Primary,secondary, tertiary heat production

[bundy150]

What are the relationships as far as providing BTU's in the room? Do all 3 provide significant heat output or is only 1 burn assist doing most of the work? How do all 3 figure in to the burn cycle? I'm trying to better understand modern stove technology.

 

[jetsam]

Depends heavily on the stove's design. Early cat stoves (some were poorly designed models that were basically emergency retrofits for EPA compliance) put the cat at the flue collar, so it had reburn but almost all the heat went up and out. New stoves do much better, some more than others.

If you look at efficiency ratings, stoves with tertiary combustion (for example, a reburn baffle and a cat) often do worse than well-designed stoves that just have one or the other.

In theory it's a better idea because baffles/tubes might do better at roaring hot fires that could outgas a cat, and cats certainly do better at low fires. Devil is in the details, though.. in practice it seems to be less clear that hybrid stoves are a big benefit in the real world. And they can have the expenses associated with both stove types (cracked baffles, saggy tubes, dead cats).

I don't have a lab at my disposal (though some forum members do! @BKVP ?), but my impression is that a whole lot of my stove's output comes from the cat. In raging inferno mode the cat is probably a smaller percentage because a lot of reburn is happening right in the firebox. In black box low simmer mode, the cat is doing most of the work.

Not saying hybrid stoves are not good- lots of people are happy with them- but just being hybrid doesn't make it efficient at getting BTUs into the room. You need good engineers for that with any stove type.

 

[Sailrmike]

What are the relationships as far as providing BTU's in the room? Do all 3 provide significant heat output or is only 1 burn assist doing most of the work? How do all 3 figure in to the burn cycle? I'm trying to better understand modern stove technology.

It's my opinion that secondaries provide the bulk of BTU's during the first half of the burn cycle. They're burning at over 1000°F and transmit that heat nicely to the stovetop.

 

[Highbeam]

Since all “good” stove designs have efficiency ratings within just a few percent regardless of technology. The heat produced at various stages of the burn always sum to about the same number. So if a cat stove has poor primary fire output it has high catalyst (secondary?) fire output.

Just don’t worry about it since none of the technologies are wasting much more than the other. If you’re cold, turn it up.

 

[bundy150]

Would it be accurate to conclude that catalytic stoves are best for long ,slow burns and tube/baffle stoves are best for a quick, hot , short term fire? Do hybrid stoves enhance each method or interfere and cause problems?

 

[jetsam]

Would it be accurate to conclude that catalytic stoves are best for long ,slow burns and tube/baffle stoves are best for a quick, hot , short term fire? Do hybrid stoves enhance each method or interfere and cause problems?

I'd say so- not that cat stoves aren't good at short hot fires, but if that is how you want to run, just get the cheaper stove to start with.

If you want long slow burns, your only choices are cats or smoldering the load to death (or large masonry heaters, but they do short hot fires and buffer the heat in many tons of stone).

I've never run a hybrid stove, but I read good and bad stuff from owners, and see the specs on them. If they were automatically better, all high end stoves would be hybrids. I don't know that the theoretical advantages will outweigh the knowledge that you will likely eventually be replacing cats AND baffles/tubes for a lot of people.

Be interested to hear more from people who run them every day. (@Highbeam, go get a third stove so you can be the cat+noncat+hybrid guy...)

 

[begreen]

It really depends on what one needs and calls a long burn. We are on 12 hr reload cycles now with milder daytime temps upon us. Some days I am only doing a partial load in the morning and letting the heat pump cover the evening load.

 

[bundy150]

If we assume 4/8/12 hour burn times and factor in climate would it be safe to say that a stove used in a warm southern climate (occasionally) vs one used up north 24/7 would be aided by one technology vs another, and middle climates would benefit from hybrids? Applying technology to specific use or does one form or blend fit best?

 

[Highbeam]

Would it be accurate to conclude that catalytic stoves are best for long ,slow burns and tube/baffle stoves are best for a quick, hot , short term fire? Do hybrid stoves enhance each method or interfere and cause problems?

Now is where you get into the “depends” part. At the root of your question is range of allowable burn times which is directly related to the range of allowable burn rates.

Not all manufacturers have done equally well at executing the different technologies. Many cat stoves for example, are not able to burn any longer than 12 hours. That’s horrible and you may as well just save money and run a noncat.

There are a few well done hybrids that I would love to use/try but statistics show that most burners spend most time burning at the low burn rates so while it’s fun to have the ability and range to burn hot, most important is the efficient clean burning at lower output.

Right tool for the job.

 

[Highbeam]

If we assume 4/8/12 hour burn times and factor in climate would it be safe to say that a stove used in a warm southern climate (occasionally) vs one used up north 24/7 would be aided by one technology vs another, and middle climates would benefit from hybrids? Applying technology to specific use or does one form or blend fit best?

I would make no such assumption. They all get hot and all are efficient and clean. Instead spend time properly sizing a stove for your needs, getting good specs, aesthetics, and even price.

I do not value dealer service.

 

[Caw]

I thoroughly enjoy these debates. Taking a higher level view here we are discussing the nitty gritty of cat vs tube vs both...all clean burning...while the majority of the world is out there giving wood burning a bad name by burning smoke dragons and old school OWBs.

It's just interesting. Sometimes you forget that we here on the forums are the minority in burning!

RE tech I think most of the prudent points have been made. The only thing I'd add is personal preference. Cat vs non-cat life. I'm a dog person so I go tube stove all the way .

 

[BKVP]

I thoroughly enjoy these debates. Taking a higher level view here we are discussing the nitty gritty of cat vs tube vs both...all clean burning...while the majority of the world is out there giving wood burning a bad name by burning smoke dragons and old school OWBs.

It's just interesting. Sometimes you forget that we here on the forums are the minority in burning!

RE tech I think most of the prudent points have been made. The only thing I'd add is personal preference. Cat vs non-cat life. I'm a dog person so I go tube stove all the way .

That's only because you haven't owned a smart cat!

 

[jetsam]

The only thing I'd add is personal preference. Cat vs non-cat life. I'm a dog person so I go tube stove all the way .

You should switch. Let's make a deal. Talk to my salesman!

 

[Caw]

You should switch. Let's make a deal. Talk to my salesman!

View attachment 276773

Is that a snack?



In all seriousness I can't breathe he is crushing the life out of my chest. Lol. But yeah I really do feel cat vs tube stove is personal preference. They both excel in specific situations and you're already well ahead of the game having a modern version of either one.

 

[bundy150]

Do the tubes enhance/diminish/no effect the catalytic performance??
My black lab/chow mix recently died 1 month short of his 20th birthday. Best relationship I have ever had!

 

[jetsam]

Is that a snack?

View attachment 276774

In all seriousness I can't breathe he is crushing the life out of my chest. Lol. But yeah I really do feel cat vs tube stove is personal preference. They both excel in specific situations and you're already well ahead of the game having a modern version of either one.

That's why he always brings a Nylabone to these sales meetings, you never know who the client will be.

 

[Highbeam]

My dog smokes but my cat doesn’t. This pup is almost 5 months and loves those fir twigs.