We are often asked if window films can be added to Low E windows the answer is yes with the right films.  We did a test comparing low e glass vs. low e glass with Huper Optik Ceramic 30 installed.  There was a 8 degree temperature change with Huper Optik’s Ceramic 30 on an east facing window in Crystal Falls (Leander, TX).  The right window films will enhance your windows performance.  With Huper Optik’s No Risk Warranty the customer has a glass breakage and seal failure warranty matching the current warranty to ensure the customer is protected in the unlikely event of seal failure.  Take a look it is very interesting comparison.