Chimney dampers

[Hitch]

Might have some chimney dampers to make at some point in the near future.

Customer basically want two flaps that hinge in the middle, alowing the flue to be opened of closed, operated by a chain. of some other metod.


They are quite a big fireplaces, and all very old stone inside the flues. big one is about 1800mm x 500mm
Anyone done this sort of job before? Or got any thoughts on mechanisms?

This sort of thing-

 

[rusty69bus]

http://www.woodlanddirect.com/Chimn...d799a04212ae67f76c0a225873.e3eTaxiPc3mTe3aTe0
for insurpration

 

[rusty69bus]

or better
http://www.chimneydamper.com/index.htm

 

[rtbcomp]

Do they move together or independently? I can see a problem with soot or other debris getting trapped in the 'V'. Would they be better the other way up?

 

[Hitch]

Do they move together or independently? I can see a problem with soot or other debris getting trapped in the 'V'. Would they be better the other way up?

I thought about that, that would mean having to get the frame further up the chimney. And they would have to open right onto each other so it didnt restrict the smoke...

They will probably only be opperated a couple of time a year.

 

[Robotstar5]

Would an updraught rattle them in the closed position, how bout hinging down and pulling closed with chain / wire, updraught would just push them against seal.

 

[Hitch]

The other option, of course is a single flap, one side up, one side down, like you would use in round duct work.

 

[Robotstar5]

The other option, of course is a single flap, one side up, one side down, like you would use in round duct work.

Would be easier to operate then with a quadrant on pivot point and rod / lever lower down.

 

[rtbcomp]

The other option, of course is a single flap, one side up, one side down, like you would use in round duct work.

Or if that still caused them to drop too low, have two plates hinged in the centre instead of at one end. Or even near one end so the longer bit moved upwards, but there was a gap for soot &c to fall down through.

 

[scarecrow]

I think you have a bit of a nightmare on your hands there the biggest problem will be soot falling on the flap and these can be pretty big chunks so if the flap only opens up you're going to have problems opening it you might need to put some sort of release so that it can be opened both ways for cleaning . I would shorten the flap as much as possible and use the blank end on the left to set up two pulley wheel with the chain coming down into that corner with just a hook to hold it

The nicest job I seen done on the old chimney like that was a large copper hood over a big square grate about the size of the small shopping trolley the hood was like an upside down funnell which came down to around a foot above the top of the grate the chimney might need to be lined for that but you will have a lot more heat which will make up for the cost of lining the chimney

 

[Drains]

The other option, of course is a single flap, one side up, one side down, like you would use in round duct work.

Or a double flap. as you have, but butterfly. No weight to lift then - you just have to turn them.
As you say, it's a big fireplace, so just one flap might be pushing it.

 

[Barking Mat]

why cant instead of two plates you just have one, pivoting in the middle, rectangular like, like a traditional baffle any soot or deposits just falling into the fire.