Window film is making a big difference in energy savings for hotels all over the country, and now it is making big news because of its proven energy savings. California recently incorporated window film into its state building code, making it the first state to recognize window film as a practical way to save energy through reducing solar heat gain and improving window insulating performance. This code change takes effect in January 2014.
Window film was also recently found to be the most cost-effective choice for energy savings in retrofit applications. An independent study compared window film to other traditional energy-saving techniques like updating HVAC systems, air sealing and caulking, and adding R-38 ceiling insulation. Window film came out on top as the most economical way to save energy and reduce carbon footprints.
In existing buildings, including hotels, energy savings alone can offer a payback of less than two years, or a 70 percent ROI, for window film.
Many commercial buildings can also reduce their use of artificial lighting after installing window film, since it allows safe, natural daylight to enter a space without glare or UV exposure. Unlike blinds or shades, window film keeps harmful UV rays out and minimizes glare without blocking occupants’ views. Some films also offer an extra layer of security (a barrier that helps hold glass in place upon impact) or a decorative element (emulating etched or stained glass).
Different Types of Window Films
There are a few different types of window film, all of which provide benefits over untreated glass. Standard window films (reflective and lower-reflectance films) provide excellent savings during the cooling season, but reduce solar heat gain through windows year-round, even when heat gain might be helpful (during the winter). These films provide excellent net savings and an attractive ROI.
Low-e window films improve window insulating performance 24/7, and also limit solar heat gain in winter for two to three hours per day on sunny days (which are less frequent than in warmer months). Low-e window films reduce heat loss in the winter and both solar and non-solar heat gain in the summer. They keep the heat out in summer and keep the heat in during winter. Traditional low-e films offer improvement in window insulating performance of 44 percent; the newest low-e window film technology improves insulating performance by as much as 92 percent.
Hotels across the United States have used window film to successfully reduce energy costs, maintain comfortable interior temperatures, provide security, and reduce glare and UV ray exposure.
The Marriott in Winston-Salem, N.C., wanted superior comfort in its guestrooms, but the hotel’s HVAC system wasn’t able to cool the sunniest rooms down past 78 degrees F. After receiving complaints from guests, the Marriott chose to use window film to address these issues. After the film was installed, the same HVAC system was able to cool guestrooms down to 72 degrees F. The Marriott’s annual heating and cooling costs are expected to drop by 5 percent (a savings of $24,000). Projected payback for the project is approximately three years.
Maui Success Story
The Presidential Sky-Top Suite at Embassy Suites Resort on Kaanapali Beach in Maui, situated on the top floor of a high-rise building, was causing a problem for guests with its oversized, wrap-around windows that let the sun’s heat and destructive rays in. The suite’s air-conditioning bills were high, glare was getting in the way of Maui’s views, and the suite’s furniture, drapes, and floors were fading prematurely. The resort used window film to reduce total solar energy by 65 percent, decrease UV rays by 99.9 percent, and cut glare by 70 percent; the hotel also achieved 60 percent solar heat rejection. In addition, it reduced fading of interior furnishings and provided an extra layer of security by selecting window film that helps hold glass in place if it shatters.
Adam’s Mark Hotels in Dallas used window film to reduce energy costs, achieving a substantial decrease in energy usage with an ROI of two years. Film was also selected to unify the look of the three buildings in the hotel/office complex. Window film provided a cohesive, reflective look on the exterior without ruining views for guests and occupants.
According to the U.S. Department of Energy (DOE), America’s 47,000 hotels spend about $2,196 per room each year on energy (6 percent of all operating costs). If hotel managers could reduce energy consumption by just 10 percent, the DOE says those savings would have the same financial impact as increasing the average daily room rate (ADR) by $0.62 in limited-service hotels and $1.35 in full-service hotels. Window film is an economical solution for reducing energy use, increasing guest comfort, and boosting profitability.
Steve DeBusk is global energy solutions manager for Solutia Performance Film’s Vista brand. He has 28 years of experience in the energy-efficiency business. DeBusk is a Certified Energy Manager, a Certified Measurement and Verification Professional, and a Certified Sustainable Development Professional. Solutia focuses on providing solutions through a range of products, including performance window films from Vista.