3M Renewable Energy Division installed its 3M Sun Control Window Film at the National Bank of Arizona in Phoenix on the full-roof skylights of its 144,000-sq-foot headquarters to help the bank save in electricity costs. The 18,000 square feet of skylights allowed natural light to flood the premises. But with daily average high temperature in mid-summer of 102 degrees, and monthly rainfall averages under one inch, the skylights increased cooling costs.
The bank decided to take advantage of a comprehensive energy-efficiency rebate program being offered by its local electric utility, Salt River Project. With a grant, the bank installed 3M Window Film. The bank’s energy-efficiency makeover also included the installation of a new 250-ton chiller to supplement the old one, together with the addition of lighting sensors and new lighting technology. However, the full advantages of these upgrades would not be realized unless something was done to address the heat transmitted through the skylights.
The 3M Sun Control Window Film Prestige Exterior 40 was applied to the exterior of the glass. It reflects up to 97 percent of the sun’s heat-producing infrared light, and 99.9 percent of ultraviolet rays. The film is estimated to be saving the bank 249,000 kWh per year, and the total program is saving about 747,000 kWh per year, translating to more than $74,000 in electricity cost savings in the first year.