Julie Garrett

I hadn't realised there was another reply. Plus I've decamped from Bulgaria back to the UK.

In reply to the most recent reply, for anything requiring a smooth finish when using sand I have to sieve the sand as it's river sand with tiny pebbles.

The actual house chimney internal cross section is 20cm / 8 inches, but it has a bottle neck down to 6 inches where the internal 'pipe' will attach. What cross section should I make the horizontals if I use brick instead of pipe?

How long can I make the horizontal lengths if the above dimensions are taken into account?

The chimney itself will be at least 25 foot taller the height of the rocket stove.

I have the most recent book on my Christmas wish list.

You do not have to use pipe 6" or 8"  A tunnel of any size can be built using soft red brick. Just smooth the inside with clay for easy flow of the hot air.

Now this makes it much easier. I have a need to recycle as much of the renovation/ build materials as I can, as I have no real way to dispose of it easily. So two walls full of soft red bricks and even more of the clay being used up is a bonus.
Neat clay or should it have a portion of sand?

My guess for this to work is that the clay would have to be smeared as the tunnel was being built (arm up the hole) or you would get a flat topped tunnel?

Is it as safe reference gasses leaking as a metal pipe would be?

Would you 'mortar' with clay between the bricks or lay them dry?

Thanks everyone so far for answering.

When you say air space underneath, is the airspace open to the room like vent ducts or sealed with stone and cob around the edges?

The climate is inland continental European. Hot long summers, cold but short winters (minus 18C to minus 26C). At the moment, being the beginning of October it's 20C to 28C in the day time but evening times needs jumpers or a fire lit for a short while as it drops to low teens centigrade. It's been known to be high teens to low twenties into November. Spring starts late February early March. I won't be here this winter, so I can carry on looking for bigger pipe. Though the standard wood burner exhaust pipe is the 6 inch size.

I assume that the cob mass will still be effective though I won't get the additional effect of the floor becoming part of the mass?

Thanks for that. I'm doing the build in Europe and the largest exhaust pipe I can find is 6 inches. How much will this size reduce the length I can have?

On the other hand I'm lucky that house I'm renovating has old, 60+ year old, soft bricks in the walls I am knocking down and theres a 50 cubic metre hill of clay on what will be my lawn, when I find uses for the clay.

My second question of the day.  

What is the maxium length of the exhaust on the horizontal before going up the house chimney? The plan is for the exhaust to run horizontally for 24 feet, then do a horizontal 'U' bend under my bed to then horizontal again for another fifteen feet before hitting the vertical. There will be a clean out at the usual places, plus one at the base of the vertical to use as a chimney warmer when needed. The vertical will be two storey and a tall attic with another few feet above roof line. Is this too much? All pipework will be inside the house (central chimney stack). Our house will be upsidedown, bedrooms and bathroom downstairs, living and office space upstairs (mainly because the view from upstairs is excellent and wasted if only seen when we are in bed).

Thanks.

Hello all, I've been a member for some time, but not active. I have the Ianto Evans and Leslie Jackson book for reference.
I will be building two or maybe three rocket stoves in this upcoming year and need some clarity of certain aspects for my main house one.

Can someone please clarify what the temperature is likely to be directly under the combustion chamber and barrel and for how deep this temperature is likely to go in a stone Rocket Mass Heater base sitting on a concrete slab of between six inches and nine inches thick (my spirit level was wonky at the earlier stages of construction so the slab went down at varying thicknesses). The slab is sitting on four inches of polystyrene which is on plastic Damp Proof Course on top of sixteen inches of sand/ gravel and broken stone. There is also underfloor heating pipes in the concrete slab at a depth of four to six inches (just in case the rocket stove isn't suitable for our needs- my disabled hubby may need an easier to use system in the future). I'm a belt and braces girl.

My initial design had the rocket stove in a certain position so I designed the underfloor heating pipes to not be directly under the stove, but, the actual placement of walls has shown that I really could do with the Rocket Mass Heater in a different position where there will be some pipes underneath it. If the temperature directly under the combustion stove and the barrel isn't high enough to melt the plastic pipe I would like to go with the new position.


Thanks for any help.

 

Thanks for the reply and links.
I can understand the BOOMSQUISH aspect. Years ago my ex-husband plumbed in a multifuel back boiler for radiators and hot water, but didn't put in a relief valve. Nearly every night, midwinter, after he had banked the fire, we would be woken by the pipes banging and the cylinder 'growling' to itself. The only thing we could do was get up and run half a bath of hot water to force cold water into the system.

Those links will be great. As for the DVD's, at the moment they are well out of my price range, but closer to the time, they will be budgetted for.

Thanks.

I am no where near construction stage yet, but I was wondering about the possibility of having the more normal skinny pipe wet underfloor heating system with a separate pump added to the rocket stove mass heater?

Basically I'm thinking that the whole house could be set up with the mirco bore pipes under the floors, with the usual pump and switch, but have the pipe wrapped around the stove or passed through the mass somewhere to pick up its heat from there?

The downsides I can see are, you wouldn't be able to have the pump on a timer as there would be no knowing when you would be using the stove. You could only have the underfloor heating when the stove was lit, and/or there was heat in the thermal mass. The underfloor heating system would cool down the thermal mass faster than it would normally cool down. Without experimentation there is no knowing how far away from the high heat of the rocket stove itself the micro pipes would have to be, so they didn't get too hot (no one wants to walk on a floor that can burn feet).

The upside I can see is that on chilly evenings you could light the rocket stove and have the underfloor heating on all night and wake to a whole house warmth the next day, before you top up the heat again.

I'm sorry if this has been asked before, if so can you link me to the relevant thread.

Thank you.
Julie