The employees of Hangar 405 in Frankfort, Kentucky, at the Capital City Airport were often subjected to the 20 degree Fahrenheit outdoor temperatures each time the floor to ceiling hangar doors were opened to relocate aircraft. It was a struggle to recoup the heated air produced by the four ceiling-mounted, forced-air gas heaters. With a temperature set point of 56 degrees Fahrenheit, much of the heat remained at the ceiling level due to stratification. Hangar 405 needed an efficient way to circulate the trapped heat down to the occupants to reduce utility costs and increase worker comfort.
Enter Big Ass Fans who installed a 20-foot HVLS fan from the 40-foot peaked ceiling to help destratify the air and reduce the reheat time. Data loggers were installed at 5, 15, and 35 feet above the finished floor to monitor and record space temperatures. An additional logger was installed to track gas usage with and without the fan in motion.
Without the fan, data loggers recorded an average temperature difference of 6 degrees Fahrenheit between the floor and ceiling even after the hangar reheated. That meant wasted money in heating costs as the heated air rose to the high ceiling area. In addition, the average air temperature at the occupant level was increased by 1.5 degrees Fahrenheit.
Once the fan was installed, the temperature difference was reduced to less than 1 degree, allowing for significant savings in heating energy used. “In the winter time it was cold because all the heat was up at the ceiling. It would normally take an hour or two to reheat but now with the fans, as soon as you close the doors, the heaters kick on and immediately move that warm air down,” explained facility manager Steve Seager.
HVLS fans are engineered to slowly circulate the heat collecting at the ceiling level back to the occupant level to minimize heating costs and maintain comfort. The first year after installation, Hangar 405 realized an estimated net savings of $2,650 over a five-month period.
Brandon Steele is a sustainability engineer at Big Ass Fans in Lexington, Kentucky. He is primarily responsible for assessing corporate and customer facility energy efficiency and waste reduction.
