BAS Soars to New Heights

The airline industry went into a nosedive two years ago and is still struggling to recover. But a stormy economy wasn't able to bring down one airport project—the new Continental Airlines Terminal E at George Bush Intercontinental Airport in Houston, Texas. Planning for the project began in the late 1990s when the economy was still flying high.


The airline industry went into a nosedive two years ago and is still struggling to recover. But a stormy economy wasn't able to bring down one airport project—the new Continental Airlines Terminal E at George Bush Intercontinental Airport in Houston, Texas.

Planning for the project began in the late 1990s when the economy was still flying high. Designers had two goals in mind: to create a terminal that would provide passengers a pleasant and efficient traveling experience, and at the same time, deliver state-of-the-art operations and maintenance capabilities.

One way in which designers have achieved both of these goals is by monitoring building systems to an extent not typically seen in airports. Many facilities, of course, have building automation systems. But in planning this state-of-the-art terminal, the design team went several steps further.

The first seven gates in the 23-gate, 600,000-sq.-ft. terminal, designed by Corgan Associates, opened for business on time in June 2003. While travelers look through windows reaching three stories high, Continental Airlines employees are looking at real-time reports on the company's intranet to monitor the electrical and operating status of every system in the building.

In many ways, the project is one-of-a-kind, and one major reason for its uniqueness has to do with ownership of Terminal E.

Owning your own terminal

Most airport terminals are owned by municipalities. In fact, the rest of the Bush Airport is owned and operated by the Houston Dept. of Aviation. For Terminal E, however, Continental leased the ground from the city, enabling the airline to build a terminal in its headquarters city to its own specifications. Doing so required that Continental take total responsibility for operations and maintenance that would otherwise be handled by the city.

"We have responsibility for everything from pay phones to cleaning the floors to signage, even the plumbing and toilets in the terminal," said Rob Walker, senior manager for Continental Corporate Real Estate and project manager for the Terminal E project. "In light of that, we built in a [building automation system] that allows us to monitor a number of points in the building from our desktops. This building was built with facility maintenance in mind."

And much of the facility management is indeed automated. With windows that run continuously from the terminal's scalloped roofline to its terrazzo floors, the terminal building sparkles with natural light. Multiple levels of indoor lighting can rise and fall to adjust to daylight through a lighting control system that uses photocells for ambient light compensation.

Likewise, the HVAC systems scale up and down in different parts of the building—especially during non-peak hours—through scheduling that is determined by the BAS. This allows for energy savings while still keeping travelers comfortable.

No ordinary BAS

But the BAS extends beyond HVAC and lighting to literally every piece of mechanical equipment, even elevators, escalators and moving sidewalks. Facility maintenance staff, and others with appropriate access, can monitor equipment from their computers—or wait for alerts on pop-up screens.

"We can sense voltage overruns, so we can tell if we are having a problem with the moving sidewalks," Walker said. "We can get a service call out before they shut down."

Travelers keep moving, and as a result, stay happy. But airline passengers need more to be content than just being kept in constant motion toward their destinations. They also want a comfortable environment, from their arrival at the airport until they depart on their flights.

This is why the monitoring and controlling of systems extends beyond the building proper to the boarding bridges that funnel people between the door of the plane and the terminal gate. For these bridges, about 50 analog and digital parameters are currently monitored with the approximate capability of 400 points through the use of a solid-state solution using programmable logic controllers (PLCs) instead of hard-wired relays, which provide a much more limited scope of information. The ultimate goal is that Houston's hot and humid air, particularly in the summer, won't be passengers' first impression of the city.

In addition to the real-time information provided by the BAS, the operations staff uses CCTV cameras to ensure that boarding bridges function as smoothly as possible. But it is the BAS that provides vital information on the status, position and movement of a bridge, as well as indicates whether the exterior doors are open when a flight is not at the gate. Moreover, the bridge can be pre-cooled prior to flight arrival and shut down when not in use to maximize energy savings.

Another major advantage of advanced BAS is that personnel receive routine maintenance data that previously required an on-site inspection. Through this kind of monitoring, the operations department can ensure that flights leave on time.

In order to make all of this happen, Carter & Burgess engineers worked closely with Continental's operations staff to understand the airline's processes. In this way, the engineers could specify not only the right equipment, but also the diagnostic tools and parameters for measurement.

