Sidewinder (Lateral) Batch Box Rocket 8” in Argentina
Recently my husband and I converted our Rocket 8” for a Lateral Batch Box Rocket 8”and we’re running into some smoke problems from the p channel and now from the fire box.
Where did we go wrong? We need help Rocket experts please criticize!
Fire box: 33cm width/ 43cm height/ 71 cm depth
Portal: 7.5cm width/31cm height
P-channel: 5cm width/ height 3cm = 15cm2 (believe Peter’s is 16cm2)
Primary Air Channel: 36cm2 and 60cm2 (we haven’t decided which one to keep, see below for pictures)
Riser: 113cm height respecting 20cm octagonal diameter bottom to top. We left a space of 30cm above the top of riser without refractor brick, this elevated space is covered with a recycled cast iron side oven plate on top. (This is experimental in hopes of making a hot oven on top) We’ve made what some people call a Japanese Bell on top of the riser.
Here’s a picture of our original Rocket, worked perfect for 4 years straight. We decided to convert to the BBR in order to heat up water in a recycled water tank in a barrel, which heats up water in less than one batch no problems in this part of the design.
The circuit of the BBR is unusual compared to most, firstly it has been built into a cob wall, where the fire box entrance is on the outside of the house. Note: We will eventually inclose the area where the door to the firebox is. Perhaps our system is suffering from outdoor temperature differences or southern wind inflow? It is winter now, fluctuating from -2C to 16.
How does the heated air flow in this system…(sorry I’m not Sketch Up savvy)
As you can see in this picture, the firebox entrance is currently outdoors, the firebox is in the wall, pooping out of the wall in the inside of the house.
The heat riser is inside the house. Heated air from the riser is guided back outside dropping into our water heater barrel and at the bottom of the barrel it is guided back into the house (crossing below the heat riser).
Heated air continues to circulate through the cob bench and out the chimney. This route runs approximately 16 meters in length ( measurement starts from the top of the heat riser to top of chimney. Q: Is this route too long for a BBR 8”?
We recycled an old cast iron stove frame instead of a custom made fitted door. As you can see the door is smaller than that of the brick fire box and thus giving us 2 optional primary air intakes. The oval size has a fitted door to control air intake 32cm2.
The opening underneath (60cm2) the iron frame is wide open, we will close this off only to access the ashes. When we seal this part, there is still smoke.
(Cut triangular bricks are set in place since this photo in order to respect the inner volume size of the fire box design)
Taking a look in the inside, we have put ceramic glass so we can watch the burn from inside.
You can see our p-channel intake at top left of the ceramic glass.
Why did we do the p-channel design like this?
This is the shortest p-channel length we could do from cool air inside the house directed over the portal (40cm length channel).We soon learned that smoke came out when lighting our fire but once roaring the air was sucked in fine. But when opening and closing the door to the house this caused a puff of smoke to come in. We did not for-see the air pressure change as a problem…?
After using this fire beast more and more we couldn’t reverse the small waves of smoke coming inside our home leaving a nasty stink and of course fear of Carbon Monoxide poisoning, we have our alarm on to let us know.
Another guess here for the p-channel smoke is that inflow of outside air from the firebox door + air intake is streaming in the direction that p-channel is lined up with inside the house.
Below you can see how we’ve placed the p-channel inside the firebox.
I wonder if the solution is so simple to just flip the p-channel around? We’ve done this backwards, without considering the physics of air flow…
Q:Is another solution to drop the p-channel from above the heat riser? Or will this give a chimney effect and still have problems with air pressure when opening and closing the door to the outside?
Thank you to all who have come this far and taking your time to assess where we went wrong!