Window films have been used for decades for many reasons, but one primary benefit of architectural films are their ability to reduce energy costs in buildings and homes. Advances in the manufacturing of architectural window films (e.g. using all-metal films with no dyes to change color and innovative adhesive systems that securely adhere films to glass for many years) have enabled film manufacturers to typically offer 10-15 year warranties on many products used in non-residential settings, and often lifetime warranties in residential applications. Window films of today are durable products, protected by UV-absorbing layers that usually block 99% or more of the UV rays and a resilient scratch-resistant coating for easy cleaning and no maintenance. Many applications around the globe have been in service for more than 20 years providing long-term energy savings while maintaining a nearly-new appearance.
Solutia Performance Films recently launched a new architectural window film with the brand-name EnerLogic™. Unlike most window films that produce savings only during the cooling season, EnerLogic window film is an all-season, low-emissivity (low-e) film that produces both cooling and heating season savings. Low-e films typically produce the greatest overall annual savings when comparing films with similar solar-control properties. With its patent-pending low-e coating that produces an emissivity of 0.07 (versus the 0.35 of most other low-e window films), EnerLogic window film will produce superior energy savings to all other films.
EnerLogic window film improves window insulating performance sufficiently to give single-pane windows dual-pane performance. Likewise, adding EnerLogic window film to dual-pane produces triple-pane performance. Since we are now talking about whole-window performance, U-value must be used, rather than R-value, as R-value is specific only to a single layer of a multi-layer product. Given EnerLogic’s U-value, and using different frame types (e.g. aluminum without a thermal break, aluminum with a thermal break, wood, and vinyl), one can compute the annual average U-value of EnerLogic window film added to single, double, and triple-pane glass with a specific frame type, and compare this value to the annual average whole-window U-value of windows with the same frame type. Performing this analysis for the various windows types, the U-values of windows with EnerLogic film are lower (better) than the U-values of windows without film. For example, EnerLogic window film added to single-pane 6mm (1/4 inch) clear glass, for a 914 mm x 1219 mm (36 inch x 48 inch) window with an aluminum frame with no thermal break, produces an annual average U-value of 4.78 W/sqm/deg K (0.842 BTU/hr/sqft/deg F). The same frame with dual-pane clear glass of the same thickness, with a 12 mm (1/2 inch) air-space and no film applied has an annual average U-value of 4.905 (0.864). So, adding EnerLogic window film to a single-pane window improves the insulating performance as if one replaced the existing glass with dual-pane glass with an air-space. Similar results are obtained using different frame types. Using these methods, the same can be said for adding EnerLogic window film to dual-pane glass and obtaining triple-pane insulating performance.
EnerLogic window film is a low-cost, high-return technology that compares favorably to other popular energy-saving measures both in terms of energy efficiency and cost savings. In fact, EnerLogic window film typically outperforms most of the alternatives in terms of simple payback.
Because the cost to upgrade a building with EnerLogic is typically much less than the costs involved with other upgrades, and because EnerLogic is often eligible for utility company rebates, your return on investment comes even faster.
EnerLogic window film produces a pleasing improvement in low-e window film appearance and more importantly from an energy-savings standpoint a significant improvement in window insulating performance, giving single-pane glass dual-pane glass insulating performance, and giving dual-pane glass triple-pane glass insulating performance. This improvement in insulating performance, coupled with the film’s solar-control properties, result in unequalled energy savings compared to other standard solar-control and conventional low-e films.