"Everything in this building has a data port. It's a big wiring infrastructure with miles of cables," said Allen Clark of Walker Engineering Group, the contractor that handled the electrical construction. Moreover, the PLCs installed on each loading bridge feed even more wire into the terminal's complex electrical and communications infrastructure.

Putting current into miles of wire

Terminal E is served by two high-voltage 12.47-kilovolt (kV) underground utility lines, each fed from different utility substations. Each utility service feeds into one of four manual transfer switches. Each of the manual transfer switches then feeds two 12.47-kV/480-volt transformers.

Due to the size of the building, there are two electrical service entrances, one each on the west and east sides (see Figure, p.52). Each service entrance consists of four transformers that feed into two independent 5,000-amp draw-out switchgear lineups. Each switchgear lineup is configured as a main-tie-main, with a normally open tie-breaker and PLC-controlled automatic rollover. In the event of a loss of one utility source or transformer, the tie-breaker automatically closes, restoring power to the entire bus. Each bus and utility transformer is sized to carry the entire load so that building operations can continue with little or no downtime. The advantage to the facility operations is that the system is automatic and under their control, as opposed to being dependent on a single utility transfer switch and transformer to ensure continued operation of the facility. As another level of redundancy, the manual transfer switch on the transformer primary can be switched by the utility in the event that one of their lines would be out of service for an extended period of time.

This configuration, along with an analysis by design engineers that determined a low incidence of utility outages related to the airport utility circuits, led to the conclusion that an emergency generator would not be required. This decision saved valuable real estate and eliminated future maintenance for the life of the facility.

Moreover, centralized lighting inverters and uninterruptible power supply systems are also deployed throughout the building for critical loads. The lighting inverters provide centralized, easily accessible locations within the electrical rooms for maintenance vs. the lower initial cost associated with individual battery packs in the lighting fixtures.

"It's instantaneous. The lights don't even blink," Walker said, though he will know what has happened just by looking at his computer screen. The BAS provides real-time breaker status for each of the main switchgear lineups and reports when a utility circuit drops and when it is regained. "Everyone seems to lean on an emergency generator. But with two utility circuits, we have redundant power."

Of course, the electrical system is invisible to travelers. They only see high spaces and natural light from clerestory windows—and for now, only in a limited section of the terminal.

The seven gates open today serve domestic and international outbound flights, but ultimately, Terminal E will be an international destination terminal (see "International High Point, p.50). Because of this, Terminal E was designed to handle every type of aircraft in the Continental fleet. Multiple aircraft parking positions allow for most gates to accommodate multiple kinds of jets, from small aircraft for regional travel up to the widebody 777s. This affords a tremendous amount of flexibility in operations, an important consideration in light of the fact that the terminal will witness increasing domestic and international traffic.

Pinnacle of comfort and security

Final realization of the Terminal E master plan also depends on developments outside the terminal. Convenience and security in parking garages is a particular area of focus, not only in Houston but on numerous recent projects through the country (see "Lighting the Path," p.50).

But the quality of life inside the terminal is the key to customer satisfaction, and Continental is creating a very friendly environment in Terminal E. Its responsibility for the entire facility incorporates concessionaires, and Carter & Burgess's electrical design responsibility included finishing out spaces for the food courts, concessions storage areas and some of the restaurants and retail stores.

"New airports are like shopping malls where we land airplanes," Walker said. Concessionaires in Terminal E include more than 30 name-brand outlets in a 50,000-sq.-ft. "airport mall."

The airline wants travelers to be comfortable, and that includes relaxing between flights. In the center of the massive terminal will be the members-only, three-story Presidents Club, the largest lounge in the Continental system. Appreciative international travelers will find individual shower stalls and a full valet service. The Presidents Club also will have 60 private carrels with online connections and a media room. Travelers with children will particularly appreciate the family rooms where parents can stretch out with their children in a space that offers couches and videos to keep the kids occupied. Floor-to-ceiling windows in the Presidents Club will continue the terminal's signature panoramic views. Travelers look out over an impressive atrium on one side or at the airfield on the other.

