King County International Airport-Boeing Field in Seattle is one of the nation’s busiest nonhub airports, averaging 200,000 takeoffs and landings annually. The airport’s main terminal, originally constructed in 1929, underwent a significant energy retrofit in 2017 to save energy and reduce operational costs.
Thanks to lighting and mechanical improvements, the airport has seen $31,000 in annual savings from its 2015 baseline. It also saves 391,499 kilowatt-hours and 26,105 therms of natural gas annually—a 60% reduction in energy usage.
The largest portion of the airport’s savings comes from mechanical upgrades. The airport facility managers replaced the multizone rooftop units with a variable refrigerant flow (VRF) system and a dedicated outdoor air system coupled with a high-efficiency heat-recovery ventilator capable of 90% heat recovery. The VRF system provides facility managers with a high degree of control over the system, as they can set different cooling levels needed to maintain comfortable temperatures in various zones. Retrofitters expect these upgrades to save $19,335 alone in annual heating and cooling costs. These improvements to the HVAC system, coupled with employee education, have also eliminated the plug load from employees’ personal energy devices, such as space heaters and fans, leading to even more energy savings.
The second aspect of the airport’s retrofit was a lighting-system upgrade. For interior lighting, the facility managers replaced 32-watt fluorescent bulbs with 15-watt LEDs with advanced lighting controls such as occupancy and daylight sensors, allowing for even deeper energy savings. They also replaced outdoor ramp and parking lot lighting with LEDs that dim through an occupancy-sensing system.
Airport staff reported that the new bulbs made some areas too bright, so the facility managers dimmed the lights to 75%, which let them gain even more energy savings. The lighting upgrades save $3,200 annually—a 47% reduction in lighting energy costs.