New Furnace Day: Drolet Heat Commander

[FixedGearFlyer]

You're burning better stuff than I am currently. All I've got inside at the moment is white elm. Im not seeing burntimes any where near that impressive. My heat load is fairly high though.

We didn't have burn times like that with the Tundra, either. We're easily getting 3 or 4 hours more heat, even though the coals are lasting about the same amount of time.

We have a mix-n-match house: the second floor is buttoned up tight with new windows, double stagger stud walls, and 7 inches of high-R insulation.

The first floor is a drafty mess with old windows and poured polystyrene beads in the walls.

 

[usernametaken]

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!

This is my issue with the Max Caddy on really cold days. Either load early and get a ever increasing coal bed or wait for it to burn down enough for a proper reload while the house continues loosing temp. If this unit was rated to my sq/ft, I'd upgrade my 1 year old unit in a heartbeat. I'm still wondering why no larger models anymore from SBI? Meeting 2020 standards too challenging?

 

[brenndatomu]

increasing coal bed or wait for it to burn down enough for a proper reload while the house continues loosing temp.

So what do you do when that happens?
Do you rake coals forward?
Add some pine?

 

[usernametaken]

I do rake them forward and when low enough use the smallest splits I can find in my piles to get it going hot/fast. That said, this isn't a super common issue. It takes single digit nights and/or lots of wind for it to happen which isn't super common in western MA. I'd say I'm 90-95% good as is but when it happens, the temptation to crack open the ash pan just a hair is tugging at my like a devil on my shoulder...

Another thing I've learned to do is during the waking hours, per Caddy's instructions, I do smaller hotter fires. I use my smaller splits and load 4 in an angled crib so they criss cross a little with big gaps between them. This helps create less coals and burn down what coals are left under and around the crib...

 

[brenndatomu]

I do rake them forward and when low enough use the smallest splits I can find in my piles to get it going hot/fast.

Doing this with pine or some other low/no coaling species will get you heat again while the coal pile burns down (without adding to it) especially if the splits are a little shorter and they can be stacked mainly behind the coal pile, but still touching it, that way the ashes don't cover/insulate the coals again...

 

[usernametaken]

I've read about that and may have to try some of my pine supply the next time I'm in that pinch. I have a rack of pine in the basement for our open fireplace in the LR so it could be sacrificial in this capacity as well.

 

[sloeffle]

When I see the fire is down to coals I just turn the timer to 60 minutes and walk away. Next time I come back, the coals are normally burned down to about nothing. I put my next load in and I'm back off to the races. The fan and bath timer mods are the two best mods you can make to your non-computer controlled furnace. 90% of the wood I'm burning is dead ash so I don't get the burn times like some folks do.

One of these days I'll have a fancy computer controller furnace.

 

[brenndatomu]

The fan and bath timer mods are the two best mods you can make to your non-computer controlled furnace.

Isn't that one mod?

 

[sloeffle]

Isn't that one mod?

Hmmm, I didn’t take common core math so I think it’s two mods.

Please see my work below:

Fan mod = 1 mod
Bath timer mod = 1 mod

 

[usernametaken]

You guys have to point me to a thread(s) to learn about said mod(s).... I'm up for some learning...

 

[sloeffle]

You guys have to point me to a thread(s) to learn about said mod(s).... I'm up for some learning...

They are in the long tundra thread. @brenndatomu might know the page(s). I know the bath timer should work with your furnace but I’m not sure about the fan mod. Doesn’t the Max already adjust the fan speed based off of heat output ?

 

[brenndatomu]

The fan and bath timer mods are the two best mods

Hmmm, I didn’t take common core math so I think it’s two mods.

Please see my work below:

Fan mod = 1 mod
Bath timer mod = 1 mod

Oh...well, see I read that as "fan-and-bath timer"...and since they are called bath fan timers... but I see what you were trying to get at
I agree though...these mods turn the Caddy/Tundra style furnaces from dud, to stud! Well...dud might be a bit strong...
Mod 1, bath fan timer + mod 2, temp controller + mod 3, speed controller, =

They are in the long tundra thread. @brenndatomu might know the page(s).

