Double Pane Low E Windows U Factor

Blocks 94 of the sun s ultraviolet rays.

Double pane low e windows u factor.

This figure illustrates the characteristics of a typical double glazed window with a low solar gain low e glass with argon gas fill. Window type u factor ratings. Two panes of glass with sundefense low e protection and insulating argon between the panes. 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.

Double pane dual pane glass naturally performs better than single pane glass for energy efficiency as the space between each pane acts as an additional layer of insulation from the heat or cold. Three panes of glass also available on select product lines for increased energy efficiency. The only exception to this rule are roof and skylight windows with low e smartsun glass which offer a u factor of 0 35. Energy star provides recommended u factors for your climate.

Low e glass is optimal for conserving energy because it reduces ultraviolet uv and infrared light penetration to limit heat transfer. Fiberglass frames can be either hollow or filled with foam insulation. Gases are heavier than air and therefore provide insulation resistance to air. Old metal casement window 1 3.

Low u factors are most important in heating dominated climates although they are also beneficial in cooling dominated climates. Some triple pane windows may have a u factor as low as 0 15. Double pane with low e. The best high performance double pane windows may have a u factor of 0 30 or lower indicating that they are very energy efficient.

Vinyl frames are low maintenance and provide good thermal insulation. Sections may be hollow or filled with foam insulation. Energy star certified windows come in a variety of framing materials. Triple glazed windows may have a u factor as low as 0 15.

Generally speaking windows all have a u factor between 1 3 and 2 and the lower the number the better. Fiberglass frames are strong durable low maintenance and provide good insulation. Good quality single pane window 1 0. Most windows now carry this rating so it s becoming easy to make comparisons.

Good single pane with storm window 6. Double pane clear and low e. Very hot sunny climates. Double paned windows may have a u factor at or below 0 30.

Blocks 95 of the sun s ultraviolet rays. Low e is a microscopically thin and virtually invisible coating that is applied to the side of glass that faces. Double glazed low solar gain low e glass. 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.

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 e smartsun windows and doors feature the best heat insulation of all andersen products with u factors ranging from 0 24 to 0 25.