Backdraft shutter

[Tim Lamb]

Our cooker extract allows in cold drafts in windy weather.

Anyone care to venture opinion/experience of the *in line* gravity type?

[T i m]

<snip>

Problems with the soup powder blowing about Tim? ;-)

Cheers, T i m

[Steve Walker]

They do the job, but suffer from clunking as air pressure changes with passing gusts. If you don't mind the odd clunk, then they're okay.

[The Natural Philosopher]

they clatter in high wind

But they sorta work to stop air coming IN

[Chris Hogg]

+1 I installed one in the extractor fan duct from our shower room that had no window; the duct had previously allowed quite a lot of draft making the room quite chilly, not something you want in a shower room. But as SW says, it does make little clicky noises as the flap opens and closes in the 'breeze'.

[Tim Lamb]

In message [e-mail], Chris Hogg [e-mail] writes

Thanks all.

Hmm.. Rather as I suspected. Although in a valley, our house is very exposed to SW winds. I keep meaning to try attaching plastic/rubber strips to the external shutters to stop them clattering but thought I ought to explore alternatives first. The cooker extract draws complaints so is first on the list for action:-)

Next question.. what about powered flaps? Do they exist as an optional fitting? Looping the fan supply to some sort of actuator within the extractor housing might not invoke part P!

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[Steve Walker]

The term you need is "motorised damper".

[Mike Clarke]

BTDTWTTS. I stuck some 'D' section rubber draft excluder strip to the back of the bottom of each strip. It reduced the clattering noise but didn't eliminate it.

[Brian Gaff (Sofa]

Also special cowls on the outside can help, I've noticed several types when I could see but don't know what is actually inside it. Brian

[Tim Lamb]

Snip

Ah! Thanks. Don't quite fit the modest cost target:-(

I have seen mention of *thermally operated* which hinted at the wax expansion/contraction model. Nothing so far on a *Duck.. duck* search:-)

I'll look again tonight. Today is mix/pour the concrete and fit the holding down bolts for a barn re-roof!

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[The Natural Philosopher]

I have one of those built into the actual fan

[The Natural Philosopher]

how about this?

[Tim Lamb]

Ah. Thermo actuator! That's the kiddy. Thanks.

Big price range in there. Tempting to replace the main bathroom one as an experiment.

Doesn't solve the kitchen problem as that is an unshuttered vent from a hob extractor. Outlet vertical (chalet bungalow) in the soffit so the gravity type problematic. I may try moving it along a bit to create a horizontal run of pipe.