5 Difference between Vacuum Glass & insulated glass

Insulating glass was invented by the Americans in 1865. It has good heat insulation, sound insulation, beauty, and can reduce the weight of buildings. It is made of two (or three) pieces of glass, using a high-strength and high-air-tight composite adhesive to bond the glass pieces to an aluminum alloy frame containing a desiccant to make high-efficiency glass.

Vacuum glass was invented in 1993  in Australia, since its innovation,scientists and researchers are still trying to develop new technology to increase its safety performance and large scale production & application.

Now 2022 is coming, insulated glass now is widely applied in world almost every high rise buildings combining with new low-E coatings,new spacer systems,new structures to make the ultimate performance of insulated glass..While vacuum glass is still on the development stage and will be the trend and become the priority when designing and renovating old buildings,then what’s the difference between vacuum glass and insulated glass?

  1. Glass edge Sealing systems.

Both insulated glass and vacuum insulating glass consist of two pieces or more, join them together to make a empty space,the biggest difference is the sealing technology.

insulated glass structure

insulated glass structure

The edge sealing for insulated glass consist below:

  • Spacer: aluminium spacer,superspacer,TPS spacer,stainless steel spacer,and other warm edge spacer as low conductivity.
  • Desiccant: to absorb the humidity and moisture inside the glass.
  • Primary sealant&secondary sealant. To seal glass,prevent glass from water,moisture ,and form the IGU structure &strength.
  • Air or argon inside, argon will be filled to decrease the U value caused by convection.


While vacuum glass adopt different sealing edge, there’s no air or argon inside the glass which eliminate the possibility of heat convection.

  • To prevent glass contraction, micro pillars are placed evenly between glass panels.
  • Glass edged is sealed with low temperature metal solders or glass solders to prevent air,or vapors penetrated the glass.
  • Getters that is been embed inside glass panels will continuously absorb the vapors and moisture after glass was installed and ensure the super long lifetime of vacuum glass.
  1. The materials inside the sealed structure

With above complicated system,what’s inside the sealed structure?

The edge sealing system in insulated glass contain air or argon,while vacuum glass structure keep a high vacuum degree space inside the glass.

Commonly used insulating glass spacers have thicknesses of 6mm, 9mm, 12mm, 15mm and other specifications.The thickness of the gas spacer is directly related to the thermal insulation performance.

In the case of the same glass material and sealing structure, the larger the gas spacer layer, the larger the thermal resistance.But when the thickness of the gas layer reaches a certain level, the growth rate of thermal resistance is very small.

Because when the thickness of the gas layer increases to a certain extent, the gas will produce a certain convection under the action of the temperature difference between the glasses, thereby reducing the effect of thickening the gas layer.

insulated glass units contain air or argon inside the achieve the lowest thermal convection

insulated glass units contain air or argon inside the achieve the lowest thermal convection

Reasonable spacer thickness is 12-16mm to ensure the best thermal insulation performance.That’s the reason why 6+12A+6 because the most popular insulated glass structure,and why the insulated glass are always thick.

Different from insulated glass,vacuum glass contain 0.3mm high vacuum degree space.

  • The vacuum space cannot be very big because the air pressure will force glass to contract,while the bigger vacuum space,the higher air pressure that increase glass breakage ratio.
  • 3MM vacuum space is enough to isolate the medium of thermal convection and conductivity,as well as the medium of sound transmission.
  • 3mm vacuum space also ensure the glass extremely thin,which is even thinner than same combination laminated glass and suitable for old buildings which require better thermal and soundproof performance without changing original windows system.
vacuum glass-HaanGlas vacuum glass product

vacuum glass-HaanGlas vacuum glass product


Even though the glass used in both VIG and IGU are same: 1 piece high performance low-E coated glass to reduce the heat radiation ,and another piece monolithic glass,but the space between 2 glass panels decide the different property of the glass:

  1. Vacuum glass thermal insulation performanceis 1/4 that of IGU because vacuum space eliminate the air heat convection, and micro supporting pillars and edge sealing materials becomes the only medium of heat conduction.
  2. Vacuum space remove the sound transmission medium and t0.3mm space also changed glass resonance frequency and make it better isolate low and medium frequency noise.
  3. Vacuum glass is even thinner than same combination laminated glass and decrease the glass weight used in windows&facade.
  4. The permanent sealing edge ensure super long lifetime without decreasing performance.
  5. Vacuum glass eliminate the air expansion or contraction caused by the temperature and altitude,which make yourfacade more flat and more beautiful.

Even though the development of vacuum insulating glass is slow,but now with our fully tempered vacuum glass products and the largest available sizes-1700*3200,VIG can be widely used in architectural industry to replace traditional insulated glass,and we do believe HaanGlas will contribute our power to build a low carbon world.

HaanGlas is your turnkey vacuum glass supplier in China,we offer world class vacuum insulating glass products and contribute to a better world.