An adaptation of automobile catalytic converters designed to reduce pollution and increase efficiency in wood stoves isn't exactly burning up the market, but two manufacturers are optimistic.
Catalytic Damper Corp. of Conway, Ark., is poised to begin production near Flint Hill, Va., of such a device, its in.ten'si.fire, a catalytic combuster that can be installed in the flue of most wood stoves. It will join similar devices built for wood stoves being offered this year by between 30 and 40 manufacturers, according to a spokesman for Corning Glass Works, which apparently developed the first such combuster.
In 1977, Robert VanDewoestine, a Corning research scientist, was concerned about a buildup in his chimney of creosote -- a fire hazard -- from his wood stove. VanDewoestine had been involved heavily in research that led to development of the catalytic converter used to reduce autombile exhaust pollution, and it occurred to him that the technology could be adapted to reduce pollutants in wood smoke.
Gases formed in stoves and in automobile engines are similar, but "wood smoke is a lot more complex," according to Fred Noll, a Corning product engineer whose responsibilities include catalytic combusters and window glass for wood stoves.
The major problem was coming up with a catalyst and with a honeycombed configuration that would mix this catalyst with the smoke without interfering with the draught in a wood stove, Noll said.
Another problem was convincing the company that "there was money in the product," he recalled.
The combuster works by lowering the temperature at which wood smoke will burn from 1,100 degrees Fahrenheit or more to between 500 and 600 degrees and then helping it burn. "Since smoke is fuel, now you're releasing heat that would have gone up the chimney or collected as creosote," Noll explained. The result is an average gain in efficiency of between 10 and 15 percent, he said.
"We're actively working to find better catalysts," Noll said, adding that the goal is to increase the device's life beyond 6,000 hours, but that he doesn't foresee significant additional gains in efficiency.
"A lot of people get the efficiency bug and focus on that," while the combuster's "main function is to get rid of creosote or reduce it significantly," thus cutting the chance of a chimney fire, agreed Eric Hutchinson of Catalytic Damper Corp. Hutchinson said his company's add-on combuster will reduce "47 dangerous wood-smoke compounds" by an average of 75 percent, and trim creosote formation by an average of 80 percent and by as much as 90 percent.
Jerry Taylor of Acme Stove, one of about a dozen area stores specializing in wood stove sales, has reservations about the two companies' claims. Taylor has tested a stove with a combuster and says that, although he has verified energy savings, "I don't see a tremendous change" in creosote formation in stoves with built-in or add-on combusters. Taylor is secretary-treasurer of Washington-based Acme, which operates five stores between Bowie and Warrenton and four others farther away. He has been selling stoves for 30 years.
He explained that a combuster will work only when the stove's temperature rises to between 500 and 600 degrees -- a process that he says takes 45 minutes to an hour when starting cold with average wood -- and that, once the fuel has reached the charcoal stage, there's no creosote to burn. This means that the combuster is not operating for a significant amount of time, he said.
Taylor also said that newspapers, magazines with color, coal or trash cannot be burned without damaging the combusters.
He said that sales were "fairly decent" in 1980, but dropped last year. On the basis of early sales, Taylor expects "a good, strong season this year." He noted that only about half a dozen of the "several thousand" stoves that Acme sold last year included combusters.
Hutchinson of Catalytic Damper Corp. predicts that 70,000 of the 1 million stoves expected to be sold in the 1982-83 season that starts next month will have combusters. His company's add-on combuster will be available next month in wood stove stores, hardware stores and building-material stores. Models with 6-inch, 7-inch or 8-inch collars for circular, top-flue stoves will retail for $200, while a rear-flue-stove adapter will cost $30.