WHAT MAKES A REPLACEMENT WINDOW ENERGY-EFFICIENT?
Any replacement window you purchase should come with a label from the National Fenestration Rating Council (NFRC). The NFRC conducts independent tests to measure several aspects of a window’s thermal performance.
When reading the label, pay particular attention to these measurements:
- U-value measures how well a glass system prevents heat from escaping. The lower the U-value, the better the glass system.
- Solar Heat Gain Coefficient (SHGC) measures how well a product blocks heat caused by sunlight.
- Visible Transmittance (VT) measures how much light comes through a product.
- Air Leakage (AL). The lower the AL, the less air will pass through cracks in the window assembly.
- Condensation Resistance (CR) measures the ability of a product to resist the formation of condensation on the interior surface of that product.
One of the largest single components in a window unit is the glass. There are many types of glass available, from single pane to multiple layers. It is critical that the glass in your new windows offers the best insulation to keep your home warmer in winter and cooler in summer.
The measure of glass performance is the R-value. The higher the R-value, the better the insulating factor of the glass system. Our windows achieve a remarkably high R-value rating, ranging from 4.5 to 10!
Another key indicator is a window’s U-value. U-value measures overall thermal conductivity of the entire window unit, including glass, frame and sash. The higher a window’s U-value, the better the energy performance. U-value depends on:
- Quality of the materials used
- Type of materials used
- Engineering and design of the window
- Quality of assembly
Marvin windows installed by Twin Cities Siding Professionals are engineered to insulate, achieving a low U-value.
IT COSTS YOU NOTHING TO FIND OUT
Curious about what we can do for your home? Call Twin Cities Siding Professionals at 651-571-9557 for a FREE, no obligation in-home evaluation and estimate. It never hurts to find out!