Experience with catalytic wood stoves

[m7040]

Considering updating our wood stove to a Vermont Casting or Woodstock soapstone stove using catalytic combustion. Using an older non catalytic Jotul stove at the moment and it works fine but uses a lot wood and is not quite big enough on cold days. So we would consider upgrading to a larger and latest design wood stove. The Jotul is easy to operate and will burn anything we put in it but has to be tended to often to keep it going. Was wondering about your experience with medium size Vermont Casting or Woodstock stoves. Precautions to protect the catalytic converter, start ups, maintaining the fire, extended burns during the night, ash removal, savings in wood burned compared to older stoves, any other comments you would care to share with us?

 

[jpolcyn]

I can not speak of the brand you are talking about but i run a catalytic stove in my home. So i will give you my experiences.

1. you need a thermostat on the stove because cataytic will only work once stove is over 450deg.

2. Replacing the honeycomb is EXPENSIVE.

I have since quit using the catalytic as i have found it to be easier and see no real difference in just using a damper in the pipe.

They say they are more efficient but i just do not see it.

 

[CobyRupert]

Following thread.
My understanding is a catalyst stove burns more of the wood gases that would otherwise go up the chimney.
Does this create lease creosote in the chimney?
Does it extract more heat and make stove more efficient so you burn less wood? (Above commenter says not really… but if you’re burning gas that would otherwise be wasted..?)
Does it make exhaust cooler? That is, is more heat extracted, or does stove have to be so hot for catalyst to operate that it’s hard to tell?

 

[ponytug]

Following thread.
My understanding is a catalyst stove burns more of the wood gases that would otherwise go up the chimney.
Does this create lease creosote in the chimney?
Does it extract more heat and make stove more efficient so you burn less wood? (Above commenter says not really… but if you’re burning gas that would otherwise be wasted..?)
Does it make exhaust cooler? That is, is more heat extracted, or does stove have to be so hot for catalyst to operate that it’s hard to tell?

The idea, stress on idea, is that the catalyst is able to burn (oxidize) more of the combustion gases, so what goes up your chimney has less unturned organic, aka creosote, in it. That makes it more efficient (more heat from the wood) and cleaner burning. However, until the catalyst is up to temperature, it is just a normal, double combustion stove. As @jpolcyn points out, you need to get the catalyst to temperature and keep it there, and not overheat heat it by over fueling the stove at full draft. So, it takes a tiny bit more attention to look after one, but once you get the feel for it, it is easy, I think.

Some other brands use straight metal catalysts, which are somewhat cheaper to replace. We looked at getting a Princess until our homeowners' insurer nixed the idea, as it had to be dealer installed, and no dealer was willing to travel to where we are. Classic catch22.

All the best,

Peter

 

[joeyd]

I have a Woodstock Soapstone stove and I love it for the warmth and looks. The catalytic converters seem to be the wave of the future with all the hoo-haw over climate change. I foresee a ban on non catalytic stoves if things continue on.
You can burn with or without the converter, the stove has to be hot enough to re-burn the gasses. The temp required to switch over may vary with manufacturers but I can switch over at 250 degrees external which I think is 500 internal. (I switch at 275). Often we will have a small fire just to take the dampness out of the house on rainy days and never use the converter. We burn just under 3 cords a winter so I cannot really tell you if it saves wood or not. I burn a mix of hard and soft wood from my property so it is always varies year to year how much we go through.
I replace the ceramic converter with a stainless steel one and it was not very costly around $150. I do not have to worry about the ceramic coating now.
As far as creosote build up I think that has more to do with volume burned and fuel moisture. Intuitively I think the less carbon in your smoke the less build up but the more you burn you get the picture. Woodstock has a great web site that answers many of your questions.

 

[Doughknob]

I have had stoves and furnaces, but never one with a catalyst. However, I have always understood that the catalyst was mainly for "emissions reduction." The main purpose of a catalyst stove is Not to provide for a user burning less wood.

As others have said, it "MAY" add a little more heat per log, but not noticeable. I do think Vermont Castings make quality stoves.

I have heated my whole houses with wood for 23 years and find that it does indeed take a lot of wood to do so all winter. I go through, on average, 3 cords per season.

 

[Snobdds]

On my Blaze King, the catalyst works good. It burns the smoke, which has a lot of energy still left in it.

The key is to burn very seasoned wood. If your always burning marginal quality wood and not very seasoned wood, you will struggle with it. I have reburn tubes on the stove at my cabin, and it too works good. The wood quality can be a little bit less picky.

I get longer burn times with the catalytic stove. I have yet to replace the catalyst on the stove and it's at least 7 year old now.

The biggest problem for me and my elevation is oxygen. These new stoves are tight and are not made for 6,000+ ft elevation and the lack of oxygen. I always have to keep the doors open to get a hot burn.

 

[arizona98tj]

I find it interesting, such as in this thread, concerning the amount of wood used during a heating season. Rarely does anyone ever comment on the status of their house. How many square feet, how much insulation, the quality of the windows, wall thickness, how many cold days (ie., -30F to -40F), quality of wood, etc. Yet, people state they burn XX cords of wood per heating season but is it the stove's fault or is it the house. You can put a top dollar high-efficiency stove in a poorly built house and still burn just as much wood.

