In aluminium joinery systems, thermal break (thermal barrier) technology is the single most critical factor determining the energy performance of the building envelope.
What Is a Thermal Break and How Does It Work?
Aluminium has a high thermal conductivity of 160–200 W/m·K — approximately 6 times that of steel. In an uninsulated aluminium profile, a continuous metallic bridge forms between the outer and inner surfaces, directly conducting heat.
In a thermal break system, the inner and outer shells of the profile are connected via polyamide 6.6 (PA 6.6) strips. PA 6.6 has a thermal conductivity of just 0.3 W/m·K — roughly 500–600 times more insulating than aluminium.
Polyamide Strip Types and Uf Values
- 14 mm strip: Uf ≈ 2.4–2.8 W/m²K — basic insulation, economical solutions
- 24 mm strip: Uf ≈ 1.8–2.2 W/m²K — mid-range residential and commercial buildings
- 34 mm strip: Uf ≈ 1.3–1.6 W/m²K — energy-efficient building standards
- Double barrier: Uf ≈ 0.9–1.2 W/m²K — Passive House and A++ building class
Condensation Risk and Warm-Edge Analysis
When thermal break width is insufficient, the interior surface temperature drops below the dew point, causing condensation. 2D heat-flow analysis using THERM software identifies this risk at the design stage. ICS provides complimentary THERM analysis reports for critical projects.
Mechanical Strength: Tensile Testing
EN 14024 mandates the following tests for thermal break profiles: 6 kN/m longitudinal shear strength, 1 kN/m² transverse load resistance, and thermal cycling performance between −20°C and +80°C. ICS profiles are CE-certified for all these tests.
Would you like technical support on this topic?