Category Archives: Window Films

NFRC and Window Films

If you glance at a window film manufacturer’s list of statistics and your eyes may glaze over due to the sheer volume of data. All of this information is and has always been tested, verified and provided by the manufacturer itself. But third party verification is now on the horizon. Enter the NFRC: the National Fenestration Rating Council. The NFRC is a 30-year-old organization that administers the only uniform, independent rating system for windows, doors, etc. All new windows come with this sticker on it. Solar Heat Gain Coefficient (SHGC) (upper right) relates to how much heat the glass cuts down, U-factor (upper left) relates to heat loss. Window film, on the other hand, does not use this system. 

All film uses Total Solar Energy Rejected or Heat Gain Reduction as the means of measuring heat rejection. You can figure an SHGC but you would still be using the manufacturer’s numbers. Thus, comes the NFRC certification, to add credibility to the manufacturer’s numbers. Plus, it will make sure that the playing field is level between manufacturers. Furthermore, entry into the ENERGY STAR program is a possibility now for window films. While the NFRC board approved procedures for film in early 2005, everything should be in place by mid-2006. Certified energy ratings for window film will be soon upon us, which is good news for both window film installers, like us, and anyone else who wants better performance out of their glass.

Window Films and Window Warranties

Most of the time, installing window film will void the window manufacturer’s warranty but the film manufacturers have backup warranties. That is the simplest explanation of the relationship between window films and window warranties but it is also a completely unsatisfactory explanation of a subject that deserves at least a little more thought. For the purposes of this article, we will limit ourselves to talking about double pane glass: low-E or standard, tinted or clear. Single pane glass rarely has warranty issues while triple pane is rare. We will also assume a standard window film from a reputable manufacturer, such as 3M or Vista. Professional window film installations come with 3 warranties.

  1. The easiest warranty to explain covers the film itself. Generally, there is a lifetime warranty covering any kind of deterioration of the film. Deterioration can take the form of bubbling, peeling, hazing; all are symptoms of adhesive failure. Fixing adhesive failure requires removing the bad film and reapplying new film.
  2. The second warranty covers what the film manufacturers refer to as “Thermal Shock Breakage”. Essentially, this means that the film is warranted not to break the glass for a given period of time, generally 2-5 years. The reason why the glass may break is because filmed glass absorbs more heat than unfilmed glass. The added heat stress, on rare occasions, causes the interior pane to crack. Most films designed for home usage are safe on windows, every so often this occurs, generally because of a flaw in the glass.
  3. The third warranty covers seal failure of the glass. The film manufacturers are aware that many glass manufacturers void their warranties, so every film installation comes with a warranty against the seal failing, which is the main reason why the window warranty comes up in the first place. The standard seal failure warranty lasts for 2-3 years. Even better, Vista and 3M offer warranties that will take over the manufacturer’s warranty at a minimal cost. That way, no coverage is actually lost.