New Furnace Day: Drolet Heat Commander

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No need to shut the blower off with my Kuuma, I leave the door open during the loading process and can open it at any point during the burn cycle without any smoke being released into the basement,
Same here...seldom any smoke...if there is any, it is very light and dissipates almost immediately, and almost never can be smelled anywhere else in the house...not like back when I had the Yukon...it had a smaller door and a larger chimney, but when the HX needed cleaned it would spill smoke, and man did that reek sometimes!
 
The newest software download actually does this. For me it helps get the fire going better on a colder start. And it doesn't suck ash out the fire box. Eric actually let me know of this software update

I've been scratching my head about the "fan off = no ash or smoke spillage on reload" thing. The fan doesn't blow into the firebox, so I wasn't understanding why it being on or off makes any difference. On our HC, which is on the original firmware, we can reload with the blower on and don't have any smoke or ash spillage.

I think I understand, now. Do you guys have your blowers connected to a return duct system, or are you pulling your return air directly from the room the furnace is in? If you're pulling from the furnace room, the room would be at negative pressure with the fan on and I can see how spillage could happen.
 
I've been scratching my head about the "fan off = no ash or smoke spillage on reload" thing. The fan doesn't blow into the firebox, so I wasn't understanding why it being on or off makes any difference. On our HC, which is on the original firmware, we can reload with the blower on and don't have any smoke or ash spillage.

I think I understand, now. Do you guys have your blowers connected to a return duct system, or are you pulling your return air directly from the room the furnace is in? If you're pulling from the furnace room, the room would be at negative pressure with the fan on and I can see how spillage could happen.

I do not have the cold air return hooked up to the air filter box of the HC. I'm pulling directly from the basement, air has to travel down the stairs back to the HC.

I think my issue was more related to the blower fan pushing air out the front of the furnace near the loading door. I get a lot of air blowing out the hole between the ash lip and main door. Your theory on negative pressure might be valid, however, I NEVER had an issue with the Tundra leaking smoke or ash.

Eric
 
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I do not have the cold air return hooked up to the air filter box of the HC. I'm pulling directly from the basement, air has to travel down the stairs back to the HC.

I think my issue was more related to the blower fan pushing air out the front of the furnace near the loading door. I get a lot of air blowing out the hole between the ash lip and main door. Your theory on negative pressure might be valid, however, I NEVER had an issue with the Tundra leaking smoke or ash.

Eric

Ah. That makes sense, too. That's one of the spots I sealed. The whole front of the air jacket was pretty drafty, especially that spot, around the ash pan door, and the bottom edge.
 
Ah. That makes sense, too. That's one of the spots I sealed. The whole front of the air jacket was pretty drafty, especially that spot, around the ash pan door, and the bottom edge.

I sealed up everything EXCEPT that area around the doghouse air hole. It might take a couple layers of high temp silicone to fill due to the size of the gap.

Eric
 
I sealed up everything EXCEPT that area around the doghouse air hole. It might take a couple layers of high temp silicone to fill due to the size of the gap.

Eric
Would folding/stuffing some gasket material like this in there work better?
 
Would folding/stuffing some gasket material like this in there work better?

I don't think the gap is that large. Here is a photo before I calked. I just tried hight temp silicone and it looks like a 4 year old child's art project.

Eric
 

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I don't think the gap is that large. Here is a photo before I calked. I just tried hight temp silicone and it looks like a 4 year old child's art project.

Eric
I think that flat gasket material would work well on that...it is 1/8" thick x 1" or so wide, if it was folded over and stuffed in there, I think it would seal that up nicely...
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Mid-Winter check-in:

We're still thrilled with the Heat Commander. Our burns are longer, we get more heat in the house for the same amount of wood in the box, and the plenum (and the duct work upgrade it enabled) is a huge step up from our T1. Plus, we load it and walk away while it micro manages the burn all day long.

Our wood consumption is hard to compare because the winter has been so mild. We're at about 50% of our normal use; my gut says that the HC accounts for 15 or 20% of that.

The big thing is comfort. The heat output is much more evenly spread through the burn and our house sits at 68 to 70 for the entire day with very little temp swing. No more sweating in the first 3 hours of a burn or bundling up while a huge coal bed burns down.

In fact, the coal bed isn't an issue at all. The HC's grill air does a great job of burning down the coals and producing meaningful heat in the last 20% of a burn. I haven't had to wait for the bed to thin out before reloading, at all.