The first mention of the temp controller is page 13 IIRC...click on the link at the bottom of this post, it will take you to a index of sorts for that thread...go from there. The bath fan timer is really part of the temp contoller mod.
The blower speed controller...I guess that has been a bit of a "secret squirrel op" so far...little mentions of it here n there.
As far as if the Max has the "auto blower speed controls"...depends on the age I think...but even the newer ones still don't have true variable speed motors...just "multi speed"...that the computer selects the speed of...those can and have been improved upon too.

 

[usernametaken]

My blower has 6 speeds and the computer adjusts between them based on the plenum temp sensor. It it does not switch speeds based only on plenum temp though. It needs to see a sustained temp for a certain period of time before kicking up the speed. I'll hit the thread and do some reading. Thanks guys.

 

[FixedGearFlyer]

So . . . I need to eat some crow.

That light creosote buildup I mentioned?

100% my fault.

If I leave the door cracked for 4 or 5 minutes instead of 1 or 2, the fresh load of wood is much more engaged and the Heat Commander goes straight to a beautiful secondary burn when the door is latches.

I was rushing it before. The HC still got the fire up to a good burn, but all of the smoldering and creosote was from the start of the burn when I shut the door on a not-hot-enough fire that was mostly kindling burning.

For the past 4 or 5 days, I've made sure the splits were all engaged and lively before closing the door and it's made all the difference.

Kudos to the HC for always saving my too-quick fire starts. Shame on me for taking the automated fire management of the HC a bit too far.

 

[Boilers]

I’m half tempted to upgrade from the Heatmax 2 to the new Commander. One thing kind of holding me back is the specs. It seems like you guys have reported longer burn times and increased output, but furnace specs aren’t any different than the Heatmax 2... what gives?

 

[trx250r87]

I’m half tempted to upgrade from the Heatmax 2 to the new Commander. One thing kind of holding me back is the specs. It seems like you guys have reported longer burn times and increased output, but furnace specs aren’t any different than the Heatmax 2... what gives?

I can only compare to the Tundra I previously had in the same house. The HC seems to deliver more heat into the house period! I also don't have to babysit the HC like I did with the Tundra. I much prefer the light and walk away approach.

I was able to sell my Tundra for a reasonable amount. I figured it was about 6 years old and I might as well get something for it before major cracking or firebox failure. I also enrolled in SBI's "connected" program back in October. This made the Heat Commander upgrade a no-brainer for me.

Eric

 

[andym]

I’m half tempted to upgrade from the Heatmax 2 to the new Commander. One thing kind of holding me back is the specs. It seems like you guys have reported longer burn times and increased output, but furnace specs aren’t any different than the Heatmax 2... what gives?

I also have a HMX2. I think the difference lies in two areas: the computer control gives a more even heat output. And it appears like the coal build up issue has been eliminated, thereby allowing you to reload sooner (when needed).

 

[Boilers]

I can only compare to the Tundra I previously had in the same house. The HC seems to deliver more heat into the house period! I also don't have to babysit the HC like I did with the Tundra. I much prefer the light and walk away approach.

I was able to sell my Tundra for a reasonable amount. I figured it was about 6 years old and I might as well get something for it before major cracking or firebox failure. I also enrolled in SBI's "connected" program back in October. This made the Heat Commander upgrade a no-brainer for me.

Eric

I guess I just find it odd.... even from the Heatmax 2 to the Commander, Drolet made major changes to the furnace, both physically and from a control standpoint. I just don’t understand how the specs ( heating sq ft, BTU, etc) haven’t changed whatsoever. Actually comparing the two, Drolet has posted very few specs on the Commander compared to previous/other models.

I love my Heatmax but I have 2 rooms with no ducting and they tend to be chilly! From reading posts,I feel like the Commander could/should do the job a little better (plus provide some new features) but the current data doesn’t support that.

 

[Gbawol42]

I almost upgraded from my heatmax 2 myself just for the new coal burning down enhancements they did. The computer burn I kinda already do with my "mods" that I have done to the furnace. I feel however I need a little more btu in the house, so if they come out with an upgraded Heatpro model I might jump on that.

