Coal stoves & dampers

ianc1200

ianc1200

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I've had a rather nice cylindrical coal stove re-furbished - it's cast iron, and slightly larger than a Faversham stove. I'm going to install in my bawley yacht, and went to me local canal-boat chandlers today to get a flue pipe made up. I asked whether they could put a damper in at the base of the flue, & they said it was frowned upon because it's controlling the stove by restricting the flue, whereas controlling by the air inlets of the stove is much safer. This particular stove only has a flap for the ash at it's base, although I can see it is possible to leave this slightly open. Other friends have said a damper in the flue as a way of shutting down the fire is better. Any thoughts?
 
Restricting the flue could lead to fumes, containing carbon monoxide, leaking into the cabin!
 
Vic is absolutely correct, a real No-No!!
Further thought, I've seen a solid fuel stove with a pivoted air-inlet flap into the flue to reduce draught, say in windy conditions.
Could that be what was suggested by friends?
 
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ianc1200 said:
I've had a rather nice cylindrical coal stove re-furbished - it's cast iron, and slightly larger than a Faversham stove. I'm going to install in my bawley yacht, and went to me local canal-boat chandlers today to get a flue pipe made up. I asked whether they could put a damper in at the base of the flue, & they said it was frowned upon because it's controlling the stove by restricting the flue, whereas controlling by the air inlets of the stove is much safer. This particular stove only has a flap for the ash at it's base, although I can see it is possible to leave this slightly open. Other friends have said a damper in the flue as a way of shutting down the fire is better. Any thoughts?
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Hi! I do not see any difference between a wood/coal stove in a boat versus a house. We have had one in our house for 25 years and it has a built in damper, just like all the other household ones i have seen. Ours is located within the stove just before the flue exit and restricts and extends the route of the exhaust just before it exits into the flue pipe. It does not shut fully. It is essential to get maximum efficiency. With the damper open as the fire heats up we first start to restrict the air inlet valve at the base of the stove (ours os controlled by a bimetalic strip) and once a good fire is underway we close the damper. This results in the burn getting hotter but the fire and flames reducing somewhat and the fuel lasts longer. It is very impressive when you get the conditions right. Without the damper far more heat just goes up the chimney. And yes, we have a co alarm at home too.

Www.solocoastalsailing.co.uk
 
Plum said:
Hi! I do not see any difference between a wood/coal stove in a boat versus a house. We have had one in our house for 25 years and it has a built in damper, just like all the other household ones i have seen. Ours is located within the stove just before the flue exit and restricts and extends the route of the exhaust just before it exits into the flue pipe. It does not shut fully. It is essential to get maximum efficiency. With the damper open as the fire heats up we first start to restrict the air inlet valve at the base of the stove (ours os controlled by a bimetalic strip) and once a good fire is underway we close the damper. This results in the burn getting hotter but the fire and flames reducing somewhat and the fuel lasts longer. It is very impressive when you get the conditions right. Without the damper far more heat just goes up the chimney. And yes, we have a co alarm at home too.

Www.solocoastalsailing.co.uk
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Most houses have a lot more ventilation than most boats. And taller chimneys. And a great deal more volume.
 
ianc1200 said:
I've had a rather nice cylindrical coal stove re-furbished - it's cast iron, and slightly larger than a Faversham stove. I'm going to install in my bawley yacht, and went to me local canal-boat chandlers today to get a flue pipe made up. I asked whether they could put a damper in at the base of the flue, & they said it was frowned upon because it's controlling the stove by restricting the flue, whereas controlling by the air inlets of the stove is much safer. This particular stove only has a flap for the ash at it's base, although I can see it is possible to leave this slightly open. Other friends have said a damper in the flue as a way of shutting down the fire is better. Any thoughts?
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Modifying your chimney can be dangerous and worse still potentially fatal. I can not just not see it being worth the risk.
 
Dampers are smaller diameter than the flue on domestic stoves, even when fully closed the one's I've seen only close the outlet by 60%. However boats aren't houses, the flue on a boat will be very short and the draw up the flue/chimney will be much less than a domestic installation. Bear in mind that heat loss from the flue will also reduce the draw. I'm not conversant with boat installations but they might benefit from insulated/twin wall flue. I reckon the damper is probably a bad idea in short.
 
ianc1200 said:
I've had a rather nice cylindrical coal stove re-furbished - it's cast iron, and slightly larger than a Faversham stove. I'm going to install in my bawley yacht, and went to me local canal-boat chandlers today to get a flue pipe made up. I asked whether they could put a damper in at the base of the flue, & they said it was frowned upon because it's controlling the stove by restricting the flue, whereas controlling by the air inlets of the stove is much safer. This particular stove only has a flap for the ash at it's base, although I can see it is possible to leave this slightly open. Other friends have said a damper in the flue as a way of shutting down the fire is better. Any thoughts?
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Used to have a solid fuel stove/boiler (anthracite peas), which had a built in chimney 'damper'. This however, allowed air into the chimney just above the stove & acted more as a flow regulator when the wind at the top of the chimney gusted, eliminating sudden surges through the fuel bed. Sometimes a bit noisy when it flapped open/shut.
 
Well this is very interesting.

I had a boat with a coal stove and a damper in the flue for 28 years, and lived on board her through two English winters. I am still alive, and I have always recommended including a damper in the flue. To be precise, not the butterfly type but the slide type, which will not twiddle itself open in a gust and which cannot close the flue completely.

I can see that closing the flue completely will mean that carbon monoxide will find its way into the cabin, but that is an extreme case.

In my experience, the "draw" on a boat's flue can be very strong indeed, and one needs a means of moderating it.

For what it's worth, I favour the H type head.
 
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ianc1200 said:
I've had a rather nice cylindrical coal stove re-furbished - it's cast iron, and slightly larger than a Faversham stove. I'm going to install in my bawley yacht, and went to me local canal-boat chandlers today to get a flue pipe made up. I asked whether they could put a damper in at the base of the flue, & they said it was frowned upon because it's controlling the stove by restricting the flue, whereas controlling by the air inlets of the stove is much safer. This particular stove only has a flap for the ash at it's base, although I can see it is possible to leave this slightly open. Other friends have said a damper in the flue as a way of shutting down the fire is better. Any thoughts?
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If you have not already done so, you may like to read the guidelines for solid fuel stoves in boats covered in the Boat Safety Scheme for inland craft:-
https://www.boatsafetyscheme.org/stay-safe/solid-fuel-stoves/new-stove-new-chimney/
And the document that the BSS refers to at:
http://www.soliftec.com/Boat Stoves 1-page.pdf

Interestingly, there is no mention of the danger of dampers so i guess from all the responses you have had you must still be undecided.......

Www.solocoastalsailing.co.uk
 
FWIW I have a charcoal fuelled Dickenson stove. It has a damper, supplied as part of the chimney kit by the stove dealer. It’s useful when the draw is too strong. But a CO alarm is essential
 
Many thanks for all the replies. We have a digital CO detector, & am leaning towards having a damper & seeing if we get any reading (& not then using the damper if we do get a significant reading).
 
ianc1200 said:
Many thanks for all the replies. We have a digital CO detector, & am leaning towards having a damper & seeing if we get any reading (& not then using the damper if we do get a significant reading).
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Either fit the stove manufacturers chimney kit or a very accurate and professionally made copy.

Modification or departure from the manufacturers design could find you in the same position as the owner of mv Arniston!
 
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