Consequently, mechanical contractors are opting for fabric duct because of its light weight, even air distribution, and installation ease.

DUCK AND COVER

Mechanical contractor, Darryl Couvillion, president, Darryl's Refrigeration, Belle Chasse, La., had the challenge of air conditioning temporary tent barracks erected at Belle Chasse Naval Air Base for Hurricane Katrina disaster relief workers.

Couvillion outfitted each tent with two 5-ton Carrier 2,000 cubic feet per meter central air conditioners at opposite ends of the barracks. The units are connected to 6-inch diameter runs of TufTex fabric duct manufactured by DuctSox (DuctSox.com), complete with 2-inch diffusion vents that run in a linear pattern at the 4 and 8 o'clock positions.

The Computer Aided Design (CAD) duct design of Norman Pratts, sales associate, for manufacturer's representative, Air Side Equipment, Baton Rouge, La., proved to be critical to the project's success because of the many elbows as well as the duct runs that were required to fit perfectly through the tents' triangular trusses without kinking.

"I think everyone involved in the project is quite satisfied with the fast-track production and the aesthetics of the installation," said David McIntyre, president, Air Side Equipment. "If it weren't for fabric duct, tent conditions would be unbearable."

PERMANENT CAMP MEETING

Mechanical contractor Jeff Flaherty, project manager for General Heating and Cooling, Bartlett, Tenn., didn't take tents seriously until he landed a lucrative contract for a permanent tent structure with Nueva Direccion Church, Memphis, Tenn., that included fabric ductwork.

The selling point of fabric duct for the 15,000-square-foot church was aesthetics as well as budget. Consultant engineering firm, Gala Engineering, Memphis, specified DuctSox's white Sedona fabric because it blends visually with the church's white fabric structure. The Sedona offers Comfort-Flow airflow where 85 percent of the air distribution is through linear vents and 15 percent comes directly through the fabric itself for the ultimate in quiet and draftless air dispersion.

"The church officers definitely liked the look of fabric duct versus the alternative of spiral metal duct with protruding registers," said James Fleck, design engineer, Gala Engineering.

Installing the perimeter ductwork parallel to the church's round contours was challenging. DuctSox custom manufactured nearly every length of duct in a very slight degree elbow that helped the perimeter system gradually curve with the church's shape. Four 10-ton Trane packaged units provide air conditioning.

TENT FUN

Tents are also booming as both temporary and permanent structures for meetings and weddings at golf courses and banquet halls. For example, at The Links at Carillon, a Plainfield, Ill.-based golf course, Melody Chapman, wedding coordinator, uses the facility's new 4,500-square-foot tent for wedding receptions.

"Like any special event, you can't have a summer wedding reception in a hot environment, it has to be very cool," said Chapman. "The tent with heating and cooling really extends the season for golf outings as well."

The Links at Carillon uses two York 15-ton packaged units to supply 72°F air to three runs of 20-inch fabric ductwork that hangs from the tent's rectangular-shaped ceiling.

Now serviced by Jacobazzi Heating and Cooling, Plainfield, Ill., the tent's IAQ is controlled by two thermostats located one at each end of the structure.

BIG TOP COOLING

Circuses are perhaps becoming the greatest tent IAQ innovators while trying to keep paying customers comfortable. One North American touring circus company uses a combination of 80 tons of custom-manufactured mechanical rooftop equipment designed specifically for portability, noise reduction, and lightweight struc-ture by Engineered Environments Inc., Cincinnati.

The system includes a fabric duct air dispersion system by DuctSox and a building auto-mation system that rivals most stationary theater buildings.

The circus's 170-foot diameter, 60-foot high main tents HVAC system bathes a capacity of 2,500 spectators and 55 performers in a gentle flow of comfortable 74° air at all times. Besides human comfort, the draftless airflow is also critical to the accuracy of aerial acrobatics, smoke effects, juggling, and balancing artistry commonly used in circuses.

The main tent system air is brought near the top of the four-point tent with two opposing vertical columns of DuctSox's premium Sedona Comfort-Flow fabric duct.

It branches into a perimeter loop approximately 50 feet above the spectators and performers to provide gentle, even airflow superior to conventional metal duct/register systems that would have been prohibitive because of weight.

Outdoor air used is approximately 25 percent and determined by CO2 sensors that are monitored by a Trane Tracer DDC building automation system.

As more organizations seek the less expensive facility approach of tents, the business of air conditioning and heating them will continue in the future.

Publication date: 03/27/2006