Thermal Performance of Vacuum Glazing with Tempered Glass Panes

  • Yueping Fang
  • Trevor J. Hyde
  • Farid Arya
  • Neil Hewitt
Conference paper


The thermal performance (U-value) of 0.4 × 0.4 m and 1 × 1 m double vacuum glazing (DVG) and triple vacuum glazing (TVG) using annealed and tempered glass panes with pillar separations of 25 and 50 mm respectively was simulated. It was found that (1) for both dimensions of DVG with 0.03 emittance low-emittance (low-e) coatings, the U-values at the centre of the glazing area of the DVG made of annealed and tempered glass panes were 0.57 and 0.30 Wm−2 K−1, a reduction of 47.4 %; (2) for both dimensions of TVG with 0.03 emittance low-e coating, the U-values at the centre of glazing area of the TVG with annealed and tempered glass panes were 0.28 and 0.11 Wm−2 K−1, a reduction of 60.7 %. The reduction in U-values for both DVG and TVG results from the significant reduction in pillar number, leading to the large reduction in heat conduction through the pillar arrays. The reduction in U-values from using tempered glass panes instead of annealed glass panes for TVG is larger than that for DVG; this is because the radiative heat transfer of TVG with three glass panes is much lower than that in DVG with two glass panes; therefore, the heat conduction through the pillar array in TVG plays a larger role compared with that in DVG. The reduction in pillar number in TVG results in a larger reduction in U-value compared to DVG; thus, using tempered glass panes in TVG confers a greater advantage compared to DVG, given that DVG can also achieve a large reduction in U-value when switching from using annealed glass panes to tempered glass panes.


Annealed glass Tempered glass Vacuum glazing U-value and pillar separation 



Radius of support pillar (m)


Surface heat transfer coefficient (Wm−2 K−1)


Thermal conductivity (W m−1 K−1)


Pillar separation (m)


Thermal resistance (m2 K W−1)


Thickness of glass pane (m)


Temperature (°C)


Thermal transmission (Wm−2 K−1)

Greek letters


Hemispheric emittance of a surface


Stefan-Boltzmann constant (5.67 × 10−8) (Wm−2 K−4)



Surfaces of glass panes shown in Fig. 20.1


First, second and third glass panes


Refer to warm and cold ambient temperatures




Glass pane number of TVG


Vacuum gap number






Total resistance of TVG


  1. 1.
    Zoller F (1924) Hollow pane of glass. German Patent 387655Google Scholar
  2. 2.
    Collins RE, Robinson SJ (1991) Evacuated glazing. Sol Energy 47:27–38CrossRefGoogle Scholar
  3. 3.
    Collins RE, Simko TM (1998) Current status of the science and technology of vacuum glazing. Sol Energy 62:189–213CrossRefGoogle Scholar
  4. 4.
    Fang Y, Hyde TJ, Arya F, Hewitt N, Eames PC, Norton B (2014) Indium alloy-sealed vacuum glazing development and context. Renew Sust Energy Rev 37:480–501CrossRefGoogle Scholar
  5. 5.
    Hyde TJ et al (2000) Development of a novel low temperature edge seal for evacuated glazing. In: Proceedings of World Renewable Energy Congress VI (WREC2000). Brighton, UK, pp 271–274Google Scholar
  6. 6.
    Friedl W (2011) USB ultra sonic bond—proceeding of glass performance days (GPD) conference, 17–20 June. Tampere, Finland, pp 299–300Google Scholar
  7. 7.
    Zhao JF, Eames PC, Hyde TJ, Fang Y, Wang J (2007) A modified pump-out technique used for fabrication of low temperature metal sealed vacuum glazing. Sol Energy 81(9):1072–1077CrossRefGoogle Scholar
  8. 8.
    Collins RE et al (1999) Paper presented at glass in buildings conference, Bath, UKGoogle Scholar
  9. 9.
    Manz H, Brunner S, Wullschleger L (2006) Triple vacuum glazing: heat transfer and basic mechanical design constraints. Sol Energy 80(12):1632–1642CrossRefGoogle Scholar
  10. 10.
    Holm R (1967) Electric contacts, theory and application, 4th edn. Springer, Berlin, pp 9–16Google Scholar
  11. 11.
    Wilson CF, Simko TM, Collins RE (1998) Heat conduction through the support pillars in vacuum glazing. Sol Energy 63(6):393–406CrossRefGoogle Scholar
  12. 12.
    Zhang Q-C, Simko TM, Dey CJ, Collins RE, Turner GM, Brunotte M et al (1996) The measurement and calculation of radiative heat transfer between uncoated and doped tin oxide coated glass surfaces. Int J Heat Mass Transfer 40(1):61–71CrossRefGoogle Scholar
  13. 13.
    Griffiths PW et al (1998) Fabrication of evacuated glazing at low temperature. Sol Energy 63(4):243–249CrossRefGoogle Scholar
  14. 14.
    EN ISO 1007-11 (2000) Thermal performance of windows, door, and shutters—calculation of thermal transmittance—part 1: simplified method. BrusselsGoogle Scholar
  15. 15.
    Fang Y, Eames PC, Noton B, Hyde JT (2006) Experimental validation of a numerical model for heat transfer in vacuum glazing. Sol Energy 80:564–577CrossRefGoogle Scholar

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Authors and Affiliations

  • Yueping Fang
    • 1
  • Trevor J. Hyde
    • 1
  • Farid Arya
    • 1
  • Neil Hewitt
    • 1
  1. 1.School of the Built EnvironmentUlster UniversityLondonderryUK

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