Need Advice for Father in Law's Garage 40X26 Two Story

Here's the deal...he built a garage that is a...I don't know. It has a name but I can't remember what it's called. It looks similar to what I put a picture of below. Anyway, he has a Harman Mark something or other out there but he says it isn't cutting it. The building is on a slab with gravel and the structure itself has had sprayfoam insulation applied internally.

Now mind you I haven't been back since the summer to see it but after seeing the guys spraying the foam (I kind of work with them) I can't believe there are any air leaks beyond the overhead doors/entry doors/windows.

Tonight he called and asked what I knew about coal stoves. That was easy, not much Truth be told he's the reason I found this place and started burning coal. He's talking to someone about a DS wood/coal combo Economiser and time is kind of the essence apparently.

I told him that a wood/coal combo wasn't in my vocabulary and that stove was a compromise. He then told me that his salesman said DS didn't make a strictly coal stove with more BTUs. About 15 seconds online told me otherwise. The 1600 is more BTUs and coal only.

He's not hooked on DS per se so I'm asking you guys for your opinions. This building is two stories in the center, will eventually have a ceiling fan (when there is power), and houses a medium excavator, a D4 dozer, and whatever other single piece of equipment he wants in there. There is a lot of metal but they aren't going in and out, just sitting all winter.

What stove (DS, LL, other) would work for him. The middle section of the garage has a 14' ceiling (rough guess) and the upstairs is 8' tall. The outer rooms that are common but could be skirted off are roughly 8' ceilings. Oh yeah, inside flue chimney top to bottom, stove is on ground floor.

I have not looked at any prices. While important, they are not the deciding factor. That is reserved for what gets the job done.

40x26 is only 1040 sqft, even 2 stories would only be 2080sqft, do you know if it is a mark 1, 2 or 3 just wondering how much coal he is burning per day and what does he mean not keeping up. If the whole building is spray foamed heat loss should be minimal, just wondering if all the heat is hanging at the ceiling?

I can't guess what to buy, but I can suggest to stay away from any wood/coal combo if you intend to burn coal. I have yet to see one that does a good job burning coal. IMO.... The only thing great about a wood/coal combo is the sales pitch.

It sounds like it's a good time to do a heat loss. You can guess & stuff in about any ol' heater that's bigger than what you have, but unless there is a bit of time spent to do some actual calculations it's going to be a guess at best. That means we need hard facts & details. Correct size, thickness of walls and insulation. Are there interior walls or is it one big room? Does it have interior sheathing, or are you looking at the bare insulation? What's it got for a roof & what in it for insulation? Is it vented? Is there any insulation under the slab?

You might want to look at the air movers that move the
stratified hot air back to floor level as it sounds as if all the heat
is simply rising and staying there until it is cooled down.

The ones I saw in popular science many years ago had a very
small fan in the top of the pipe that was hung in mid air and the
fan pulled all the air into the pipe and blew down to ground level.

look at it as great room with a 2 story opening and the single air mover is
in the corner sucking all the hot air at the ceiling height constantly
and pushing the hot air down to the floor two stories below.

I don't think they use anything other than a small round fan housing that
is mounted to the end of the pipe.

I have a wood/coal combo. It heats my house, but it's much better with wood than coal.

I'm done with wood though, and as soon as I can, there will be a 'real' coal furnace in this place

SWPaDon wrote:I have a wood/coal combo. It heats my house, but it's much better with wood than coal.

I'm done with wood though, and as soon as I can, there will be a 'real' coal furnace in this place

99% of "Combo" stoves are made to burn wood, and do that part well..

1. make sure that where the stove is, there is some fresh air supply. Often people assume a building is huge and there is plenty of air, but if no new air, youll get less draft and less burn, less heat. The Harman is a great stove, my Coal guy has one ( Mk 3 Harman) in a garage that size and its does very well ( has a blower I believe)
2. Ceiling fans, 4 of them...
3. Can duct some heat off the top of that Harman with some duct work and a small blower, OR put a coil in it ( circulate some hot water) and put a Reznor up somewhere, that will surely bring the heat out away from the stove.
4.He may not need another, or bigger stove.
IF he doubts the Stove, try to find a used Harman, they don't last long
Good luck!!

Seems I made a finger error last night when starting this thread. The garage is 40X36.

I guess his biggest problem with the Harman is he's afraid of warping the grates trying to burn hot enough to keep it warm in the building and it's small (according to him) coal load. I think he's convinced that the DS would get him 24-48 hour shakes with it's 160# load.

Coalfire, I think that is his biggest problem as well, heat not moving and staying upstairs. I haven't been up to see the garage heated but know it has one staircase going to the second floor and no return air vents (so far as the last time I saw it). That puts it just like my garage, the heat (for the most part) will not go upstairs until people break the thermal barrier by walking up and down the stairs. If that's the case he heat is only 14'. Still if it isn't moving...

Freddy, I'll try to answer the questions after I talk to him again today. I haven't seen it since the summer when it went up.

Is he looking to not use any electricity and stay 'radiant'? That is not a tiny space, and the 160 lbs a day seems plausible. Heat distribution, or just warm the structure? Lots of options, and wood/anything is NOT a good choice. Like the Tarm units you are seeing on all the craigslist listing for the last 3 months.......3 fuels......none burning well...heavier that a battleship.....and costly. Better than nothing, but not much better. The heat rising can be solved by an 'air handler' of sorts, but lets face it, the fact that heat rises cannot be altered very effectively without some ability to redirect it.

Here's what I have. 6" walls with 3" sprayfoam. Ceiling/roof has 6" sprayfoam. Slab is insulated. Main room is the only area that has an upstairs. The outer rooms are 9' tall. Middle room has a 12' ceiling, not insulated to the room above but heat doesn't transfer that much as it's always 20°F cooler up than down.

His Harman is either the Mark I or II, he can't remember but knows it's not the big one. That puts it at either 50K or 70KBtu. It will maintain 70°F when not too cool outside but struggles to maintain 50°F below 20°F outside.

Oh yeah, his biggest heat loss is his overhead door. There is really nothing to be done about that fact. There are a bunch of high efficiency windows but I don't know the sizes.

This property lost it's power 5 days ago and still has none so a blower unit isn't really what he wants. Just a big ass stove that will do the job and can be throttled down when not needed.

He's looking at the DS products so I found the phone number for him, thanks NEPACrossroads! I think I've swayed him from the wood coal Economizer model although he'd love to be able to do wood on the shoulder months when it's not worth starting a coal fire.

You guys are the best source out here as usual.

I'd be having him get one of those 15 hitzers for sale over by you.

Scottscoaled wrote:I'd be having him get one of those 15 hitzers for sale over by you.

I saw them this morning and mentioned it. I can't figure out how you drop one of those in a condo and expect people to feed them though. Sounds like a nice job for me, make a trip around the resort once a day to shake and feed, take the rest of the day off.

Who's in Vermont, you or your father in law? How about a Home Heater, they're made in Bennington, Vermont.

My brother runs a waste oil heater,
in his 30x50 steel insulated building .
Plenty of FREE oil as he works on cars, and developed a free oil network.
Concrete slab. He is very happy with it!
Dvc 500 for home heating.
Very similar to attached pic.

Well thank you all for the replies and help. He made his mind up after talking to DS Machine yesterday. Whew....that was close...thought I was gonna have to give him the advice to push him over the edge. The problem there is when it didn't work well enough in his eyes, you know who's gonna get the blame right?

Here's what he is going with http://www.champaigncoalandstove.com/resources/DS ... Max160.pdf

Should do the job and let him burn wood if he wants to.

Thanks again folks.