catalytic stoves

[rmcfall]

Do catalytic stoves provide more comfortable even heat than noncat stoves?

So does a catalytic cast-iron stove put out the same sort of "gentle" even heat that a NONCAT soapstone stove produces? What about compared to a CAT soapstone stove?

For that matter, how does a NONCAT soapstone stove compare to a CAT soapstone stove?

 

[MountainStoveGuy]

Its more the burn charateristics then the stove material. Cat stoves can be burnt at slower speads then non cat stoves. Non cat stoves are a lot less maintenance. Thats the general argument.

 

[rmcfall]

Right. But isn't it true that a noncat soapstone stove produces a more gentle even heat for longer periods of time than a cast-iron noncat stove?

So does a catalytic cast-iron stove give off the same kind of blasting heat that a noncat cast-iron stove gives off? I would think there would be a difference because of the different burn characteristics...in that the cat stove would be able to burn at a steady rate for a longer period of time?

Taken a step further, how would all this compare to soapstone stoves--both cat and noncat?

 

[MountainStoveGuy]

since you have more control over the burn rate in a non cat cast stove, then yes you can achieve lower surface temps like a soapstone stove. I dont think it would make any difference in soapstone. I can only get soapstone to about 500 degrees. So if your thinking soapstone go with the less maintenance version. One property of soapstone is of course it holds the heat far longer after the stove is out. But yes, i think you could in theroy, make a cast stove hold lower temps then a secondary burn one.

 

[elkimmeg]

Cat stoves vs non cat has been debated within the past week or two. I can only speak from my experiences with one line of cat stoves, Vermont Castings, besides being the cleanest EPA tested stove the Defiant. It has other advantages to extend its burn time. The secondary air is controlled with a probe sensor in the catalytic chamber. The sensor is attached to a spring which controls the secondary air inlet. As the stove heats up it will expand closing the air damper as the stove cools it contracts and opens up the secondary air damper. This combination provides automatic extended even heat range. The primary air inlet still can be controlled manually to its desired opening. When the cat lights off, it burns the particles left in the smoke at a high temp, extending the heating cycle of the stove. Cat stoves require more user intervention and more maintenance and a good draft. You have to decide, if you are willing to do the maintenance and regulating its controls, to get the maximum out of it. Soapstone, more expensive, has properties of retaining heat providing a long even heat range. If you can find that, and automation of the secondary air controls and the advantages of a cat stove you would hit the sweet spot with a soap stone. Comparing the soapstone vs cat or automated secondary air controls performances may be impossible to do. Your draft strength has to be factored in and wood quality. MSG advice is dead on. You are asking a very complicated question. The home layout, draft conditions, a heated room size, wood supply and species and moisture content, desired goals, and finances, are a lot of variables to consider. In the end you will have to compromise and take the best educated guess. Them learn to manuplicate and operate what ever your choice you make, to achieve the optimum results

 

[Sandor]

Burnt a medium Regency freestanding for 10 years. Never could get an overnight burn that did not leave the glass black.

Built new home and got the large Regency freestanding. Burnt for 2 years and could never get an overnight burn that did not leave the glass black. Thought I could dampen down to get an overnighter. Nope. Must have an agressive fire to keep the secondary burn process going, which is not good for longevity. House was hotter than hell when the stove was operating the way it needed to be efficient (secondary burn), and not smoking.

Lesson: The larger firebox in a non-cat stove produces more heat, not a longer burn. (if operated efficiently)

Used two different VC Resolute Acclaims the last 3 years. Possible to get overnight burns because you can fill the to the brim with the topload feature, especially with rounds. Secondary burn process is unique and works rather well. Needs the air to perpetuate secondary burn. Nice stoves.

New to me this season is a CAT, soapstone stove. You can burn this at a lower temp and still get secondary burn. This is the key between cat and non-cat stoves. My house is comfortable and it cut my wood use by 40%. Overnight burns are automatic (once you learn how to control it). I will never go back, period.

 

[saichele]

A lot may vary based on the specific stove. I burned a Napoleon 1400 freestanding for 5 yrs, and it did a nice job of heating a 1350 sq.ft. ranch. 'overnight burn' meant warm it up, load it to the gills, cut it back to about 10%, and 6 or 7 hrs later you ahd enough coals to start again. Glass wasn't a big problem. Some buildup inthe lower corners, cleaned glass once or twice a week.

