Double Pane Low E Windows U Factor

Low e glass is optimal for conserving energy because it reduces ultraviolet uv and infrared light penetration to limit heat transfer.

Double pane low e windows u factor.

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. Low u factors are most important in heating dominated climates although they are also beneficial in cooling dominated climates. A double pane glass is a term to describe the process of adhering two pieces of glass together to create a.

Energy star provides recommended u factors for your climate. Old metal casement window 1 3. Double pane with low e. 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.

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. Low e is a microscopically thin and virtually invisible coating that is applied to the side of glass that faces. Energy star certified windows come in a variety of framing materials. Good quality single pane window 1 0.

This figure illustrates the characteristics of a typical double glazed window with a low solar gain low e glass with argon gas fill. The best high performance double pane windows may have a u factor of 0 30 or lower indicating that they are very energy efficient. Good single pane with storm window 6. Double paned windows may have a u factor at or below 0 30.

Three panes of glass also available on select product lines for increased energy efficiency. Fiberglass frames can be either hollow or filled with foam insulation. The only exception to this rule are roof and skylight windows with low e smartsun glass which offer a u factor of 0 35. Most windows now carry this rating so it s becoming easy to make comparisons.

Blocks 95 of the sun s ultraviolet rays. Consult specific manufacturers for nfrc rated u factors and shgcs for products of interest. Some triple pane windows may have a u factor as low as 0 15. Double pane clear and low e.

Gases are heavier than air and therefore provide insulation resistance to air. 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. Additionally the window selection tool compares average simulated energy costs for your location based on various window types. Blocks 94 of the sun s ultraviolet rays.

Two panes of glass with sundefense low e protection and insulating argon between the panes. 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. Triple glazed windows may have a u factor as low as 0 15. Window type u factor ratings.

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. Vinyl frames are low maintenance and provide good thermal insulation.