For example: I live in a 6 year old house that was built for Northern Minnesota. That means 6" walls, good insulation, good windows, etc. We see many sub -30F days during the heating season. We get great solar gain from our southern windows assuming it is not cloudy. I can't begin to run our wood stove all day long as it would get far too hot. I burn 1.5 to 2 cords of mixed (poplar and oak) per season to keep our 1100 sq ft house warm. The wood is stored in a wood shed and is typically 2 or 3 years seasoned before it sees our stove. Our wood stove is as old as the house.

I'm not trying to stir the pot here but it seems that some of the very important things that are important to the discussion are often left out.

 

[Snobdds]

I find it interesting, such as in this thread, concerning the amount of wood used during a heating season. Rarely does anyone ever comment on the status of their house. How many square feet, how much insulation, the quality of the windows, wall thickness, how many cold days (ie., -30F to -40F), quality of wood, etc. Yet, people state they burn XX cords of wood per heating season but is it the stove's fault or is it the house. You can put a top dollar high-efficiency stove in a poorly built house and still burn just as much wood.

For example: I live in a 6 year old house that was built for Northern Minnesota. That means 6" walls, good insulation, good windows, etc. We see many sub -30F days during the heating season. We get great solar gain from our southern windows assuming it is not cloudy. I can't begin to run our wood stove all day long as it would get far too hot. I burn 1.5 to 2 cords of mixed (poplar and oak) per season to keep our 1100 sq ft house warm. The wood is stored in a wood shed and is typically 2 or 3 years seasoned before it sees our stove. Our wood stove is as old as the house.

I'm not trying to stir the pot here but it seems that some of the very important things that are important to the discussion are often left out.

Well, it would only subtract from the conversation to get bogged down in details. It's easier to just assume a house has adequate insulation for it's climate.

 

[deserteagle71]

Google "Blaze King wood stoves", that will provide you with answers to most of your questions regarding operation of a catalytic convertor stove.

My house came with an "Earth" brand wood stove - non catalytic convertor. It was very pretty - but like yours, had to be tended constantly and didn't put out that much heat. So in 1995 I bought a Blaze King - only because that's what the local hardware store carried. LOVED the stove - it proved to be a great investment. But a couple years ago I had to go to a pellet stove, only because firewood is almost impossible to get where I live in northern Nevada. I was having to drive 250 miles (one way) to Oregon for firewood and then even that source dried up.

As I said, I loved using the stove (used it for 24 years) - I much preferred using it compared to my current pellet stove. After two years with the pellet stove I still can't get used to having the sounds of fans running constantly. Yes, it takes electricity to run a pellet stove - so when the power goes out, unless you have a generator you have no heat. The Blaze King was totally silent and put out constant heat - unlike the pellet stove which turns on and off via thermostat.

Using a catalytic convertor stove is not that much different than using a regular stove. You build a hot fire to let the heat and fumes ignite the catalyst. Then you turn down the air control depending on how much heat you want the stove to put out. The important thing to remember with a catalytic convertor stove is that you can't be burning all your unwanted trash in the stove as certain things will plug up/destroy the catalytic convertor. Wood or clean paper only! These stoves put out essentially no visible smoke once the catalytic convertor ignites. Very little creosote buildup in the stovepipe - I cleaned my chimney only twice a year just to be on the safe side - because the creosote is also burned by the catalytic convertor. Ash depends more on the type of wood you burn - I burned mostly juniper (cedar) because that's what grows wild around here - and had to empty ashes only about once a month. On the other hand, if I burned elm that produced a lot of ash I'd have to empty ashes every couple weeks. The catalytic convertor will have to be replaced at some point. I changed mine after 18 years.
This is my Blaze King, a year before I replaced it with the pellet stove:

This is a photo of the catalytic convertor glowing up inside the top of the stove (hard to see and photograph!):

There is a thermometer in the top of the stove. Note that it is pointing at 1300 degrees. You'll see no flames in the stove once the catalytic convertor is lit and you turn down the control. The catalytic convertor will be providing all the heat as it burns the vaporizing wood fumes.

Can't speak for other stoves - but with the Blaze King I would build up a good hot bed of coals, then shove in a large piece of wood and turn down the control. That would last a good 12 hours of keeping my big house at 70+ degrees. Blaze King claims up to 40 hours of heat on one loading of wood if the control is turned down to low heat. This is a shot of my firewood at the time - logs ~ 18" in diameter split in half, 16-18" long, fit in the door of the stove easily.

Bottom line is this. If I could find an affordable, accessible supply of firewood I would yank my pellet stove and put the Blaze King back in. I'm nearly 80 years old now and had wood heat all my life except for the past two years with a pellet stove. The Blaze King is by far the best, the most efficient wood stove I've ever used. Not saying other brands aren't as good - no experience with other catalytic convertor stoves so I can't comment on them.