Vacuum glass application in passive house windows

Vacuum glass application is very wide,from household products,renoval and new construction windows,BIPV,etc,the main application is building make it able to replace triple glass units and create more comfortable environment.

The importance of windows&doors

Building doors and windows can cooperate with the walls to play a good thermal insulation effect, reduce the energy loss in the room, and play a vital role in building energy conservation and emission reduction.

In the building envelope, the door and window system occupies 1/6 of the total surface area, but the energy lost through doors and windows is 6 times that of walls, 5 times that of the roof, and 20 times that of the ground, accounting for about 50% of envelope total energy consumption.

Windows and doors occupy a small proportion of the overall envelope,but it’s weakest point of building energy efficiency because of high thermal conductivity.

For all glass curtain wall ,and high rise buildings with glass curtain wall, glass account at least 70% of overall envelope,the windows&doors thermal insulation performance decide the overall building energy consumption.



High Performance energy-saving glass

High performance energy saving glass emerged with the development of glass processing,glass coating technology,Materials technology to cope with the higher and high energy used in keeping indoor temperature.

  • Glass coating:Lower and lower emissivity coated glass from single silver,double silver to now low-E coating.
  • Spacer materials:From traditional aluminium spacer,stainless spacer,warm edge spacer,composite warm edge spacer to TPS insulated glass.
  • Glass make up:From monolithic glass to insulated glass,triple glass units,and then vaccum glass.

More and more new creative products were developed,for example heat mirror insulated glass,thermochromic glass, smart glass etc.

To achieve the high thermal insulation performance requirement of passive house,glass has to be thicker and thicker,while there’s always a barrier for insulated glass to decrease once more.

Currently the lowest U value of triple glass units is 0.6W/M2.K.Whether it’s combination of varies low-E,argon,and warm edge spacers.

Glass Combination LT % LR % Tsol % Rsol % U-Summer day U-Winter night SC SHGC
6 MT70#2+16AR+6C+16AR+6 MSE84#5 53 15 20 39 0.6 0.71 0.3 0.26
6 MD80#2+16AR+6C+16AR+6 MD80#5 50 13 24 18 0.54 0.6 0.38 0.32
6 MUS1.16#2+16AR+6C+16AR+6MUS1.16#5 74 17 43 34 0.73 0.76 0.59 0.52
6 MD80#3+16AR+6C+16AR+6MSE88#5 60 12 27 29 0.7 0.76 0.39 0.34
6 MT70#2+16AR+6C+16AR+6 C 59 16 23 40 0.88 1.06 0.31 0.27

To further decrease the glass U value, vacuum glass becomes the only option for architects and designers.

Whats vacuum glass?

Vacuum glass uses special sealing solder and technology to artificially build a 0.3mm high vacuum layer between two layers of flat glass. Because the vacuum layer between the glass, heat conduction and convection basically do not exist, the sound cannot be transmitted, and the LOW-E reflective layer on the flat glass can reflect more than 95% of the heat radiation, so the vacuum glass has the function of heat insulation and noise reduction performance is far surpassing insulating glass.



Glass Combination Lowe Types Coating Emissivity U value(w/m2.k) SC SHGC LT %
Triple Glass Unit
Single +Single 0.072,0.072 0.78 0.587 0.511 0.725
Triple +Single 0.021,0.072 0.74 0.345 0.300 0.61
Triple Glass Unit
Single +Single 0.072,0.072 0.76 0.587 0.511 0.725
Triple +Single 0.021,0.072 0.72 0.344 0.299 0.61
Quadruple Glass Unit
Single +Single 0.072,0.072 0.69 0.533 0.464 0.659
Triple +Single 0.021,0.072 0.639 0.315 0.274 0.555
Vacuum IGU
Single 0.103 0.64 0.520 0.452 0.593
Double 0.055 0.52 0.400 0.348 0.557
Triple 0.021 0.41 0.347 0.302 0.615
Vacuum IGU
Online +Online 0.18,0.18 0.58 0.523 0.455 0.517
Single +Single 0.072,0.072 0.41 0.517 0.45 0.659
Triple +Single 0.021,0.072 0.40 0.309 0.269 0.555

Vacuum glass can be further made into insulated vacuum glass to further decrease glass U value.



Vacuum glass application

Vacuum glass application in passive house windows will take advantage of extremely low thermal conductivity not only help decrease the windows overall thermal conductivity,but also saved frame profiles.With vacuum glass,customers can achieve the aimed U value with much thinner windows systems.

Profile type Windows system Frame conductivity Vacuum glass-U=0.45W IGU-U=1.62 Triple glass IGU-U=0.74
polyethylene-aluminum 72 0.9-1.0 0.9-1.0 1.7-1.8 1.1-1.2
Thermal break Aluminium 75 <1.0 <0.8 <1.6 <0.9
PVC 88 1.0 0.8 1.6 0.9

Even though vacuum glass now is still under development,still many shortage,such as high price,high non-conforming ratio,cannot make large panels,but now HaanGlas has working with China premium vacuum glass manufacturers and able to supply high quality vacuum glass with below advantages:



1.Glass to be tempered with Glaston dual chamber tempering furnace to ensure glass flatness and glass even strength.

2.No air aspirating holes,big distance between supporting points to have better visual appearance.

3.Low temperature metal sealing(<250 degree) to ensure tempered glass even strength.

4.Successive production furnace,monthly output 20K sqm.

5. 10.3 double silver low-E ,test U value :0.47w/m2.k

10.3 single silver low-E ,test U value :0.71w/m2.k

6.3+0.3+3mm tempered vacuum glass is available.

7.Warranty time: 15 years.

Kindly contact if you have any vacuum glass requirement,HaanGlas will be your best vacuum glass manufacturers and supplier in China.