Portable wood furnace

[stape00]

Hello all. I am looking for some edumacated thoughts. I work in northern wisconsin and I need a way to heat a handful of different uninsulated cabins and workshops so I can do repairs in them. The idea is to use a wood furnace with blower to move some warm air into whatever work space I need to be in. I would have the furnace on a trailer so I could move it around this property I manage.

I'm not looking to get these places to sauna temp rather to get them from 20° to 43° maybe. I have access to a good amount of wood to burn. I'm trying to save some electric costs and I like wood stoves. I don't like propane heaters in work spaces.

Insulated flexible duct would run from the stove and into the building/area. I would section off the work area whatever building with a tarp and or 1 inch foam board when possible.

Ideas? Concerns? Hopes and dreams?

 

[brenndatomu]

You'll probably want to use an old school furnace...I don't think that the newer clean burn furnaces run high enough supply duct temps to overcome the low air temps that your blower with have as "return" air. Also, you will need some pretty good BTU's to bring a below freezing cabin temp up to a decent working temp in a reasonable time.
And make sure you oversize the flex duct since it is known for poor flow characteristics...and would otherwise be a poor choice for supply duct, since inside a building, it is not rated for use with a solid fuel furnace...but probably OK for this application

 

[stape00]

You'll probably want to use an old school furnace...I don't think that the newer clean burn furnaces run high enough supply duct temps to overcome the low air temps that your blower with have as "return" air. Also, you will need some pretty good BTU's to bring a below freezing cabin temp up to a decent working temp in a reasonable time.
And make sure you oversize the flex duct since it is known for poor flow characteristics...and would otherwise be a poor choice for supply duct, since inside a building, it is not rated for use with a solid fuel furnace...but probably OK for this application

Thanks. Exactly the type of thoughts I was looking for. Using oversized flexible duct because of the airflow problem. I might to to run regular rigid duct for whatever distance I can then flexible.

 

[Highbeam]

If you can’t have propane or diesel or kerosene then I would run a generator in the truck and run a cord to a portable electric resistance heater. They sell some big 240 volt heaters for cheap.

 

[Shrewboy]

How big are the cabins? are they all just 1 open room?

 

[Geoff C]

Are you against kerosene? Those 23k btu heaters work well.

 

[stape00]

How big are the cabins? are they all just 1 open room?

Cabins are about 18x30 but the bathroom shower area that I want to renno is more like 7x18 which are partially walled off and I can temporarily partition them more.
My little work shop is about 12x16

 

[stape00]

Are you against kerosene? Those 23k btu heaters work well.

Trying to avoid fuel smells and open flames in the work area.

 

[stape00]

 

[jetsam]

It's been done.




For your application, I would for probably be looking at a space heater to warm up my immediate area more than a trailer-mounted furnace.

What is the normal way the cabins get heated when occupied?

 

[stape00]

It's been done.

View attachment 268289


For your application, I would for probably be looking at a space heater to warm up my immediate area more than a trailer-mounted furnace.

What is the normal way the cabins get heated when occupied?

They don't get used in the winter. I'm just trying to trade some fallen trees for some degrees of heat.

 

[Seasoned Oak]

Personally id go with those tank top propane heaters. Extremely portable. Good clean heat. No smell, does a nice job on a small space. I have half a dozen of those and use then frequently in multiple properties.
Without a chimney in those cabins you options are extremely limited. Im afraid any kind of exterior trailer mounted stove will have you pissing in the wind. A headwind at that. Just IMO.

 

[moresnow]

So the cabins have power? Electric heaters. Or wait until spring
Where are you located in N. Wi? On a decent winter I can't imagine dragging a trailer around to seasonal cabins that are shut down! Oooooh the snow.

 

[jetsam]

They don't get used in the winter. I'm just trying to trade some fallen trees for some degrees of heat.

If this is a long term thing and you are willing to invest in some gear, you could build or buy a wood gasification setup. You can fill BBQ tanks with woodgas, which would give you a "free" source of gas for portable propane heaters. Depending on how good your filtration is, you may spend a lot of time/money cleaning and replacing heaters as they gum up, and vent-free propane units aren't cheap. (You can run your truck on woodgas too.... with the same caveats about things gumming up and the cost of equipment.)

There's also the possibility of using a liquid loop to bring heat to a radiator, but that's not a project I would suggest to anyone who is not an engineer, as "closed loop" and "bomb" are near cousins.

No practical way of doing forced hot air really comes to mind, though you could probably make a dent with 2 insulated oversized ducts and a furnace (you would need to take return air from inside the structure).