3 Steps to Carbon Neutral Airports: Step 1

Editor’s note: this is the first post of a three-part series. The first post, outlining opportunities to reduce the amount of energy that airports use, appears here; the second post, stressing the importance of using on-site, clean, renewable energy, appears here.

We see it all over the news — the aviation industry is getting a bad rap in terms of the carbon emissions associated with air travel. The industry is experimenting with biofuels, has increased fuel efficiency, streamlined flight routes, and even reduced travel speeds.

However, air travel is only responsible for 2% of global CO2 emissions (much less than that of road travel). Buildings in the United States are accountable for 48% of CO2 emissions in the U.S.2.  There is a huge opportunity to focus on reducing CO2 emissions associated with buildings.

There are two major components to a facility’s total carbon footprint: embodied and operational. Embodied carbon footprint is the impact of the extraction, harvest, manufacture, transportation and installation of the materials in a building as well as the disposal, recycle or reuse of those materials at the end of their useful life. The operational carbon footprint of a facility is associated with the ongoing operations and maintenance of the facility. I see three major steps that airports can take to reduce (and ultimately neutralize) its operational carbon footprint; here is the first.

Reduce the Amount of Energy Used
The greatest opportunity to maximize energy efficiency in a building is to properly address its orientation.  Long facades should ideally face north and south. At airports, building orientation is often pre-determined by runway placement and site constraints. Designing the building envelope to respond to the given solar orientation is critical. Using daylight sensors or timers to dim or turn off lights in day lit areas during daylight hours reduces energy associated with artificial lighting. Occupancy sensors allow lights to be turned off when spaces are not in use. This is especially effective in restrooms, storage areas and holdrooms where occupancy fluctuates.

Reducing the amount of space that needs to be air-conditioned can have a huge impact as well. Natural ventilation is not always practical when you’ve got acoustic and air quality issues and in cold climates, it may not be practical from a thermal comfort standpoint. However, natural ventilation is successful in some of the smaller, regional airports in hot and temperate climates. The Palm Springs Airport has an open air concourse and the newly opened terminal at Palomar Airport in Carlsbad, CA has operable windows. At the new North Concourse of the San Jose International Airport, displacement ventilation is a more efficient HVAC system than the traditional overhead system, as it delivers air at a lower velocity and higher temperature directly to the occupied zone.

It’s important to look at the big picture of energy infrastructure. Only so much can be done to improve the efficiency within a specific building if it is connected to an existing central plant. Since many central utility plants at airports were built several decades ago, they are ripe for upgrade or replacement with cleaner, more efficient equipment and technologies, such as thermal energy storage, combined heat and power, microturbines and ground source heat pumps.

Endnotes 

1. Ethical Corporation website: “Aviation — The Need for Green Sky Thinking”
2. U.S. Green Building Council

Nellie Reid is a Director of Sustainable Design for Gensler. She founded the Los Angeles chapter of the U.S. Green Building Council and served as board vice chair from 2004 to 2007. She also founded the A+D Sustainable Design Leaders Summit, a meeting of sustainable design leaders from 50 large architecture and design firms. Reid thinks that “sustainability should not just be a noble goal, but a core factor in all decisions.” Contact her at nellie_reid@gensler.com.