Window Films – What to Look For

Films are another great option for improving the efficiency of your homes windows. This option is most commonly exercised when a homeowner is looking for an upgrade without necessarily replacing the glass or other aspects of the window. Window films are commonly sold as extensions to your existing windows. 

Window Films

Window films are exactly what they sound like, films applied to your homes windows to help reduce the energy lost through your windows and glass. These films block against solar heat gain, and protect against UV exposure. Films are most commonly adopted in southern climates because they can also block the suns heat in the winter. 

They are also particularly useful for homeowners who are looking for an unobstructed view out of their window and don’t have a need to prevent glare or heat gain. They are also an excellent choice if you have a furniture layout that blocks a portion or all of the window. Finally, they are always a recommendation for public buildings such as art galleries or museums who are trying to prevent color from being washed out of their exhibits. 

Window films consist of three layers: 

Window Film Cross Section

Films typically have three layers: an adhesive layer that sits against the glass, a polyester film layer, and a scratch-resistant coating. You may also choose options such as tints, UV blockers, or thicker films that offer security. Low-e films are also emerging as an energy-saving option.

Window films are the first window attachment to be rated by the National Fenestration Rating Council (NFRC), which also created window labeling and ratings for consumers. The NFRC’s Window Film Energy Performance Label looks like this:

NFRC Sample Label

The effectiveness of these reflective films depends on:

·        Size of window glazing area

·        Window orientation

·        Climate

·        Building orientation

·        Whether the window has interior insulation.

Window films have some overall disadvantages:

·        Loss of interior light or visible transmittance

·        Extra care required for cleaning

·        Reflections