MountainHigh
Selective Tree whacker
I'm not sure I follow. First, a modern high efficiency EPA stove will struggle to operate correctly whilst attempting to heat soak a 10k lb masonry chimney. They require an insulated 6" (?) class A chimney specifically so they keep the heat within the chimney. Second, I'm not sure why it makes sense to have 1) a system to do inground heat with the boiler and 2) a second natural gravity heat system. If a person is spending the money for the floor heat why wouldn't he just have a large storage unit fed by a wood boiler and a backup boiler?
Either way, neither of those systems has anything to do with building a massive fireplace center mass and using the mass of the chimney to store heat.
Not trying to get into a pissing match, I just don't understand what you are saying.
Glad to have a conversation. Let me explain further from my own experience.
I have a 2500 sq. ft. home - 2x6 kiln dried fir construction, some vaulted ceilings and double pane windows - R20 walls, R40 ceilings, with tall 27' high, 5'x 2' CENTRAL Brick Chimney with tile liners(6"x10" flue) that runs my PE Summit Free standing wood stove very well. I heat 2 stories without the need to run any backup even on the coldest days, if I can be around to tend the fire. Yes it takes longer to get up to temp than a straight steel pipe, but once it does, it holds heat for several hours on 2 floors even after the stove goes out. Will any EPA wood stove work on such a chimney? No, I have tried various other brands of stoves with less success. You need a large stove that throws a lot of raidant heat and one that puts enough heat up the chimney to get the large thermal mass warm enough to draft well. Hence, a Cat stove, which does not put up a lot of heat up the chimney, would need something else.
I know that current regulations state one has to have a steel liner on new wood stove installation, but if I was building today, I would look at ways of placing a single wall steel liner inside a large thermal mass with a concrete pour around the steel, to provide heat transfer into the thermal mass itself. IF that turns out to also not be allowed (wonders never cease) by a building inspector, then I would still build my home around a straight up central "approved" chimney, so as to keep the heat in the centre of the home and make the heat source also provide some utility as a gathering place and informal food stove top as well. A house with a central chimney passive heat storage system, enables such consistent heat conservation and pleasing warm radiation over time with wood alone, that I can easily leave windows cracked open on both floors to obtain natural movement of fresh air in the dead of winter.
In my case, I plumbed in all the required hookups to take hot water from a robust wood stove water jacket and into my hydronic heat backup boiler expansion tank system with its own distribution pump that will run off natural convection and battery, but never actually joined the two systems, as insurance would no longer cover my home (so I was told). Hence, my isolated compact Hydronic Heating system with low profile radiators in all the rooms and heating in the slab itself, serves as backup heat when I am away.
Lots of variables in setting up a central heating system, but my main beef is the fact that new homes are mandated in such a way to keep homeowners on the treadmill of paying to be on the grid.