What is a good U-factor for a window?
between 0.17 and 0.39
In a cold climate a good U-factor for a window is between 0.17 and 0.39. (That’s between R-6 and R-2.5). Lower is better with U-factor–the opposite of R-value, when higher is better. The low end of that range is only achievable with higher-quality triple-glazed windows–windows with three layers of glass.
What does window u-Value mean?
The thermal transmittance, otherwise known simply as the u-Value for windows is the measurement that indicates the rate the heat transfers through a window. The measurement comprises of three different, but equally important, factors.
What is the best U-value?
The best insulating materials have a U-value of close to zero – the lower the better. Building regulations currently stipulate that for a new building, the elements must have maximum U-values as follows: Wall – 0.3 W/m2k. Roof – 0.15 W/m2k.
What does the U in U factor stand for?
thermal transmittance
R-Value is a measure of thermal resistance, or the ability of an object or material to resist the flow of heat. U-Value is a thermal transmittance, or the heat loss through a structural element.
What U-value is needed?
To put that into context: a single-glazed window will have a U value of 5.0, a standard double-glazed window around 1.6 and triple glazed around 0.8. Building Regulations require a wall of no worse than 0.3, roof 0.16, and ground floor 0.22. All of these U values are written as W/m2K.
What is the U-factor of Pella windows?
between 0.15 and 1.20
Definitions. A rating based on how much heat is allowed to transfer through the product. The NFRC website states U-factor ratings for fenestration products generally fall between 0.15 and 1.20.
Is a higher U-value better?
U-values can tell you how well an insulated glass unit (IGU) will hold in heated or cooled air. The lower the number, the better the insulating performance. U-values generally range from 0.1 (very little heat loss) to 1.0 (high heat loss).