Like the T1, it needs to have the heat exchangers cleaned every two or three weeks, but it's a nearly identical exchanger design, so that's not surprising.

We have noticed a little more creosote build up than with the T1 in the stove pipe and masonry chimney. It hasn't been an issue and isn't running or dripping anywhere - I can just see a light glaze when I inspect the chimney and pipe. A bit of creosote conversion powder and a monthly brushing seem to be all that's needed to keep things spic and span, but it's more than the twice-annual cleaning we did with the T1.

An added cost will be a chimney liner next summer. The HC would definitely benefit from a 6 inch liner in our 7 inch square masonry chimney. In cold weather, our Fields baro can't quite hold the draft to -.06 and we end up closer to -.08. I'd like to fix that and cut down on the amount of cold baro air in the flue, which should also cut down on the chimney creosote.
 
Great write up! My experience has been exactly the same. The only difference for me is that I have a manual damper and not a baro. I noticed that even when the draft is high (closer to .1) the HC still handles the burn very well and does not let the fire get out of control.

The last few overnight burns have been perfect for me. Load at 9:30pm and at 6:30am the house is at 70-71 degrees and there is enough coals to light off without the need of kindling or a torch.

Eric
 
We have noticed a little more creosote build up than with the T1 in the stove pipe and masonry chimney. It hasn't been an issue and isn't running or dripping anywhere - I can just see a light glaze when I inspect the chimney and pipe.

This would be a concern for me. Should not be seeing this on a 2020 EPA certified appliance. This means you are not burning all the gases and are wasting fuel, period.

A bit of creosote conversion powder and a monthly brushing seem to be all that's needed to keep things spic and span, but it's more than the twice-annual cleaning we did with the T1.

Should NOT be needed to keep a chimney clean on a wood burning appliance which is 2020 certified. ;lol


I'd like to fix that and cut down on the amount of cold baro air in the flue, which should also cut down on the chimney creosote.

I actually added an OAK to my BD (which uses ALL outside air to control my draft) therefore -increasing- the amount of frigid cold air entering my chimney by way of the BD. Have seen temps as low as 11° entering my BD from the outside. Still have ZERO creosote issues......just flyash.

Taken right before it enters my BD. I believe this was the time a couple years ago when we hit -27°F.

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This is what a chimney of a properly burning 2020 certified furnace should look like. Taken after one full heating season. BTW, full disclosure, this was taken a handful of years ago before I put my OAK on my BD and Lamppa supplied baffles in my HX (which now come with all new ones). What I see now is pretty much the same stuff, but the flyash is brown/black and a little more "fuzzy" looking. Definitely nothing that needs to be cleaned monthly ( !!! ) ...or even yearly for that matter.

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All units no matter what will smoke a little until up to temperature. If he has a masonry chimney, it will be cooler than without a liner, either insulated or not. I highly doubt it's a case of wasting fuel.
 
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All units no matter what will smoke a little until up to temperature.

I agree. I have been starting at least one fire almost every day this heating season due to our milder winter this year so far and the fact I am working from home so I can micro-manage small loadings better. I fully expect to see what I always see when I clean my chimney next fall though.....flyash.

If he has a masonry chimney, it will be cooler than without a liner, either insulated or not.

I agree, however that is no excuse. You still need the proper gases (wasted fuel) present over time in order to develop it. Without prolonged exposure of those gasses being present, there will be no creosote. Creosote is a tell-tale sign and doesn't lie. Yes, you do need the proper (lower) chimney temps as well, but you need BOTH to create creosote. I'm mixing cold outside air up my chimney and don't have any issues. I do get accumulation of some really fluffy/flaky flyash around my BD where the cold air enters, but nothing that would require me to clean it every month.
 
I agree. I have been starting at least one fire almost every day this heating season due to our milder winter this year so far and the fact I am working from home so I can micro-manage small loadings better. I fully expect to see what I always see when I clean my chimney next fall though.....flyash.



I agree, however that is no excuse. You still need the proper gases (wasted fuel) present over time in order to develop it. Without prolonged exposure of those gasses being present, there will be no creosote. Creosote is a tell-tale sign and doesn't lie. Yes, you do need the proper (lower) chimney temps as well, but you need BOTH to create creosote. I'm mixing cold outside air up my chimney and don't have any issues. I do get accumulation of some really fluffy/flaky flyash around my BD where the cold air enters, but nothing that would require me to clean it every month.
That's probably just from moisture condensing on the BD area and then the ash is sticking to it. I have yet to see anything other than dark dust in my cookstove and heat stove (inside the unit and flue), but I don't smolder either of them.
 
