Post by jrl on Jun 20, 2014 7:27:13 GMT -8
I'm working on a design to build a rocket heater with a fire brick J tube and riser directly in my fireplace. Rather than use a barrel as a vessel for radiating heat and then exhausting to my masonry chimney (no ducting through cobb or anything in this setup), I'd like to use the fireplace itself as the radiating vessel. By this I mean that the front of the fireplace would be plated up with steel like a fireplace insert would be. From the front you would see only the feed tube and the steel facing and maybe an access door or cleanout port on the front of the feed tube. Inside the fireplace (already lined with fire brick), the riser would blow hot exhaust into the fireplace chamber. The damper up in the fireplace would be replaced with a steel sheet. On one side of the fireplace it would be walled up with an opening near the bottom to basically make the fireplace a bell that can only exhaust under the side wall. The little side chamber would exhaust up the chimney flue.
A picture is worth a 1000 words, and I drew a crude drawing in MS Paint, but the attachment feature is not working. I get "Error: This forum has exceeded its attachment space limit. Your file cannot be uploaded."
I will try to post it later.
What do you think the viability of this type of system is? My observations are that the whole, all-masonry fireplace would act as big thermal mass like any fireplace. The steel front facing would radiate heat into the room. Adding a blower tube in and out of the chamber would convect more heat into the room. The side wall with bottom exhaust port would make the whole fireplace chamber a big bell.
Do you think I should still put some sort of barrel or tank over the riser to get that 2" gap concept, and just leave the bottom of it open so it exhausts into the fireplace chamber below the barrel?
The masonry chimney has good draft and should always create negative pressure in the system (theoretically), but I don't want this thing back puffing into the living space if the wind blows or something. Do you think sealing the front facing will be sufficient to keep the CO and exhaust within the fireplace?
My objectives are:
- Utilize the fireplace (currently never used)
- Add supplimental heat for spring and fall in my living room (I burn anthracite coal in a big stove on a bigger hearth downstairs in the winter)
- Achieve complete combustion of material via rocket
- Use scrap wood and tree branches from some trees felled last year, nicely seasoned and dry now, but will rot in a couple years if I don't use it.
My constraints are:
- Money - I only want to spend a few hundred.
- Space - The fireplace is small (36 W up front x 24 W in back x 30 tall x 21 deep). This prohibits the use of a large barrel and would make for a really small CSA and riser to fit the space if I can't use the chamber itself as the barrel. My using the fireplace as the vessel, I can put a 6 inch system in there.