 

[FixedGearFlyer]

I guess I just find it odd.... even from the Heatmax 2 to the Commander, Drolet made major changes to the furnace, both physically and from a control standpoint. I just don’t understand how the specs ( heating sq ft, BTU, etc) haven’t changed whatsoever. Actually comparing the two, Drolet has posted very few specs on the Commander compared to previous/other models.

I love my Heatmax but I have 2 rooms with no ducting and they tend to be chilly! From reading posts,I feel like the Commander could/should do the job a little better (plus provide some new features) but the current data doesn’t support that.

All I can offer is that after moving from the Tundra to the HC, we are toasty and warm like never before, even in the sub-zero weather we're having right now. Two full loads per day and we get 12 hours burns with a house temp sitting at 70 all day long. When it's in the teens, we were just doing one burn during the day.

The coaling changes are huge - in weather like this, we used to see the house temp drop 10+ degrees while trying to burn down the coal bed in the last 2 hours of a burn. Now, we get heat through all phases.

It's been absolutely fantastic!

 

[brenndatomu]

Two full loads per day and we get 12 hours burns with a house temp sitting at 70 all day long. When it's in the teens, we were just doing one burn during the day.

What do you do when its 30-40* out?

 

[FixedGearFlyer]

What do you do when its 30-40* out?

If it was last year, we would have used electrix baseboard heat for a few hours or had a very small fire.

A month before the unexpected Heat Commander swap in November, we'd installed a PP130 pellet stove to help us keep more even heat during the shoulder seasons and the coaling stage of the Tundra. So, on those warmer teens and twenties winter days, we're running the HC during the day, the letting it cool to about 60 over night and using the PP130 with a Pellet Miser to hold it there if the house temps drop further.

If we'd known the HC was coming, I don't think we would have put the PP130 in.

 

[maple1]

If it was last year, we would have used electrix baseboard heat for a few hours or had a very small fire.

A month before the unexpected Heat Commander swap in November, we'd installed a PP130 pellet stove to help us keep more even heat during the shoulder seasons and the coaling stage of the Tundra. So, on those warmer teens and twenties winter days, we're running the HC during the day, the letting it cool to about 60 over night and using the PP130 with a Pellet Miser to hold it there if the house temps drop further.

If we'd known the HC was coming, I don't think we would have put the PP130 in.

Cold climate mini-splits really shine for shoulder and in between situations.

 

[usernametaken]

All I can offer is that after moving from the Tundra to the HC, we are toasty and warm like never before, even in the sub-zero weather we're having right now. Two full loads per day and we get 12 hours burns with a house temp sitting at 70 all day long. When it's in the teens, we were just doing one burn during the day.

The coaling changes are huge - in weather like this, we used to see the house temp drop 10+ degrees while trying to burn down the coal bed in the last 2 hours of a burn. Now, we get heat through all phases.

It's been absolutely fantastic!

Posts like this keep me wondering if the HC could handle our square footage and huge duct runs. My biggest complaint with the Max Caddy as said before is when it's really cold, there is a big temp drop waiting for the coals to burn down. Sure, I can reload on a tall coal bed but that will just make the coal bed deeper at the end of the next burn cycle. The timer mods etc. won't help me because if I'm nearing a reload, the intake damper is open anyway. The only thing I can really do is cheat and crack the ash clean out a bit to get some air up under the coal bed which works but is a system I would consider suboptimal because of all the babysitting.

Another thing that has me interested is less frequent loading. To have total control over my system I do more frequent, smaller loads during the day. This allows me to keep the fire really hot on colder days or let it burn down some on average days so we don't overheat the house. Doing this I can keep my place between 70-72 all day with all three thermostats set at 72. But again, it's babysitting. Currently, I really don't mind because I'm stuck at home all day with my daughter doing remote schooling during C19 and this gives me something to do. However, doing two loads a day as described here is intriguing.

 

[brenndatomu]

Posts like this keep me wondering if the HC could handle our square footage and huge duct runs.

I bet we will see a Max Caddy version of the HC before long...