Cat vs NonCat

[Tony D]

Looking for peoples opinions/experiences with catalytic and noncatalytic stoves and inserts. Why you think one is better/worse than the other. And when I say noncatalytic i mean a stove/insert that still has some sort of reburn technology. Thanks in advance for any input!

 

[HotCoals]

I like cat stoves because of the long slow burn without overheating the house in the shoulder seasons.
When it's really cold out both types get the job done ok.
Cat stoves have a little more seasonal maintenance to them and a extra lever for the by-pass.
To each their own. Cheers!

 

[Sprinter]

And away we go...

TonyD, it's a good question. It usually generates a lot replies. Have fun.

 

[Ashful]

The "cat vs. non-cat" question is a perennial, and always a hot topic. In the end, both get the job done, although as mentioned, cat stoves really excel when the heating needs are low. When it's cold, and the stove is cranking, both work equally well.

The shoulder season / "low and slow" comments are based on the fact that the catalytic stove can achieve reburn at roughly half the internal temperature of a non-cat stove. This enables them to be turned down much lower, all other conditions being equal, than a non-cat stove. This is pretty much their sole advantage, coming at the cost of a little added complexity and cost.

In response to a similar question last year, I typed the following response:

If I could paint with a very broad brush (sure to get myself into trouble here), I'd recommend one technology versus the other, as follows:

Cat stove: for those who like to fiddle with things. Engineers, technicians, frustated orthodontists. Anyone who ever put a high performance cam in their car; or "chipped" it, for you younger folks. Geeks who wants performance at any cost. Guys who aren't married.

Non-cat stove: anyone not fitting the above description... or more importantly, those having wives who may be less than entirely impressed that your cat stove has a few percent higher efficiency, or can burn a few hours longer and a few degrees cooler than a non-cat.

My wife's an engineer, but painfully short-tempered... not sure which camp that puts me in.

 

[BrotherBart]

I have always been a non-cat guy. But a member here Todd, who has owned more stoves than most dealers , tells me that cat stoves are really good for long even burns and I trust that Todd knows what he is talking about.

I would let my sister marry someone that heats with a cat stove. But that big honkin steel non-cat is staying in my fireplace.

 

[fossil]

Not a question of what's "better"...they're both "better". It's just a question of what you prefer, what fits your particular need/location, what fits your budget, and what you'd like to have in your house. Cat stoves and non-cat stoves are both "better"...better than everything that came before them in terms of heating efficiency (wood consumption) and trying to minimize environmental impact (which ain't zero, no matter how we do it). Rick

 

[begreen]

Not entering this discussion though I prefer a KISS stove. There are already so many old threads on the topic in which you will find as many opinions as there are postings. Be a careful reader. For some this is a religion.
https://www.hearth.com/talk/threads/heat-output-cat-vs-non-cat.106452/
https://www.hearth.com/talk/threads/building-a-house-picking-a-new-stove-cat-or-non-cat.88521/
https://www.hearth.com/talk/threads/cat-vs-non-cat-pros-and-cons.87312/

 

[eujamfh]

Own one of each. I would not hesitate to go either one - find the stove that fits your needs and what you think looks good. I put those two in the order on purpose…IMO if you are using it for heat, fitting the stove to your needs (size, flow, burn time) is most important. BUT….also understand that sometimes that means a stove that is less then appealing to one or the other…

In fact, that is how I ended up with a mid size stove. It looks great and we love it in the room where we spend 90% of our time. BUT, the big cat is in the formal living room and that is the one that carries the winter. We are lucky to have space for two and ended up with one of each.

So figure out your needs, and then look at what looks good. I think the technology is a moot point. The cat will cost you a couple hundred over a 6-10 year period to replace…probably make up in gas spent on the saw and splitter by being able to let things burn a bit slower. Never really got down to that close a cost comparison - but I bet its a wash or near close in the end.

Just my thoughts.

 

[dafattkidd]

Most of us are very happy with the units we use to heat our homes. That being said, this time of year you get the Blaze King (super cat stove) owners boasting of 30 hour burn times. I am very happy with my "big honkin' steel non cat" but man do those Blaze King threads impress me.

One benefit of having a non cat is that I burn a lot of construction debris. If I had a cat stove, maybe some of the nails and screws, or occasional pre-primed scrap trim that inevitably get tossed in the stove would gunk up the cat. I can burn this stuff with a little less concern.

 

[stovelark]

Remember years ago with Jotuls, their cat designs (except the FL 12 cat) didn't seem that great, not many 3 and 8 cats around today but still tons of FL 12's. Having said that, we recently brought the Blaze Kings onboard, haven't had much experience with them yet, but they seem to burn nicely. They are a little unusual looking, but seem to be a viable heater. Still prefer my non cats for ease of operation, but understand the cat folks side of it too. I agree with others, find the best looking stove that fits your needs and budget, hopefully its a Jotul F400 or F500, hee hee. Good luck.

