(yet another) retro fit CAT thread

[SmokeyCity]

so..I found this retrofit cat add on.. (see JPEG pic attached) and was considering inserting it above the exit collar on my 30NC

I noticed that the ad says this thing is NOT recommended for EPA approved stoves. I emailed the company but got no reply yet.
Anyone have any idea why this device is not recommended for EPA stoves? My 30NC *is* a EPA approved - but of course - I wanna do it anyway :=)



p.s Feel free to flame me for this idea but be warned I will filter your response thru a catalytic converter and if you arguments against it are mostly smoke.. well... you what will happen to your comments ...

 

[Rob From Wisconsin]

I bought the exact same retrofit some years ago.
I didn't work very well, acting more like a funky damper.
I doubt the catalyst aspect of it ever really worked.
Finally trashed it.....

 

[SmokeyCity]

Thanks! you saved me some wasted $$!

Id still like to find something that works

I bought the exact same retrofit some years ago.
I didn't work very well, acting more like a funky damper.
I doubt the catalyst aspect of it ever really worked.
Finally trashed it.....

 

[EatenByLimestone]

Welp, most EPA stoves are fairly draft sensitive. Add this to the mix and it could be too much.

Matt

 

[cmonSTART]

Ya, I agree with EBL. They do tend to be a bit finicky. It will be interesting to see what the company says.

 

[Rob From Wisconsin]

Probably the most effective CAT retro's are for the old-fashion "smoke dragons".
They typically involved the addition of an assembly near the flue exit, along with
a bypass flapper gate that was closed to force the smoke exhaust solely through the
catalyst element. The reasons why they were effective was because they were
able to properly divert/contain the smoke and were located within the firebox (heat).

The retrofit you were looking at is neither - smoke can & does leak around the element,
and it is hard to maintain enough heat to light-off the catalyst, because a significant
amount of heat is lost rising-up through the stove pipe.

 

[Rob From Wisconsin]

I think most people are interested in these devices because their stove lacks "staying power".
I guess you could call it "stove envy".
But, in all seriousness, I remember buying a larger EPA stove with hopes of getting all kinds of
heat and rediculously long burn times. Truth was I got not much of either.
My purchasing of this device a was a desparate attempt to enhance the "love life" in my
failing love with my stove. In the end, we went our separate ways.........

 

[SmokeyCity]

yep, they had infinite draft and had room to get the CAT in the box because there was no baffle or tubes

Probably the most effective CAT retro's are for the old-fashion "smoke dragons".
They typically involved the addition of an assembly near the flue exit, along with
a bypass flapper gate that was closed to force the smoke exhaust solely through the
catalyst element. The reasons why they were effective was because they were
able to properly divert/contain the smoke and were located within the firebox (heat).

The retrofit you were looking at is neither - smoke can & does leak around the element,
and it is hard to maintain enough heat to light-off the catalyst, because a significant
amount of heat is lost rising-up through the stove pipe.

 

[sesmith]

Agreed on the draft issues.

You can figure that it's gonna take 550-600 degrees to make that one light off. If you have single wall stove pipe and a magnetic thermometer (or infrared) will read 300 ish at the stove pipe where the cat would be, you can be pretty sure it would light off. A more accurate way would be to use one of the thermometers you insert into the pipe and measure the actual flue gas temp. If you can't get the temps up to that, it'll never light off. Also, that one has a 1.5" catalyst. That's kind of an odd ball as most of the wood stove 6" round catalysts are 2"deep. When I was looking for retrofit catalysts for my stove, I also ran across the same one you found. I wondered if this 1.5" catalyst was the same thing Sud Chemie calls the "Enviecat 3041" (see chart at bottom of page).


http://www.sud-chemie.com/scmcms/web/page_en_7529.htm


If so (and I could never find any proof) it would be be less efficient than the better catalysts they sell. So, if you're already starting off with a fairly efficient EPA stove, you'd probably be wasting your money buying this one.

Scott

 

[North of 60]

What are you trying to gain from this. A properly running EPA stove already does this and better than with an add on.

 

[SmokeyCity]

Im trying to determine what, if anything can be gained. I

What are you trying to gain from this. A properly running EPA stove already does this and better than with an add on.

 

[sauer]

I dont see the point of creating hight temp situations in the stovepipe when that cat lights off. You would want that in the stove, not in the pipe
nice gimmick though

 

[BrotherBart]

What are you trying to gain from this. A properly running EPA stove already does this and better than with an add on.

Even a Napoleon?

 

[North of 60]

What are you trying to gain from this. A properly running EPA stove already does this and better than with an add on.

Even a Napoleon?

Even with the Kia Ralf.

 

[Rob From Wisconsin]

Agreed on the draft issues.

You can figure that it's gonna take 550-600 degrees to make that one light off. If you have single wall stove pipe and a magnetic thermometer (or infrared) will read 300 ish at the stove pipe where the cat would be, you can be pretty sure it would light off. A more accurate way would be to use one of the thermometers you insert into the pipe and measure the actual flue gas temp. If you can't get the temps up to that, it'll never light off. Also, that one has a 1.5" catalyst. That's kind of an odd ball as most of the wood stove 6" round catalysts are 2"deep. When I was looking for retrofit catalysts for my stove, I also ran across the same one you found. I wondered if this 1.5" catalyst was the same thing Sud Chemie calls the "Enviecat 3041" (see chart at bottom of page).


http://www.sud-chemie.com/scmcms/web/page_en_7529.htm


If so (and I could never find any proof) it would be be less efficient than the better catalysts they sell. So, if you're already starting off with a fairly efficient EPA stove, you'd probably be wasting your money buying this one.

Scott

The catalyst I had seemed to be an ordinary ceramic unit - nothing special.
Like I said before, I was looking for longer burn times, and perhaps slowing-down heat
being shot up the flue so quickly, which seems to be an issue with a lot of EPA stoves.

 

[cmonSTART]

Someone here on hearth.com did an awesome cat retrofit to an old pot belly stove. I remember they did a great job, but I don't remember who it was.

 

[Rob From Wisconsin]

In my long-winded research some years ago I did stumble across a
catalyst retrofit kit that did mount above above the stove, in the flue.
It was large/bulky & stood out like a "sore thumb".
But, on the other hand, it did seem to have an effective bypass method,
along with having some thermal mass, which could help in keeping
the catalyst lit. The only problem is that the mfr. went out-of-business some time ago.

 

[Peter B.]

Someone here on hearth.com did an awesome cat retrofit to an old pot belly stove. I remember they did a great job, but I don't remember who it was.

I don't know that 'awesome' is an apt description, but I was proud of the concept and execution.

With a pseudo 'base burning' design including a duct from (near) the stovebox floor to an upper baffle (above which the catalyst sat), the burn was very clean, with (typically) no visible smoke from the chimney. There was also a rudimentary secondary air supply. The catalyst housing tended to 'finish' with a white to light cream dusting after a fire. There was definitely reduced creosote output, but enough to sweep twice a season.

After twenty years use, I'm afraid the internal modifications I made have reached their useful lifetime, and - though I don't know what will replace it yet - the Round Oak will likely be retired from service as of this spring. There is very definitely a performance 'hit' without the internals.

Peter B.

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[Rob From Wisconsin]

The retrofit kit I had definitely wasn't white/grey on the element.
It was black/brown - not engaging at all.