Before you buy and install replacement windows in Denver, CO, you need to take into account several important labels and ratings. Window performance in terms of energy efficiency must be prioritized over aesthetic value as this will determine the savings and return on investment you can potentially enjoy in the long run. The NFRC conducted standardized and independent test methods to complete the following energy performance ratings:
U-Factor (U-value) measures the rate of heat loss and the insulating capacity of the product–with general ratings between 0.20 and 1.20. The lower the U-factor, the less heat will be lost as the window is more resistive so a reduction in wasted heating expenses can be achieved.
Solar Heat Gain Coefficient (SHGC)measures how well a window blocks unwanted solar heat—with ratings expressed between 0 and 1. A lower rating indicates lower heat transmission, which is favorable in warmer climates.
Visible Transmittance (VT) measures daylight or visible light transmission through the window. The rating is between 0 and 1—the higher the number, the more you can maximize the available daylight.
Air Leakage (AL) is an optional rating thatmeasures the window’s ability to keep air out. The lower the AL value, the lesser the amount of air that passes through joints or cracks. Lower air leakage consequently reduces heating/cooling costs.
Condensation Resistance (CR) is another optional rating that measures the window’s resistance to water build-up; expressed in numbers between 0 and 100. A higher CR rating indicates better resistance.