Jane Ashworth

Thank you for your comments Scott, good to know these finer details of water heating systems. We did rush into changing our system to try and get ready for the cold winter so there's still much to experiment with...

THANK YOU PETER!

Thank you Peter for clarifying in such detail, it's greatly appreciated and we keep learning better how your system works.

You commented here "What has been done wrong in your implementation is just a flap hanging over the port, with generous openings left and right." (I'd like to clarify on what you mean by "right")

When looking at the (not so clear) photo of our existing p-channel I would like to point out that there is only one opening, directly above where the flap is (this makes the opening on the bottom of the horizontally placed channel). The right side we had soldered, so this is closed and no air is moving directly from right to left (if this is what you mean?). The flap you see hanging is the size of the cut we made for injecting air above the portal and so after we made this cut we bent the metal out to make the flap.

Thank you!

Thanks again for all your comments, I hope that the video showed in more detail how the system is running. We're going to have the p-channel switched around sometime this week so we resolve the pressure problem and post the temperature exiting the chimney.

In regards to the p-channel Peter, to make sure we don't do another "BLOOPER"!!!  
Would it be better to position the channel within the portal with the air ejecting from the top? And do you recommend having a flap here?

(After reading so many forums on p-channels I thought I understood that above and in front of the portal is the most effective for adding turbulence... but now that we will switch the direction of the channel I don't believe it's a good idea to have a longer length of channel running in the firebox that will most likely effect the air temperature injecting into the portal. Would love to know more thoughts on this part of the design)

Satamax, good observation, the fire was very slow in that moment to get started as the whole system was completely cold and humid. Usually after the first lot it's much more active, also probably due to the water tank getting nice and hot.

Next we have to decide where we'll put in the bypass to avoid the water tank we'll post an update how that goes.



You are all so wonderfully helpful! Much appreciated.

Here's a short video of our BBR 8" that should help clarify how it's laid out.

Thanks again to all!

Thanks guys!

Yes it is a long run. We were actually planning to put in a divider so we can switch between heating water in the barrel or have it go straight to the bench. We should be able to do this where the pipes meet the barrel.

For those ever thinking about heating water it's a good idea to have this option so you never over heat your water system and avoid pipes busting. We do have a thermometer to install to keep check of the water temperature and this system does has an emergency escape pressure pipe that reaches the height of our water storage tank, not sure of the correct terminology for this.

We'll check the temperature at the exit of the chimney, that's good to know. The draft seems to be pulling well and we cleaned all of our ducts when we made the change so there shouldn't be any blockage.

Thanks for confirming the pressure difference from inside and outside. It was quite obvious when we had a burn going that this was a huge problem, so we'll have to dismantle part of the fire box to have it redirected outside. It's hard to see the whole system from the pictures and my description, I'll see if I can get a video clip posted so that's more clear.
To clarify we're still building the house, so when I say the firebox door is outside it is at the moment but this part of the house will be enclosed this coming year...but as the system is in two separate rooms there will still be a pressure difference so we'll have to get that p-channel on the same side of the firebox door.

Thanks again and I'll keep posting updates

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!

Measurement breakdown:
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!