At Woodstock Soapstone, when asked if we use catalytic combusters in our wood stoves, our answer is an emphatic yes! Since we began using catalytic technology in 1982, we have found it to be the cleanest and most efficient way to burn wood. Catalytic design was one of several technologies developed as a response to the Environmental Protection Agency’s mandate for wood stove manufacturers to produce cleaner burning stoves. Early designs were often difficult or expensive to operate and maintain, and some manufacturers opted for alternatives to the catalytic combustor to achieve the EPA emissions requirements. Here at Woodstock Soapstone, we have developed an easy to use a catalytic system that our customers swear by. To learn more about catalytic technology, please read on.

Note on EPA Efficiency Ratings

The EPA assigns a 72% efficiency rating to catalytic stoves, and a 63% efficiency rating to non-catalytic stoves. Although this is a difference of 9 percentage points, it is actually an increase in efficiency of 14% for catalytic stoves compared to non-cats. 72%/63% = 1.14, or a 14% difference.

3. Catalytic combustors are more economical than non-catalytic stoves. Because they start operating efficiently at lower temperatures, catalytic stoves generally have longer burn cycles, lower stack temperatures and higher heat transfer rates than non-catalytic stoves. This means that the heat generated stays in your home rather than going up your chimney to the great outdoors. The longer burn times and high efficiency and heat transfer rates of catalytic stoves also mean you burn less wood to heat your home. It’s that simple.

4. Catalytic stoves burn cleaner than non-catalytic stoves. Current EPA regulations restrict only particulate emissions. Catalytic combustors provide dramatic reductions in airborne particulates, but catalysts are also highly efficient at burning other compounds in the exhaust stream, such as carbon monoxide, methane, benzene, and volatile organic compounds. This thorough combustion means higher efficiency, lower emissions, and safer performance (less creosote in the chimney because the exhaust is mainly CO2 and water vapor).

5. As an added bonus, catalytic stoves are often more durable than non-catalytic stoves. Catalytic stoves burn very cleanly and efficiently at low to medium heat outputs, as noted above. The thermal stress of burning particulates and volatiles is concentrated in the catalyst, which is a durable ceramic material built to withstand normal temperatures up to 1,700 degrees. Focusing all of the high temperature activity in the catalytic combustor allows other stove components to stay in comfortable operating temperatures and not get overheated.

Non-catalytic stoves require insulated fireboxes and much higher temperatures to achieve secondary combustion and begin burning particulates and gasses in the exhaust. The insulation material is usually firebrick or ceramic. The insulation improves EPA emissions but decreases heat transfer efficiency. If a non-catalytic stove is over-fired, the whole firebox may be damaged by thermal stress. This would result in a large repair job with a hefty cost for the replacement parts needed to repair your stove.

• Inexpensive and easy to replace. Replacing a catalytic combuster is a matter of taking the old combuster out of the stove and removing it from its cast iron frame (by removing two bolts).

Place the new catalyst in the cast iron frame, bolt the frame together again and put it back into the stove. You’re ready to go.

Our catalytic combusters are fully warranted for the first three years you own your stove, and carry a pro rated discount for the fourth, fifth, and sixth year (when replacement catalysts cost $80.00 - $100.00 depending on the age of the stove. After the six-year warranty expires, the replacement cost of a catalyst is $125.00.