A glass guy told me that window film causes window seal failure on double pane glass and low-e glass.  Multiple homes that I have visited have bad seals already. The glass has a slight fog or the seal is drooping from the top and sides. This is before tinting.

Please explain to the homeowner that window film does not cause seal failure on a properly manufactured window.  In Arizona specifically, many homes have bad seals from a window manufacturer that is in a lawsuit with its sealant manufacturer.

Confusing? Window seals can go bad. Reputable window film tint manufacturerโ€™s test their products on the different types of glass available. Film-to-glass charts that show approved applications are available for dealers using architectural films. If the product is found safe for the glass and the seal fails or the glass has a thermal shock fracture (breaks), your dealer should help you get the glass replaced.  Some film manufacturerโ€™s warrant the seal and glass as long as there is an existing warranty on those items: seal 2-3 years and glass warranty for 5 years.  There are many window film products tested and safe for double pane and low-e glass. If you want clear views along with your protection, donโ€™t hesitate, use window tint.