Chimney Balloon for woodburning stove

agentgonzo · 27 Jun 2013

You can poke health-and-safety holes in every situation. Growing up, our chimney had a thing installed in it (presumably when the house was built) where there was a lever you moved to block/unblock the chimney. It blocked drafts and you moved it before lighting the fire. We did this every time we had a fire over the course of 15 years and never once lit a fire forgetting to move the lever.

If chimney balloons were so dangerous that people died all the time when using them, surely the nanny-state that we live in would have banned them.

"You still want a balloon to stick up your chimney?"
Yes, I do. It will block drafts and make the house warmer when I the fire is not lit. I will remove it each and every time before lighting the fire.

I have many many knives in my kitchen, but I have never once stabbed myself in the face with them. Please do not assume that I am a moron who will die unless suitable supervised.

agentgonzo · 27 Jun 2013

Thank you to all that have been helpful so-far. Chimsock has a draght excluder that would be harder-wearing than a simple balloon - thanks!

Onetap · 27 Jun 2013

agentgonzo said:
You can poke health-and-safety holes in every situation.

Slightly OT. Someone (don't recall who) who was in the SOE in WW2 commented that shortly after they'd arrived in France, they had been petrified by things that should have been of no concern and unconcerned by things that should have caused them to run and hide. With experience, they learned to tell the difference.

The relevance to this is that Norcon seems well-informed about heating; he thinks a chimney balloon is not a good idea.

I know that the primary combustion generates a huge amount of carbon monoxide (CO) by pyrolysis, that the toxic (very) CO should be burned during the secondary combustion and that flue or fixed ventilation obstructions can stop both secondary combustion and the removal of combustion products. I think it is not a good idea. I would sooner cut my toe nails with a chainsaw.

agentgonzo said:
If chimney balloons were so dangerous that people died all the time when using them, surely the nanny-state that we live in would have banned them.

They haven't. Just don't volunteer to be the first. I think if you go back to your HETAS installer, he will probably be able to suggest a chimney fitting for such a problem as yours.

agentgonzo said:
I have many many knives in my kitchen, but I have never once stabbed myself in the face with them. Please do not assume that I am a moron who will die unless suitable supervised.

I haven't. I merely offer an opinion on a subject that I happen to know something about.

The best thing before sliced bread was sharpened knives.

agentgonzo · 27 Jun 2013

Onetap said:
I know that the primary combustion generates a huge amount of carbon monoxide (CO) by pyrolysis, that the toxic (very) CO should be burned during the secondary combustion and that flue or fixed ventilation

To the best of my knowledge, CO is generated when you have a deficiency of oxygen. This happens in stoves because the door is closed and you have restricted the airflow.

When you are lighting the fire, the door is open and so there is not this deficiency of oxygen. I would expect the level of CO to be generate at this time to be very low.

Onetap · 27 Jun 2013

agentgonzo said:
To the best of my knowledge, CO is generated when you have a deficiency of oxygen.

With all due respect, the best of your knowledge isn't very hot.

CO (and other combustible gases and volatile vapours) are generated during any solid fuel combustion. They should be mostly burned unless, as you say, you restrict the oxygen supply. The flames you see are a gas fire, in effect.

agentgonzo said:
This happens in stoves because the door is closed and you have restricted the airflow.

Or if you've obstructed the fixed ventilation, or stuck a balloon up your chimney; the combustion products can't rise up the chimney, no fresh air and oxygen enters the room through the ventilators, the oxygen in the room is depleted, products of incomplete combustion spill into the room.

agentgonzo said:
When you are lighting the fire, the door is open and so there is not this deficiency of oxygen. I would expect the level of CO to be generate at this time to be very low.

I would not.

Corgigrouch · 27 Jun 2013

agentgonzo said:
It doesn't matter whether I need a DEFRA exempt stove or not. I have one. I'm not about to install another stove.

I was attempting to build the larger picture before offering a solution but with an attitude like yours, I think that you can go an swivel..

Mike2007 · 30 Jun 2013

agentgonzo said:
I got a stove installed in my living room last year. It's a DEFRA-approved clean-burning stove, which means that you can't close it down completely. As a result when it's not in use (which is only 2-3 times a week or so - Central heating is fine and the fire is for fun only!), there is a small downdraft into the living room. It's not a major problem, but as I'm a bit of an efficiency freak, I'd like to stop this draft.

I've looked at chimney balloon, but most of them are large (to fit an entire chimney). The house doesn't have a chimney, so there is an external flue that goes up to the roof. The internal diameter is 5" (~150mm). Does anyone know of any chimney balloons for the purpose of putting in a flue-pipe that is easy to use and remove before each fire and put back the following day?

Thanks.

A 5" is too small to be run as an external (factory made) chimney, it needs to be 6" ID (8" ED). Even then there is probably going to be a poor pull in cold months. Replace with 6" twin wall and anti downdraft cowl.
Even better if you know a bricky get a chimney stack built. Don't stick things up your flue as a cheap but dodgy solution!

FiremanT · 1 Jul 2013

.

agentgonzo said:

When you are lighting the fire, the door is open and so there is not this deficiency of oxygen. I would expect the level of CO to be generate at this time to be very low.

Click to expand...

Click to expand...

Try explaining that to he families of a least 7 people that have died over the last 3 summers, from CO produced by barbecues, on which they had finished cooking, brought into tents and awnings, which by definition are not airtight.

And I am fairly sure that your old flap (damper) did not close off the flue, merely reduced the opening.

With sincere apologies and greatest respect to any such families who may read this and who may be offended or upset by this post

pns1953 · 4 Jul 2013

Without wishing to get involved with the debate about whether such things are safe / necessary, for an alternative to the 'balloon' approach how about something like this: http://www.chimneysheep.co.uk/

Quite a neat idea I thought - I've not tried one but probably will get one for my open fireplace for next winter. They do actually suggest that you shouldn't need such a thing for a wood-burner - but will also do custom sizes if you have the need.

tryitandsee · 6 Jul 2013

As I understood things regarding stoves is that they need ventilation in order to stop 'rusting,' when not in use.
Moisture/condensation etc will sit on the metal parts and rust. especially the ash pan and metal collar where flue joins the stove.

My little MORSO recommends keeping the dampers open allowing moisture to keep away. However on really cold mornings when not in use it can produce a down draft causing the room to smell of soot

I'm not sure if I'm imagining it but I seem to think you used to have a lever on the verticle flue pipe that closed the pipe shut (like a sluice paddle valve). However, I probably saw that on some old French thing on holiday in remotest farm house somewhere

tryitandsee · 6 Jul 2013

I'm not imagining it here it is

www.gratefireplaceaccessories.co.uk...Damper/10468?gclid=CMj6jPPsm7gCFUTItAod2WwAUw

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Chimney Balloon for woodburning stove

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