Most of the heat loss in patio doors can be attributed to conduction through solid materials (eg. thermo spacers, glass, door sashes and frames).  Heat conducts from the warmer to the cooler side of the door.  All our insulated glass units are made with warm-edge spacers that reduces conductivity by 75% when compared to conventional aluminum spacers, offering superior insulation performance.

Some reasons that our doors are rated as energy-efficient doors: Energy-Saving Low-E Glass Slower Convection and Conduction with Argon Gas Avoid Condensation and Decay Preventing Air Infiltration