Thread: Shed heating ornament

Originally Posted by shedhappens

The length some blokes go to stop their beer freezing

Not to mention their ar$%.

Dean

Originally Posted by shedhappens

The length some blokes go to stop their beer freezing

True... I fired it up the next day too, for a bit of warmth while I bottled the latest batch of home brew

I'll throw up one final pic with a coat of pot belly black... when I get around to it....

why a draft/damper in the bottom and one in the flue? Is there a reason other than to ...well why not

Originally Posted by eskimo

why a draft/damper in the bottom and one in the flue? Is there a reason other than to ...well why not

I have looked at a few factory built pot bellies and slow combustion heaters and they seem to have both. I'm no expert but I assume that the top one retains the heat in the stove and the bottom one controls the flow rate of air.

'Why not?' is a valid reason in itself. Another one is if there are more levers and other controls to play with, it looks better featured, and one scores highly with wankfactor based on the appearance and the apparent level of skill required to operate, especially to mesmerised and unknowing onlookers.

If you close off both dampers it starves the fire of air and the fire goes out quicker.

Originally Posted by Gerbilsquasher

I have looked at a few factory built pot bellies and slow combustion heaters and they seem to have both. I'm no expert but I assume that the top one retains the heat in the stove and the bottom one controls the flow rate of air.

'Why not?' is a valid reason in itself. Another one is if there are more levers and other controls to play with, it looks better featured, and one scores highly with wankfactor based on the appearance and the apparent level of skill required to operate, especially to mesmerised and unknowing onlookers.

You are pretty much on the money on both counts. I am sure there are many more controls that can be built in. Our kitchen stove has a vent that is sited after the oven and flue damper which lets air into the heated air flow going to the flue. This reduces the air flow from the firebox and allows the oven to cool down a bit. It also has a vent on both the ash door and the firebox door.

Dean

I did also toy with the idea of forced air induction (I am a petrolhead... does it show?) by running compressed air directly into the combustion chamber... um I meant stove... I do have a 3/8" BSP tap...

Perhaps a ring of 'air injectors', 8 in total, at 45 degrees apart. Maybe next time.

Originally Posted by Gerbilsquasher

I did also toy with the idea of forced air induction (I am a petrolhead... does it show?) by running compressed air directly into the combustion chamber... um I meant stove... I do have a 3/8" BSP tap...

Perhaps a ring of 'air injectors', 8 in total, at 45 degrees apart. Maybe next time.

May give you problems burning out later on would get the cast and the spacer ring to the semi oxidised state. can burn the a....se out of seamless steam pipe made into a crucible using 1/2 plate at bottom dont last long with a good shot of air through the glowing charcoal.I admire your idea though.,but all that hard work and quality workmanship would be a shame.seen the drums and flue red hot in the one the old garage in town here had.and how the soot used to rattle in the flue when it got baked and broke loose. John. a couple of ceiling fans if you got the height on low slow get you down to the ''wife beater'' [bluey singlet] in no time flat on a cold night.

I am no expert on forced air induction into slow combustion stoves and pot belly stoves but I would have to agree with j.ashburn with the faulty shift key lol. I have a faulty one myself but mine just does not type the letter at all unless I press it hard.

If you want to go that way you should line with fire bricks but they will also burn out faster.

I think the next step would be to feed the inlet air in via a ring which would give a more even burn. You also need a convoluted flow path for the smoke to exit, which would slow the flow. Some heat transfer fins on the lower part of the flue section with a fan to blow the heat out into the shed. You will also want some turbulance here to move the heat around inside the flue so it can be transferred to the fins.

One of the best looking stoves I have seen was a horizontal electric motor casing about the size of a 44 gallon, sorry 200 litre drum. Fins and all.

Dean

Nah, induced draught is the way to go. Negative firebox pressure means no smoke in the shed. That's a great thing.

Phil

No need for forced air. Leave the flue damper wide open. The flue, when heated, controls the draw. A secondary supply of air will naturally enter if catered for.I posted a pic of my heater earlier in the thread. Here is another from during the build which shows my primary and secondary inlets.

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The pipes that enter from the back of the fire box super heat and introduce the secondary air. A 6mm plate (heat shield/baffle) sits directly on top of the perforated sections of pipe. This forces the flame path forward before it detours around the 6mm plate and back again to the flue (below the stainless separator visible at the top portion of the barrel.The two pipes seen across the top outer barrel are the primary air source. This supply is separated from the flame path by another stainless separator that directs the air flow over the glass of the door. This is what keeps the glass clean. It then passes under the grate visible in the second pic to feed the fire from underneath.Both sources initiate from an outside intake. This ensures that I'm not have the air from the shed sucked through the heater and up the flue.

Attachment 273573

The outside supply pipe tail was not yet fitted when I took the pic.On top of the barrel I have what I call a manifold, bent out of stainless, to which I have a run of 5" gal duct mounted.

The duct then bends and terminates approx. 4m away from the heater. This gives excellent convectional draw and pumps out heated air 60 degrees or more (my shed thermometer maxes at 50).

Attachment 273586 Attachment 273574 Attachment 273575 Attachment 273576

The thermal mass of the 30 plus fire bricks inside the barrel ensures the heater retains a lot of heat long after the fire has died, and also offers excellent heat refraction during the burn for max efficiency.

Craig.