HOME ABOUT US MEMBER COMPANIES THE MANY REASONS TO USE STEEL WINDOWS AND DOORS SPECIFICATIONS / INSTALLATION PRODUCTS REPLACEMENT VS. RESTORATION RECYCLABILITY STATEMENT FAQ's CONTACT US     NARROW SIGHTLINES STRENGTH VERSATILITY LIFE CYCLE HISTORIC REPLACEMENT FACTORY FINISHES INSTALLATION CLASSIC HARDWARE THERMAL PERFORMANCE FIRE RATING SECURITY PRODUCTS SPECIAL APPLICATIONS       THERMAL PERFORMANCE. A popular misconception about windows is that aluminum thermally broken windows outperform steel windows. Laboratory tests run by individual manufacturers demonstrate that because the total window surface area constituted by the frame is so small, the effect of the material is almost negligible. Window thermal performance is actually a function of the type of glass and glazing procedure. Thermal breaks are essential to aluminum windows because aluminum is a more efficient thermal conductor and thus prone to sweating. Thermal breaks do not necessarily improve thermal performance. Steel window ventilators often outperform alternatives because they are not subject to deformation and are therefore less likely to leak.   © The Steel Window Institute (2006) Contents are the property of the Steel Window Institute, its members or others who have licensed the information. All rights reserved.