External wood heat for the garage.

[mercuryv8]

Look what I made.

https://photos.app.goo.gl/9iSV7q7w7jLanVu4A

https://photos.app.goo.gl/9iSV7q7w7jLanVu4A

Since it dropped down to -37 here night before last it's a good time to stay inside and read all the slick 60's updates. I figured someone maybe interested in how I'm setting up to heat the garage. My setup seems to work really well. If the fire is going full bore you can't hold your hand on the vent inside the garage. I've got a few things to finish up. I'm going to weld pipe threaded connections for running water through it in the summer. (Going to try to heat the kids pool... make myself a hot tub ) Needs a chimney cap, and insulate the main body.

I'm also throwing around the idea of pushing the air from inside the garage back outside (through the jacket surrounding the hot tube coming into the garage. ) Then it will be the same air from inside the garage circulating through the heater. I kind of like the way it is now though because the garage is so leaky if I have positive pressure inside the air will always be moving the right direction. Any thoughts ?

Nic

[The Big M]

Nice fab work!

Recirculation through a concentric tube would definitely up the efficiency, but I'd think you'd need to have the hot air outlet separated from the cold air return by a fair distance so the hot air actually disperses in the garage before being drawn back in. What you have looks nice and simple, and with recirc I might be concerned about combustible dust being run through the hot stove if you do any woodworking out there (I went with a radiant tube in my garage with fresh-air combustion for this reason).

My only thoughts might be to eliminate the elbow on the air outlet from the stove and just run it straight through (i.e rotate the stove 90 degrees), unless there's a reason it's set up this way. Also, if the air is that hot I wonder if it might eventually burn through the thin-wall ducting? At any rate I'd consider insulating the air duct to keep some heat in before it gets to the wall.

As for the water, if you run some copper tubing around the chimney in a helical fashion I bet you'd recover a lot of waste heat, but the neighbours might wonder what you're brewing, lol.

[mercuryv8]

Nice fab work!

Recirculation through a concentric tube would definitely up the efficiency, but I'd think you'd need to have the hot air outlet separated from the cold air return by a fair distance so the hot air actually disperses in the garage before being drawn back in. What you have looks nice and simple, and with recirc I might be concerned about combustible dust being run through the hot stove if you do any woodworking out there (I went with a radiant tube in my garage with fresh-air combustion for this reason).

My only thoughts might be to eliminate the elbow on the air outlet from the stove and just run it straight through (i.e rotate the stove 90 degrees), unless there's a reason it's set up this way. Also, if the air is that hot I wonder if it might eventually burn through the thin-wall ducting? At any rate I'd consider insulating the air duct to keep some heat in before it gets to the wall.

As for the water, if you run some copper tubing around the chimney in a helical fashion I bet you'd recover a lot of waste heat, but the neighbours might wonder what you're brewing, lol.

All great points thanks for the comments. Wood dust could definitely be a problem, solvents too. Yet another point to leave it as it is.

That elbow is there because I share the yard with the kids LoL. It kind of makes the yard flow better to have it oriented that way. Also makes the chimney 1m from the roof. Which is the spec in my town for this thing to be considered a "fireplace" vs "fire pit" Although I don't know how that distinction makes much difference. One thing I don't have a picture of is the new blower motor I have on it. For 20 bucks I bought one of those bouncy house blowers. I wired it to a dimmer switch so I can turn it down. What I like about that is it can provide enough volume that I can lower the output temperatures. The only thing that happens is if the fire dies down it can end up pushing cold air into the shop.

I did end up just wrapping some pink fiberglass around the tube. Your right it made a big difference. I have yet to put some cladding on it.

The copper tube maybe fun just for the looks of it. The neighbours and my wife already think I'm crazy for driving what I'm sure is the only vehicle on the block without a computer in it.

I'm actually pretty pumped about the water heater. My wife bought a big above ground pool. I think it has three foot sides or something like that.

Nic

[FarmMotorSports]

I'm a big fan of wood fired boilers. RV antifreeze not water, so if you don't fire it during bad weather it doesn't freeze.

Copper leader pipe to pex supply, for coils or radiators anywhere where you want heat. The pex takes up less room than Warm air pipe.

I stoked and maintained one for over five years for a past emloyer. Once a day feedings.

Contamination from shop or stove is unlikely to migrate to the other.

And Pex can be covered or bury it in corrugated plastic pipe if you want.

A simple electric water heater control mounted on the boiler or a inside radiator can regulate the inducer, and control temp. They can be fancy and regulated, inside a small tin dog house, or exposed and simple like yours.

[slick4x4]

Nice work !
Buy yourself a "fan limit switch" (they use them on furnaces)
They kick on when warm , off when cool
I had a very similar wood furnace I built for my house
Just start a fire & the fan switch will cycle off & on
Until it gets hot enough to stay on the whole time
Saves electricity & keeps from blowing cold air in
... best place to mount is high up & near the outlet

[mercuryv8]

Nice work !
Buy yourself a "fan limit switch" (they use them on furnaces)
They kick on when warm , off when cool
I had a very similar wood furnace I built for my house
Just start a fire & the fan switch will cycle off & on
Until it gets hot enough to stay on the whole time
Saves electricity & keeps from blowing cold air in
... best place to mount is high up & near the outlet

I like that. I see it has a manual on setting. I could mount it inside the garage duct and run the fan like that till it was warm.

