BIFORIUM / GUIDE
WHAT WARM EDGE CHANGES
The coldest part of an IGU is often the perimeter rather than the centre. Spacer material and geometry therefore matter for condensation risk, Uw and a clean dark line within a minimal frame.
A warm-edge spacer reduces the edge thermal bridge and affects edge temperature, whole-window performance and the visual line of the IGU.
Centre and edge are different
Ug describes the central glass area; the perimeter additionally depends on spacer and frame.
Colour also matters
A black or dark spacer is less visible in a minimal aluminium system.
Sealing determines service life
The spacer works with primary and secondary seals, making fabrication quality critical.