Window Film for Buildings

Window film for buildings is also known as window tint or architectural window film. It is a thin layer of polyester-based film that is applied most commonly to the interior of flat glass windows. It is commonly used on retrofit projects and installed by trained professionals. For example, the premier brand Vista Window Film is a laminate of strong polyester and metalized coatings bonded by adhesives. A scratch resistant coating is applied on one side; a mounting adhesive layer and a protective release liner are applied to the other side. When the release liner is removed, the side of the film with the adhesive is applied to the interior surface of the glass. Architectural window film can be clear, colored, or patterned to blend with various design schemes. Various thicknesses are available for solar, safety, or security applications.

How Does Window Film Work?
As solar radiation strikes a piece of glass, window film blocks harmful UV rays and regulates the levels of heat and light passing through the glass. Solar radiation from the sun is divided into 3 components; visible light we can see, and infrared and ultraviolet rays which we can only feel. The amount of heat and light rejected is all dependant on the type of window film selected.
Energy-saving window film enhances the solar and thermal performance of a building's windows. It does this by reducing excessive solar heat gain – reducing cooling loads and peak demand. In addition, low emissivity (or low-e) window films improve the insulating properties of windows – offering increased cooling season savings and the added advantage of heating season savings.

Window film can deflect up to 99.9% of UV rays and about 79% of the solar heat that filters through unprotected windows. Therefore, it significantly reduces cooling costs for buildings. In general, for every 150-250 square feet of window area protected by high-performance window film, the load on the building’s cooling equipment is reduced by 1 ton of air-conditioning (12,000 BTU/hr). Independently-verified actual field measurements have shown an average of 8.8% annual energy savings from adding window film.

Window Film ROI
Impressively, average payback on window films is often less than three years, which is quite an improvement over window replacement, which often takes longer than 15-20 years. As an added benefit, many utility companies offer rebates specific to window films that cover as much as 50% of installation costs, greatly increasing the speed of ROI. (If your utility company doesn’t list window films specifically, they may still be eligible for Custom Measures rebates which can offset installation costs by as much as 30%.)