Now have the VC WinterWarm Large, a cat insert, and whle it makes a lot of heat (been keeping up with a 2500 sq. ft. farmhouse most of the winter), I don't get any longer burn times. Weekdays, when it's maybe 7 hrs between loading, not usually a problem. Weekends, it's a new fire every morning.

Based onthe limited experience, I think were it me, I'd go with the non-cat in soapstone for three reasons.
1) the cat needs to get hot to run right, and based ont he reporting I think you're going to have trouble running it up to 500 without burning a good load of wood getting there.
2) the CAT is more complex, and is a potentially expensive thing to replace.
3) The soapstone is already going to have the effect of extending heating times, not sure the cat would provide enough improvement to be useful.

Steve

 

[elkimmeg]

Unfortunately steve has the one stove insert Made by Vermont Castings I cannot recomend. It is an entirely different stove than the free standing Encore or Defiant. Never to less he has made vaild points. If you intend to burn 24/7 a cat stove makes sense
If recreational burning weekends ect do not even consider a cat stove. If you do not want to be bothered with a little extra opperational controls don't buy a cat stove. If a bit mechanically inclined and willing cleaning the cat is not a big deal. Replacement
is nothing labor wise if already there examining it. IF it is serviced by a dealer then. Do not buy a cat stove. If you service it and it need replacement off brand combusters can be bought for as little as $60 depending the model required, but 50% less than manufacture relpacements.

Personally money is an issue I would focus on tightening up your new home, getting an effecient heating system, then see what you can afford concerning a wood stove. Your climate is not as harsh as th upper 48 (Tenn) You could get lucky finding a real decent used stove saving money and still getting the job done. Sandor indicates the Vc's Resolute Acclaim did the job. I have one that in your climate wold really work well. Mine takes care of a large zone down to 12 degrees outside 900 sqft with two sets of stairs exiting to higher levels

BTW The new non Cat VC Encore Ever burn technology has been real popular and VC top seller since introduction this heating season

 

[roac]

Based onthe limited experience, I think were it me, I'd go with the non-cat in soapstone for three reasons.
1) the cat needs to get hot to run right, and based ont he reporting I think you're going to have trouble running it up to 500 without burning a good load of wood getting there..

Steve

Steve,

A cat needs to get to 500 degrees to start operating, but that isn't outside stove surface temp, it's inside the firebox temp. Big big difference in the two. With a proper light off and dry wood 500 degrees can be reached quickly and the cat engaged.

 

[hawse]

Define overnight burn,Speaking for myself on a jotul f3cb load at 10 pm run up to 400 damper down slowly all the way.5 AM load with kindlin open the ash pan door and away you go this non cat anbd the glass stays clear.Diferent stoves diferent technique and desighns.As far as cats this being more of a question,Turning them way down to extend burn times-would that effect the lifespan of the cat element?

 

[saichele]

Based onthe limited experience, I think were it me, I'd go with the non-cat in soapstone for three reasons.
1) the cat needs to get hot to run right, and based ont he reporting I think you're going to have trouble running it up to 500 without burning a good load of wood getting there..

Steve

Steve,

A cat needs to get to 500 degrees to start operating, but that isn't outside stove surface temp, it's inside the firebox temp. Big big difference in the two. With a proper light off and dry wood 500 degrees can be reached quickly and the cat engaged.

Fair enough. I didn't know how efficient the soapstone would be at pulling the heat out of the firebox. I guess I was conceptualizing it as being more like a wood boiler, where the firebox never really gets hot because the heat exchanger's pullingoff so much heat.

I don't have any experience of soapstone, so I'll defer to those that do.

Steve

 

[Corie]

No, turning a cat combustor stove down low won't affect the longevity of the combustor, providing you only damp it down to far as to keep the cat firing.

As far as my .02 regarding this topic, I only have experience with a cat stove, so I have no room to discuss the other type. My cat stove (Dutchwest 264CCL) has no problem maintaining overnight burns. It provides comfortable even heat, and it isn't rocket science to operate the unit. Of course one has to ensure the temperature is correct before engaging the combustor, but otherwise, it's not difficult.

