Quick answer: Thermal break aluminum framing uses a non-conductive polyamide isolator (typically 14-32mm wide) between the interior and exterior aluminum surfaces. This breaks the thermal bridge that otherwise allows heat to transfer directly through the metal, dramatically improving U-factor. Required by Florida Energy Code for most commercial fenestration in Climate Zones 1 and 2.
Aluminum is a thermal conductor — heat transfers through it at 1,400 BTU·in/hr·ft²·°F. Without a break, the interior and exterior surfaces of an aluminum frame are at nearly the same temperature, defeating the purpose of insulated glass. The thermal break (polyamide) interrupts this conductivity, allowing the interior surface to stay closer to room temperature.
Standard thermal break widths: 14mm, 18mm, 24mm, 32mm. Wider = better U-factor. Common Florida commercial frames use 24mm or 32mm thermal breaks. The wider thermal break also reduces condensation risk on the interior frame surface during cold weather.
Florida Building Code Energy Conservation chapter (FBC EC) requires commercial vertical fenestration in Climate Zone 1 (South Florida) to meet U-factor ≤ 0.50. Climate Zone 2 (rest of FL) requires ≤ 0.55. Without thermal break, aluminum framing typically pushes total U-factor to 0.65-0.85 — fails code.
Kawneer Series 501T, 601T, 701T (T = thermal break). YKK AP YHS 50 TU, YHS 60 TU. Tubelite T14651. EFCO 433. All offer current FL Product Approvals and Miami-Dade NOAs.
Thermal-broken aluminum frames cost 15-25% more than non-thermal-broken equivalents. The premium is required by code for most commercial work, so it's not really an optional cost — it's the baseline.
Thermal-broken framing must pair with low-E insulated glass to achieve target U-factor. The framing alone is necessary but not sufficient. The complete assembly U-factor is calculated per NFRC 100 procedure.
Thermal break aluminum framing uses a polyamide isolator between the interior and exterior aluminum surfaces. This breaks the thermal bridge that would otherwise allow heat to conduct directly through the metal, improving U-factor.
Yes — Florida Energy Code requires commercial vertical fenestration to meet U-factor ≤ 0.50 (Climate Zone 1) or ≤ 0.55 (Climate Zone 2). Achieving this without thermal break is nearly impossible.
Standard thermal breaks are 14mm-32mm wide (about 0.55"-1.26"). Wider thermal breaks (24mm-32mm) achieve better U-factor.
Kawneer (Series 501T, 601T, 701T), YKK AP (YHS 50 TU, YHS 60 TU), Tubelite (T14651), EFCO (433) all offer thermal-broken commercial storefront systems for Florida.
Thermal-broken aluminum frames typically cost 15-25% more than non-thermal-broken equivalents. The premium is effectively required by Florida Energy Code, so it's part of the baseline cost.
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