Everything Drolet Tundra - Heatmax...

Highbeam

Minister of Fire
Dec 28, 2006
16,221
Mt. Rainier Foothills, WA
I recall asking SBI about the rear clearance and they said it was only to access the air filter and fan, and to only pay attention to the stove pipe to wall specs .

Eric
That’s great that they said that but the installation requirements require 16-18 (sorry I forget) minimum clearance to combustibles to the filter box. It’s one of the very few hard requirements.

I could understand providing recommended maintenance access but this is a required clearance.

I’m in a shop situation with an overhead door so I want to be up to spec.
 

JRHAWK9

Minister of Fire
Jan 8, 2014
1,141
Wisconsin Dells, WI
We chatted about my plans last spring but I have 3 Johnson control digital controllers controlling the damper, blower on, and blower speed, 3 powered dampers, 8 relays, a 24vac transformer.

It allows the gas furnace and wood furnace to operate in a common set of duct work with both systems being authorized to operate at the same time, though they don't operate at the same time...most of the time. It absolutely works.
sweet! 8 relays :eek: ;lol It's nice having a fully automated system isn't it? Sounds like a more complicated version of mine, although mine's not sharing return ductwork. IIRC, you had to because you have your furnace in the garage or something.

I recall you mentioning something in this thread about wanting to come up with something, but I don't recall hearing any details.
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,125
NE Ohio

Highbeam

Minister of Fire
Dec 28, 2006
16,221
Mt. Rainier Foothills, WA
So what's your question then?
I read it online in the manual. Is it a mistake, has anybody gotten written clarification to ignore it, is it real, and do all furnaces have this silly requirement? You know, basically WTF is it with that lame requirement?
 

KC Matt

Burning Hunk
Oct 29, 2016
116
Kansas City
sweet! 8 relays :eek: ;lol It's nice having a fully automated system isn't it? Sounds like a more complicated version of mine, although mine's not sharing return ductwork. IIRC, you had to because you have your furnace in the garage or something.

I recall you mentioning something in this thread about wanting to come up with something, but I don't recall hearing any details.
That's correct. The tundra is attached to both supply and return, and the only option is to install it in the basement garage. I spent 3 years figuring out how to make this really work starting with the on/off switch the furnace came with. Since I have a job and couldn't spend every minute of every day babysitting this thing I had to figure out a way to automate it. Today it's as close to perfect as it could be. It's the Mahomes of furnace installs.

I posted my schematic last fall or spring and didn't get much feedback. Ran it by my buddies who work with electronic circuits for a living and didn't get much help. Finally just figured I would do it. Built an enclosure, wired it up, walked away, came back to find errors, fixed them and walked away came back looked it over and didn't find errors, plugged it in, fired it up and.....the damned thing works.
 

KC Matt

Burning Hunk
Oct 29, 2016
116
Kansas City
I read it online in the manual. Is it a mistake, has anybody gotten written clarification to ignore it, is it real, and do all furnaces have this silly requirement? You know, basically WTF is it with that lame requirement?
If you have clearance for the chimney you are good. Use double wall black pipe the clearance is 6". ZERO clearance is needed for the cabinet of the furnace aside from the front.
 

JRHAWK9

Minister of Fire
Jan 8, 2014
1,141
Wisconsin Dells, WI
That's correct. The tundra is attached to both supply and return, and the only option is to install it in the basement garage. I spent 3 years figuring out how to make this really work starting with the on/off switch the furnace came with. Since I have a job and couldn't spend every minute of every day babysitting this thing I had to figure out a way to automate it. Today it's as close to perfect as it could be. It's the Mahomes of furnace installs.

I posted my schematic last fall or spring and didn't get much feedback. Ran it by my buddies who work with electronic circuits for a living and didn't get much help. Finally just figured I would do it. Built an enclosure, wired it up, walked away, came back to find errors, fixed them and walked away came back looked it over and didn't find errors, plugged it in, fired it up and.....the damned thing works.

I had the same issues when asking master electricians I know to look over my wiring. Basically ignored me. I think it's a liability thing. Don't want to give an OK in case something would happen and then have the "well you OK'd it for me" thrown back at them.

That's awesome though. Glad it works for ya. I should look for that schematic.

edit. I found the post and now I remember it. I remember having a hard time following what you were trying to accomplish.
 
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brenndatomu

Minister of Fire
Aug 21, 2013
4,125
NE Ohio
I read it online in the manual. Is it a mistake, has anybody gotten written clarification to ignore it, is it real, and do all furnaces have this silly requirement? You know, basically WTF is it with that lame requirement?
NFPA rules...applies to everything
Use double wall black pipe the clearance is 6". ZERO clearance is needed for the cabinet of the furnace aside from the front.
Same clearance for both single and doublewall pipe...Englander NC30 is that way too...and the cabinet clearance is 11" on one side, 24" on the other
 

KC Matt

Burning Hunk
Oct 29, 2016
116
Kansas City
It's funny, but I think those guys clock out and don't want to think any more. One buddy is an engineer who designs integrated circuits for a living, another builds refrigeration systems and another troubleshoots stationary backup generators. All of those are more complicated than what I built but nobody wanted to get involved in this thing. I understand.

