DFW makes its terminals more energy efficient, by Carroll McCormick.
Reducing power consumption by 10% and water consumption by 25% are key goals of the seven-year Terminal Renewal and Improvement Program (TRIP) at Dallas-Fort Worth International Airport.
This will be largely achieved by concentrating nearly 70% of the renovation’s budget for the four TRIP terminals (A, B, C and E) on mechanical, electrical and plumbing systems. The other 30% will be spent on architectural finishes. The renovations include high-efficiency motors; reduced air infiltration; fewer entrances and revolving doors; improved wall and roof insulation; high-efficiency variable air volume systems; and low-pressure piping systems.
The 10/25% target reflects the airport’s commitment to sustainability formalised in its Environmental Management Policy. It is also part of a memorandum of understanding (MoU) DFW signed with the US Environmental Protection Agency (EPA) on February 22, 2012. Other targets outlined in the MoU include optimising materials management through recycling, reuse, conservation and providing annual data on the impacts of these goals. In return the EPA will help DFW reduce its environmental footprint, provide a single point of contact to discuss sustainable strategies and provide tools that quantify economic and environmental benefits.
“The great value of this MoU is in the relationship building and networking that will take place between DFW and our federal level environmental regulator,” explains Julie Ludeman, the airport’s Communications Director, TRIP.
On the water consumption front DFW calculates it will easily beat the 25% target. It already estimates that it will save 5.5 million gallons (20.8 million litres) of water a month, a 40% reduction, with equipment such as automatic faucets/taps and toilet flushing. Other water-saving initiatives include drip irrigation, rainwater collection and water reuse.
The building, and its glass in particular, is a rich place to obtain savings. Replacing the 40-year-old windows in the terminals with low-E, fritted glass will reduce heat gain and save about 100 tons (91 tonnes) of cooling capacity per terminal. Fritted glass has enamel images fired onto its surface, which reduces solar gain and glare. “The mechanical systems reflect the efficiencies of the glass,” Ms Ludeman says.
The terminal designs also maximise the use of daylight in order to reduce energy consumption. Window shading will help keep heat gain within reasonable limits. Signage will use LED lighting, which require 70% less energy than fluorescent tubes. Improved light control systems and dual-level fixture switching will further reduce the electrical bill.
A tremendous reduction in the energy required to heat and cool the terminals will come from the use of fanwall technology. This consists of multiple fans for each of the 42 cooling units in each terminal. Since the fans operate independently of each other, they can be taken offline or brought back online as cooling and heating requirements change. The result is reduced energy consumption. A test of the system in late 2011 identified a 34.45% decrease in the energy required to cool a section of Terminal A.
A new ability to control the indoor environment will also reduce energy waste. “For the first time we will be able to control all the terminals from a central location. For example, we will be able to control the HVAC [heating, ventilation and air conditioning] from the central area,” says Perfecto Solis, Vice President of Airport Development and Engineering Department, DFW.
DFW is not seeking Leadership in Energy and Environmental Design (LEED) Green Building Rating System certification for the work. With the project already on a tight budget, the extra funds that pursuing LEED would involve in terms of initial outlay, plus the need to monitor, track and record applicable data, makes it too expensive. However, other capital projects have given the airport a very LEED-oriented attitude. “As sustainability relates to capital programmes like ours, we try to achieve LEED silver for stand-alone buildings. We completed a 10,000sq ft [929m2] environmental affairs department in April 2010. We built a geothermal farm under the parking lot for it and reduced electrical/mechanical costs by 30%,” Mr Solis says. Another example is the new fire station at the north end of the airport which opened in September 2011. It was designed to obtain LEED silver certification.
In the TRIP design, project management, construction methods and operation, DFW is following a script with a familiar LEED ring. “With the terminals we try to take the best LEED thinking and develop our programme around that. Sustainability is a cornerstone of DFW. It is a philosophy we bought into years ago,” Mr Solis explains.