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... I do get accumulation of some really fluffy/flaky flyash around my BD where the cold air enters, but nothing that would require me to clean it every month.

So, I should clairify. I don't NEED to clean it monthly. I chose to and really mean "spic and span." As in, clean pipe and flue walls. I'm a bit eager with our oversized masonry chimney that has a few issues at the crown, doubly so because this house (an old, 1890s rennovated one-room schoolhouse) actually lost the second floor in 2003 (7 years before we bought it) to a chimney fire. Putting in a liner next summer will be wonderful.

The creosote I'm seeing is very light glaze, nothing even remotely close to causing an issue, even over multiple seasons if I got lazy and let it go.

With 36 feet of oversized masonry and a metal roof that forces me to clean from the bottom clean out in the winter, I make sure we never get meaningful buildup. It takes 20 minutes to run the brush up to the top, scrub on the way down, and vacuum out the debris.

To your point, I agree that creosote means unburned fuel in the flue gas. It would be great if it was just fly ash, but I'm still very happy with the performance we're getting.
 
That's probably just from moisture condensing on the BD area and then the ash is sticking to it. I have yet to see anything other than dark dust in my cookstove and heat stove (inside the unit and flue), but I don't smolder either of them.

Agreed but imagine a BD along the whole chimney lol. A masonry chimney will never reach internal wall temperature that an insulated chimney would. Even dry 15% firewood means alot of condensation able to fourm on a cold surface... unlike insulated pipe which can carry that moisture out the chimney.
 
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Agreed but imagine a BD along the whole chimney lol. A masonry chimney will never reach internal wall temperature that an insulated chimney would. Even dry 15% firewood means alot of condensation able to fourm on a cold surface... unlike insulated pipe which can carry that moisture out the chimney.
My exterior class A chimney gets icicles at the top sometimes. It can happen in any chimney.
 
Wow your coals look like they burn so much hotter than my heatmax 2

The metered air supply through the bottom ash grate is a game changer in getting useful heat out of the coal bed. Because it fires it with a direct air supply from underneath the coals, the furnace captures an amazing amount of heat from them and the house temps don’t drop until the coal bed is burned down significantly.

It’s been 2 hours since I took that video and the furnace is still meeting the demand for heat and cycling the thermostat upstairs, despite a stiff wind and current temps at about 5*F.

I am both so very impressed with the furnace and so very warm and toasty in my house. :-D

On a night like this with the Tundra 1, we would have ended up with a deep coal bed that took a few hours to burn down, but that didn’t cycle the furnace fan and push heat into the house enough to maintain the set temperature. While waiting for the coal bed to thin out, the temps in the house would drop by 10 degrees. The Heat Commander seems to be able to keep up evenly through the entire burn. It makes me giddy!
 
Wow your coals look like they burn so much hotter than my heatmax 2

Here's what it looks like now, just shy of 12 hours into the burn. Between the last video and this one, I raked the coals over the grill. Raking the coals was the first and only time I touched the furnace after loading it at 9:00am this morning.

I'll keep an eye on the temps upstairs and reload when it finally stops keeping up. Thermostat is set to 70 and it's currently 71, so no reload, yet!

 
The metered air supply through the bottom ash grate is a game changer in getting useful heat out of the coal bed. Because it fires it with a direct air supply from underneath the coals, the furnace captures an amazing amount of heat from them and the house temps don’t drop until the coal bed is burned down significantly.

It’s been 2 hours since I took that video and the furnace is still meeting the demand for heat and cycling the thermostat upstairs, despite a stiff wind and current temps at about 5*F.

I am both so very impressed with the furnace and so very warm and toasty in my house. :-D

On a night like this with the Tundra 1, we would have ended up with a deep coal bed that took a few hours to burn down, but that didn’t cycle the furnace fan and push heat into the house enough to maintain the set temperature. While waiting for the coal bed to thin out, the temps in the house would drop by 10 degrees. The Heat Commander seems to be able to keep up evenly through the entire burn. It makes me giddy!
Wow! What kind of wood did you use for that load?
I like my HMX2 but may consider an upgrade before the new stove credits expire!
 
Sounds like everybody wants to dance with the new girl... ;lol
 
Wow! What kind of wood did you use for that load?
I like my HMX2 but may consider an upgrade before the new stove credits expire!

Well-seasoned soft maple. We burn about 90% red maple with a bit of hard maple, birch, ash, and aspen mixed in.