In message , The Natural Philosopher
writes
On 13/03/2021 14:43, Tim Lamb wrote:
In message , Steve Walker
writes
On 13/03/2021 09:31, Tim Lamb wrote:
Snip
On Fri, 12 Mar 2021 22:27:06 +0000, Steve Walker
wrote:


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!

The term you need is "motorised damper".
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!



how about this?

https://www.cef.co.uk/catalogue/cate...to-shutter-fan

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.



--
Tim Lamb