Help sizing a Catalytic stove

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tabner

Burning Hunk
Jan 17, 2019
230
Eastern CT
quick update if anyone was wondering. Gonna stick with the hyper heat pump unit - qualifies for more rebates, in addition to the obvious benefit of better heating in low temps. I have signed the paperwork and am moving forward with it all. Picked up a hybrid electric water heater, since current hot water is off the boiler. hybrid water heater is $1200 minus a $750 instant rebate out the door from state of CT, and then a $300 federal tax credit this spring, so literally a $150 hybrid heat pump water heater. Anywho, i'm just waiting on the final signatures to come through on the heat pump install (rebates, energy audit, state approvals, blah blah). as soon as that's all squared away I'm going to go buy the GM60. Dealer is giving me a 10% cash/carry discount on the stove and blower. I'll update/review as i move along here.
I've been reading as much as I can here, to learn as much as I can, and I have a random catalyst question I'm wondering if someone could explain. I understand you want to always keep the cat above a certain min temp, to avoid stalling. And during 24/7 burning in deep winter that seems fairly straightforward. But in shoulder seasons, if you fire up for one night, or one day, the stove is going to run out of fuel eventually (whether that's 8 hrs or 24 hrs, depending on the load size). How does the cat handle it if you're not there when the stove runs out? it seems unreasonable to guarantee you're going to be home, or awake, right when the load runs out. Or does it (ideally) literally burn up every bit of fuel before dropping below active temp, so that when it goes inactive, there's very little left for smoke/creosote?
 

stoveliker

Minister of Fire
Nov 17, 2019
2,871
Long Island NY
What I learned here is that the creosote is produced in the beginning of the cycle (when leftover moisture is still present). At the end no creosote is produced. And smoke is absent at the end of the cycle. Just glowing coals.


So it's fine to let it run out of fuel with the bypass closed.

Good luck and happy heating with the new playthings!
 
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tabner

Burning Hunk
Jan 17, 2019
230
Eastern CT
Sorry for the endless stream of questions, there's clearly a lot involved here. Just put the 50% down payment on a GM60, should be here in a couple weeks. Hoping I can throw out one more question:
I noticed in the forum here reading on the Blaze Kings and looking through some manuals, with the catalytic stoves and the importance of draft, if you have to run too much horizontal in your stove pipe, they recommend two 45s rather than a 90. I can't find specifics called out in the GM manual, but I'm just wondering if i can describe my 'potential' setup and see if this will be an issue for me.
Chimney is 8" square tile, inside a cement/cynder block square, that goes up through the center of the house and out the peak. I'll be connecting about 6 feet off the floor of the basement. So that's a couple feet in the basement, the whole first floor, second floor, a couple feet of attic space, and a few feet above the peak (at minimum, 24' total). Because of the way the stove needs to face, i want the stove pipe to come straight up out of the stove and then cut left, horizontally into the chimney. Between the width of the stove, the 13" clearance to the wall, and about 10 inches through the wall to the chimney, i am guestimating (I can measure more precisely later) about 36" of straight vertical, then cut horizontal about 33" to the chimney. Based on my chimney size and design, I think it should be decent draft? But is that a dangerous amount of horizontal stovepipe? It will be double wall, if that helps, and the 10" through the wall into the chimney will be Class A.
Sorry for a million long-winded questions, and I appreciate the help.
 

tabner

Burning Hunk
Jan 17, 2019
230
Eastern CT
Sorry, add on question: clearances are all listed as "to combustibles". If I tile the wall, can you reduce the clearance? Or does it still count as combustible? It would be really nice to have down that 13" side clearance
 

tabner

Burning Hunk
Jan 17, 2019
230
Eastern CT
Picked up the GM60 yesterday. I think it's a really good looking stove. Can't believe how big the front glass is. i grew up heating with wood in Northern VT, and i remember small fire boxes, tiny opaque glass doors you could barely see through, and one stove with zero glass. Compared to that, this thing looks like a giant glass fireplace. I'm still a little scared it's going to roast my den, but hopefully using what i've learned here about cold air returns, and low burning cats, i can make it work well. My mini split system gets installed in mid-Dec. And the stove probably won't be till late January - gotta do some hearth work and burn the rest of my oil tank. I'm sure I'll be back with plenty of questions.
Thanks again.
 

begreen

Mooderator
Staff member
Nov 18, 2005
91,319
South Puget Sound, WA
Sorry, add on question: clearances are all listed as "to combustibles". If I tile the wall, can you reduce the clearance? Or does it still count as combustible? It would be really nice to have down that 13" side clearance
That does not qualify for clearance reduction. Even with proper NFPA shielding, the lowest clearance would be 12".
 