Also, I noticed someone earlier mentioned the high cost of replacing the catalyst. If you purchase one of the stovecombustor.com units, it isn't a ton of money. You also have to take into account that there are some parts on the other stoves that can wear out and require replacement. The air induction tubes (the ones with the holes) are considered a wear item and may have to replaced periodically. You'll may also have to replace the insulation that sits on top of the baffle, as it made degrade and break apart over time.

 

[Eric Johnson]

That's a good question about what constitutes an overnight burn. For me (I've got a boiler), an "overnight burn" during cold weather (single digits to low teens) would involve loading the firebox at around 11:00 p.m. and finding a nice bed of coals in the firebox at 7:00 the following morning. That range expands accordingly as the outside temps rise. Typically, a 10 to 12-hour burn is certainly possible when the temps are in the high '20s and '30s. When it's below zero, however, you're talking more like 4 hours between loads, which involves getting up in the middle of the night to tend the fire. Sometimes I can talk my wife into doing that, but usually it's me dragging my ass out of bed at 3:00 a.m.

 

[Mo Heat]

Right. But isn't it true that a noncat soapstone stove produces a more gentle even heat for longer periods of time than a cast-iron noncat stove?

So does a catalytic cast-iron stove give off the same kind of blasting heat that a noncat cast-iron stove gives off? I would think there would be a difference because of the different burn characteristics...in that the cat stove would be able to burn at a steady rate for a longer period of time?

Taken a step further, how would all this compare to soapstone stoves--both cat and noncat?

The cat vs. non-cat thing is incredibly complex. For instance. My VCWWL cat cast iron (convection) insert has max 50,000BTU/hr. It can warm the 1000 sq ft hearth room in a few hours and keep it warm. Even with an ENORMOUS amount of window area and a slab basement floor (carpeted). And, if you sit in front of the huge glass, you get REALLY warm. Or, you can damp it down, sit right in front of it and keep toasty warm with just a couple splits in there, letting that big room stay pretty cool (65 - 66), and if you do it right, the glass won't even get very dirty. The big trouble with the VCWWL is combustion control with full loads due to the NON-air-tight cast iron design and assembly issues. This is not a good long burn heater for that reason, even though I can squeeze an 8 hour burn and still rekindle without a lot of fuss. And that's not even filling the box, which I'm still afraid to do.

Now, take the Blaze King cat stove that Chesley recently installed. It has twice the wood capacity, about half the glass size (I'm guessing a bit here from looking at photos), is made of steel instead of cast iron, and claims burn times of 40 hours. And yet, the maximum BTU per hour is 40,000. Why? Probably because it has firebrick in there insulating a lot of that high heat transfer steel from the serious flame. But that keeps things efficient AND reduces the steel heat transfer rate. Add a couple fans to the back to convect the cat compartment heat and allow lower burn rate with lots of heat extracted and you start to see why those incredible burn times are at least possible while milking every available BTU out of the load, but without driving you out of the room even though it's a steel stove. Chesley has easily gotten 24 hour burns with only half a load after only firing this thing for a couple weeks. Wow! That's impressive. His only real complaint has been dirty glass, and from my experience, he'll probably learn how to fire this thing to prevent that in a year or two. It heats quick (being steel) but can still be burned slow. It has both convection and radiant capabilities (again, being steel it probably radiates like a banshee if you really crank it). In my mind, this may be the best of both worlds. Great (quick and efficient) heat transfer AND a LONG, SLOW burn rate. Or crank 'er up and get run out of the room. I hope Chesley will post more as he gets more familiar with his stove.

So anyway, there are all sorts of ways to look at things. I was once 'sold' on soapstone, but I am strangely leaning back towards steel (currently, I'm in the middle with cast iron). Having a cast iron stove that does NOT seal well and allow precision control over firing levels is a pain. Steel stoves are welded air tight and can be computer robotic manufactured. They may not be as pretty, but that's the trade-off. Some now-a-days have much nicer ornamentation. Maybe you don't even care about this or clean glass if you're a serious wood heat seeker. Add an ash pan to a steel stove and you increase the possibility of air infiltration, but if you can get that one additional gasket right, in my mind this is near the perfect stove WITH A CAT!

Of course, I've never had a non-cat EPA stove, so my experience is limited to my brother-in-law's Jotul Kennebec, but that little guy just seems to burn fast and consume a lot of wood for my taste when compared even to my drafty VCWWL with more gaskets and leak potential than an old convertible car top.

