ABSTRACT
Solar-control films are used worldwide as an effective means of lowering building energy costs by reducing excessive solar heat gain through windows. Determining energy savings from actual installations is difficult due to the common practice of implementing several energy conservation measures simultaneously and due to annual variations in the many factors that can affect a building's energy usage. To isolate and quantify the energy-saving benefits of solar films, an energy analysis study on a conventional office building was undertaken using the U.S. Department of Energy (DOE)'s sophisticated DOE-2 energy-simulation software. The study included several types of solar films applied to various glazing systems. Various cities were included in the study to illustrate the energy savings in different climates and to show the effect of differing electricity costs. Based on the most typical types of installations and on customary installation costs for medium-size commercial projects, the average return on investment (payback) from solar film application was an impressive 2.65 year. These savings were the result of reducing annual electricity kilowatt-hour (kWh) usage by an average of 6.6% and reducing peak summer month kilowatt demand on average by 6.4%.