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tabner

Burning Hunk
Jan 17, 2019
230
Eastern CT
I still have the oil/hot water baseboard furnace, but I'm not using it now other than to heat my hot water. I was told that a heat pump water heater might work too. At that point getting rid of the oil business might be an option. For now I'm leaving it as is; it's a safe back up (oil tank is large), and I can run that system off my generator too.

@stoveliker I just noticed you mentioned a Heat Pump water heater here and I wanted to give you some feedback. As part of my project I have to switch my hot water from the oil boiler over to one, so I just bought one last week. A rheem 50 gallon is $1200, but the state of CT has an instant rebate on it of 750$, until the end of the year. And then if you buy one before 12/31, there is also a $300 federal tax credit. Not sure if you have anything similar in NY to the instant rebate right now, but might be worth checking before the end of the year. Or if you know anyone in CT....
I haven't actually run it yet because i'm waiting till my oil runs out, but i did plumb it all up the other day and ran the electric. I really like the look of it. They come standard with WiFi and an app so you can see exactly how it's running and how much hot water you're using (my wife and her 45 min showers are in big trouble). They also pull like 5 to 8 degrees of temp out of the air which is cool for me because it's going to pull heat in the summer, and in the winter with the woodstove i don't care anyways. It also acts as a dehumidifier you don't have to empty - being in my basement, that's another plus.

Anyways, for whatever it's worth, just wanted to throw that out.
 

stoveliker

Minister of Fire
Nov 17, 2019
2,871
Long Island NY
@stoveliker I just noticed you mentioned a Heat Pump water heater here and I wanted to give you some feedback. As part of my project I have to switch my hot water from the oil boiler over to one, so I just bought one last week. A rheem 50 gallon is $1200, but the state of CT has an instant rebate on it of 750$, until the end of the year. And then if you buy one before 12/31, there is also a $300 federal tax credit. Not sure if you have anything similar in NY to the instant rebate right now, but might be worth checking before the end of the year. Or if you know anyone in CT....
I haven't actually run it yet because i'm waiting till my oil runs out, but i did plumb it all up the other day and ran the electric. I really like the look of it. They come standard with WiFi and an app so you can see exactly how it's running and how much hot water you're using (my wife and her 45 min showers are in big trouble). They also pull like 5 to 8 degrees of temp out of the air which is cool for me because it's going to pull heat in the summer, and in the winter with the woodstove i don't care anyways. It also acts as a dehumidifier you don't have to empty - being in my basement, that's another plus.

Anyways, for whatever it's worth, just wanted to throw that out.

Thanks. Unfortunately it's not in the works for me this year. I also have some hesitance to take out the oil burner, because I'm not sure I can get enough free wood here in the long term to rely on that to heat my home (when it's really cold). So I feel safer having my oil furnace in running order - and having that heat my water is a good way to keep the cast iron furnace warm (as letting it cool down to room temp risks cracking it, or so I'm told; I don't have a lot of experience with oil heat, having lived in Eastern TN and overseas before moving here).

Although, with my daughter reaching her teenage years fast (and my son not far behind), a wifi check on their usage is quite appealing :cool:

Do I understand it correctly the heat pump is inside the home? Clearly I did not research these things yet, but I assumed it'd be outside. If it cools and dehumidifies inside, that's clearly not the case.
Is that efficient? In shoulder season, I'm running a heat pump to heat, and then I'm again running one to heat my water... (though with efficiencies above 100% at "basement temps", there are no conversion losses... - have to think a bit about that...). And why does one not have to empty the water it pumps out of the air in the basement...? (simply a hose to a sewer line or something I'm not getting?)

