Is bigger better? There is a trend towards 6 foot coil lines in sheet metal shops from the standard 5 foot. But just how strong is this trend?

Dave Frieden, vice president, sales and marketing for Iowa Precision, said the trend has been surfacing over the past four to five years. "The trend probably isn't 50-50 yet, more like 60-40," he said, adding "Climatemp of Chicago was one of the first."

Out of the last 31 coil lines sold, Frieden said 10 were 6-foot lines and 20 were the more commonly seen 5-footers. The other was nearly two meters, or 80 inches, built for a European customer.

Use of 6-foot coil steel for ductwork allows contractors to use fewer connectors; fewer flanges, fewer corners, etc. That can mean considerable labor savings in the field, and less chance for leaks. But not all duct shops want to go the six-foot route. Contractors are used to handling the five foot lengths, and the six footers can be more cumbersome for installers. In the fabrication shop, a new six foot coil line is more expensive by perhaps as much as $100,000, and other machinery - such as a beader or plasma cutting table - also need to be super-sized to accommodate the larger stock.

Tom Esper, general manager of the Duct Connection, Troy, Mich., chose a 6-foot coil line when they opened for business a couple of years ago "because we didn't want to feel foolish later on if everyone else was going to 6 foot." However, the trend has been slow to materialize and for the most part his company is still producing 5-foot lengths.

The Duct Connection has a steel-producing partner, Glomar Inds., which makes getting the 6 foot stock less of a hindrance, but others may be held back by the lack of steel availability. Especially, Esper said, when the automotive industry was running red-hot and chewing up most of that steel to build cars. Now that the auto market has slowed down a bit, he said, there should be more availability of 6-foot coils for hvac ductwork. But, he said, "the designers and the engineers have to specify it," and so far they're not widely doing so. In fact, he said, "We still get calls for 4-foot" even though 6-foot lengths are more economical to install because of the fewer fittings and connections involved. Old habits die hard, apparently.

Who's the customer?

Esper said he thinks more 6-foot is being specified in Southern California and Texas, and it may take a while for the trend to show up elsewhere. Some shops that fabricate pretty much for their own installation purposes have an edge, he pointed out, since they have more control over what is produced and installed, whereas pure fabrication shops like his own are held to the demands of the customers.

Kim Trinkley, Central West Machine, has sold and brokered many, many new and used coil lines over the past 20 years, and considers 6-foot coil lines "the wave of the future." The reason? Do the math. "Six foot lines need only five joints per 30 feet, versus 6 joints on 5-foot lines." While there are still some drawbacks impeding the movement to 6-foot lines, Trinkley said it is becoming almost impossible for 5-foot coil lines to compete economically with 6-footers.

Tom Martin Sr. of T.H. Martin Duct Systems in Cleveland said that while a 6-foot coil line was considered with the company's recent shop expansion, "We're happy now" with the current 1987 Iowa Precision coil line outfitted with a new AMS controller. "It runs like a new machine. Any ideas of a 6-foot (coil line) are on hold for now," he said. A 6-foot line would be a nice addition, he said, but would also require a little more bracing in the ductwork, and require a bit more deftness in material handling, perhaps even requiring one person positioned on each side of the cutting table.

Rick White of Dee Cramer Inc., Flint, Mich., has a 6-foot Engel coil line that was installed two years ago, but the 6-foot capability is just starting to be utilized. "It's the way everybody will go," he said. "There were two issues at the time we bought it, though. There was the higher price of the equipment, but also we were loading steel with a forklift back then and we really needed an overhead system. Our new facility has one. We were also able to bring in a new, larger cutting table at the time of our expansion."

White said there should be savings gained from shop to installation. "Producing six foot lengths shouldn't cost us much more than producing five foot lengths," he said. "Then you have the savings in all the fewer joints that are needed."

B.J. Lefler of B.J.'s Metal Works in Missoula, Mont. recently bought a 5-foot coil line, and considered a 6-foot. But he said, "You need two guys to handle it, to turn it between the drives and to put on the TDFs." B.J. added several pieces of equipment from Central West Machine when he landed a couple of hospital jobs, but decided against adding the 6-foot coil line. He added that it's not easy getting the 6-foot stock in Montana.

Frieden of Iowa Precision said he remembers some of the same trend many years ago as the industry moved from standard 4-foot lines to the bigger 5-foot lines. "We probably haven't sold a 4-foot line in 20 years," he said. He echoed the thought that not a lot of 6 foot coil steel stock is available right now for the hvac market, but "supply will increase as demand increases."

A manual on shop layouts published in the 1970s and updated in 1981 by Snips magazine noted that use of coil steel rather than flat sheet stock could make a sheet metal shop more productive and profitable. However, it made no mention of 6-foot coil lines. An example: "L-shaped duct production from 48-in. and 60-in. wide coils."

Lockformer showed its Duct-O-Matic II at the AHR Expo. It handles up to 6-foot coils and can produce blanks for L-sections and wrap-arounds at up to 75 feet/minute. A Grid Auto Feed System simplifies coil selection and feeding. Beading and notching are integral with the system, and corner notches such as Slip & Drive, TDC, Snap Lock and Pittsburgh are standard.