Post by tardis on Apr 17, 2012 11:31:58 GMT -8
Thanks for the tips so far! The weather is warming up here in northern NY, and as soon as the permit comes through (this week I hope!), the building of the addition will begin. In the meantime, I'm figuring out my RMH plans and building experimental burn chambers.
Certain considerations have made the plan shift to a wood floor instead of a slab, which has changed some other plans. I think I've figured out the weight issues with extra joists, shorter spans and reinforcement, but I'm still a bit concerned about fire hazards. Answers to any of these questions would be most helpful.
Specs:
J-shape combustion unit
8" 55Gal system with 2" top gap and 1 1/2" riser/barrel gap
~32-33 ft of run, with a long bench and wide bed combo for the mass
I'm currently planning the cob furniture and the placement of the ducts therein, and I'd like to keep the ducts as low as possible for good heat distribution. However, since I'm building on wood, the combustion chamber is placed a good 8"-10" above the floor. 4-5" of airspace and 4-5" of mineral/clay along with the recommended reflective material for radiant heat protection. I'd rather keep the mass shorter, with the pipes laid as low as possible. I'm curious now about the temperatures of the first lengths of ducting, as well as inside the "connection chamber" between the barrel and the duct work. Should I build everything 8-10" above the floor, and if so, can I bring it down again where the temperatures are safe? Will the drop adversely affect draft? Is there a safe solution that will let me place the ducts lower to the ground, so that the mass need not be so tall?
The combustion unit will be sufficiently far from any walls, though the mass will run along some walls after the first 6' or so. How much mass should I place between the pipe and the walls, and can I put the mass right up to the wall, using a few extra inches of cob, or should I leave 6"+ of an air gap instead? (I'd prefer to put the mass against the wall, for space reasons, unless anyone thinks it's a fire hazard, or that the walls will steal too much of the heat.)
Thanks again to everyone who contributes here. This project would never happen without you!
Certain considerations have made the plan shift to a wood floor instead of a slab, which has changed some other plans. I think I've figured out the weight issues with extra joists, shorter spans and reinforcement, but I'm still a bit concerned about fire hazards. Answers to any of these questions would be most helpful.
Specs:
J-shape combustion unit
8" 55Gal system with 2" top gap and 1 1/2" riser/barrel gap
~32-33 ft of run, with a long bench and wide bed combo for the mass
I'm currently planning the cob furniture and the placement of the ducts therein, and I'd like to keep the ducts as low as possible for good heat distribution. However, since I'm building on wood, the combustion chamber is placed a good 8"-10" above the floor. 4-5" of airspace and 4-5" of mineral/clay along with the recommended reflective material for radiant heat protection. I'd rather keep the mass shorter, with the pipes laid as low as possible. I'm curious now about the temperatures of the first lengths of ducting, as well as inside the "connection chamber" between the barrel and the duct work. Should I build everything 8-10" above the floor, and if so, can I bring it down again where the temperatures are safe? Will the drop adversely affect draft? Is there a safe solution that will let me place the ducts lower to the ground, so that the mass need not be so tall?
The combustion unit will be sufficiently far from any walls, though the mass will run along some walls after the first 6' or so. How much mass should I place between the pipe and the walls, and can I put the mass right up to the wall, using a few extra inches of cob, or should I leave 6"+ of an air gap instead? (I'd prefer to put the mass against the wall, for space reasons, unless anyone thinks it's a fire hazard, or that the walls will steal too much of the heat.)
Thanks again to everyone who contributes here. This project would never happen without you!