Thanks for the education!
 

Highbeam

Minister of Fire
Dec 28, 2006
19,529
Mt. Rainier Foothills, WA
Thanks. Unfortunately it's not in the works for me this year. I also have some hesitance to take out the oil burner, because I'm not sure I can get enough free wood here in the long term to rely on that to heat my home (when it's really cold). So I feel safer having my oil furnace in running order - and having that heat my water is a good way to keep the cast iron furnace warm (as letting it cool down to room temp risks cracking it, or so I'm told; I don't have a lot of experience with oil heat, having lived in Eastern TN and overseas before moving here).

Although, with my daughter reaching her teenage years fast (and my son not far behind), a wifi check on their usage is quite appealing :cool:

Do I understand it correctly the heat pump is inside the home? Clearly I did not research these things yet, but I assumed it'd be outside. If it cools and dehumidifies inside, that's clearly not the case.
Is that efficient? In shoulder season, I'm running a heat pump to heat, and then I'm again running one to heat my water... (though with efficiencies above 100% at "basement temps", there are no conversion losses... - have to think a bit about that...). And why does one not have to empty the water it pumps out of the air in the basement...? (simply a hose to a sewer line or something I'm not getting?)

Thanks for the education!

there’s a condensate drain.

these heat pump water heaters are a no go for those of us with no basement since they’re noisy and very tall with the compressor and evaporator mounted on top of a regular water heater tank.
 

stoveliker

Minister of Fire
Nov 17, 2019
2,871
Long Island NY
there’s a condensate drain.

these heat pump water heaters are a no go for those of us with no basement since they’re noisy and very tall with the compressor and evaporator mounted on top of a regular water heater tank.

Ok. That's what I thought. Thanks

I am dehumidifying my (finished) basement with a small minisplit head (Mitsubishi has a dehum mode where it runs at low speed and not very cold), but it's not ideal. Sometimes I have to add the plug in one I have. So this might be interesting, though noise and my hesitation above so far win out. I'll read up a bit though.
 
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tabner

Burning Hunk
Jan 17, 2019
230
Eastern CT
As highbeam said, yes, condensate drain. You can just drop it into a floor drain or a utility sink. I tied it directly into a waste pipe. I won't be able to speak to the noise issue until i've run it, but i believe they are not as loud now as they use to be. Down south i think people like to put them in the garage, if they don't have a basement, since it's pretty warm out there anyways it makes sense. I am looking forward to not having to empty a large dehumidifier every couple days all summer. Not to mention i listen to the dehumidifier kick on all the time anyways, might be an even swap on the noise ;lol
I wanted to make the switch years ago, and shut down the oil boiler in the summer, but i was told the same thing as you - seals will dry up and crack, etc. Not sure if it's true, or it's just the oil man trying to keep my boiler running 365!

This 50 gallon is about 22" dia, and i think about 6 foot tall.
 

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begreen

Mooderator
Staff member
Nov 18, 2005
91,319
South Puget Sound, WA
@stoveliker I just noticed you mentioned a Heat Pump water heater here and I wanted to give you some feedback. As part of my project I have to switch my hot water from the oil boiler over to one, so I just bought one last week. A rheem 50 gallon is $1200, but the state of CT has an instant rebate on it of 750$, until the end of the year. And then if you buy one before 12/31, there is also a $300 federal tax credit. Not sure if you have anything similar in NY to the instant rebate right now, but might be worth checking before the end of the year. Or if you know anyone in CT....
I haven't actually run it yet because i'm waiting till my oil runs out, but i did plumb it all up the other day and ran the electric. I really like the look of it. They come standard with WiFi and an app so you can see exactly how it's running and how much hot water you're using (my wife and her 45 min showers are in big trouble). They also pull like 5 to 8 degrees of temp out of the air which is cool for me because it's going to pull heat in the summer, and in the winter with the woodstove i don't care anyways. It also acts as a dehumidifier you don't have to empty - being in my basement, that's another plus.

Anyways, for whatever it's worth, just wanted to throw that out.
This is a better question asked in the DIY or Green Room forums.
 
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