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.

Double pane low e windows u factor.

Double paned windows may have a u factor at or below 0 30. Good quality single pane window 1 0. Consult specific manufacturers for nfrc rated u factors and shgcs for products of interest. 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 clear and low e. Most windows now carry this rating so it s becoming easy to make comparisons. Energy star provides recommended u factors for your climate. Double pane with low e.

Fiberglass frames can be either hollow or filled with foam insulation. Blocks 94 of the sun s ultraviolet rays. 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.

Very hot sunny climates. 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. Sections may be 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.

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. Gases are heavier than air and therefore provide insulation resistance to air.

Low u factors are most important in heating dominated climates although they are also beneficial in cooling dominated climates. Low e glass is optimal for conserving energy because it reduces ultraviolet uv and infrared light penetration to limit heat transfer. Two panes of glass with sundefense low e protection and insulating argon between the panes. Energy star certified windows come in a variety of framing materials.

A double pane glass is a term to describe the process of adhering two pieces of glass together to create a. Window type u factor ratings. Old metal casement window 1 3. Three panes of glass also available on select product lines for increased energy efficiency.

Some triple pane windows may have a u factor as low as 0 15. 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. 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 glazed low solar gain low e glass.

This figure illustrates the characteristics of a typical double glazed window with a low solar gain low e glass with argon gas fill. Blocks 95 of the sun s ultraviolet rays.