What is a warm edge spacer bar, and how does it improve insulation?

A warm edge spacer bar is designed to reduce heat loss around the edge of a sealed unit, improving energy efficiency. Acting as a thermal break, a warm edge spacer bar slows down heat transfer, lowering the U-value of the window. Many energy efficient windows now use a warm edge spacer bar as standard to maximise insulation and reduce condensation.

U-Values WER - Window Energy Rating Sealant Desiccant Gas Spacers Manufacture Product