what is the best OUTSIDE wood burner to buy ?

I put in the bigger one I forget what the square footage was for it , but it is big enough to do the house and the shop (when I buid it). I figured it would pay for itself after 3-5 yrs ,, I have all the wood I will need up on the top of the property,

It will use a bit more wood than an inside stove, but , all the mess is outside, no smoke dust, bugs, etc in teh house, no hauling wood inside, I had a wood shed close by the stove,, now I use trailers loaded and placed in front of the stove , a whole lot easier to load that way,,

the cost of my whole unit I am putting around 8,000,, the piping is expensive, you need two runs of it with no spices, @ about 2.50 a foot,, plus the main circulator pump was 500, and I have 4 zones @ 250 each,, approx,,,,

insatll was probably 1000, give or take,,

I put my pipes 5 feet in the ground, figured that would be deep enough,, and only put the round insulation around the pipes, [this is made for the pipe--both runs lay inside and it close around them],,,, IF I was to do it over again, I woudl maybe build a box and stuff it with insulation in addition to the round piece, I do get a little heat loss thru the ground towards the middle of the season,, not enough to make a difference in the heat to the house though,

I love the outdoor stove compared to my inside wood stove I had in the old house , as it is connected to the baseboards and the WHOLE HOUSE stays warm , comapred to the inconsistancies of the wood stove,,

I did put a back up propane "woodstove" in the living room, just in case,,

hope taht helps pat

I've got a dozen farmer-neigbors with outdoor boilers near me - and most of them burn wet and scrap wood that works fine for them. Especially with no close neighbors and smoke is not an issue.

I've got an EPA rated outdoor hot-air furnace that was designed to be attached to a house on the outside. With mine, I built a large insulated room around it and it works great since I can store four full cords inside - where the wood gets warm and dry before burning. But, hot air has it's advantages and disadvantages - like anything else. Hot-air does not travel well without thermal loss, like hot-water does.

I don't know what your sitution is. I heat a large farm-house and a large workshop and barn 100% with wood. Also all our hot-water. I have hundreds of acres of hardwoods - but even with that - the wood I use certainly isn't free. I spend a lot of time, year-round, cutting, dragging, loading, unloading, splitting, etc. Also time keeping chainsaws running, chains sharp, maintaining two log-splitters, etc.
I'm by myself - so all-in-all, I don't regard the wood as cheap.

The EPA is just getting ready to intervene and force outside furnace makers to produce something more efficient. There are two on the market now - so you might want to check around a bit. There are also areas in the US looking to ban the standard outside wood-burners.

I'm not a fan of government controls - but to be fair - anything labeled as "woodstove" has to meet EPA efficiency requirements and that has resulted in much more efficient stoves. Furnaces will be next.

The reality is - a fire needs to be hot to be efficient. It's close to impossible to have a low-fire adjacent to a water tank and not have it get cooled off too much. One answer is a hot-water storage system that is used in many places in Europe. Whenever the fire is going, it is run to the max - and the hot water is stored in large insulated tanks. Then the fire is shut down - and not fired up again until the tanks cool down. Some of these systems can go for days between firing. Tarm sells them in the US but they are expensive.