Furnace Recommendation

Boilers

Member
Mar 19, 2018
60
Indiana
Another long post here...

I recently decided my wood was mostly too wet. I cut down a couple standing dead elms, and to my delight, most of the wood is near 20% moisture. I’ve been splitting (by hand) several pieces a day to keep a decent stock going. So I’m burning dry wood for now!

I haven’t noticed much difference in heat output :(.

I did however finally get around to hooking my manometer up to my hot air duct. My initial readin was 0.03!!

Since I had some spare sheet metal around, I decided to make a damper for my 14” main duct. See attached photos. At furnace speed 1, I’ve now got 0.2 in H2O. I just did this tonight, so I haven’t had much time to evaluate the possible benefits. Air velocity at the vents is obviously decreased quite a bit, but hopefully the fan will stay on a lot longer. Time will tell. I’ll report more later.

I still need to install the thermostat. This should help a lot. Many times I’ll wake up in the morning to find a lot of coals in the firebox, but very long intervals between when the fan kicks on. More air should keep the coals going and keep them from blanketing over with ash. We’ll see.

Lastly, I still have not rerouted my cold air to pickup heat off the furnace room. I think this should also boost the heat output significantly. More to come!
 

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Boilers

Member
Mar 19, 2018
60
Indiana
Thermostat is installed!

So when I was controlling the damper manually, I would only have it open for 30 (ish) minutes at startup, and also when the firebox was down to just coals.

Now with the thermostat, the damper could potentially be open for much longer, or even the entire burn cycle if the gap between temp and setpoint is big enough. This is unfamiliar territory for me. Ive always been careful to NOT leave the damper open. Is there any risk here or am I just a noob?
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,072
NE Ohio
Having the damper open all the time was what SBI was blaming the cracks on (early on) with the T1...I think you'll find it a very inefficient way to run...it makes a lot of heat quick, but a load on lasts 3 hours.
I unhooked the T-stat on mine after a day or two...never used it again...just used the bath fan timer and the temp controller.
 

3fordasho

Minister of Fire
Jul 20, 2007
808
South Central Minnesota
Having the damper open all the time was what SBI was blaming the cracks on (early on) with the T1...I think you'll find it a very inefficient way to run...it makes a lot of heat quick, but a load on lasts 3 hours.
I unhooked the T-stat on mine after a day or two...never used it again...just used the bath fan timer and the temp controller.
This^^. Damper open is hot but inefficient. These furnaces should make enough and efficient heat with the damper in the closed position once firebox temps are where they need to be.

I'm heating 3400 sq ft (too much) with the original Tundra and it does the job 90% of the time and the damper is closed except when the timer forces it open for cold starts/reloads, or the temp control opens if when flue temps drop below the set point. A few of us (myself included) run a paper clip on the damper door to open the closed position ever so slightly - but that's it.

I don't the use thermostat - but the timer and flue temp control are a must have IMHO.
 

Boilers

Member
Mar 19, 2018
60
Indiana
Do either of you have a link for this temp controller? I know there’s a lot out there... what’s the best one that doesn’t cost an arm and a leg?
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,072
NE Ohio
Click the link on the bottom of this post...that takes you to the glossary of the large Tundra thread...look for the temp controller pages.. IIRC it starts around page 13. I and many others used a Mypin brand with good results. ($20-30) There is another new T2 owner here that just put one on his...I'll see if he wants to share about it. It appeared to me that it's even easier to put on the on the T2 than it was the T1
 
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Boilers

Member
Mar 19, 2018
60
Indiana
Click the link on the bottom of this post...that takes you to the glossary of the large Tundra thread...look for the temp controller pages.. IIRC it starts around page 13. I and many others used a mypin brand with good results. ($20-30) There is another new T2 owner here that just put one on his...I'll see if he wants to share about it. It appeared to me that it's even easier to put on the on the T2 than it was the T1

Thanks! Funny... I am an automation engineer. I could easily rig up a solution. Problem is, everything I’m familiar with is industrial and costs thousands of dollars.

