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Thermal Calculator

Thermal breakage occurs when different points within a glass pane get heated to different temperatures. This temperature difference creates thermal stresses in glass causing breakage if the temperature difference exceeds a certain amount. This is similar to a glass tumbler breaking when hot water is poured into it in cold weather.

The software is able to calculate the temperature difference likely and classifies the risk of thermal breakage as high, medium or low, depending upon several criterion outlined by the user.


  • Glass type used, for amount of energy likely to be absorbed by glass
  • City, for environmental factors and solar intensity
  • Orientation of facade for solar intensity
  • Size of glass panels
  • Architectural factors like shading, internal blinds, type of glazing, etc.


  • Likely temperature difference expected between 2 points of the same glass pane
  • Risk of thermal breakage
  • Whether heat-treatment of glass (tempering or heat strengthening) is required to avoid thermal breakage.
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Thermal Breakage

Due to uneven heating of the glass pane different areas within a pane expand and contract at different rates. Due to different rates of expansion and contraction, stresses develop in the glass may cause Thermal breakage. Thermal Breakage is directly related to the temperature difference across the glass pane, and is in the range of 32 to 46 degree Celsius. Temperature difference depends on several factors such as Solar Intensity, Type of glass, and Shadows on portion of glass, Type of Internal Shading, Glass Orientation etc. The thermal Breakage module takes into consideration all the above factors and calculates the risk of thermal breakage for a given configuration of glass.

If you need a calculation to be made, please contact your AIS Technical Sales Manager.