CAT vs Down Draft in Top Load Stoves

[Gadget]

I am trying to advise my father on a stove for his home and the VC Defiant or possibly even VC Encore seem to be a good fit but I am uncertain whether to go with the CAT or Non-Cat model.

The reason I am looking at the VC line is because I currently have a VC resolute Acclaim and am very happy with its performance and features. One feature that is a must is Top Loading. If anyone has suggestions for other top load brands/models that should be considered over the VC then please say so and say why.

Even though I am happy with my noncat VC I see that the efficiency is greater with the CAT models.

If I were to complain about anything on my Resolute Acclaim it would be that you have to be running it fairly hard to get the desired efficiency. Is a CAT stove any different in that regard? Is it any better at running half throttle so to speak?

Knowing my dad, he will occasionally get into some wood that is not cured as well as it should be. Does one system handle greenish wood better than another?

Any other known pro's and cons between cat and non-cat?


Thanks for your help.

 

[schortie]

Your Resolute Acclaim is a non-cat, but not the same system as the Defiant or Encore. The latter use the Everburn (downdraft) system. There have been plenty of discussions of everburn here if you do a quick search. Be prepared, it's not pretty. With this system, you have to get the stove good and hot to engage the secondary burn, much higher than most CAT stoves. One caution would be that the refractory material they use to make the secondary burn chamber doesn't seem to last more than a few years. I don't think that this material lasts much longer on other manufacturer's downdraft stoves either, but I've been wrong before.

 

[summit]

tell him to get a Jotul... or if he is absolutely set on a top loader, Harman top loaders are far superior to VC...

 

[Diabel]

Neither stove will perform as it should with sub-par fuel.

 

[grommal]

Wood that's not fully seasoned will not work well in any modern stove, I think, whether it's a cat or not.

As others have noted, you definitely should read up on the Everburn saga in other threads here. Most folks are not praising it.

Another top loader to look at would be the Quadrafire Isle Royale. Our last stove was also a top-loading VC, and we typically loaded it that way. We agonized long and hard when we bought our new stove in the spring about whether we were willing to have a stove that loaded only front or front/side. Had we decided we could not live without the top-loading feature, the Isle Royale would have been our clear choice.

 

[Gadget]

Thanks for the advice so far.

So if I went the the CAT version of the VC Defiant or VC Encore, I would avoid having to get the stove as hot before engaging the reburn and would avoid whatever other problems there are with the everburn system.

What about the top load Harman, Isle, Lopi and and other top load non-cats, are they still going to require hotter temps before I can engage the reburn compared to CAT models?

 

[North of 60]

Gadget, I think they are saying stay away from both of them. As far as the CAT goes, if the wood cannot be verified as DRY stay away from the CAT. Its would be like running low octane in a high performance motor. Resulting in a melted/crumbling aluminum piston. The piston being the CAT. KEEP reading and Good luck.
N of 60

 

[Slow1]

I ran the an Encore Non-Cat/downdraft stove last year. It took a couple months and a lot of reading/help from folks here to actually figure that stove out, which I was able to do. However, in the end you can see that I still took the loss and replaced it.

Bottom line - the stove was touchy and had to run very hot to run clean. When it was running in optimal mode to run clean - nice bed of coals and good dry wood - it had a tendency to overheat the back of the stove near the flue collar. So, even with the stove running "as designed" it would start to glow back under the heat shield which was by VC definition an overfire condtion. Once this started there was nothing I could do within the specs of the stove to stop it - i.e. cutting the air back completely wouldn't stop it. Mind you this happened to me on less than 1/2 full load of natural wood (oak in this case) on more than one occasion. So... confidence in the stove went down quickly. Second issue is that to get the everburn happy takes a good hot bed of coals which in turn may take a bit of work to get built up enough - meanwhile you are not likely burning in optimal clean mode (I care about this, you may or may not). Last big (objective) thing - when it was running well, the flue temp would be in the 450-500 range (surface temp) which I always felt was a lot of heat headed up the stack and wasted.

I can't recommend this "downdraft" technology to anyone. I liked the top loading at the time, but have not missed it yet to be honest. I'm quite happy to load 1/2 as often (or less) from the side and have to spend far less time messing with the stove and more time enjoying the heat. I bought the VC stove on the reputation it had and on recommendation of folks who had them for years - I had rather hoped that the company had only improved on things. I obviously feel I made an expensive mistake.

Granted this may well just have been my own configuration/environment/operating habits. However I don't think I'm alone in this experience and in any case a stove shouldn't be that touchy.

