Sources of heat - what to do?

[blackthorn]

I know you said you were not interested in electrical heat, but I use a combination by using electric to run a radiant oil heater. My shop is well insulated, 30x40x12 feet high and I live in south-central BC Canada. We usually do not get killer cold here in winter but often run temperature well below freezing. The oil heater keeps my shop between 45 (cold day) and 55 (most of the time). I also have a wood stove and when I am going to be out in the shed working on a project, I fire-up the wood stove a half hour or so prior to commencing work. I usually leave the heater set at maximum and have not found the cost to be prohibitive, although I suspect that would vary from area to area. Works for me.

[Beerd]

...........I live in south-central BC Canada. We usually do not get killer cold here in winter .............

You must send it all south to the States

[MT Gianni]

In most climates burning one therm [100,000 btu] of LP gas produces one gallon of water. The main function of the vent is to remove the water vapor. I read manufacturers instrucions for 30 years in the field as a gas technician. I never saw one for an unvented heater that did not require a permanent opening of at least 100 sq in free are communicating directly with the outdoors. I also never approved one as they are illegal in Montana.
You cannot find a better vented area heater than a Rinnai.

[Lloyd Smale]

that's what I use. Only downside is they produce lots of moisture and things tend to get a coating of rust if you don't keep anything metal oiled. It really can be a problem if you turn the heat off when you leave and start it back up when you use the room. If you keep it a constant temp it doesn't seem to be a bad. I was worried about c02 when I went this route but my buddy who has two rental appartments above his garage said hes heated those appartments for 15 years with unvented wall furnaces and has had no problems what so ever.

I've had a wall-mount ventless gas heater in my 'workshop' (12'x24') for something over twenty years. Shop was built on a slab at the back of my detached (unheated) garage and is well-insulated...ceiling and walls...and heater has kept space 'comfortable' even through coldest stretches of our flatland winters. To minimize gas usage, my practice has been to keep heater turned down 'low' during heating season and turn up a half hour or so before I plan to start working.

https://www.farmandfleet.com/product...ee-heater.html

Bill

[Lloyd Smale]

you might want to consider a wood pellet heater. Probably produces less moisture and they will burn wood pellets or corn from your feed mill. Down side is there more expensive then a gas stove.

[Cast_outlaw]

You could try a forced air furnace from an rv draws fresh air for burning and exhausts in the same port. 10a dc witch could be run off a deep cycle battery and solar panel in the 50-80w range

[lightman]

I'm not seeing anyplace where you state the size of your room, unless I missed it. I know you said no electric but a thru the wall a/c-heat pump combo would work well. Electricity prices should be cheaper than propane or kerosene in most locations and not have the moisture problems. Just a thought, would really hate for any of those nice H&G molds to get a spot of rust! LOL!!!!

Also, as mentioned, insulation is king.

[AK Caster]

I have owned Modine natural gas fired heaters for decades. Currently have one mounted in the corner of our workshop and one in the garage. They work great with minimal venting. Controlled by an inexpensive wall mounted thermostat.
I can heat up a 1,000 sq foot workshop from 35F to 65F in about 15 minutes.

[Petrol & Powder]

The OP is very adamant about not using a vented device.

The Modine units hung from the ceiling and fueled by natural gas or propane are historically excellent units in large spaces (garages, workshops, etc.) but they require a vent.

So, with the criteria of the heating source being some type of unvented unit, we are down to: electric, propane, natural gas, kerosene or a radioisotope heater powered by Plutonium P-238 !

Since nuclear powered radioisotope heaters are rather pricy and have some stringent licensing requirements, I think we can rule that one out.
The OP said he didn't want electric, so that's out.
Building a natural gas pipeline is a bit problematic, so if natural gas isn't available - that's out.

So that leaves kerosene or propane for UNVENTED heaters.

[FISH4BUGS]

I am going to the Manchester NH Gun Show this Saturday, and will stop at Tractor Supply on the way home.
Thanks to all for the info!

[Moleman-]

Most of the rust issue you'll have is from condensation. Heat the air in the space up and cold things like your press ect or other large metal objects are now cold enough to condense water from the air or frost up. In the winter if I know I'll be using the machine tools the next day I'll set a brooder light on them to warm them slightly and put it back on for a day or so when done to keep them from rusting up.