[mercuryv8]

I'm a big fan of wood fired boilers. RV antifreeze not water, so if you don't fire it during bad weather it doesn't freeze.

Copper leader pipe to pex supply, for coils or radiators anywhere where you want heat. The pex takes up less room than Warm air pipe.

I stoked and maintained one for over five years for a past emloyer. Once a day feedings.

Contamination from shop or stove is unlikely to migrate to the other.

And Pex can be covered or bury it in corrugated plastic pipe if you want.

A simple electric water heater control mounted on the boiler or a inside radiator can regulate the inducer, and control temp. They can be fancy and regulated, inside a small tin dog house, or exposed and simple like yours.

I've seen those company built tin dog house ones. They seem pretty good if you can gather the wood to feed them. I'm in the city. So it's small scale here.

Before I cut the hole in the wall I thought long and hard about circulating water through a radiator in the garage. Two reasons I didn't were. It would have taken longer for everything to get up to temp. ( I only heat on days when I'm in there) and more complex system.

It was a tough decision though.

Also what would happen if it was too hot. How would I stop it from boiling?

Nic

[FarmMotorSports]

From what I can see from your pictures, you have built two or three times the quality of stove that my employer had. That was a huge amount of welding. And lot of quality cutting and fitting. I'm impressed with you work. Hope you get plenty of use from it.

Check with local tree cutting services. My employer took a tree services wood cuttings. So almost everything burnt was green and not normally used for heating a house. On the flip side, it was almost free, (boss sent occasional gift cards etc. Tipped when they dropped off, etc.)pre cut to 3' (fit his stove), And most importantly delivered to a corner of his yard, by the truck full. They also had a storage lot we could pick thru for dry wood when we wanted.

His Initial set up took some $$$ for piping and RV antifreeze... That electric water heater control did it all, it has a desired temp adjustment, (set below boiling), the control starts the inducer when temp is below SET temp. Inline with the inducer is a cheap power damper. The damper prevented the flue from creating a natural draft and boiling away your antifreeze during the off cycle.

My employer heated a 1800's three story farm house, and some heat to a vintage stone Barn, and a garage.
Initial fire took a lot, but quickly tapered off to one good stoking per day. Usually operating on the smoldering bed of coals stage. The poor seal of the cheap damper never smothered the fire, and the inducer had no problem bringing smoldering coals to roar in no time. The boiler was open to atmosphere, (not pressurised).it had a two foot coiled tube above the boiler to help condense any steam made. Because of the length of piping runs his had a small circulation pump.

[Blackwaterforge]

Nice!

[mercuryv8]

From what I can see from your pictures, you have built two or three times the quality of stove that my employer had. That was a huge amount of welding. And lot of quality cutting and fitting. I'm impressed with you work. Hope you get plenty of use from it.

Check with local tree cutting services. My employer took a tree services wood cuttings. So almost everything burnt was green and not normally used for heating a house. On the flip side, it was almost free, (boss sent occasional gift cards etc. Tipped when they dropped off, etc.)pre cut to 3' (fit his stove), And most importantly delivered to a corner of his yard, by the truck full. They also had a storage lot we could pick thru for dry wood when we wanted.

His Initial set up took some $$$ for piping and RV antifreeze... That electric water heater control did it all, it has a desired temp adjustment, (set below boiling), the control starts the inducer when temp is below SET temp. Inline with the inducer is a cheap power damper. The damper prevented the flue from creating a natural draft and boiling away your antifreeze during the off cycle.

My employer heated a 1800's three story farm house, and some heat to a vintage stone Barn, and a garage.
Initial fire took a lot, but quickly tapered off to one good stoking per day. Usually operating on the smoldering bed of coals stage. The poor seal of the cheap damper never smothered the fire, and the inducer had no problem bringing smoldering coals to roar in no time. The boiler was open to atmosphere, (not pressurised).it had a two foot coiled tube above the boiler to help condense any steam made. Because of the length of piping runs his had a small circulation pump.

Thanks a lot. A bit of kind words can really motivate a guy. It was a bit of welding, I did the whole 6010 root and 7018 hot pass and cap on each weld.

Good tip on the tree cutting service. I got a hold of one guy (he had an ad on Kijiji). He said there is a lot of trees being cut down for the infill projects that my city is promoting. Some of the firewood I got was even on the news as people were complaining about it being cut down.

When you say "inducer" do you mean some sort of blower for the combustion chamber? The idea being no air can get in unless it's pumped in?

I worked on the chimney damper this weekend. I hope it will slow down the draft and I can get some more heat out of my wood.

I did learn something this weekend. I put a much larger blower with a speed controller on the setup and I thought that I would adjust it such that I would move as much air as I could into the garage and as long as it was above room temperature it would be ok. So with it cranked right up and the intake air being about -25 (-13 F) the air coming into the garage was about 30 (85). Well the garage never heated up. I slowed the fan down and the temperature went up... Then the shop finally started to heat up. Not what I expected.

I guess maybe the higher the temperature difference the better.


Nic

[FarmMotorSports]

Yep , the little blower pictured in some of your early photos, is similar to what I am describing. And yes the idea is the 90 percent of the air in to the fire box is pumped in. A 115v tin damper, is run inline to the inducer motor circuit. So temp is regulated in the inlet side only and is electric controlled automatically, Not manual flue dampered.

Hope you're new relationship with the tree trimmers works out. It is the best way I know of obtain wood for an outdoor wood fired unit, where you don't need to be picky about wood type and how well seasoned it is.