Can you help me understand why you favour the BK? I need to understand the key features and nuances better here...
All modern stoves work on a secondary burn principle. Whereas older stoves would burn (or smolder) wood in the firebox, and send the volatile-laden fuel-rich smoke up the chimney, all modern EPA certified stoves have some system to "re-burn" the volatiles remaining after initial combustion in the firebox. This vastly increases heat output and efficiency, from a given amount of wood, and means you can heat your home with less wood. This is a very big deal for anyone splitting and hauling enough wood to actually heat a home.
There are three primary methods of achieving this secondary burn:
1. Non-cat stoves work by introducing fresh air into exhaust path, and achieving secondary burn of these exhaust gasses without the aid of a catalyst. In order to do this, they must maintain those exhaust gasses above 1100F, which really limits how far you can turn the stove down. You will read references to the "EPA hole", a requirement from the EPA that enough air must be allowed into the firebox even with the controls fully shut down, in order to not stall this secondary burn. This is also the genesis for some of the older complaints about run-away stoves as you truly cannot shut them down, although I do believe that's mostly a problem of the past, manufacturers have gotten better at tuning their stoves to eliminate this problem that seemed to plague some of the earlier non-cats.
2. Catalytic stoves do exactly the same thing as a non-cat, but with aid of a catalyst, they can maintain this secondary burn at 500F. This allows you to shut them own farther, and achieve longer burn times at lower output rates. There is still an EPA-mandated hole, but due to having to maintain only 500F versus 1100F, it is much, much smaller. You'll hear the slang "riding the hole" in the BK forum, referring to shutting down tight, such that the only air entering the firebox is thru this hole in the air inlet damper.
3. Hybrid stoves try to achieve the best of both worlds, employing both non-catalytic reburn mechanisms (eg. tubes) and a catalyst. I'm not sure that any have met or exceeded cats on burn time or non-cats on max output, but they definitely tend to have a wider range of very low emissions. They also extend the life of a catalyst, one boasting 20 years warranty on the first combustor, as opposed to BK's 10 years for their cat stoves.
Then there's BK... unique even among cat stoves. They employ a thermostat, designed to automatically throttle the air control and give a very even heat output over all phases of the burn cycle. Other brands have this, but BK is one of the few who really got this right. Most of us are getting burn times of about 30 hours from the BK 30 or Princess, or 20 hours from the BK 20's, on the lowest rate. This low rate may not heat your house in the coldest weather, but it's very useful for cool rainy days like today in the mid-Atlantic region.
The reason I favor it for your application is that, thanks to this low and slow capability, you could buy a BIGGER stove and run BIGGER loads of wood if you went with BK, than if you were to buy a non-cat. This can give you longer periods between reloads, or conversely, less temperature swing in that mild climate and modest space you're trying to heat.
The penalty of a cat stove is that you will eventually have to replace the combustor. Some burning mostly low and slow with softwoods report a replacement every 10 - 12,000 hours. I'm at more than double that, burning hotter with hardwoods, and no signs of failure yet. The combustor costs $200 and takes about five minutes to swap, but that's enough to turn some folks off on cat stoves. There's also the issue of only burning cord wood in a cat stove, as painted lumber and other trash can "poison" the cat, whereas non-cats can burn anything that will burn.
Finally, there are some very bad older stove designs still floating around the used market, both cat and non-cat. But given the timing and history of both tech's, it definitely appears that there were more bad cat stove designs in the 1980's and 1990's, than there were ever bad non-cat designs in the 10-20 years following that. So, cat stoves got a bit of a bad reputation back in the day, which good companies like Woodstock and BK still battle today.
