Myth Buster- Does Window Film Need To Be Dark To Work?

Dark window film isn’t necessary for controlling the sun’s energy as it enters the interior of a building. Visibly clear window film can be just as effective as a dark window film.

One reason some consumers may think window film should appear dark is because the products have been referred to as ‘tint’. In fact the name tint, in reference to window film, is a holdover from the 1960s. Early window films were essentially dyed polyester material or else dyed polyester with a reflective coating (or reflective film layer) added to absorb the sun’s heat or reflect it outward. The darker the film, the more heat was absorbed. The shinier the film, the more heat was reflected.

Today’s window films are still made of polyester, but they have advanced significantly and offer a wide variety of high-performance features. Window films may have many layers of different coatings, each designed to manage sunlight and heat in various ways. They also may be in different thicknesses, different colors, have multiple layers, appear to be non-shiny (much of the reflectance is now invisible) and have scratch resistant coatings.

Window film can block up to 84 percent of the sun’s heat. A primary benefit of window film is its ability to reflect the sun’s heat energy before it enters a room, thus providing for savings on energy bills and reduced air conditioning loads.

Window films can appear visibly clear and still help the consumer to reduce their utility bills, maintain a comfortable interior temperature, block over 95% of the sun’s UV rays, cut the sun’s glare and add a measure of safety to the glass by helping to hold it together when impacted and broken.

Window films are also rated for how much light they allow in; this performance specification is called Visible Light Transmission, or VLT. A window film with a VLT of 25 percent indicates a film that allows 25 percent of the visible light to pass through a window. The lower the rating or percentage associated with the film, the darker the appearance of the window film. A film with 65-75 percent VLT would appear nearly clear.

All quality window films help to reduce many of the negative effects of sunlight, while still allowing sufficient natural sunlight to enter. If you had been using shades or drapes to keep out glare and possibly heat, window film may make your home’s interior much brighter as you no longer need to block out the sunshine just to keep your home cooler and have less glare.