 

[Todd]

I'd look into the Isle Royal, it doesn't have that tricky operating down draft system like the others and there is also no waiting for temps to come up, just open bypass, load, close bypass and adjust the air. I also heard a rumor that Jotul was coming out with a new top loading non cat maybe next year?

 

[branchburner]

What about the top load Harman, Isle, Lopi and and other top load non-cats, are they still going to require hotter temps before I can engage the reburn compared to CAT models?

The top load Harman and Lopi use the same concept of afterburn as the VC "Everburn" non-cat but those two companies seemed to execute the design better. The top load Harman and Lopi are good stoves but a bit trickier to use and need to be run hot before (and during) reburn.
The Quad Isle Royale uses the burn tube design like Jotul and many others, so I would expect this stove to be easier to use and more forgiving than Harman and Lopi top loaders.

 

[mikepinto65]

I'd look into the Isle Royal, it doesn't have that tricky operating down draft system like the others and there is also no waiting for temps to come up, just open bypass, load, close bypass and adjust the air. I also heard a rumor that Jotul was coming out with a new top loading non cat maybe next year?

what rumor might you be talking about?

 

[Gadget]

Again, thanks for the input.

If completely cured wood is required then it can be found and burned, that is not a limiting factor for the purcahse. I was just inquiring if one technology would be more forgiving than another of damp wood.

The idea of a Jotul top load sounds like a dream come true. I hope that rumor is true.

I understand that most either don’t like down draft at all or don’t like VC at all. So lets say at least the down draft VC’s are out of consideration.

- Top load is a must

- Anything that requires a fan is out of consideration.


So that leaves me with the following Top Load options mentioned above:

Isle Royale (Non-Cat)(Isn't this down draft also?) (It looks like non cats are all either down draft or burn tube and you can't have burn tubes with top load so all top load non cats are down drafts. Is this right?)

VC Defiant CAT (This is not down draft right?)

Lopi Leyden (Down Draft Non-Cat)

Harman Oakwood (Down Draft Non Cat) (The BTU’s are a little below what I am looking for, but still a contender)


So who makes a good top load Catalytic?

 

[redhat]

VC makes a good top load catalytic. I've been using cat encores the past 20 years as our primary heat source and couldn't be happier.

 

[Todd]

I'd look into the Isle Royal, it doesn't have that tricky operating down draft system like the others and there is also no waiting for temps to come up, just open bypass, load, close bypass and adjust the air. I also heard a rumor that Jotul was coming out with a new top loading non cat maybe next year?

what rumor might you be talking about?

https://www.hearth.com/talk/threads/40768/

 

[grommal]

Again, thanks for the input.

If completely cured wood is required then it can be found and burned, that is not a limiting factor for the purcahse. I was just inquiring if one technology would be more forgiving than another of damp wood.

The idea of a Jotul top load sounds like a dream come true. I hope that rumor is true.

I understand that most either don’t like down draft at all or don’t like VC at all. So lets say at least the down draft VC’s are out of consideration.

- Top load is a must

- Anything that requires a fan is out of consideration.


So that leaves me with the following Top Load options mentioned above:

Isle Royale (Non-Cat)(Isn't this down draft also?) (It looks like non cats are all either down draft or burn tube and you can't have burn tubes with top load so all top load non cats are down drafts. Is this right?)

VC Defiant CAT (This is not down draft right?)

Lopi Leyden (Down Draft Non-Cat)

Harman Oakwood (Down Draft Non Cat) (The BTU’s are a little below what I am looking for, but still a contender)


So who makes a good top load Catalytic?

The Isle Royale is NOT a downdraft stove. It's the only stove (so far) that is top-loading and uses burn tubes in the top of the firebox. The design is clever. The baffle and burn tube assembly rotates out of the way, providing a bypass exit up the flue for smoke-free loading. There are a number of IR users here, and they speak highly of their stoves.

The Oakwood is a physically large stove, and also has very large rear clearance requirements. Because of this, I'm skeptical of their quoted lower BTU numbers.

The VC cat is not, I suppose, technically a downdraft stove. I have not seen the exploded diagrams of the newer ones, but I had a 1986 Defiant Encore cat. The new stoves look just about identical to the eye. If the internal design is the same, the cat lives in a rear chamber that is also made of fragile refractory. Ours crumbled twice during the life of the stove, and I waited too long to repair it both times, so it should have probably had at least 3 rebuilds of that area in 23 years. The gas pathway on my old one actually routed the gases UP out of the rear of the firebox, DOWN through the cat element, and back UP around the left and right sides of the cat element. The fact that you had to drive the exhaust DOWN through the cat as it heated up always seemed strange to me. I feel that this funky pathway was responsible for the stove being difficult to operate, with many of the same symptoms as folks report for the downdraft stoves.

