McGill AirFlow was tapped to fabricate the ductwork for a new $27 million facility for the National Center for Environmental Health (NCEH) in this community outside Atlanta.

The five 45-ft. high, 58-in. diameter stainless steel exhaust stacks fabricated by McGill AirFlow are visible from the ground.
CHAMBLEE, Ga. - Employees at McGill AirFlow Corp. take every job seriously, but when a project involves the U.S. government and the public's health, it takes on added importance.

That's what happened when McGill was tapped to fabricate the ductwork for a new $27 million facility for the National Center for Environmental Health (NCEH) in this community outside Atlanta. The Environmental Health Laboratory is being built by the U.S. General Services Administration, the Centers for Disease Control (CDC) and the NCEH to conduct research into the environment's effect on people. Pollution, communicable diseases, birth defects and more will be studied by scientists and researchers at the new 90,000 sq. ft. facility when it opens at the end of the year.

McGill was asked by the mechanical contractor, W.B. Wallis, to produce more than two miles of ductwork for the laboratory in less than six months. McGill is no stranger to medical and laboratory projects, having fabricated ductwork for research facilities at Duke and Vanderbilt universities. Company officials decided McGill's Fountain Inn, S.C. plant was best suited for the job. The 65,000 sq. ft. plant produces ductwork for nine McGill warehouses in the southern U.S. The fully-equipped plant contains a variety of machinery from manufacturers such as Iowa Precision, Lockformer and Spiral-Helix, including a six-foot coil line.

According to special projects manager Joseph Schelble, the NCEH job took precedence in the plant's busy schedule. "We had to work some overtime," he said.

The lab's 120-in. diameter aluminum outside air duct towers above McGill AirFlow special projects manager Joseph Schelble.

Tons of duct

McGill produced almost a half-mile of medium pressure spiral duct and more than a mile of long seam welded, stainless steel duct for the laboratory's exhaust system. The project also required 145,000 lbs. of rectangular duct and fittings. In addition to the inside ductwork, McGill made five 45 ft. tall, 58-in. diameter stainless steel exhaust stacks and a 120-in. diameter aluminum outside air duct and 130 lineal feet of boiler breaching. Total weight of the oval, round and rectangular ductwork fabricated exceeded 150 tons or 300,000 lbs.

The three-story building will require about 380,000 cfm. of supply and return air and 104,000 cfm. of laboratory exhaust air. CDC officials estimate the laboratory will require nine to 13 air changes per hour.

Since air quality is so vital to NCEH research, officials demanded all ductwork have zero leakage, a specification Schelble called "almost impossible to meet." McGill workers were required to visually inspect all sides of the ductwork by hand. In many cases, the duct had to be capped and workers used a flashlight to look for pinhole-size openings. All welds also had to be ground perfectly smooth before they could be shipped to the construction site.

Changing specifications added to the job's challenges, Schelble said. "Some of the stuff was such that there were changes being made at the last minute," he said, adding that a 120-in. elbow originally slated to be galvanized had to be replaced by an aluminum one on short notice. "It took about a week just to get the rings to put that thing together."

Once the ductwork was delivered onsite in Chamblee, it was installed by workers from Scottdale, Ga.-based W.B. Wallis. While the firm was hired as mechanical contractors, it usually does most of the installation work as well - Wallis employs about 35 sheet metal workers and 50 plumbers and pipefitters, all union members. The NCEH laboratory will use a chilled water system with a custom air handling unit - Trane Co. chillers, Buffalo air handlers and Cleaver-Brooks boilers.

Company President Barry Wallis Sr., 56, said the lab project hasn't been easy, but it's nothing out of the ordinary for the eight-year-old firm. "It's all challenging," Wallis said of his work. Past clients of W.B. Wallis have included Bell South, American Telephone & Telegraph (AT&T) and the Georgia World Congress Center (GWCC) in downtown Atlanta. For the GWCC, Wallis was overseeing a complete replacement of the large convention center's air-conditioning system. Since the GWCC is a very popular convention spot, city officials could not afford to shut down the center for the ac replacement. That meant Wallis workers were always on the move, sometimes having to work in a different section of the building every week. "That was pretty challenging too," Wallis said.

The NCEH Environmental Health Lab is part of a 10-year, $1 billion modernization and expansion program by the CDC. Work at the NCEH has led to increased knowledge about the dangers of lead poisoning, preventing spina bifida and developing new methods for measuring toxins in humans.