I am getting ready to buy/build 55 wood stoves for my shop. I see the
single stackers, the doubles, all kinds. The shop is roughly 15360. It
is 40 x 32, 8' high, roof varies from 2' to 6' above that low slope.

I like it warm. I wouldn't mind having two stoves, and take them out
and switch them with the swampers each year.

I see Wolfzang (sp?) stoves, and their ilk, which is just a pretty well
sealed up 55 gal barrel. I see others, with what looks like varying
degrees of craftsmanship, mass of metal in components, differences in
vents, and a few things that makes one better than the other, as in
thicker metal, more bolts, more vents, etc.

What makes a good wood burner, and what is good to look for? Are the
more expensive ones inherently more efficient? And just what does the
second barrel do, other than provide greater surface area? And would it
be possible to mount the second top barrel somewhere other than directly
over the lower one to take heat to another portion of the shop?

Just how airtight are these? Is it necessary to monitor them very
closely with CO detectors, or is the inherent leakage of a hobbyiist
built enclosure safe enough?

Would one single stove be enough? Two singles? Two doubles?

And just how often does one have to paint these? In my area, I can get
pristine coconut oil barrels for $10 each with lids, so changing them
over the years would be probably easier than keeping up with a swamp cooler.

Class?

Steve