I had to choose a heater for my shop, which is essentially the same size, a few years ago.

I briefly considered radiant-type heaters because they can make you feel warm quickly after turning them on, even if the room is cold, much like standing in the sun feels warm even when the air is cool. I ruled these out because the exposed hot surfaces looked likely to ignite dust or, maybe, finish vapors.

The alternative was a direct-vent natural gas wall furnace. It looks a lot like those inexpensive wall heaters you can get at big box stores but it has a double-walled intake and exhaust tube that goes right through the wall to the outdoors, so there's no exposed flame and no dusty shop air is drawn into the burner. The combustion happens inside a tubular steel heat exchanger that snakes around inside the unit, and a squirrel-cage blower pushes the shop air over the heated tube. There's no filter on the thing; I just take the cover off and blow it clean with compressed air before turning it on for the season, and do that a couple more times during the winter.

The biggest problem I've had with it is that the fan isn't powerful enough to keep air moving around the room. Since the thermostat is built right into the unit itself, it shuts off when the area immediately around the heater is warmed up, leaving the distant corners chilly. It works much better if I set up a small fan nearby to circulate warmed air around the room.

My unit is rated at 17,000 BTU, BTW. I can't recommend my particular unit because it's a european make that was only briefly imported by a company that found they couldn't make any money bringing it in because the currency exchange rates sucked. There are others out there, though. If you search using "direct vent furnace" and ignore the fireplace inserts that pop up, you should find similar products.

Oh, and get a dust collector if you actually plan to use your shop. You don't want the stuff piling up on the floor, you don't want it in your HVAC equipment and you really don't want to breathe it. Bite the bullet.

Oh, to put that 17K BTU in context, I live in NE Ohio -- temps hang out in the twenties for long periods every winter, with occasional dips towards, less occasionally below, zero.

Look into the motel wall mount units---AC and heat. They have buily in filters and can handle minimal amounts of sawdust---with periodic cleaning.

I already have the window A/C unit.
Probably be mounting it next week sometime.
Temps in the winter don't go much below 30 for very long.
On cold nights it can get down into the teens. But I won't be in the shop then.
Summer temps go up around 100. Sometimes more. (Chattanooga area)

I would love to have a dust collector. But it's just not in the budget.
I could build one myself if I could get the blower wheel.
Anyone here got a big dust collector that I could get a part
number for the blower wheel so I can order one. The rest I
can fabricate up from steel drums and what not.

My most immediate concern is cooling the shop for now.
Even my giant squirrel cage blower doesn't help on days like today.
I setup my blower to blow air out the window and I enclosed it
so that it sucks hot air from up around the ceiling.
This blower came out of a commercial unit and has a 3hp motor on it.
It blows a massive amount of air. But it's still to hot today.
So I have to get the A/C unit put in. An finish the insulation/OSB.

This is a small shop. 12x20. So I may just go with a small wood stove.
I had a large wood stove in my last shop. 20x20 shop.
The shop was not insulated and not sealed well at all.
And the heater would still run you out of there from the heat.
But I also had a great source of free firewood from the place
where I worked at the time. Kiln dried hard rock maple scraps.
This time around I will have to get my own firewood.
Maybe I can get a corn stove or pellet stove. Just an idea.

I don't use paint or stain. So combustable vapors are not a problem.
Dust on the other hand I know is explosive.
But I never had a problem with it before.

Keep the ideas comming.

Thanks.

Pooh Bear

Take a look at this page. I think you'll find at least one fan wheel source buried in here...

Here is a link that might be useful: Budget Blower plans

What a really cool link !!!
Thanks a BUNCH for posting that.

Pooh Bear

Pooh,

Let me rephrase that. You can't afford not to have dust collection. Wood dust is a known carcinogen and on the same list as asbestos, tobacco, and radon. The more you do to protect yourself, the better off you will be.

Mike

We had foam type insulation blown on the walls of our shop and then spray painted to protect it. It keeps the shop cool even on really hot days and warm in the winter.

Consider the lumber, and the projects that will be stored in your shop. Do you want to subject them to the extreme changes in temperature that will happen in winter if you let the shop freeze up and then put on the woodstove? It would be better to use an overhead radiant propane heater. That way you can have it on a thermostat and keep it at a minimum temperature that is above freezing. This is what we use.One advantage is that it is really warm to work under.

There is also safety. You have been warned already about the dangers of inhaling wood dust. There are also dangers in leaving a woodstove burning unattended. The amount of time to heat up a cold shop to comfortable will tempt you to build up the fire and then leave it to warm the shop.

Do you always work for long spells? If not, you will often work in the cold since it will not seem worth it to start the stove, wait for the shop to heat and then work for a few minutes.

I got all the insulation up. Now just got to finish the OSB.
Since the insulation is up I have been using the air conditioner.
It makes a big difference to work in there and have it cool.

Now that the shop has been "tightened" up, I see what you mean
about the dust in the air. I haven't even done much and already
the dust is a problem for breathing. I am gonna have to do
something about this. Can't even sweep the floor without coughing.

Pooh Bear