 

[Huntindog1]

Cats can be burned at a lower level so as not to run you out of the room your in. That also means it can burn for a longer time.
But cat stove's cat has to be replaced after a few years , I am not sure what their life times are now , maybe 5 or 6 years.

With ceramic cats you have to be careful as moisture can crack it so if you accidentally put in so wet wood by mistake, that could harm it.

Cat stoves are more expensive, My secondary burn tube stove I got on sale for $599 and some cat stoves get up in the thousands of dollars. I did the math and it takes a long time to save any money on your heating bill if you have 3 grand in a stove and a grand in a wood splitter and then money for a flue system and money for chain saws. Most people are burning wood to save money over the cost of heating with some other type heat.

Cat stoves are nice, if you want the best of both worlds get a hybrid stove that have both technologies in them. If you got the money to spend.

I am not real patient , and dont like the idea of waiting 3 or 4 years to break even. I broke even on my investment in one heating season.

Thats my 2 cents worth.

 

[Rickb]

BK warranties there cats for 10 years.

That said I have a new BK. I have used it about 10 times so far. It is very easy to use but I did a lot of reading here before I decided on what I wanted and even more on proper operation.

 

[Todd]

I have always been a non-cat guy. But a member here Todd, who has owned more stoves than most dealers , tells me that cat stoves are really good for long even burns and I trust that Todd knows what he is talking about.

I would let my sister marry someone that heats with a cat stove. But that big honkin steel non-cat is staying in my fireplace.

Lol, yeah I've burned a few stoves in my time both cat and non cat. They all have their advantages and do the job. Personally I like cats for the long burns and more even heat.

I'd like to see some improvement on these hybrids where you could turn off those secondaries and go cat only or vice versa. Maybe the new Woodstock will have this.

 

[Tony D]

Sorry guys i didnt realize this had been done to death... Thanks for attaching the other threads. So to switch the topic a bit what is the average life of your combustors?

 

[Ashful]

Most manufacturers warranty their combuster for 5 - 6 years, most often with 2-3 years at full replacement, and then the last 3 years pro-rated. As was mentioned above, Blaze King puts a 10 year warranty on their cat, so that would seem to say they expect them to live at least that long.

A cat could last longer than 10 years, if you always burn clean and dry cord wood, or you could kill 'em almost overnight. A catalyst simply consists of a substrate, classically ceramic but some manufacturers are now experimenting with stainless, plated with some metals (palladium, platinum) that catalyze the re-burn reaction to occur at lower temperature. Ways to kill the cat are numerous:

1. Burning any painted or chemically treated wood. Won't kill the cat instantly, but will "poison" it to death, chemically reacting with the catalyst metals.
2. Burning wood filled with LOTS of galvanized or zinc plated hardware. While I've seen this quoted before, I've never seen anyone who has ever claimed to have actually killed a cat this way.
3. Regularly running the catalyst at temperatures above 1700 - 1800 F. This will cause the plating to delaminate from the substrate. A single foray up to these temperatures is not instant death, but it takes its toll over time. This most often happens when you load the stove full of too many small pieces (too much surface area per volume of wood) or a full load of very resinous hard wood (eg. walnut), and work too much volatile off-gassing thru the cat too quickly.
4. Using wood at moisture content above 20%. This has two negative effects, as far as I know:
4a. Forces one to run stove up very hot prior to engaging the cat, getting a raging fire in order to force cat light off with bunches of steam in the exhaust. I was guilty of this for much of last year.
4b. Loading into a hot stove and re-engaging the cat too early, the steam coming off the poorly-seasoned wood hits the hot cat and causes very rapid cooling, and fracture of the ceramic.

The new stainless cat's (SteelCat) have had some problems with sagging at high temperatures, pre-mature delamination, etc. These cat's have advantages, in that they won't crack the way the ceramic ones will do when thermally shocked (very fast hot/cold), but they are still in the early years of their development. Many improvements have been made in the last 3 - 4 years, but they are a less mature technology than the ceramic cat's.

 

[mellow]

If you are on the fence about a cat or tube stove then buy a Hybrid

 

[oldspark]

Sorry guys i didnt realize this had been done to death... Thanks for attaching the other threads. So to switch the topic a bit what is the average life of your combustors?

Everything has been done to death here if you have been around a while.

 

[Seasoned Oak]

One benefit of having a non cat is that I burn a lot of construction debris. If I had a cat stove, maybe some of the nails and screws, or occasional pre-primed scrap trim that inevitably get tossed in the stove would gunk up the cat. I can burn this stuff with a little less concern.

