.8 W/(m2·K)

Sound insulation

The weighted sound insulation of single vacuum insulating glass can reach 39dB，The composite vacuum insulating glass can reach 42dB

The sound transmission is effectively blocked by the vacuum layer of vacuum insulating glass. The weighted sound insulation of single vacuum insulating glass can reach 39dB, and the composite vacuum insulating glass can reach 42dB. For people living near airports, expressways and traffic trunk roads, noise is one of the important hazards that affect their lives. vacuum insulating glass can effectively isolate the low and medium frequency noise generated by traffic. It is better choice to solve the life noise and create a quiet space.

vacuum insulating glass Rw≥39dB
Insulating glass Rw≥29dB

Prevention of condensation

When the indoor temperature is 20 ℃ and the relative humidity is 65%, if use the single cavity ordinary insulating glass is used, the indoor side glass will start to condense when the outdoor ambient temperature is below 1.6 ℃. When the single cavity Low-E insulating glass is used, the indoor side glass will start to condense when it drops below - 12.5 ℃. When the vacuum insulating glass is used, the indoor side glass will start to condense when the temperature drops below - 35 ℃.

Thinner and lighter

Compared with the insulating glass which needs to increase the number of cavities, the thickness of cavities and the number of Low-E glasses to reduce the heat transfer coefficient, the vacuum insulating glass has a simple structure, light and a larger choice of optical parameters.

type of glass	configuration	U value W/（m2·K）	thickness/mm	weight（Kg/m2）
vacuum insulating glass	4TL+V+4T	0.42	8	20
vacuum insulating glass	5TL+V+5T	0.42	10	25
insulating glass	5TL+12A+5T	1.5	22	26
insulating glass	5TL+16Ar+5T+16Ar+5TL	0.8	45	38

Wide application

vacuum insulating glass used in all parts of the building can maintain its excellent performance (U value) unchanged, including facade, slope and roof; When the insulating glass is placed horizontally, the U value will be greatly improved due to the increase of gas convection, so the vacuum insulating glass is more suitable for daylighting roof.

type of glass		U value W/(m2.k)
Angle between glass and horizontal position	90 degrees	45 degrees	0 degrees
vacuum insulating glass	0.42	0.42	0.42
insulating glass	1.74	2.1	2.4

Suitable for plateau area

The air pressure in plateau area is usually lower than 0.85 atmospheric pressure, while that in plain area is 1 atmospheric pressure. If it is used in plateau area, it is easy to cause cracking and failure; The internal pressure of the vacuum insulating glass is close to zero, so it will not produce cracking when used in plateau area. On the contrary, because of the small pressure difference, it can reduce the atmospheric pressure and stress of the vacuum insulating glass and improve the safety of the vacuum insulating glass.

Comparison of insulating glass used in low altitude area and plateau area

Longer life

The edge of the vacuum insulating glass is sealed with inorganic nonmetal materials, which can protect the Low-E coating more effectively in vacuum state without aging failure. Its high temperature exhaust technology, getter and pillar technology make the actual service life of vacuum insulating glass reach 30 years.