Recycling and reusing materials removed during demolition is an important component in applying sustainability strategies to TRIP. By October 2012, contractors had recycled 48% of the material they removed from Terminal A. This includes carpeting, 54 tons (49 tonnes) of copper wire and 1,250 tons (1,134 tonnes) of other metals, to the tune of 1,328 tons (1,205 tonnes) of material so far. The airport crusher has already processed 54,000 tons (45,359 tonnes) of concrete from the demolished parking garages at Terminal A for reuse onsite.
The TRIP programme takes another chapter from LEED in the selection of new building materials. It calls for the use of environmentally responsible content, such as carpeting with recycled and locally available products, reducing energy consumption used in shipping.
Air quality is one of the most difficult environment issues facing North Texas, according to DFW. When construction peaks next autumn, as many as 2,500 construction workers will enter and leave the job sites every day. To save fuel and reduce pollution, says Mr Solis, “we will make a consolidated parking area and bus the workers to the construction sites”.
Architects have generated approximately 20,000 sheets of drawings for each phase of each terminal’s renewal. Using technology that earlier contractors and project managers could only have dreamed of, all of the drawings are stored on the ‘cloud’ computer memory for retrieval and viewing on iPads. The handy tablets are standard equipment for reviewing drawings.
All of the concepts are in a 3D model that lets contractors detect any clashes in the design/build. This ability to preview designs eliminates a lot of material waste. “All of our nearly 200,000 drawings are on the cloud to avoid printing. Everyone uses iPads. We are saving several million dollars on printing charges,” Mr Solis explains.
Avoiding printing costs and the use of seven tons (6.35 tonnes) of drawing paper is arguably a minor line item for a $2.3 billion project, but the advantages of electronic storage and retrieval of the drawings are many. “Our construction team has set up its own WiFi on the site. Using the iPads for video conferencing on issues that need instant attention avoids driving around and burning gas,” Solis says. “There is no wasting time going back and forth.”
Sustainable and green building operating practices are not simply declared a success when construction is completed, then left to fend for themselves, so to speak. The airport does what is called continuous commissioning, which is when system performance is reviewed after construction is completed to make sure systems are operating within their design parameters. Take the lesson of Terminal D, finished in 2005: Texas A&M University recommissioned all the electrical and mechanical systems and found an additional 10% in savings.
“Just because an asset has been completed and put into service it does not mean that we are done,” Mr Solis says. “With TRIP, A&M University, with which we have an agreement, is going to start working the day after commissioning so we can maximise our savings.”
What is TRIP?
TRIP is a $2.3 billion project encompassing four terminals (A, B, C and E) over seven years of construction. “We are gutting down to the existing frame and rebuilding. About 30% of the work is architectural and 70% is mechanical, electrical and plumbing,” says Perfecto Solis, Vice President of Airport Development and Engineering Department, DFW.
TRIP is 18 months into the schedule, with work currently ongoing in three of the four terminals. Jacobs Engineering in Dallas, Texas, is the engineer of record – responsible for all aspects of design and systems – for the first third of Terminal A, which will be put back into service in late 2012 or early 2013.
Jacobs Engineering is also responsible for the design at Terminal C, the Dallas Area Rapid Transit Station (DART) and the Enhanced Parking Structure at Terminal A. Dallas, Texas-based DMJM/EJES Joint Venture is responsible for the design at Terminals B and E. Irving, Texas-based Paslay Management Group is the Owner’s Representative and Dallas-based Freese & Nichols is providing professional service staff on behalf of the airport for the programme.
The work, designed to extend the life of the terminals, includes enhanced concessions, improved parking, reconfigured and expanded security checkpoints and enhanced self-service ticketing areas. Additional terminal capacity and some additional capacity for international flights will be added, plus ten more gates for domestic flights. The DART Orange Line will be extended to the airport, linking it to the city commuter system.
“TRIP gives us an opportunity to rearrange our assets to reflect our international reach and position ourselves to be very competitive in the coming years,” Mr Solis says.
DFW makes its terminals more energy efficient, by Carroll McCormick.