Vinyl window frames and sash corners are fusion welded for maximum strength and protection against air and water infiltration. Tests using the common measure of insulating ability, the U-factor, have shown that vinyl windows regularly perform exceptionally well because of the excellent thermal performance of the frame (shown in table below). Warm air stays inside during the winter and cool air stays inside during the summer. Energy is conserved and money is saved when the furnace and air conditioner don't have to work so hard to maintain the desired temperature.
Homeowners can achieve $125 - $340 annual savings* on energy bills by replacing single pane windows with ENERGY STAR® vinyl windows.
*Savings estimates based on regional population-weighted regional average annual energy use for a 2,000 square foot, single story, detached house with 15% glazing, gas heat and electric air conditioning. Estimates calculated using RESFEN 3.1 with default operational assumptions and window library. Estimates use state average utility rates (EIA, August 2004). Actual savings will vary by climate region and home characteristics. Source: U.S. Department of Energy, ENERGY STAR for Windows, Doors and Skylights