I am sure they are like me; so much demand on our time they just didn't want to get dragged into this thing. One buddy has promised to make a correct schematic for me so that when I'm gone a tech can figure out what I've built. One day somebody will need to service this thing. My schematic works, but it's not correct from a technical perspective.
 
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KC Matt

Burning Hunk
Oct 29, 2016
116
Kansas City
NFPA rules...applies to everything

Same clearance for both single and doublewall pipe...Englander NC30 is that way too...and the cabinet clearance is 11" on one side, 24" on the other
I'm sure you are correct; those are the clearances. In reality there is zero heat coming from the cabinet aside from the front of the cabinet which is substantial and cannot be ignored, and the rear chimney. Aside from that there is no heat coming from the cabinet

That’s what I’m hoping for!
Well I'm only talking about the real world. I don't worry much about regulations. If you want to be compliant for insurance purposes ignore me.
 

Case1030

Member
Dec 12, 2017
185
Manitoba
Seems they still benefit from the aftermarket temp controller mod...right @Case1030 ...
Definitely a worthwhile investment. The mod will allow the furnace to load and go.

I'm also thinking about setting a thermostat in tandem with the timer circuit to allow faster heating of the house at the same time keeping limits and low alarms in check.
 
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Case1030

Member
Dec 12, 2017
185
Manitoba
For example when I'm away for 20-24 hours I don't mind coming back to a 60f or lower house. My house backup heat is set for 50f so any thing above that is my wood furnaces job to keep above.

The timer keeps the wood at a good temp to promote secondary combustion while at the same time I have a low alarm to maintain what I believe is minimum flue temp I like to see.

The thermostat will just keep the tundra at higher temps, but not keep the damper wide open for hours on end.

When I'm at home with 12 hour reload my house isn't falling below 65f. I most of the time have it at 75f without much effort.
 

DoubleB

Minister of Fire
Mar 4, 2014
658
NE Wisconsin
I wondered about installing a small smoke baffle, even a temporary install as a test, in my Tundra. I'm sure it would get annoying - I know my friends whose stoves have those baffles, hate them. But I wish the stove door could be open without a concern about smoke spillage
I'm annoyed by some smoke spillage too when reloading on coals that are hot enough to start smoking new wood but not light it off promptly. I've also noticed that the smoke spillage stops once I get the bottom half of the firebox filled. As though when the full 9" door height is open, I get spillage, but when the bottom 4" is blocked with splits, the open top 5" isn't enough space anymore for smoke to spill out.

So with that observation I'm contemplating an experiment to put a smoke baffle at the bottom of the loading door. Could still drop splits in from the top without getting too much in the way. I probably won't get around to it soon so I vote that you give it a try. ;)

I also hope it would partially reduce the fine ash that escapes to the basement as I rake coals.
 

KC Matt

Burning Hunk
Oct 29, 2016
116
Kansas City
We have been told they will take it back. If they wouldn't, I think the EPA is the first ones i would contact so they can see how much smoke it produces between calls for heat or if the fire isn't hot enough when you shut the door. Poor poor design.
If you can get a refund for your FC, do it and move on. A Tundra is a great furnace if you are savvy enough to make it work. If not, grab your credit card and drop the money for a Kuuma.

EDIT: I have no experience with the tundra 2 but I'd take a Tundra with a good control system over anything except the Kuuma. What makes my system work is that it's adjustable, which the Tundra 2 is not.

NFPA rules...applies to everything

Same clearance for both single and doublewall pipe...Englander NC30 is that way too...and the cabinet clearance is 11" on one side, 24" on the other
I don't doubt that you are correct in terms of code or mfg specs, but that's absurd. The difference in radiant heat in single wall vs double is night and day, especially in an overfire situation. Simple observation will reveal drastic difference.
 
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Boilers

Member
Mar 19, 2018
60
Indiana
How stupid would it be to install a tundra through a wall?

I’m trying to tweak my setup... my basement has a garage type area (where the Tundra resides now) but it’s completely closed off from the finished (living area) portion of the basement. The garage stays super toasty, but
I’d rather have the radiant heat in the living area. On the other hand, I can’t be having this big noisy furnace in my finished basement!

So say I put the front of the stove through the wall maybe 15-20”. I can still maintain clearances by using a steel sheeting surround. It would be easy to fabricate and paint to look decent. I would get the benefit of all the radiant heat, without taking up a bunch of space and being an eye sore. Thoughts anyone?
 
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sloeffle

Minister of Fire
Mar 1, 2012
555
Central Ohio
It's funny, but I think those guys clock out and don't want to think any more.
I get it. I work on computers for a living and the last thing I want to hear about is someone's computer problems when I talk to them. The funny thing is that I don't even work on desktops or laptops at work. If they keep bugging me, I will help them but it usually requires beer to be present.
 

