Your best bet is to go to a quality stove shop.

Wood has a certain amount of BTUs per pound, depending upon species. If your heat loss is 50K BTU per hour, for example, you'll need a net output from wood at the same rate.

You're talking about a large amount of wood to cover 12 hours and a large stove to go with it.

An outdoor boiler with a coil might work, but they aren't suitable for everybody.

A coal stove would be more practical, but 12 hours is still a long time to hold a fire, even if you have anthracite available.

I've been heating with wood exclusively for almost 35 years. My fire goes out in a couple of hours, but the house is insulated so that it only loses a few degrees over 12 hours. Your house's insulation is the first place you should look.

Agreed, coal would like give you a much better chance of holding a fire for 12 hours.

If you really need a "set and forget" type stove, then perhaps you should be looking at something along the lines of a pellet stove or an rice coal stove.

Both types self feed from fuel hoppers and, depending on the setting, can go for many hours or even days between fill ups.

Thanks for your replies. We have 60 acres of woods and by only cutting those trees which have already died we supply ourselves with wood for the entire year so buying coal, rice, pellets or anything else would be uneconomical for us.
The house is insulated (built in 85').

OK.

Nice that you have a supply of relatively free winter fuel. Several of my friends' families' when I was growing up heated almost exclusively with wood that they cut from their own property.

That was during the height of the Gypsy Moth kills during the 1970s and 1980s, so laying in a couple of year's supply of wood at a time wasn't a problem.

Anyway, I really think you're going to have problems finding a stove that will hold a fire for that long. It really depends on how much fuel the stove will hold combined with how much heat you need the stove to put out during that period.

I have a Consolidated Dutch West stove I bought 15+ years ago. I think they are now owned by Vermont Castings or someone else. It is a catalytic stove, meaning there is a catalytic element in it that reduces creosote formation as well as producing additional heat. I also got a blower with it.

8 hours is about the best it will do with an armload of wood, throttled down. At the time, it was one of the best at this. I really don't think you'll find one good for 12 hours but who knows...

If you can get your hands on an "All Nighter" wood stove, grab it. I've seen them on Craiglist for free. I bought one in the late 70's and have used it every year since. I too have my own wood supply. The stove takes up to 22 inch logs, it is air tight and has adjustable ports for air inlet and burns for 12 hours. The coals can stay lit for a lot longer. They had 3 sizes called "the Moe", "The Mid Moe" and "The Mighty Moe". The Mid Moe heats up to 2500 sq. ft. They are really well built. The company went out of business after they and Franklin Stove Works had a law suit over patent rights. There's a lot of them still out there and going strong. If you can't get your hands on one of them, you might want to check the "Timberline" models. They are good stoves too.

windslam

I have one of those Allnighters...the Mid Moe. I've had it about 30 years now and it is still a knockout with minimal maintenence. Too bad the stove works went out of business. They do indeed burn up to 12 hours and the coals heat for much longer. Those stoves are UL listed and approved, there's even a UL tag affixed to them.

You obviously have enough acerage to not bother neighbors with an outside wood boiler... we've have one for 3-4 winters now in central MA. Fill it 2 times per day and burn mostly pine 'scrap' from a nearby sawmill, and the standing dead we take off our 5 acres. It sounds like you have an endless supply of wood. This keeps all the wood 'mess' ouside, and the wood smell also. It acn be as close or as far from you house as you chose. Ours is a central boiler model and we get our hot water from it also.