Thermal Break
CSI Division 08, Openings
A strip of low-conductivity material, often a rigid polymer, set into an aluminum window or curtain wall frame to physically interrupt the metal's path, since aluminum conducts heat and cold extremely efficiently on its own.
Why it matters
Without a thermal break, an aluminum frame carries outside temperature straight through to the interior surface, which in cold weather drops that interior surface cold enough for moisture in the room's air to condense on it. The thermal break is what keeps a window or curtain wall's interior frame surface closer to room temperature.
On a real project
A curtain wall system uses extruded aluminum framing with a polyamide thermal break set between its exterior and interior sections, preventing the cold exterior aluminum from conducting directly through to the interior frame surface during winter.
Who this matters most to
A Glazier installs curtain wall and window systems engineered with thermal breaks, and has to maintain that thermal separation carefully during fabrication and installation rather than bridging it accidentally with a metal fastener.
Where this goes wrong
An installer uses a metal fastener that accidentally bridges straight across a frame's thermal break while securing a piece of hardware. That single bridge point conducts outside temperature through anyway, creating a cold spot where condensation forms even though the rest of the frame performs correctly.