Double Pane Low E Windows U Value

Triple glazed windows may have a u factor as low as 0 15.

Double pane low e windows u value.

Some triple pane windows may have a u factor as low as 0 15. Are triple pane windows the best. High performance double pane windows can have u factors of 0 30 or lower while some triple pane windows can achieve u factors as low as 0 15. Low u factors are most important in heating dominated climates although they are also beneficial in cooling dominated climates.

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. The more panes the better right. The best high performance double pane windows may have a u factor of 0 30 or lower indicating that they are very energy efficient. 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.

Gases are heavier than air and therefore provide insulation resistance to air. Energy star provides recommended u factors for your climate. 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. 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.