DoubleB

Minister of Fire
Mar 4, 2014
658
NE Wisconsin
So say I put the front of the stove through the wall maybe 15-20”. I can still maintain clearances by using a steel sheeting surround. It would be easy to fabricate and paint to look decent. I would get the benefit of all the radiant heat, without taking up a bunch of space and being an eye sore. Thoughts anyone?
I think that's gotta be a new one. Sounds clever, but that's probably what would make me leery too. Seems the more clever the idea, the more hidden is the real reason not to.

For example, it's only after you rig up your straddle-the-fence Tundra, that you realize you can't access the damper control from the loading door. Or your draft is causing problems because the baro damper is in one room while the combustion air inlets are in the other room. Or your sheet metal shroud becomes a drumhead louder than what you're trying to avoid.

That's just me. I applaud your creativity!
 
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Boilers

Member
Mar 19, 2018
60
Indiana
I think that's gotta be a new one. Sounds clever, but that's probably what would make me leery too. Seems the more clever the idea, the more hidden is the real reason not to.

For example, it's only after you rig up your straddle-the-fence Tundra, that you realize you can't access the damper control from the loading door. Or your draft is causing problems because the baro damper is in one room while the combustion air inlets are in the other room. Or your sheet metal shroud becomes a drumhead louder than what you're trying to avoid.

That's just me. I applaud your creativity!
Great points! The damper switch could be relocated... heck I could probably mount it on the wall or on the sheet metal surround. That would look nice.

I’m sure some proper engineering could keep the sheet metal surround quiet.

I would not expect having the damper in one room and combustion air in another room to cause an issue. If a shortage of combustion air became an issue, it would certainly be harder to deal with in a way that looked good.

I may have to call SBI and see what they say. This would likely be a spring or summer project, as I need to keep this thing running right now. (Although it was like 50+ degrees today and I cut some wood in a tee shirt)

I have also thought about installing a few “thru wall” or “transfer” fans and control them via a manual switch and the temp controller. The fans would be installed near the furnace and pull the air off the front of the stove, thru the wall, and into the living area. I don’t want to rob the furnace of combustion air though... not sure if that could be an issue.
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,125
NE Ohio
I may have to call SBI and see what they say.
I'll tell you what they'll say...nope! They will never sign off on anything they have not tested.
The fans would be installed near the furnace and pull the air off the front of the stove, thru the wall, and into the living area. I don’t want to rob the furnace of combustion air though... not sure if that could be an issue.
It could be an issue for sure...could cause burn problems...could gas your household if you pulled smoke out of the furnace...wouldn't be hard to do with the doghouse air being a direct shot into the firebox.
 

trx250r87

Member
Nov 30, 2012
48
NE Wisconsin
While others have used a nail or other small, thin piece to help the front air damper remain slightly open, I use a large wire staple in the hole on the door. It never falls out or gets lost.

Eric
d1327ad56fa3ba2a541347433131f6be.jpg


Sent from my SM-G960U1 using Tapatalk
 
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Case1030

Member
Dec 12, 2017
185
Manitoba
I have two made up. One for cold, and another one for warm weather. Helps keep my draft stay in optimal range. Never falls out and always closes properly.
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Case1030

Member
Dec 12, 2017
185
Manitoba
Didn't upload the temperature controller I installed last month. Here it is.

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15468183658961582529797000234288.jpg
15468183250404115745107304790186.jpg
15468183658961582529797000234288.jpg
 
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Boilers

Member
Mar 19, 2018
60
Indiana
I'll tell you what they'll say...nope! They will never sign off on anything they have not tested.

It could be an issue for sure...could cause burn problems...could gas your household if you pulled smoke out of the furnace...wouldn't be hard to do with the doghouse air being a direct shot into the firebox.
I’ll still call and see about a through wall setup. Maybe someone has done it before.

I’m not talking about crazy high speed transfer fans. Heck, you don’t hear about people’s return air sucking smoke out of the furnace and circulating it to the house. I doubt it would be an issue, but something to be aware of. The fan(s) would be several feet from the front of the furnace. I’d also install a large grill on the other end of the wall to allow air to circulate. I don’t think it’s a bad idea. :)

I need to get that radiant heat into my living space somehow. I don’t have any other ideas at the moment.
 
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brenndatomu

Minister of Fire
Aug 21, 2013
4,125
NE Ohio
I need to get that radiant heat into my living space somehow
How about a hood over the front of the furnace...collect the heat and blow it in the house...or could just run a line over to the furnace blower. If you ran a line into the house you could shut the fan off while reloading so you don't blow smoke into the house...you could do that with the blower too...but the risk of forgetting to turn the blower back on (and don't kid yourself, it WOULD happen sooner or later) would take that idea out of the running for me.