30 U Factor Windows

The window world 6000 double hung should provide a 30 u factor and 20 shgc.

30 u factor windows.

The window world 2000 double hung should provide a 35 u value 52 shgc and a 18 air infiltration rating. U factor is the rate at which a window door or skylight conducts non solar heat flow. In colder climates in the north that are heating dominated the u factor should be less than or equal to 0 30 for windows and less than or equal to 0 55 for skylights. Simply put u factor measures how well a window keeps heat inside your home.

Triple glazed windows may have a u factor as low as 0 15. The low end of that range is only achievable with higher quality triple glazed windows windows with three layers of glass. Double paned windows may have a u factor at or below 0 30. That s between r 6 and r 2 5.

If passive solar strategies are to be used there may be a trade off with. Low u factors are most important in heating dominated climates although they are also beneficial. Epa requires that the u factor for energy star labeled products is certified and listed on the product label. Nfrc u factor ratings however represent the entire window performance including frame and spacer material.

U factor measures the rate of heat transfer and tells you how well the window insulates. Some window manufacturers have begun to add coatings that emit lower as well as use gas in spaces to decrease the u factor level. High performing double window pane set ups will have a u factor of 0 30 or lower. In a cold climate a good u factor for a window is between 0 17 and 0 39.

The window world 4000 double hung should deliver a 30 u factor and a 27 shgc. The lower the u factor the better the window insulates. In fact triple pane windows go down to as low as 0 15 which speaks a lot for their efficiency. For most energy efficient windows the whole window u factor is higher than the center of glass u factor.

In areas where air conditioning needs are minimal windows that allow for solar heat gain during the day a solar heat gain coefficient of 0 40 or higher can be considered. It s a particularly important measure for climates with colder winters. For windows skylights and glass doors a u factor may refer to just the glass or glazing alone. Solar heat gain coefficient shgc visible transmittance vt air leakage al windows.

It s usually expressed in units of btu hr ft2 of. U factor values generally range from 0 25 to 1 25 and are measured in btu h ft f. 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. Lower numbers indicate greater insulating capabilities.

For superior energy performance use windows with a u factor of 0 25 or less. 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.