So you’ve looked at your options, and are trying to decide on a wood stove. One important choice to make is whether to purchase a catalytic or non-catalytic stove. Which one is the best option for you? Each comes with advantages and disadvantages; there’s no “best” stove, only the best option for you and your home.
Whether you chose catalytic or non-catalytic, Wooden Sun wants you to make an informed choice. Catalytic stoves sometimes get a bad rap, but much of this is based on a previous generation of stoves. Early catalytic stoves were non-catalytic stoves which had been quickly adapted to meet EPA standards; the catalysts were often difficult to get to and hard to maintain, and the stoves simply weren’t as efficient as they could have been. Since then, manufacturers have vastly improved the design of catalytic stoves, and the result is a better, easier to maintain stove.
Here are the facts we have gathered together to help you make an informed choice between catalytic and non-catalytic.
Advantages of a Catalyst
If you’re looking for maximum efficiency and the cleanest burn, a catalytic stove is hard to beat. Just like the catalytic converter in your car, the catalytic combustor in a wood stove traps the smoke and other byproducts of combustion, and has a chemical coating (generally platinum and/or palladium) which interacts with the smoke and ignites it at around 500 degrees, rather than the 1100 degrees normally required. This increases the efficiency of your wood stove 5-10%, especially at low temperatures, and reduces emissions by 3-5 gm/hour. With this increased efficiency, and the ability to burn the fire very low without risk of it smoldering and producing creosote, catalytic stoves can achieve very long burn times — up to 40 hours!
Disadvantages of a Catalyst
There are a few drawbacks to a catalytic stove. The first is that the catalyst is another part that can break down, and it will eventually wear out and need to be replaced. The catalyst can also be ruined by the use of treated lumber, coal, colored or glossy paper, or other non-pure wood and fire starter sources (much as you wouldn’t put lower-grade gasoline in a high-end car). While unseasoned firewood won’t permanently damage your combustor, it will crud it up (again, like non-premium oil or gasoline in a high-end car), reducing its effectiveness. And there is an extra step in the combustion process — opening and closing the bypass damper at the correct times. A final potential drawback of a catalytic stove comes only if you have a particularly short chimney. A shorter chimney may not have the sufficiently strong draft a catalytic stove requires to function at lower temperatures, and the stove won’t be able to achieve its maximum burn time.
Advantages of a Non-catalytic Stove
So you’re concerned that a catalytic stove might require more attention than you want to give your wood stove. In short, a non-catalytic stove is simpler to operate. It doesn’t require the extra step of engaging and disengaging the bypass damper (although we still recommend monitoring the temperature to make sure you aren’t over-firing and damaging your stove). With no catalyst to damage and replace, green wood and the combustor killers mentioned above aren’t as serious a problem, although we still recommend burning only well-seasoned wood and approved fire starters at all times, and never burning trash or treated lumber. Green wood just stinks!
Non-catalytic stoves operate at their most efficient and burn the most cleanly at a moderately hot temperature. This can be an advantage in leaky old farm houses or huge spaces that need a maximum BTU output to maintain a warm environment.
Disadvantages of a Non-catalytic Stove
Although it’s easier to operate, a non-catalytic stove can’t achieve the highest levels of efficiency and the lowest levels of emissions, as compared to a catalytic. Moreover, a non-catalytic stove won’t burn as cleanly at low temperatures. And since it can’t manage the very low burn rates of a catalytic stove, a non-catalytic stove won’t be able to be able to achieve the very long burn times of its best catalytic cousins.
A Tale of Three Stoves
The Blaze King Princess catalytic stove is among the most efficient wood stoves in the world, at 88% efficiency with only 2.42 gm/hour of emissions. On high heat, the Princess will burn for up to 10 hours; on its lowest heat setting, the stove will burn for as long as 30 hours!
This is the Pacific Energy Summit, an exclusively non-catalytic stove. It’s 80.5% efficient, with 3.9 gm/hour of emissions, and a burn time of up to 14 hours. Simple to operate, this stove is both tough and reliable!
The Vermont Castings Encore Flexburn (along with its big brother the Defiant) is unique in that it can function as a catalytic or non-catalytic stove. Its readily-accessible combustor chamber makes it easy to examine, maintain, and replace the combustor. If you don’t engage the catalyst, this stove is 78% efficient. In catalytic mode, the efficiency jumps to 86%, with only 1.2 gm/hour of emissions.