Double Pane Low E Windows U Factor

Three panes of glass also available on select product lines for increased energy efficiency.

Double pane low e windows u factor.

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. Consult specific manufacturers for nfrc rated u factors and shgcs for products of interest. Good quality single pane window 1 0. Blocks 94 of the sun s ultraviolet rays.

Most windows now carry this rating so it s becoming easy to make comparisons. Old metal casement window 1 3. Double pane clear and low e. Good single pane with storm window 6.

Additionally the window selection tool compares average simulated energy costs for your location based on various window types. 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. Some triple pane windows may have a u factor as low as 0 15.

Gases are heavier than air and therefore provide insulation resistance to air. 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. 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 glazed windows may have a u factor as low as 0 15.

Vinyl frames are low maintenance and provide good thermal insulation. Generally speaking windows all have a u factor between 1 3 and 2 and the lower the number the better. Energy star certified windows come in a variety of framing materials. Fiberglass frames are strong durable low maintenance and provide good insulation.

Very hot sunny climates. Double pane with low e. Window type u factor ratings. This figure illustrates the characteristics of a typical double glazed window with a low solar gain low e glass with argon gas fill.

Low e glass is optimal for conserving energy because it reduces ultraviolet uv and infrared light penetration to limit heat transfer. Blocks 95 of the sun s ultraviolet rays. The only exception to this rule are roof and skylight windows with low e smartsun glass which offer a u factor of 0 35. Sections may be hollow or filled with foam insulation.

A double pane glass is a term to describe the process of adhering two pieces of glass together to create a. Double paned windows may have a u factor at or below 0 30. Low e is a microscopically thin and virtually invisible coating that is applied to the side of glass that faces. Low u factors are most important in heating dominated climates although they are also beneficial in cooling dominated climates.

Fiberglass frames can be either hollow or filled with foam insulation. Energy star provides recommended u factors for your climate.