I'd agree with you about the possibility of a top-load Jotul. We love our Oslo, but we do miss the top-loading convenience a bit. I would have jumped on that in a heartbeat. Unfortunately for me, if they come out with it next year, I'll still have to wait another 30 years to buy one until my current Jotul starts to show a bit of age. Either that or buy a new house so that I need a new stove....

 

[Gadget]

Grommal, Thank you for the extremely informative reply.

The Isle Royale design you describe does sound like a clever design. I called my nearest Qudra-Fire dealer today and asked them what technology it used and they were unable to tell me. I'm still waiting for a call back when they figure it out.

Thank you all for the knowledge and opinions you have shared.

 

[Gooserider]

I have an Encore Cat, purchased second hand from Elk, one of our former members... I am very far from happy with the stove - every time I've cleaned the chimney, I've ended up with GALLONS of creosote - enough to mostly fill a 16 gallon shop vac!

The refractory, which is very fragile, fell apart on me the first time I took the fireback plate out in order to do the recommended cleaning - I have managed to piece it back together with stainless safety wire and refractory cement, but it isn't right... Hard to tell if I'm getting much if any cat action, but the new replacement Stove Combustor.com cat (also recommended by Elk) doesn't seem to make a lot of dent in the smoke I get out the top of my chimney - which is only slightly less than I used to get from the smoke dragon the Encore replaced...

Right now the GF is out of work, but I'm essentially thinking in terms of doing a boiler when the money gets right - if not we would probably have been looking at a replacement stove.

I would not recommend ANY of the current line of VC stoves - The non-cats don't seem to operate well, and the cats don't hold up...

Gooserider

 

[grommal]

I have an Encore Cat, purchased second hand from Elk, one of our former members... I am very far from happy with the stove - every time I've cleaned the chimney, I've ended up with GALLONS of creosote - enough to mostly fill a 16 gallon shop vac!

The refractory, which is very fragile, fell apart on me the first time I took the fireback plate out in order to do the recommended cleaning - I have managed to piece it back together with stainless safety wire and refractory cement, but it isn't right... Hard to tell if I'm getting much if any cat action, but the new replacement Stove Combustor.com cat (also recommended by Elk) doesn't seem to make a lot of dent in the smoke I get out the top of my chimney - which is only slightly less than I used to get from the smoke dragon the Encore replaced...

Right now the GF is out of work, but I'm essentially thinking in terms of doing a boiler when the money gets right - if not we would probably have been looking at a replacement stove.

I would not recommend ANY of the current line of VC stoves - The non-cats don't seem to operate well, and the cats don't hold up...

Gooserider

I had the same experience with my Encore cat, Goose. When everything was brand new (or after being completely rebuilt), the flow through the cat was ok, and it did clean up the smoke. That lasted for a year. Then, it gradually went downhill. I'd replace the cat element after 3 or 4 years of burning, and the smoke would clean up again. Went through this every few years. The refractory in the cat area was very fragile indeed, and needed repair just to keep the chunks that fell off from blocking the secondary airflow. Looking back on it, I don't know why we put up with it for 23 years.

 

[grommal]

Grommal, Thank you for the extremely informative reply.

The Isle Royale design you describe does sound like a clever design. I called my nearest Qudra-Fire dealer today and asked them what technology it used and they were unable to tell me. I'm still waiting for a call back when they figure it out.

Thank you all for the knowledge and opinions you have shared.

Hmm. If the dealer can't tell you off the top of his/her head something so basic like that, it's a little scary. Unless you were just talking to a receptionist.

All the Quads use multiple burn tubes in the ceiling of the firebox, just below a baffle. These tubes carry preheated air which is delivered to the gases in the firebox to promote secondary combustion. This is the same way almost all the modern non-cat stoves work, regardless of brand, except for the downdraft stoves. So, the "technology" used is what most folks call burn tubes or secondary burn tubes. One thing that Quad does a little differently is that they also has extra air inlets in the rear of their fireboxes to assist with startup. This extra startup air is controlled by its own lever, and a timer on the steel models.

