It’s somewhat of a secret that window film has more than one application. If used correctly and installed by a professional, window film can deliver huge savings to building owners, especially in warmer climates.

Over ten years ago we purchased a small office building to move our business into. We moved in March, and as spring transitioned into summer and the sun came out more often, our space started heating up.  The air conditioning system (about 6 rooftop and ground based split units), could not handle the load and labored to cool down the building. The employees complained about the heat, and the high electric bill added insult to injury.

Installing new HVAC units would have been very expensive and the roof was not designed to support the additional weight. We looked for another answer and found one at the booth of a window film vendor during a vendor open house hosted by the Institute for Real Estate Management.

Their display was very simple. It consisted of a piece of glass with window film on one half of the glass. A heat lamp was positioned on one side of the glass and two thermometers were positioned on the other side, one parallel to the clear glass and the other one next to the glass covered in the film.  It became clear in a moment that the window film reduced the heat load significantly.

According to tests conducted by window film manufacturers, the film reduces heat loads from 25 to 85 percent. (Results vary depending on manufacturer and type of film; research products carefully to identify the best film for your need.)

The location of the window film is also a factor. Installing film on windows that face east, south and west are typically more effective than on the shady north side of a building, and if your building is already well shaded, window film may not help at all.

Of course window film can be used in residential (single family and multifamily) applications as well. Say you wanted to renovate an apartment complex in Phoenix and the windows are 25 years old.  Rather than buy new windows, you can use window film and market the advantage of lower electrical bills to potential tenants. Owners of residential buildings in hot climates are responsible for maintaining the air conditioning units, so reducing the solar heat load with window film makes a lot of sense since it relieves stress on air conditioners.

Secondary Benefits of Window Film

Although reducing a building’s solar heat intake is the primary purpose of window film, it has other advantages as well.  It relieves the stress and resulting wear and tear on the cooling unit, and reduces the need for individual fans, saving energy and money. Most of these films also almost completely (up to 99 percent) reject UV rays, extending the lifetime of carpeting and furniture in addition to mitigating the harmful effects UV rays on people. As the technology as developed, many film manufacturers have marketed other dual benefits their product.

Security and windstorms: The 3M company has developed a film series that will work effectively in wind storms of up to 185 miles per hour and will resist breaking and entering, if installed by an experienced and certified installer. This micro layered technology is typically blast and tear resistant (see their website for examples).

Anti Graffiti / Surface Protection Series: 3M also offers products that are graffiti and scratch resistant. They can be either 4 or 6 millimeters thick and offer protection from taggers in high risk areas by using an invisible sacrificial layer to protect glass from acid etchings, scratches and tagging. This layer can also protect window surfaces from regular wear and tear.

This product solved a recurring tagging problem we had at a commercial building we manage in a high risk area. Vagrants had repeatedly defaced the windows using keys and other materials.  We replaced the windows twice before discovering this window film.  That was eight years ago.  The surface is scratch resistant and has held up well. Though there is evidence of attempts of attacks to the surface since the installation, the perpetrators eventually became frustrated by the lack of results that they stopped attacking the building altogether. If, perchance, they have some success, we can always strip off the film and replace it rather than installing a new window.

The film offers the added benefits of heat load protection (these windows are on the south side), and privacy. The window film is dark and reflective which makes it difficult to look into the space, (preventing a thief from “casing the joint” by looking through the windows.)

Saving You Money

In select situations, window film can be used to reduce heat load, the stress on HVAC systems, electrical bills, glare and crime.  It also distributes light better in some applications.  As you troubleshoot operational problems and/or attempt to reduce energy needs, consider the use of window films as an economical alternative to window or cooling unit replacements.

Note: There are any more uses of window films. In a future article we will address how window films can be used decoratively or to increase privacy in the interior of buildings with glass walls.

Clifford A. Hockley is President of Bluestone & Hockley Real Estate Services, greater Portland’s full service real estate brokerage and property management company..  He is a Certified Property Manager and has achieved his Certified Commercial Investment Member designation (CCIM).  Bluestone & Hockley Real Estate Services is an Accredited Management Organization (AMO) by the Institute of Real Estate Management (IREM).