mykal
New Member
Posts: 3 
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Post by mykal on Sept 25, 2015 7:11:20 GMT -8
Hello I have two questions for all you tinkerers and thinkers out there.
1) My wife and I purchased a wood stove years ago and had it installed in an old stone fireplace. I have noticed that no matter how hot or long we burn the stove the rocks don't seem to pick up any heat. How can improve this performance without extensive renovations? Would it be advisable to fill the void around the woodstove with "mass" such as fire bricks or such in order to place the mass in contact with the stove? I believe this would encourage heat transfer but I am not sure of the consequences (if any).
2) If I were to build and use a barrel stove or double barrel stove to heat my greenhouse (24 x48 with double layer inflated poly and double layer polycarbonate end walls) how can I make it the most efficient? I was thinking that perhaps I could encase the entire system (sans the door opening) in a box filled with something like sand or perlite to create a kind of mass heater. Any thoughts as to making the system more efficient (like a rocket mass heater without the cost) or safer (I have small children who like to be in the greenhouse) would be greatly appreciated. |
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Post by shilo on Sept 28, 2015 11:43:16 GMT -8
1. it may shorten the stove life.
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Post by ronyon on Sept 28, 2015 16:34:03 GMT -8
As to the barrel stove, I have read extensively on doing just as you described, but not with sand or perlite, both of which are insulating in such an arrangement. Try rocks and soil contained by concrete blocks. Gravel and rebar in the webs of the block for a stable but reversible wall.
No double barrel needed since you will want a hot, fast fire,so little smoke to reburn in a second chamber, but perhaps enclose the flue pipe up to the roof.
Sand or perlite might be good top layer, or maybe a hanging sheet of metal to deflect radiant heat back to where its most useful.
Discovering this kind of heater, used in cabins , plus reading on charcoal making , is whar led me to rocket stoves.
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Post by keithturtle on Jan 12, 2016 21:28:29 GMT -8
I guess what I'm working on falls into the category of barrel stoves. s237.photobucket.com/user/keithturtle/media/tank%20stove.jpg.html?sort=3&o=0Two 20 lb propane tanks cut strategically, then welded together. Add a short piece of 4" EMT conduit to retain the flue stack, add some scrap metal legs and that is the biggest part of it. Still getting all the details together, and when the thing is done, I'll start a thread on it. I plan on making several of these, principal use is cooking and heat Turtle, still at it |
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Post by pinhead on Jan 13, 2016 5:50:45 GMT -8
Hello I have two questions for all you tinkerers and thinkers out there.
1) My wife and I purchased a wood stove years ago and had it installed in an old stone fireplace. I have noticed that no matter how hot or long we burn the stove the rocks don't seem to pick up any heat. How can improve this performance without extensive renovations? Would it be advisable to fill the void around the woodstove with "mass" such as fire bricks or such in order to place the mass in contact with the stove? I believe this would encourage heat transfer but I am not sure of the consequences (if any).
It takes a lot of radiant heat to raise the temperature of brick. In a proper RMH, the mass is absorbing both convective heat as well as radiant heat. This is why it is able to stay so warm. With the majority of your heat probably going up the chimney, you're not putting a lot of heat into the living space. If I were to build and use a barrel stove or double barrel stove to heat my greenhouse (24 x48 with double layer inflated poly and double layer polycarbonate end walls) how can I make it the most efficient? I was thinking that perhaps I could encase the entire system (sans the door opening) in a box filled with something like sand or perlite to create a kind of mass heater. Any thoughts as to making the system more efficient (like a rocket mass heater without the cost) or safer (I have small children who like to be in the greenhouse) would be greatly appreciated. Perlite is extremely insulative. Loose-fill sand is fairly insulative as well. If you were to encase the entire stove in perlite, all of your heat would go out the chimney. It would most definitely increase the burn efficiency, but that won't help you if you don't get that heat into the room. Insulating a barrel will burn it out in very short order, as well. A double-barrel stove is more efficient not because it introduces a reburn chamber; it's more efficient simply because it increases the surface area of the radiator. You get even more points if you make the second barrel a bell instead of a chimney extension:  Notice that the inlet to the second barrel is higher than the outlet. I'm not sure what your worry is, though, about the cost of a rocket mass heater; many people build them for a grand total of $0. The only thing you may have to buy is the insulation for the heat riser (perlite mixed with clay works well) and the barrel - both of which it sounds like you have already. For a greenhouse in my climate I'd opt for a bigger stove such as a 6" or larger batch box. Depending on your climate you may be able to get away with something smaller. Many people say a J-tube is safer around kids, though, because the inlet/door doesn't get as hot. I'd rather load a big batch of wood and let it burn than continuously feeding a J-tube so I'd personally opt for the batch box. |
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Post by Daryl on Jan 13, 2016 9:30:55 GMT -8
Hello I have two questions for all you tinkerers and thinkers out there.
1) My wife and I purchased a wood stove years ago and had it installed in an old stone fireplace. I have noticed that no matter how hot or long we burn the stove the rocks don't seem to pick up any heat. How can improve this performance without extensive renovations? Would it be advisable to fill the void around the woodstove with "mass" such as fire bricks or such in order to place the mass in contact with the stove? I believe this would encourage heat transfer but I am not sure of the consequences (if any).
2) If I were to build and use a barrel stove or double barrel stove to heat my greenhouse (24 x48 with double layer inflated poly and double layer polycarbonate end walls) how can I make it the most efficient? I was thinking that perhaps I could encase the entire system (sans the door opening) in a box filled with something like sand or perlite to create a kind of mass heater. Any thoughts as to making the system more efficient (like a rocket mass heater without the cost) or safer (I have small children who like to be in the greenhouse) would be greatly appreciated. Some random thoughts at lunch:
But then there are two different types of heat, direct and mass. Most woodstoves will get the room nice and hot in a short period of time. Heating with mass is a little different since it is radiant heat.
The newer woodstoves are highly efficient. That may be the reason the brick doesn't get warm.
There are newer hybrid woodstoves that are a mix of mass and metal which will also have a mixed effect on heating the room.
Take into account that when you heat mass, you are pulling energy from the gases. The stove may not work the same.
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