Nobody else has answered so I'll give my thoughts.

To me, an 8 hour burn is pretty darn good. To get longer, you probably need larger logs, which means you need a larger fire box.

The best stoves are heavy, with thick metal that gives off heat for a long time after the fire is out.

3 years ago, I was shopping for a wood stove and the $800-$1000 ones were just about big enough to hold a couple of 2X4's and they were made of thin metal.

My son finally gave up and plunked down $2500 for a good heavy stove with a large fire box. I very much doubt that you could keep a fire going for 12 hours in his stove.

I gave up on a new one and bought a heavy used one with a large fire box for $300 that turned out to be a worthless piece of junk. I know why it was available used. It is the most difficult stove to light. It is impossible to adjust the flame, and it smokes until it gets heated up.

Is it nationwide that new wood stoves must be EPA or HUD approved for emissions? They must be certified clean burning in Oregon (we care about the environment). Cool fires are dirty fires, so the new ones are probably made so they can't be dampened down to a slow crawl.

Maybe a local metal shop or blacksmith could make you a large wood stove that is air tight.

For anyone else who is burning a cool fire in their wood stove, get your stove pipe cleaned frequently. A cool fire is a dirty fire and causes creosote build-up in your stove pipe. That causes fires in the stove pipe, which can catch your house on fire.

Fisher wood stoves are excellent stoves. Not made anymore, don't think they were certified, but they are workhorses. Papabear can be loaded 2x a day, takes decent sized logs, and you can cook on it too. Not fancy like the ones you buy today, these stoves are made to throw some heat & last several lifetimes.

Brendasue

I'm late with this posting, but I agree with Brendasue concerning Fisher stoves. I had a Mamabear years ago and it was a wonderful stove. Not only was it our primary source of heat, but we also cooked quite a bit on it and it held a fire for 8-10 hours easily. One of the hints about keeping your chimney clean is to fire it up really hot every morning for 30 minutes or so to burn out any accumulated creosote during the previous day's slow burn. Of course, it is always a good idea to have a chimneysweep inspect your chimney before you start using it if it is old. You can clean your own chimney yourself with a brush sized for your chimney if you wish, but get a pro to do the initial inspection. The frequency of cleaning depends on how you use your stove and what fuel you use. If you burn conifers such as pine, fir or spruce, clean it frequently.