27 October 2026
Thermal break or not: choosing a window system for your climate
A thermal break is not automatically better — it is the right answer for some climates and an unnecessary cost in others. Here is how the decision is usually made.
The phrase “thermal break” describes a strip of low-conductivity material — usually polyamide — that separates the inner and outer parts of an aluminium profile. Without it, the aluminium conducts heat straight through the frame, and the inner face gets cold.
What the break actually does
Two things. It raises the surface temperature of the inner frame, which reduces condensation, and it lowers the whole-window U-value by removing the frame as a thermal bridge. On a cold morning, the difference between a broken and an unbroken frame is the difference between a dry reveal and a wet one.
When you need it
- Heating-dominated climates where the inner surface drops below the dew point
- Air-conditioned buildings where the frame is exposed to high summer temperatures
- Projects with a stated U-value or energy-code obligation
- Facades with large glass areas, where the frame is a significant share of the envelope
When a standard system is enough
- Mild climates with no condensation problem and no energy-code requirement
- Internal partitions and screened balconies
- Budget-driven projects where the money is better spent on better glass
Reading the numbers
Compare like with like. A U-value quoted for the glass alone is not the window’s U-value; it ignores the frame and the spacer. Ask for the whole-window figure and the standard it was calculated to.
The Jiuhua range
Our 50, 70 and 85 series are non-thermal-break systems — well suited to mild climates, internal use and screened balconies. The 110 and 115 system windows use PA66 nylon strips on a vertical isotherm layout, and the 112-2.0 sliding window uses a 20 mm thermal strip. If you are unsure which applies, send the project location and the performance target and we will tell you which system the data supports.