PLC, 4-20mA analog input card, 24v output card, thermocouple, few breakers, power supply, panel, few lights, push buttons, maybe an alarm horn... this would be the ticket! It would also cost about $2k. And that’s on the cheap end of the spectrum!
 
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brenndatomu

Minister of Fire
Aug 21, 2013
4,072
NE Ohio
I was trying so hard to figure a way of using a linear actuator on the cheap...but once I did it the way that is outlined in the thread, I realized it works so well that there was really no need to search any further.
I did just recently come across a pretty decent controller with TC input and 4-20 output for $60 though...
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,072
NE Ohio
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Case1030

Member
Dec 12, 2017
185
Manitoba
Do either of you have a link for this temp controller? I know there’s a lot out there... what’s the best one that doesn’t cost an arm and a leg?
Make sure to get a temp controller with two relays if you want to the stove to burn coals down at end of cycle or for low limit temperature. That way you can prevent creosote if not perfectly seasoned wood is used.
 

Case1030

Member
Dec 12, 2017
185
Manitoba

Boilers

Member
Mar 19, 2018
60
Indiana
Well friends, it’s been fairly mild here lately. I’m still tweaking things a bit with my ductwork to get the best output. My controller and thermocouple arrived a few days ago but I haven’t had time to mess with it yet.

Recently I have been burning lots of elm... and unfortunately, I’ve had tons of “clinkers” getting stuck to the front firebricks. The front 2 are basically destroyed. I have a lot of elm left to burn... anyone think there would be a problem with installing a thick metal plate over the firebricks in the floor? I’m going to replace these firebricks and would really like to keep from destroying them again.
 
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brenndatomu

Minister of Fire
Aug 21, 2013
4,072
NE Ohio
Leave and inch or two of ash in the bottom...clinkers won't stick, and they hold coals better this way on a long run too
 

brenndatomu

Minister of Fire
Aug 21, 2013
4,072
NE Ohio
What are clinkers? ;lol
Kinda like cinders...I'm sure you've seen 'em...hard chunks in the ashes (not unburnt wood) sometimes can be interesting colors
 

JRHAWK9

Minister of Fire
Jan 8, 2014
1,138
Wisconsin Dells, WI
hmmm, I'm not sure. I don't know what harm they would do....?? Whatever doesn't fall through the grate and into the ashpan (when lighting a fire in a cold furnace), I just move what's there off to the side and load kindling.
 

Boilers

Member
Mar 19, 2018
60
Indiana
hmmm, I'm not sure. I don't know what harm they would do....?? Whatever doesn't fall through the grate and into the ashpan (when lighting a fire in a cold furnace), I just move what's there off to the side and load kindling.
Clinkers: bits of sand and dirt in (or on) the wood, that melt and turn into a lava-like substance. In my case, the lava is seeping into the voids in the firebrick and becoming permanently attached. They only seep in so far, so the remaining amount protrudes from the brick. Once the fire cools, these clinkers become hard as a rock, and nearly impossible to remove from the brick without damaging the brick.

Some types of wood tend to have more of this “contamination” than others. Red elm seems to be very bad. These only form when the fire is very hot. All of mine have occurred in front of the ash pan hole, where the combustion air heats the coals.
 

JRHAWK9

Minister of Fire
Jan 8, 2014
1,138
Wisconsin Dells, WI
Clinkers: bits of sand and dirt in (or on) the wood, that melt and turn into a lava-like substance. In my case, the lava is seeping into the voids in the firebrick and becoming permanently attached. They only seep in so far, so the remaining amount protrudes from the brick. Once the fire cools, these clinkers become hard as a rock, and nearly impossible to remove from the brick without damaging the brick.

Some types of wood tend to have more of this “contamination” than others. Red elm seems to be very bad. These only form when the fire is very hot. All of mine have occurred in front of the ash pan hole, where the combustion air heats the coals.
very interesting. I've never encountered them, at least that I know of. I don't burn elm though.
 

maple1

Minister of Fire
Sep 15, 2011
9,875
Nova Scotia
I get a few, burning mostly sugar maple. But they are never a problem, just look like a hard coal in the ash. I also keep a bed of ashes of an inch or two in my box. Really helps protect the refractory.
 
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