Design really comes into play with both CAT and non-CAT stoves. Soapstone adds more design complexity. In my mind, you almost have to be familiar with a specific stove, the wood you burn, the house it's in, your presonal firing objectives, your own biases, your mechanical abilities, etc., etc. Buying a cat stove seems similar to buying a car with a standard transmission. These days, a lot of people I meet have never even driven a std shift. It boggles my mind. I watched the smog inspection punk kid put my VW in reverse and drive off the dynomometer! Then he threw it in third for a second try before I made it out there and ask for someone who was born in a previous generation to get my certificate for a price less than a transmission repair.

So many things to consider... No easy answers.

 

[rmcfall]

I appreciate all the feedback everyone has given here. While in some respects I am asking this question because the answers will help me determine what type of stove I purchase for our new house (as I am not taking our old stove with us), I am really curious about the differences from more of a theoretical standpoint. That said, I realize that because I am in KY the climate is not real harsh...however, I am more interested in putting money into a woodstove than an efficient heating system (i.e., furnace)...simply because I have enjoyed burning wood 24/7 in the past and look forward to doing the same in the future. I am especially curious about the differences between cat and noncat SOAPSTONE stoves...again, more from a theoretical standpoint where the myriad of influencing variables is held constant. Again, all the feedback everyone has provided is really helpful.

 

[MountainStoveGuy]

I think we covered the soapstone vs cast cat issue, what else would you like to know?

 

[Rhone]

This all brings me back. Honestly, I'm not sure they advertise the secondary burn technology correctly. When I first got my unit I was under the impression that with a secondary burn unit there's no babysitting. As in, fill my unit full of wood, light the kindling, wait until the fire starts moving, and within 15 minutes turn down the air supply and away to work I go knowing that my secondary burn is going to happen. Um... doesn't exactly work like that. I need to sit and wait until my unit is really going before I can turn the air down. Usually, that means waiting until all the logs have charred over. I bet that's about the same time waiting for a cat to warm up no? I guess the secondary burn has the benefit that, if you have to leave before it's ready you can turn down your air setting without damage and have a chance of secondary burn happening. Next, they make it sound like the secondary burn once it reaches 1100 degrees happens. No, it needs the presense of an external flame. The secondary burn flame is not self sustaining, without the presence of a flame from your wood, it goes out. Happened this morning, my secondary burn was hot enough to happen but the flames weren't reaching up high enough to light it off. I use a trick when that happens, put a piece of kindling on the top of my wood. Once my kindling lit, it sustained my secondary burn which, once going for a minute gets my unit cranking out the heat and starts the tops of my wood burning, which is what sustains it afterward. Amazing how much heat the secondary burn adds, I'm guessing probably the same amount as a cat as burning secondary gases whether from a secondary burn chamber or cat should net around the same energy but based on the age of a cat. As I understand it Cat units start out more efficient than secondary burn units and progressively as their cats get clogged and dirty they get less efficient. By mid-life (2-3 years) a secondary burn and cat unit are the same efficiency, and by the end of a cats life (5+ years) they're operating at less efficiency than a secondary burn unit. Then you get a new combuster and start the process again. Back to the secondary burn sometimes I put wood in there and the flames go right up to the secondary unit and within minutes I can walk away, for me that happens less often than having to wait for all the wood to get charred and then I can turn my unit down. And, my wood is rather wet so maybe the norm is the flames reach the secondary burn to keep it going.

I'm curious the difference in burn times. I understand why a cat unit should be able to extend a burn, and my argument has always been if an extended burn is useful as having wood burn for 11 hours puts out very little heat/hour and you better have one heck of a well insulated house for it to be useful, I don't know if there's a big difference in burn times or if it's based on how much risk the manufacturer is willing to take. My Hearthstone Clydesdale seals tighter than a clam every time and with my unit pretty full I get 14 1/2 hour burns, my secondary burn unit ignites every couple seconds for most of the time. I'm thinking if I actually loaded it to the brink I might be able to get 16 hours out of it. But, again it has to do with usefulness. Me setting my unit to a 14 1/2 hour burn my house will lower in temp to be about 55 degrees by the end as my house loses way too much heat. Too bad Mo your unit doesn't seal tight, you explained about the 4 metal pieces having to line up exactly on your unit and the ashpan drawer. Anyway, my unit advertises 10 hour burns and honestly I don't know where they're coming from. I always get 9 hour burns with the air setting on half and a normal load of wood. That's definetely not the norm because I see it too, others with secondary burns don't seem to be able to turn their unit down as much as I can. I've been pondering if it be that manufactures of secondary burns don't want to risk them failing EPA standards and overkill the air settings.

