30 U Factor Windows

Simply put u factor measures how well a window keeps heat inside your home.

30 u factor windows.

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. Lower numbers indicate greater insulating capabilities. The lower the u factor the better the window insulates. Low u factors are most important in heating dominated climates although they are also beneficial.

It s usually expressed in units of btu hr ft2 of. The window world 4000 double hung should deliver a 30 u factor and a 27 shgc. Epa requires that the u factor for energy star labeled products is certified and listed on the product label. U factor is the rate at which a window door or skylight conducts non solar heat flow.

U factor measures the rate of heat transfer and tells you how well the window insulates. 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. The low end of that range is only achievable with higher quality triple glazed windows windows with three layers of glass. Solar heat gain coefficient shgc visible transmittance vt air leakage al windows.

The window world 2000 double hung should provide a 35 u value 52 shgc and a 18 air infiltration rating. High performing double window pane set ups will have a u factor of 0 30 or lower. It s a particularly important measure for climates with colder winters. Nfrc u factor ratings however represent the entire window performance including frame and spacer material.

In fact triple pane windows go down to as low as 0 15 which speaks a lot for their efficiency. U factor values generally range from 0 25 to 1 25 and are measured in btu h ft f. Some window manufacturers have begun to add coatings that emit lower as well as use gas in spaces to decrease the u factor level. In a cold climate a good u factor for a window is between 0 17 and 0 39.

Double paned windows may have a u factor at or below 0 30. It s a measure of total heat flow through a window or door from room air to outside air. For superior energy performance use windows with a u factor of 0 25 or less. If passive solar strategies are to be used there may be a trade off with.

The window world 6000 double hung should provide a 30 u factor and 20 shgc. Triple glazed windows may have a u factor as low as 0 15. Gases are heavier than air and therefore provide insulation resistance to air. That s between r 6 and r 2 5.

Lower is better with u factor the opposite of r value when higher is better. 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.