In part one of this two-part blog, we went over some of the ratings and descriptions you’ll find at or near the top of a NFRC window label. This label, offered by the National Fenestration Rating Council, is required for all window manufacturers and contains information about efficiency, performance and other important factors.
At Peach Building Products, we’re happy to explain these kinds of labels for any of our products, from replacement windows to shades, blinds, doors and all our other high-quality products. Let’s go over the rest of the NFRC window label and what you need to know about it.
Visible Transmittance (VT)
There’s an area of every NFRC label that’s labeled “Additional Performance Ratings,” and that’s where you’ll find the area for Visible Transmittance (abbreviated VT). VT refers to how much light is able to pass through the window, with a rating that spans from 0 to 1 – closer to 0 means less light passes through, while closer to 1 means more light passes through.
For window purchasers, it’s important to consider both VT and solar heat gain coefficient, which we went over in part one. Not only do you need to know how much sun the window will let in, you need to know how it handles the heat transfer here as well, ad how this impacts your view or the darkness shade of your window.
This is an optional rating, meaning you may not find it on every window you look at. When it is present, though, the Condensation Resistance rating starts at 0 and ranges all the way up to 100, tracking how well the window resists condensation on the interior section. You want a rating as close as possible to 0 here, signaling that condensation is not common and will not be a dripping or water damage risk.
Just to the right of the VT rating we described above is a number for Air Leakage. This is another optional rating, but most manufacturers do include it. The closer your Air Leakage number is to zero, the less heat gain and loss is taking place through cracks in window assembly, and the better off you’ll be in terms of your energy bill and comfort.
Most NFRC labels will also contain at least one of the following certifications at the bottom:
- WDMA: Short for Window and Door Manufacturers Association, this is a trade group that sets standards for both windows and doors. These standards are considered very high.
- Energy Star: This logo means the window exceeds energy standards of efficiency in its region, rather than just meeting them.
- Hallmark: This rating also comes from the WDMA, and serves as their recognition of excellence. This is a badge of honor for many manufacturers who are able to attain it.
For more on reading NFRC window labels, or to learn about any of our window and door services, speak to the staff at Peach Building Products today.