 

[Todd]

For that matter, how does a NONCAT soapstone stove compare to a CAT soapstone stove?

I haven't had the cat stove very long but this is what I have noticed so far, since I changed over from a non cat soapstone stove to a cat soapstone stove.

The cat stove burns longer on the same amount of wood as the non cat while producing more heat. I can get my cat stove up to 700 deg on a low burn if I want. Non cat would have to be medium to high burn to maintain 500-600. Non cat low burn 350-400, and had to tweak air control to maintain flame for secondary burn. Both have even heat but cat stove seems a little more controllable with longer burns. The glass never gets dirty with my cat stove while my non cat dirtied up on low burns.

I haven't done any maintenance on the cat stove yet, but looks easy to just lift the top, unbolt , and clean or replace as needed. I think the cost of replacement should pay for itself from firewood savings. For 24/7 burning I personally like the cat stove better.

 

[rmcfall]

Thanks everyone for their feedback on these questions. It sounds like NON cat soapstone stoves may produce a more "gentle" heat than a catalytic cast-iron stove, but that burn times might be better with a catalytic cast-iron stove compared to a non cat soapstone unit? In terms of CAT soapstone stoves, it sounds like "gentle" heat and long burn times can both be achieved.

Todd--you are speaking from experience and it really sounds like you are enjoying the cat soapstone stove much more than your previous noncat soapstone unit. Anything you aren't crazy about with the soapstone and cat combination?

For that matter, how does a NONCAT soapstone stove compare to a CAT soapstone stove?

I haven't had the cat stove very long but this is what I have noticed so far, since I changed over from a non cat soapstone stove to a cat soapstone stove.

The cat stove burns longer on the same amount of wood as the non cat while producing more heat. I can get my cat stove up to 700 deg on a low burn if I want. Non cat would have to be medium to high burn to maintain 500-600. Non cat low burn 350-400, and had to tweak air control to maintain flame for secondary burn. Both have even heat but cat stove seems a little more controllable with longer burns. The glass never gets dirty with my cat stove while my non cat dirtied up on low burns.

I haven't done any maintenance on the cat stove yet, but looks easy to just lift the top, unbolt , and clean or replace as needed. I think the cost of replacement should pay for itself from firewood savings. For 24/7 burning I personally like the cat stove better.

 

[Todd]

Thanks everyone for their feedback on these questions. It sounds like NON cat soapstone stoves may produce a more "gentle" heat than a catalytic cast-iron stove, but that burn times might be better with a catalytic cast-iron stove compared to a non cat soapstone unit? In terms of CAT soapstone stoves, it sounds like "gentle" heat and long burn times can both be achieved.

Todd--you are speaking from experience and it really sounds like you are enjoying the cat soapstone stove much more than your previous noncat soapstone unit. Anything you aren't crazy about with the soapstone and cat combination?

Nothing so far, I don't think I'll ever go back to steel or iron stoves. The only option I would like to see with this stove is some kind of top grill rotisserie option.

For that matter, how does a NONCAT soapstone stove compare to a CAT soapstone stove?

I haven't had the cat stove very long but this is what I have noticed so far, since I changed over from a non cat soapstone stove to a cat soapstone stove.

The cat stove burns longer on the same amount of wood as the non cat while producing more heat. I can get my cat stove up to 700 deg on a low burn if I want. Non cat would have to be medium to high burn to maintain 500-600. Non cat low burn 350-400, and had to tweak air control to maintain flame for secondary burn. Both have even heat but cat stove seems a little more controllable with longer burns. The glass never gets dirty with my cat stove while my non cat dirtied up on low burns.

I haven't done any maintenance on the cat stove yet, but looks easy to just lift the top, unbolt , and clean or replace as needed. I think the cost of replacement should pay for itself from firewood savings. For 24/7 burning I personally like the cat stove better.