Cat vs NonCat

[Dave A.]

Yep, saw that in the brochure at the Harman store when I was considering their insert. Didn't get the Harman so can't say whether it's true or not, but it certainly looks impressive for a non-cat, though it is the "dreaded downdraft" technology.

After checking the replacement cost of the relative fragile refractory chamber parts, and figuring that they had taken the firebox from their freestanding oakwood which was designed for top loading and put it into an insert without the top loading feature, I decided against it, as much as I really liked it -- big square tall glass door, bypass control, andirons to keep logs away from the glass, no burn tubes, nice looking unit for a steel insert.

 

[Dave A.]

most also agreed that the units were chosen in a fashion to intentionally exaggerate the differences.

I have to agree, that as much as the blue curve represents what I experienced with my Century insert, when I use dry wood and turn the air control low on my Summit, I can achieve a much flatter curve than that blue curve indicates.

And also, it needs to be understood that if you have a stove that's not undersized for your house, if it's a little warmer over the first few hours and cooling off towards the end of the burn, it's not that important or even a problem. Otoh, if your stove is undersized, and never really warming you up enough, you will mind that cooling off towards the end of the burn a lot more.

 

[begreen]

The Harman graph is a sales piece at best. It also doesn't show thevariances in non-cat stoves. A soapstone or high-mass, cast iron jacketed steel stove has a flatter curve than a thin skinned steel stove. Nor does it quantify the difference between a radiant and convective stove. I have been heating with wood for a long while and the eveness of heat in our house has never been better since putting in the T6. And that is with it being installed in a smaller living room.

 

[stovelark]

Totally agree with BG. I went from an Oslo to an Enviro Kodiak steel stove and while I could overheat the area downstairs (with either stove) if I wanted to, I had enough temp control to control their output. I do believe its more important to correctly size the stove to the area that you are heating rather than what material the stove is made of. If you are off in size (stove oversized to room area heated) naturally a soapstone and cast iron has the better chance of not running you out. The graph obviously is biased toward their opinion, Hearthstone does the same thing in their promo ads. Proper stove operation and knowing your own stove is always the best answer. As to Harman and VC, their down drafting refractory sec burn systems are not very robust and the replacement is painful and expensive. There are a lot of old Jotuls, Quadrafires, Pac Energy and Enviro stoves out there doing their work, year after year. BTW, their sec tubes and ceramic baffles are a lot more affordable and much easier to replace too, than the aforementioned down drafters' components. No matter what style stove we all burn, burn with care and dry seasoned wood.

 

[Dave A.]

The Harman graph is a sales piece at best.

Well, maybe Seasoned Oak will see this and contribute his experience of how uniform the heat output is or isn't over the burn cycle. I believe he uses a Harman. I'd be interested.

A soapstone or high-mass, cast iron jacketed steel stove has a flatter curve than a thin skinned steel stove.

I'd have to agree with you on that. Though my Summit B doesn't have as much cast iron as the Aderleas, it does have a wide bay cast iron top and bay ash lip which noticeably output heat over the latter stages of the burn.

 

[Seasoned Oak]

Well, maybe Seasoned Oak will see this and contribute his experience of how uniform the heat output is or isn't over the burn cycle. I believe he uses a Harman. I'd be interested.

I have to differ with begreen slightly. Harman was not my first stove nor is it the only stove i use ,but it is the best and by far the longest burning. You do indeed get long even burns with this downdraft tech. Iv had burns into 20+ hours with this stove which i could never get with my englander which has the same 3CU ft firebox. The biggest difference between the Harman and say a BK King IMO is i cant turn the harman down as far.Even at the lowest setting its putting out some serious heat.Perhaps thats why they make smaller versions of my stove now. IMO for all intents the chart reflects my experience with Harman vs other non -cat stoves. That said: yes some non cat,non downdraft stoves are better than others and perhaps the chart does not reflect that fact [/quote]

 

[begreen]

Harman appears to have done a good job with the TL-300. Capacity helps, but it's not the whole picture. For example, it's not unusual for Super 27/Spectrum owners to get 12-16 hr burns. That's with a 2 cu ft stove. Controlling the secondary burn rate seems to help extend the burntime.

 

[Seasoned Oak]

Harman appears to have done a good job with the TL-300. Capacity helps, but it's not the whole picture. For example, it's not unusual for Super 27/Spectrum owners to get 12-16 hr burns. That's with a 2 cu ft stove. Controlling the secondary burn rate seems to help extend the burntime.

Exactly, i would venture to say if i could turn my harman lower it may go 40 hours too like a BK ,but of course with a lower heat output as well. Thats were a cat stove shines is the ability to scale back the burn rate....nice in the shoulder seasons.

