I have two 4" extractors, one in the kitchen, another in a bathroom. In windy weather both let a lot of draught in when not on. I got some plastic louvres from B&Q. which are designed to close when the fan is not blowing, but the wind just sucks them open and causes them to rattle. Basically they're far too flimsy.
Is there a better quality product - perhaps an electrically operated 4" vent?
The more up market models may have either a solenoid, or thermally operated flaps.
Many centrifugal (cf. axial) fans will have an inbuilt one way flaps as these are intended to be used on extraction systems serving multiple rooms.
Burlington Bertie submitted this idea :
Newey do a rather good one with the slow acting mechanical louvre. Basic cost is around £30, with a variety of control options such as timer, PIR and humidity controlled available at extra cost.
In message , Burlington Bertie writes
I've just installed a loo fan marked "ICON Airflow" which operates in the same was as the iris of a camera. The closure is in three sections and rotates in the same plane as the wall to clear the opening. I can't find it on google tho'
Keith submitted this idea :
That is the make/model I mentioned earlier as sold by Newey & E.
Try -
I recently came across a fan made by Manrose
This opened the louvre when the fan was switched on & closed it when the fan was off.
In this instance (after 12 years use) the mechanical link was broken. I e-mailed Manrose asking for price & availability of a new cover inc link and they sent one for free - good company.
On 13 Jan 2007 09:45:54 -0800 someone who may be "Burlington Bertie" wrote this:-
They have to be lightweight, otherwise they would provide too much resistance and restrict (partly or fully) the airflow.
The next best alternative is a hooded louvre, which has a hood over the louvres which prevents them flapping around so much as it prevents direct wind effects (though not pressure effects). Old versions of these had a single balanced pivoted flap, I see that one modern design has the more normal three flaps (no doubt they are reducing their manufacturing costs).
You might also consider a mushroom shaped terminal, if the problem is direct winds blowing in.
As others have said the better designed product is a fan with integral shutters. These can have any terminal placed on the outlet of the duct, even plain grilles (though make sure they keep the rain out).
|I have two 4" extractors, one in the kitchen, another in a bathroom. In |windy weather both let a lot of draught in when not on. I got some |plastic louvres from B&Q. which are designed to close when the fan is |not blowing, but the wind just sucks them open and causes them to |rattle. Basically they're far too flimsy. | |Is there a better quality product - perhaps an electrically operated 4" |vent?
I also will have much the same problem with my Cooker Hood extractor fan when I fit it. The house is *very* well insulated, and the kitchen area requires only about 500w from a towel rail so the new 5 kW Wok Burner, will cause massive overheat. The whole cooker can put about double that power into the kitchen.
I need a louvre/air outlet which is almost airtight when not in use.
Neweys are a rebagded something at a better price. Any idea who made the fan?
Cheers
Adam
Many thanks - plenty to go on there.
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