Trends in Green

Reducing Peak Energy Demand

• By Darrell Smith
• 06/01/15

With the cold weather behind us, many school building managers are looking for ways to save money and make buildings more comfortable. As the sun heats up during the day, so do temperatures inside school buildings. A/C systems often must work overtime during the costliest period of the day — when peak electric rates are charged.

A very cost-effective solution to this problem is professionally installed window film. With window film, buildings can have a sleek look, save money, reduce glare and hotspots. The International Window Film Association estimates installing Window Film may be up to 91.5 percent less than installing new windows.

Whether placed on the outside or inside of glass, today’s modern window films may cut cooling costs by 30 percent, repel about 80 percent of solar heat gain and some even have the same energy saving capabilities as low-e glass. Return on investment (ROI) is often less than three years and some utilities even offer rebates for window film installation!

For example, to help encourage the reduction of peak energy demand, Dominion Virginia Power offers an average $2,100 towards the installation of window film in Virginia commercial buildings. Dominion Virginia Power’s non-residential window film helps reduce the cost of installation making it more affordable for businesses to reduce solar heat entering buildings through windows by prescribed amounts. In California, many local municipalities offer rebates and tax credits. For example, California’s Proposition 39 helps eligible school projects improve energy efficiency, expand clean energy generation and energy retrofits.

Retrofitting does appear to be the solution most environmentalists are pushing for. The Preservation Green Lab at the National Building Trust for Historic Preservation published its own report recently, which concluded that in almost all cases retrofitting and renovation are better options for energy efficiency. That report was based on a 75-year life cycle analysis of six different varieties of buildings in four American cities. It cited energy savings of four to 46 percent and revealed immediate ROI rather than years down the line.

Window films give the exterior of buildings a uniform, modern look, without the unappealing look of shades and curtains haphazardly open or closed. Unlike window attachments, they also require no human or mechanical intervention because window film is a passive product that performs round the clock. Professionally installed window film can reduce glare by more than 50 percent, allow 30 to 80 percent of visible light in, and block up to 99 percent the sun’s ultra violet (UV) rays.

Protection against UV rays is something property managers should consider when looking at building upgrades. Window film can shield building occupants against the damaging effects of sun exposure. Regular windows used in mid-century buildings often provide no protection from sunlight and expose people who sit near these windows to UV rays, which can cause premature aging of the skin as well as various skin cancers. In the winter months, the sun hangs lower in the sky and can shine directly into school windows; this can potentially cause eyesight damage. By employing window film, building mangers are able to block out harmful UV rays and cut down on glare, while still allowing windows to be fully used and allow in abundant light.

Window film can also make glass more resistant to breaks and shattering from impacts with foreign objects. Professionally installed film may help to hold the window together after an impact break, thus preventing any additional damage to the window frame or people inside the building.

In summary, professionally installed window films can achieve many of the same energy efficient benefits at a fraction of the cost of window replacement while also providing important health benefits. Facilities managers overseeing school properties and grappling with energy efficiency issues need to take a serious look at window film. It could be an ideal solution to both help maintain structural integrity of the original building and deliver the energy savings.

This article originally appeared in the issue of .