Same here. I burn a lot of pine construction lumber. Lathe boards, wall studs, floor joists, ect. YOU never know if theres some varnish on those bare looking floor boards although they usually are oak. It all burns good in any of my 4 NON cat stoves in various locations

 

[Highbeam]

If you are on the fence about a cat or tube stove then buy a Hybrid

The Lopi version is the best yet but the other brands are guilty of being non-cats with a cat added for emissions control. Not long burners yet. I do believe that this tech could really mature into a situation of the best of both worlds.

Myself, I own one stove of each type. I believe that the cat stove is a superior home heater (mine burns for 30 horus straight!) but that the non-cat is a superior trash burner workhorse. By trash I mean firewood that wouldn't go into the cat stove. Pallet chunks, lumber, greenish firewood, uglies. Non-cat is more durable, simpler to operate, and much cheaper to buy.

We have lots of perennial topics. Part of the fun. Also know that technology improves and as more people try cat stoves you will get more data points. These recurring debates are not just the same thing over and over.

 

[begreen]

Sorry guys i didnt realize this had been done to death... Thanks for attaching the other threads. So to switch the topic a bit what is the average life of your combustors?

That varies a lot and the technology is still being experimented with. 5 years seems to be about average, but we are seeing a new generation of cats that may work better. Still too early to tell. The catalytic convertor is not the only failure point. Depending on the stove design, the cat holder, gaskets, refractory assemblies, throat hood all are potential service points. Often after 5-10 yrs of service there can be a lot of rebuilding going on in this area of intense heat. Some stoves have better designs than others in this area. And of course, it depends on the person running the stove. Abuse carries a penalty with a cat stove or a non-cat.

 

[Ashful]

Myself, I own one stove of each type. I believe that the cat stove is a superior home heater (mine burns for 30 horus straight!) but that the non-cat is a superior trash burner workhorse. By trash I mean firewood that wouldn't go into the cat stove. Pallet chunks, lumber, greenish firewood, uglies. Non-cat is more durable, simpler to operate, and much cheaper to buy.

We have lots of perennial topics. Part of the fun. Also know that technology improves and as more people try cat stoves you will get more data points. These recurring debates are not just the same thing over and over.

Very thoughtful post.

 

[oldspark]

Still some out dated info about cat stoves out there (unless they changed it by now) so research is key, users views are always good.

 

[Dave A.]

Blaze King puts a 10 year warranty on their cat, so that would seem to say they expect them to live at least that long.

Don't own a Blaze King so am only going by what I've read mostly here about them. But my understanding (and hopefully someone in the know will correct me if I'm mistaken) is that 10 year warranty on the cat only applies to the stove and cat purchased initially in the last few years. If you buy a replacement cat for an older BK stove (not covered with the 10 yr warranty) or a new cat after the 10 year period they're not covered for 10 years. So it sounds more like a marketing decision rather than that their cats are better longer lasting than others, (lest someone concluded that based on length of warranties).

Also, haven't seen it mentioned (and I don't own a cat stove so this is only from what I've read) as well as producing longer burns, the cat stove will supply more uniform even heat over the whole burn cycle than a non-cat stove -- A flatter heat curve. Where the non-cat with lets say a 10 hour burn cycle, will supply the bulk of that heat in the first few hours, the cat stove will be supplying btus more uniformly over it's burn cycle.

 

[HotCoals]

Don't own a Blaze King so am only going by what I've read mostly here about them. But my understanding (and hopefully someone in the know will correct me if I'm mistaken) is that 10 year warranty on the cat only applies to the stove and cat purchased initially in the last few years. If you buy a replacement cat for an older BK stove (not covered with the 10 yr warranty) or a new cat after the 10 year period they're not covered for 10 years. So it sounds more like a marketing decision rather than that their cats are better longer lasting than others, (lest someone concluded that based on length of warranties).

Also, haven't seen it mentioned (and I don't own a cat stove so this is only from what I've read) as well as producing longer burns, the cat stove will supply more uniform even heat over the whole burn cycle than a non-cat stove -- A flatter heat curve. Where the non-cat with lets say a 10 hour burn cycle, will supply the bulk of that heat in the first few hours, the cat stove will be supplying btus more uniformly over it's burn cycle.

I think you're right on all counts.

Even with the 10 year I think only the first 3 years are fully covered.
I would buy my stove over again.
Not just because it is a cat but because it also has a huge firebox.
Because of these two items twice a day loading in the cold is very easy.
I don't stuff it full..usually about 2/3.
Load around 6am then again between 7 and 10 pm depending.

 

[Ashful]

...as well as producing longer burns, the cat stove will supply more uniform even heat over the whole burn cycle than a non-cat stove -- A flatter heat curve.

This is the graph, which produced some debate when I posted it two years ago, from Harman:



While everyone agreed that these curves are roughly representative of their respective technologies, most also agreed that the units were chosen in a fashion to intentionally exaggerate the differences. There's no statement as to whether these units are linear, logarithmic, squared (power density), etc.