Double Pane Low E Windows U Factor

Very hot sunny climates.

Double pane low e windows u factor.

Most windows now carry this rating so it s becoming easy to make comparisons. Some triple pane windows may have a u factor as low as 0 15. A double pane glass is a term to describe the process of adhering two pieces of glass together to create a. 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.

Energy star certified windows come in a variety of framing materials. Vinyl frames are low maintenance and provide good thermal insulation. Low u factors are most important in heating dominated climates although they are also beneficial in cooling dominated climates. Energy star provides recommended u factors for your climate.

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. Good quality single pane window 1 0. Double pane with low e. Old metal casement window 1 3.

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. Additionally the window selection tool compares average simulated energy costs for your location based on various window types. This figure illustrates the characteristics of a typical double glazed window with a low solar gain low e glass with argon gas fill. 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.

Double pane clear and low e. Double glazed low solar gain low e glass. Window type u factor ratings. Fiberglass frames are strong durable low maintenance and provide good insulation.

Fiberglass frames can be either hollow or filled with foam insulation. Double paned windows may have a u factor at or below 0 30. Low e glass is optimal for conserving energy because it reduces ultraviolet uv and infrared light penetration to limit heat transfer. The only exception to this rule are roof and skylight windows with low e smartsun glass which offer a u factor of 0 35.

Gases are heavier than air and therefore provide insulation resistance to air. Two panes of glass with sundefense low e protection and insulating argon between the panes. Low e is a microscopically thin and virtually invisible coating that is applied to the side of glass that faces. Triple glazed windows may have a u factor as low as 0 15.

Three panes of glass also available on select product lines for increased energy efficiency. The best high performance double pane windows may have a u factor of 0 30 or lower indicating that they are very energy efficient. Consult specific manufacturers for nfrc rated u factors and shgcs for products of interest. Blocks 94 of the sun s ultraviolet rays.

Generally speaking windows all have a u factor between 1 3 and 2 and the lower the number the better. 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.