The Isle Royale model is unique in that it has top loading, while still having the tubes and baffle forming the ceiling of the firebox. So, they had to devise a way to swing those tubes and baffle out of the way for loading. They worked it out so that when you swing that assembly (using a handle on the side of the stove) it also opens up a short-cut pathway in the rear of the firebox ceiling for the smoke to exit directly up the flue. As I said before, it's a pretty clever design. If the Jotul rumor is true, it will be interesting to see how they tackle the same design challenge. Your best bet is to just hike down to the Quad dealer and have a look at it yourself.

The only things that bothered me just a bit about the Isle Royale design had to do with the location of the baffle/tubes during loading and swinging. In the old VC, there was nothing much to damage when you lowered splits into the stove from the top. With the Isle Royale, if you were very careless, it looks like you could damage a tube or poke a hole in the ceramic layer of the baffle. Also, since the baffle/tube assembly needs room to swing, I don't think you can load the stove to its true full capacity from the top. It's a big stove, so that's probably ok, but if you really wanted to pack it, you might need to use the front door.

 

[Backwoods Savage]

VC makes a good top load catalytic. I've been using cat encores the past 20 years as our primary heat source and couldn't be happier.

I'm betting that indeed you are very happy with that VC stove and are happy for you.

VC did indeed make a good stove 20 years ago. However, we must remember that change is the only constant in this world. VC has changed a lot and it appears that the change has not necessarily been for the good. They have changed hands a couple times too so the stove you buy today will be much, much different from the stove you bought 20 years ago.

 

[MishMouse]

The Harman stoves do have a learning curve and they seem to be more tricky then the Isle Royal.
Adding less then seasoned wood to the equation also adds to the difficulty in getting the afterburn to work properly.
The biggest key to the stove is building a good coal base at least 2-3 inches.
This makes the stove very efficient when burning 24-7, but not as efficient when burning just a nightly fire.

But, one option that the Harman has that was a big selling point for me was the grill insert option.
Grilling steaks, sausages, hamburgers, chicken, fish, veg's etc... in the middle of winter is priceless.
Actually for me I grill more with my Harman then I do with the BBQ.
Since I load the stove in the morning, by the time I get home around 9-10 hours later all that is left is a big pile of wood charcoal which works perfect for grilling.

A side note: If the Isle Royal offered a grill option, there is a great possibility that I would have went that route as apposed to my TL-300.

 

[branchburner]

Mish, I feel the same about my Oakwood and agree with every word you said (except my firebox is smaller, so burn times shorter). This time of year, I really feel like the lower burn temps of a cat stove would be nice. But in the dead of winter, I do love my heating beast, and its grill.

 

[Gadget]

Re: Harman

I must admit I'm a little surprised to find people who use the grill option. I figured it was just a gimmick that probably would never get used. Good to know.

How is the clean up. Can you just leave the grill in the stove and let it burn off the grease?

 

[summit]

Re: Harman

I must admit I'm a little surprised to find people who use the grill option. I figured it was just a gimmick that probably would never get used. Good to know.

How is the clean up. Can you just leave the grill in the stove and let it burn off the grease?

it's one of the best gimmicky options ever devised... we used one on the old floor model Oakwood, and it worked great... the mess all dripped into the coals and burned of withing 5 minutes after cooking, and it made the best burgers and steaks on some good maple and oak coals.... we even tried some hickory chips and apple pellets once...

 

[Gooserider]

While I can agree about the wondrous virtues of grilling inside a stove, I don't know why one needs a special "factory made" attachment to do so...

I've used two approaches that both work nicely...

1. I have a grill thing that I think was originally intended for campfires and the like - it has two grill sections that hinge together at one end, and a handle on each section on the other end, with the sections locked together by sliding a ring over the two handles... Open it up, stick the food in, and close the two sections and latch them together - I then stick the closed unit in the stove through the top door, with the handle sticking out a little. After a minute or two flip it over, then remove, open the grill up and take out the food...

The gizmo I have is a bit clunky and I've found the wires are a bit light and flimsy - If I were making it from scratch, I'd probably use the same basic idea but make it from expanded steel, or possibly recycle a couple of cut down oven racks...

2. Even nicer - works great for steaks, probably not good for small food... Get stove to stage where wood is charred in, but not doing ashy coals... Season steak, open stove, drop steak directly on hot coals. Close stove, Wait 1-2 minutes, open, flip steak to a different area of coals w/ BBQ tongs, close and wait another minute or so, remove and eat...

Either way, no extra grill attachment required... It would probably also be possible to make a custom grill setup for any stove - just cut down an old oven rack, and put some legs on it...

Gooserider