A separate Young Travelers Club offers views for children to watch the planes and the workers on the tarmac. They get snacks and games in their lounge area. Like all the spaces in Terminal E, this one is engineered to assure the overall project goal of a positive experience for passengers. The Young Travelers Club is a fun, safe and supervised atmosphere for unaccompanied children waiting for flights.

Passengers without the time to take advantage of retail or lounge facilities still have a treat in store. In the center of the terminal, a video wall encircles the elliptically shaped atrium and will certainly catch the eye of even the most rushed traveler. Continental commissioned pop artist Peter Max to create a mural incorporated into the architecture. The artwork appears to float on 77 video screens that line the atrium walls—which of course, required a significant amount of electrical power.

Last but not least, Continental employees will have their own place in the new terminal, the largest of the airline's three main hubs. About halfway through preparation of the construction documents, Continental elected to add a 250-person employee cafeteria. Gordon's Galley, named after Continental CEO Gordon Bethune, is situated next to the company store, providing employees a place to relax and enjoy a great meal. Carter & Burgess was able to provide the needed electrical infrastructure to this space by utilizing spare conduits that were incorporated into the original underground ductbank system early in design.

With flexible spaces and an accommodating electrical system, adjustments such as adding a cafeteria are possible, though still challenging, with tight timelines. It's simply good planning to allow for whatever changes might be needed. In fact, Carter & Burgess allowed for approximately 20% spare power into the infrastructure to allow for growth as well as changing operations. There are spare breakers and panels, plus spare conduit in the ground for pathways for future growth.

For now, though, sights are set on the end of December, the target date for opening the second phase of Terminal E. If the remaining 18 gates aren't quite ready for holiday traffic, Rob Walker reports, they will certainly be ready for passengers arriving in Houston at the end of January 2004, just in time for Super Bowl XXXVIII. It will be time to party, and for Continental Airlines to celebrate its new home.

Lighting the Path: From Car to Terminal

Keeping travelers comfortable and content inside the terminal is important but only part of the game. The trip from parking facilities to terminal is another stretch of ground that design professionals must cover in guaranteeing security and convenience for air travelers, and lighting design plays a major role.

Two major U.S. international airports—Seattle-Tacoma and Minneapolis—have both undergone parking garage lighting retrofits in the past year to improve convenience and security.

Until recently, the 5-million-sq.-ft., seven-story parking garage at Sea-Tac was illuminated by a high-pressure sodium system that created shadows and dark spots. Visibility was poor, not only for drivers and pedestrians but also for security personnel monitoring the surveillance cameras.

ECS Engineering, Seattle, evaluated systems from several manufacturers by installing them in an area within the garage. Based on the systems' performance, designers specified 6,400 fixtures from Holophane with 100- and 175-watt metal-halide lamps in the driving, parking and pedestrian areas. The units include an enclosed glass refractor that provides the necessary balance of vertical and horizontal illumination to promote lighting uniformity.

Because the garage is a public access area, ECS followed Illuminating Engineering Society (IES) guidelines for emergency egress lighting. Some of the new luminaires are connected to the emergency generator system and use quartz re-strike lamps. However, because existing power sources were at capacity, most new emergency egress fixtures could not be connected to the existing system.

ECS specified four emergency lighting uninterruptible power supply (UPS) units to power more than 1,000 of these fixtures. Since the UPS system assures that power to the fixtures is constant, the luminaires connected to the UPS units were without quartz re-strike lamps.

In addition, all lighting fixtures were installed with an automatic timeout device, which reduces the potential for non-passive end-of-life failure of the metal-halide lamps by extinguishing the lamps for 15 minutes each week. The device is designed so that all of the lamps on a circuit cannot cycle simultaneously.

At Minneapolis-St. Paul International Airport, the parking garage underwent a comprehensive lighting retrofit in its parking garage earlier this year, switching from standard metal-halide to more energy-efficient pulse-start metal-halide lamps by Venture Lighting.

New lamps meant that a new energy source was needed since the current ballast system was not compatible with the new pulse-start technology. A new ballast technology offered improved lumen maintenance and lamp color uniformity due to better lamp-to-lamp power regulation and improved system efficiency. The system also offered higher lumens, up to 105 lumens per watt over the course of the lamps rated life compared to lamps using CWA ballasts.

