Double Pane Low E Windows U Value

Low u factors are most important in heating dominated climates although they are also beneficial in cooling dominated climates.

Double pane low e windows u value.

Gases are heavier than air and therefore provide insulation resistance to air. Very low emissivity windows offer the best improvement you can obtain in window insulating performance. Are triple pane windows the best. Energy star provides recommended u factors for your climate.

Triple glazed windows may have a u factor as low as 0 15. Low e coatings usually applied to the inside layers of insulating glass manage the amount of light and heat either conducted through a window or reflected away from it. The best high performance double pane windows may have a u factor of 0 30 or lower indicating that they are very energy efficient. Triple pane windows work best when enhanced energy performance is a key objective.

Additionally the window selection tool compares average simulated energy costs for your location based on various window types. Low e windows have u value and emissivity values that range from 0 02 to 0 20 which means that 80 to 98 of the room s heat is reflected back into the room in the winter. The u factor will approach the very low 0 15 point if there is a gas such as argon or krypton between the layers of glass glazing. Some triple pane windows may have a u factor as low as 0 15.

For most energy efficient windows the u factor for the entire window assembly is higher than the u factor at the center of the glass.