 

[Ashful]

Controlling the secondary burn rate seems to help extend the burntime.

Yep. This is really the big factor in BK's performance, right?

As to downdraft vs. cat... you could have the best (or worst) of both worlds, if you buy an old Jotul. The F12 is a downdraft cat stove.

 

[begreen]

Exactly, i would venture to say if i could turn my harman lower it may go 40 hours too like a BK ,but of course with a lower heat output as well. Thats were a cat stove shines is the ability to scale back the burn rate....nice in the shoulder seasons.

I lit up the T6 yesterday. 48F outside. I only put in 4 splits, but that kept the house comfortable without being overwhelming for 12 hrs. Mass rules.

 

[stovelark]

Being a top loader, the FL 12 was the only Jotul down drafting cat It was also the most successful Jotul cat stove too, hands down. Still a lot of units out there.

 

[simple.serf]

I typically prefer Cat stoves, every one I have used (not at my current location) has operated flawlessly.

That being said, I currently burn a non cat stove. I have some issues, most of which can be attributed to draft, operator error (there are two operators...) or a recently discovered air leak. I also prefer to burn long and slow, which this type of stove isn't well suited for.

For me, It's probably a mental thing, I'm sure that in my location with it's specific problems, any stove would have some issues.

For the record, I am a food production equipment technician.

 

[Seasoned Oak]

There is a difference in the way burn tube vs downdraft stoves handle the reburn. It seems with my englander 30, some of the flue gases get by the burn tubes and i often get smoke out the chimney. THe harman on the other hand forces all the flue gas thru a ceramic reburn chamber at the bottom of the stove and once engaged does not let any flue gas by unburned. I get virtually NO smoke after the initial warm-up.

 

[stovelark]

FYI- any sec burn tube stove operating at the normal temps (stove top 400-700 deg) with dry seasoned wood operates with virtually NO smoke. That's to be be expected with any secondary burn system stove, cat, non cat tube, non cat down drafters too.

 

[oldspark]

FYI- any sec burn tube stove operating at the normal temps (stove top 400-700 deg) with dry seasoned wood operates with virtually NO smoke. That's to be be expected with any secondary burn system stove, cat, non cat tube, non cat down drafters too.

Yep, my summit only smokes for a short time after start up and then nothing through the burn, reload maybe a little.

 

[Seasoned Oak]

FYI- any sec burn tube stove operating at the normal temps (stove top 400-700 deg) with dry seasoned wood operates with virtually NO smoke. That's to be be expected with any secondary burn system stove, cat, non cat tube, non cat down drafters too.

Unless you have personally tested every stove on the market, with every kind of wood ,you can't make a valid claim as to how every one will operate. My two different burn tube stoves (NC-30 englander and Country hearth 2000) DO smoke at times even at 650 deg burning 100 Yr old dry wood.More so at higher air settings.These are 2 very different designs.The harman does not smoke at all with the same wood,and the same stove top temps ,at any air setting. I am only comparing the stove models i own and operate,not any other models. The 2 burn tube stoves i own were 1/4 and 1/5 the price of the harman so i dont expect superior performance or perfection. They get the job done,smoke or not.

 

[oldspark]

Good point Oak, seems like my summit quits smoking at a fairly low temp but as you stated others with different brands dont see the same thing, plus wacky temp gauges dont help.

 

[stovelark]

OK hee hee, guess that is a valid point. But of the many stoves I have worked on and ran, to include Quadrafire, Jotuls, Lopi, Country, Century, Hearthstone, Jotul cats, Vermont Castings downdrafters and catalytic models, Avalon, Pacific Energy Vermont Castings sec air tube models, THAT I PERSONALLY HAVE OPERATED- they all operated virtually smoke free emissions after they were at operating temps of those mentioned. PS- Have a nice day.

 

[Seasoned Oak]

OK hee hee, guess that is a valid point. But of the many stoves I have worked on and ran, to include Quadrafire, Jotuls, Lopi, Country, Century, Hearthstone, Jotul cats, Vermont Castings downdrafters and catalytic models, Avalon, Pacific Energy Vermont Castings sec air tube models, THAT I PERSONALLY HAVE OPERATED- they all operated virtually smoke free emissions after they were at operating temps of those mentioned. PS- Have a nice day.

I agree that most EPA stove do operate smoke free,and it seems you have experience with more models than i have,but they also all have different emission levels. Than harman happens to be less than a gram. I don know of any other Non-cat stove that low, but results will vary.
I just recently found out why my NC-30s may be smoking is there is a 1/2 inch gap all along the refractory board that lets flue gas and smoke go directly up the chimney and bypass the burn tubes. that will surely cause some smoke. Apparently that gap is not part of the design.Im not trying to make an argument,just giving my pwn personal experience with these particular stoves.