In addition to the planned goals of energy savings and increased light output, the airport is also benefiting in other ways. Improved light levels provide much clearer images for the airport security cameras throughout the parking garage.

International High Point

When the new Federal Inspection Services (FIS) building, currently under construction at Bush Intercontinental Airport in Houston, is completed in early 2005, Continental's Terminal E will begin to handle arriving international travelers.

Continental will place its international ticketing area, with 48 positions, in the FIS building. The City of Houston and Continental are partners in building this central facility, which sits just north of Terminal E and connects with the terminal by both a secure bridge for passengers who have cleared security and a sterile bridge for the arriving international customers.

Adjacent to the FIS building, the new International Bag Room connects to the existing Continental Domestic Bag Room. Located in the first floor of the existing parking garage, this 80,000-sq.-ft. room is full of conveyors and will be powered by a dedicated electrical system designed by Carter & Burgess.

The existing domestic bag room's electrical service shared power with both the existing parking garage and portions of existing Terminal C. A potential problem in the parking garage was the possibility of the baggage system shutting down and crippling Continental's operations. In addition, expansions of Terminal C have required additional capacity that did not exist. By combining both the domestic and international bag rooms into a common electrical service, reliability can be improved for these separate mission-critical systems and capacity is also freed up for other projects.

Improving Air Quality: Vehicles Go Electric

Once bags are sorted, they are transported on one of various kinds of ground service equipment (GSE), traditionally a diesel-powered fleet. Diesel fuel causes emissions that Houston doesn't need. "We trade back and forth with Los Angeles for who has the most air pollution," jokes Rob Walker, senior manager for Continental Corporate Real Estate. But to Continental, the people of Houston and the Texas Commission on Environmental Quality, emissions are no laughing matter.

"Continental, with the City of Houston, made a major commitment to reduce emissions at the airport. Continental is committed to having an all-electric fleet by 2005," Walker says. At terminals B and C, electric GSE chargers are being added at the gates for electric-powered vehicles being developed to address federal air standards.

Terminal E presented an opportunity to install the chargers in a new facility, rather than as a retrofit, even integrating them into the BAS. Of course, that required design of electrical service to handle this significant additional consumption.

Whether it's a baggage cart, a catering truck or fueling equipment, any vehicle in the electric GSE fleet can use any charger, which are attached to the 480-volt electrical distribution within the building. Electric-powered ground service vehicles can plug in at any gate during the day in between servicing planes at Terminal E, topping off their power in just 20 minutes.

At night—when the terminal's electrical load is lightest—all ground service equipment is corralled for a full charge. The charging system is computer controlled so that each vehicle will be given the exact amount of electricity it needs, making it very efficient.

Continental has made a huge capital commitment for electric ground service equipment and is paving the way for other airports looking at this environmentally friendly option.

No comments
Consulting-Specifying Engineer's Product of the Year (POY) contest is the premier award for new products in the HVAC, fire, electrical, and...
Consulting-Specifying Engineer magazine is dedicated to encouraging and recognizing the most talented young individuals...
The MEP Giants program lists the top mechanical, electrical, plumbing, and fire protection engineering firms in the United States.
Commissioning lighting control systems; 2016 Commissioning Giants; Design high-efficiency hot water systems for hospitals; Evaluating condensation and condensate
Solving HVAC challenges; Thermal comfort criteria; Liquid-immersion cooling; Specifying VRF systems; 2016 Product of the Year winners
MEP Giants; MEP Annual Report; Mergers and acquisitions; Passive, active fire protection; LED retrofits; HVAC energy efficiency
Driving motor efficiency; Preventing Arc Flash in mission critical facilities; Integrating alternative power and existing electrical systems
Putting COPS into context; Designing medium-voltage electrical systems; Planning and designing resilient, efficient data centers; The nine steps of designing generator fuel systems
Designing generator systems; Using online commissioning tools; Selective coordination best practices
As brand protection manager for Eaton’s Electrical Sector, Tom Grace oversees counterfeit awareness...
Amara Rozgus is chief editor and content manager of Consulting-Specifier Engineer magazine.
IEEE power industry experts bring their combined experience in the electrical power industry...
Michael Heinsdorf, P.E., LEED AP, CDT is an Engineering Specification Writer at ARCOM MasterSpec.
click me