A Green Ramp

New system at Sea-Tac puts 'green' into preconditioned air.


Much of the “green” news that lands on our desk has more to do with a newly constructed terminal. Water-saving toilets and energy-saving HVAC systems aren’t all bad, we suppose, but it definitely makes our day when we find an airport trumpeting a green ramp initiative.

Last month, the Seattle-Tacoma International Airport went online with a PCA system that is expected to save airlines more than $15 million in annual fuel costs and reduce the airport’s carbon footprint by 40,000 metric tons each year, too.

The airport built a centralized plant to deliver PCA through 15 miles of pipe to each of the airport’s 73 jet gates. The central plant houses four 750-ton chillers that fill 16 ice storage tanks with ethylene-glycol solution cooled by electricity furnished by the airport. Four secondary pumps circulate the chilled liquid through pipes to the gates for cooling.

Alternately, the airport’s steam plant heats water that is piped to gates for heating. A heat exchanger at the gate directs the conditioned air through a telescoping duct on the jet bridges, to a ventilation hose and directly into the aircraft’s cabin.

In addition, Sea-Tac obtains about 90 percent of its power from hydro-electric dams and 10 percent from renewable energy and nuclear sources. Both the cooled and heated air generated from PCA, therefore, emits substantially less pollution than the jet fuel in the aircraft’s auxiliary engines.

What’s more, Sea-Tac took advantage of the largest federal grant of its kind to offset the costs of the $43 million project. Nearly $22 million is covered by Voluntary Airport Low Emissions Grants from the Federal Aviation Administration. Airport Development Funds, which come directly from fees charged to airlines, will pay the remainder. These fees will be offset by decreasing operating costs for a projected payback for the project in less than three years.

After first hearing the news, we posted a link within our ever-growing Ground Support Worldwide LinkedIn Group. One astute member wondered how the system controlled the flow and temperature for different sized aircraft.

“At the ramp level, connected to the jet bridge is a control for the hose hook-ups,” Perry Copper, the airport’s media and public affairs manager, reported back to us. “There are three settings: Wide Body, Narrow Body and Regional. The ramp handler selects which is appropriate for the aircraft at hand.”

For larger aircraft there are two hoses that can be hooked up (757, 767,747, 777, 787, A330, A340).

“Each gate is set up for the type of aircraft that could be at that gate,” Copper adds. “The hot and cold going into each of the air handlers at the gate are constant. The aircraft will then meter how much heating and cooling it needs.”

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