Search results
Results from the WOW.Com Content Network
U-factor is a rating system that measures the energy efficiency of building materials like doors, windows and skylights. This system was devised by the National Fenestration Rating Council (NFRC), and is used by the ENERGY STAR program (1, 2).
U-factor is the rate at which a window, door, or skylight transmits non-solar heat flow. For windows, skylights, and glass doors, a U-factor may refer to just the glass or glazing alone. NFRC U-factor ratings, however, represent the entire window performance, including frame and spacer material.
The U-factor, succinctly put, is the measure of a window’s performance in terms of its thermal transmittance. While that might sound a tad complex, think of it as the rate at which a window allows heat to pass through it. It quantifies how well a window acts as a barrier to the flow of heat.
Window ratings provide valuable information about factors such as U-factor, solar heat gain coefficient, visible transmittance, air leakage, and condensation resistance, all of which can impact a home’s comfort, energy costs, and environmental impact. The most common window ratings are U-Factor, SHGC and VT.
Factors to Consider. When purchasing ENERGY STAR qualified windows, look for the U-Factor and the Solar Heat Gain Coeficient (SGHC). The U-Factor measures how well the window in-sulates. While the U-Factor can take any value, in general for windows it ranges from 0.20 to 1.20. The lower.
U-factor is a factor in a well-known equation involving multiplication. The heat loss equation shown here states that Q — the rate of heat flow through a building assembly (in Btu/h) — is equal to the area of the assembly (in ft²) times the ΔT (in F°) times the U-factor (in Btu/ft² • hr • F°).
U-factor indicates how much energy will be lost from a building through its windows by specifying how many BTUs can pass through one square foot of material in an hour.