Foam insulated window frames give a higher thermal efficiency over hollow frames. When cured within the foam; millions of small air pockets are created that significantly improve thermal, and sound efficiency. For years, people have used polyurethane foam for numerous thermal applications. Today polyurethane foam can be found in steel and fiberglass doors, walls, attic insulation, pretty much anywhere an airspace needs insulation. Panes Window Manufacturing uses only USDA (United States Department of Agriculture) certified organic foam - safe, odourless, and the highest performance available on the market today.