I haven't looked too much into them, but Heatmaster has some new units that utilize an O2 sensor to monitor for clean burns. I know on mine it could run on less air toward the end of the burn cycle and gain some efficiency....if it only knew what the exhaust was looking like.
Tell me more. Do you mean putting an 800 gallon water tank in the basement in the loop from the OWB to my hoot something like that? Thanks.
Basically, yeah. Your boiler runs most efficiently when you run it wide open, then not at all. If you had thermal storage, you would run the boiler hard to top off your storage temp...then shut it down until it needs heat added. You'd have to build a fire every day or two is the only downside.
So far the boiler has been working great after repairs, its also been very mild till just recently with the polar vortex, but wood usage has been hard to gauge For 3 or so months I've been burning lumber cutoffs and just recently started to feed it oak and poplar
Is they’re some kind of formula for determining how much storage you need based in your btu requirements or the frequency of the fires you burn or is it just a matter of building as much storage as you have space for.
Take your top temperature (probably 180) and your lowest useable temperature for heating. Low temp depends on what type of heating system you have. Let's just say 150. That's 30 degrees of temperature you can offload into your house. Now, we need to know how much heat your house needs per hour. Let's make up numbers and say, on average, it needs 40,000 BTU/hour. In one gallon of water you can store 250 useable BTUs (8.34*30). To heat your house for 1 hour you'd need 160 gallons of water going from 180 to 150....so 800 gallons would last 5 hours (800/160). 24 hours in day / 5 hours = 3 fires a day. These are made up numbers, but that's the math to size your system. Most will say it is hard to go too big if you can heat on lower temperature water.
There are several good sources for heat storage tanks...if you have the room/access, bulk milk tanks can be bought at auction pretty reasonably...also, used LP tanks...those can be stood on end or stacked to take up less room. Some sort of insulation would need to be applied, or insulated walls around the tank(s) then too...
As you guys probably imagine my stove burns continuously once I start it it’s hard for me to imagine it actually going out due to no demand for heating water. I wonder if it would just idle with the damper closed between calls for heat. Maybe like it does in the spring/fall when temperatures are warmer. I would be using significantly less wood either way. I wonder if most folks put their storage in the basement or bury it in the ground between the OWB & the house. I suppose every situation is unique. I’m thinking of area consumed by storage in the basement. Everything is a give & take I suppose.
Storage is best in the building you are trying to heat. I have 2 x 500 gallon propane tanks spray foamed, boxed in with 2x4 framing (studs insulated w/R13) and blandex over that. Even with all that the heat loss keeps the 24x48' outbuilding at 45-55F all winter long with no other heat sources there besides the boiler and piping. I would not consider installing storage in the ground.
