What is the most important thing to keep in mind when selecting the right products and installing new windows? A high performance rating. While aesthetics are an important factor, performance ratings should be considered first, before you select your specific windows for remodel.
The U-factor rating of a window or door measures insulating ability, and the solar heat gain coefficient measures the door or window’s ability to block the sun’s heat. The best performing doors and windows have a U-factor of .30 or less and a solar heat gain coefficient of .30 or less. As a rule of thumb, the lower the U-factor the more energy efficient the product is.
The best windows also are double-glazed, gas-filled with low-e coatings and have insulating spacers to reduce the likelihood of condensation.