Sky Huddleston wrote:
I don't know how large your house is, but running this heater on pellets constantly will likely heat you out of your house. Unless your house is over 2200 square feet, that is! Also, adding a flue damper will increase the burn time.By how much varies, but my estimates are anywhere from 14 to 20 hours.
Do note that a pallet of pellets is 4' X 4' X 4' which is half a card in terms of volume. Pellets are usually more than wood in terms of cost, people buy them for the convenience of a super long burn time.
You also must factor in that most pellet stoves use 15 to 30 dollars of electricity each month and their parts go out quite frequently and are very expensive to replace and time consuming to rebuild as electric pellet stoves are overcomplicated to say the least. The only wear part here is a 304 SS burn grate that one replaces yearly or so, and the part costs ten dollars. So this heater is already cheaper to operate just on the fact its non-electric alone. Thats not even factoring the cost of the replacement parts for conventional pellet stoves.
Pellets are an alternative to electric, fuel oil, and propane. In many area's of the country, you'll be hard pressed to beat the price of wood. Which is why this heater can also burn wood, too!
Aha! That may be the piece I was looking for. Just because I CAN
run the rocket heater on 2 bags of pellets a day, doesn't mean that I will WANT
to run it that long. (Honey, it's too hot in here, let's open a window). And if I run it less, then I will burn less. In the coldest part of the winter, I usually do 3 feedings a day on my soapstone (radiant) woodstove, Once in the morning to warm it up for dressing and bathroom activities, once around 1 or two in the afternoon to take the chill off and keep the burn going, but only if it is really cold, and once just before going to bed to keep the burn through the night. So really only 3 armloads of wood on the coldest days, and possibly less than that depending upon how cold it gets.
Also, "adding a flue damper will increase the burn time". Now I'm still in the studying and learning stage, but I kind of got the impression that you don't want anything slowing down the exhaust from a rocket heater (because it no longer sounds like a rocket?). I assumed that was because you don't want backdraft or smoke ending up coming out of the feeder hole into the living space. In my soapstone wood burner, I've found that I have to open the damper whenever I open the feed door or I can fill the house with smoke. So a rocket heater CAN have a flue damper? Does'nt that get a bit fiddly trying to keep it adjusted just right to lessen the burn rate and yet still allow enough of a throughput to keep the smoke from coming out the input?
I did call it a pallet of pellets, didn't I? That's what I get for trying to be alliterative. I really only meant a ton of pellets. Which makes sense if one pallet of pellets is half a cord (half a ton?).
I agree that pellets should cost more because of their convenience. They are processed sawdust, and like all things processed cost more than the raw materials used to make them. However, I would much rather schlep around a 40pound bag of pellets(my chickenfeed comes in bigger bags than that!) then to try and keep wood ready and available. Others may wax poetic about traipsing out into the cold snowy woods, hewing down a stately tree and processing it into stove sized bites, but not me. Growing up, my father's idea was that we should cut wood (and usually at 5am in the morning) the morning after I had partied too hard. That and being in the land of the long-thorn where they can stab through leather gloves, boots and tractor tires, has kind of dampened my enthusiasm for tree harvesting. So I am willing to pay for convenience. And in my opinion, that's why some pellet stoves have more moving parts, for the convenience. Some have connections to a thermostat, which make it pretty much like any gas or electric furnance. It only feeds pellets as it needs to, to raise or lower the temperature of the rooms it is charged with heating. In this case, all you would need to do is keep the pellet hopper full (and you can get F.O.U.S hopper feeders - Feeders of Unusual Size - so you wouldn't even have to do that very often).
Don't get me wrong, we just went through 3 hours of no electric after a storm (longest in 5 years, so I guess we were due), so I understand the need for not being tied to the grid. In fact, that was one of the considerations behind our choosing a soapstone stove, the fact that it could keep the pipes from freezing without the need for electricity. But just because I understand it, doesn't mean I wouldn't want the convenience that comes with electricity and pellets.
It seems then that you offer a good middle ground. Pellets, so convenience over wood and comparable burn rates, but no electricity so less convenience than a more automated system. Have you given any thought to maybe running on very low wattage/amperage? Something that might be sustainable by a deepcycle battery? The three uses for electricity (that I see) are pellet delivery, thermostatic control and starting a burn in a cold stove. You have already solved the pellet delivery, a low amperage solution could also take care of the thermostatic control. The only problem I see with a low watt electric system is when it needs to start a cold stove. That low of an amperage would not operate a heater to start the pellets. Or could it? I suppose it could, but that would take a lot of juice from the battery so you couldn't do it very often.
Anyway, I'm rambling.
Once again, more questions than answers.