100mm In-line Extractor Fan Vent Back Draught Shutter With One Spring And Two Flaps

Works fine. Ignore the comments about the spring being too weak. It’s not supposed to close on its own. It opens fully when the fan is on and partially closes when the fan turns off. It then closes fully if there is a draught. This is how it’s designed to work. It’s fitted with foam on the back of the flaps to stop them rattling which seems to work fine too.

well it works. kind of. it does help to stop the freezing cold wind blowing through my ceiling vent over my shower cubicle. a lot actually, compared to not having one at all. noise wise, its ok. not silent, when the wind is blowing strongly you can hear it rattling. another buyer gave feedback and recommended putting some thin foam under the flaps... i may try that later. fitting was and still is a nightmare. it is supposed to be compatible or at least work with manrose fittings. that is not true. at all. the device does have a slightly larger opening on one end, above the flaps, which you would assume allows it to push fit onto the electric motor housing (the fan), but it doesn't. its close, but not quite. it needs about another 1mm to fit comfortably. i ended up warming it up with a hair dryer and forcing it onto the housing. a liberal application of "gaffer-tape" and that thing is NEVER coming off. the flexi hose is held on with a zip tie... normally. again, the "gaffer-tape" fixes that issue, lovely.so after a few weeks of use, would i recommend it?strangely, yes.but be prepared to use a bit of ingenuity to get it to fit. Of course, you can just cut the flexihose and and just shimmy it into place with zip-ties. but where's the fun in that?

Good value and works as expected

We bought this to stop our new extractor fan whistling. Now fitted the whistle has stopped. However we now have this flapping. Not great. But better than the previous noise.

Lightweight twin flap single spring unit. Plastic appears a little flimsy and the spring doesn’t appear to be adequate. However fitted in line between new fan and flexi pipe. Simple use of gaffer tape. Flap appears to work well so all in all a good product.

The two flaps designed to return to closed by gravity assisted by a resistance spring to stop opening too wide ….like butterfly wings. Spring is too weak and one flap ends up falling on top of the other.Tried removing and refitting spring the other way round.No difference.

Simple to install and works very well.

Put this item in to stop back draft, was sceptical of product after reading reviews. Have to say the rebate allowed snug fit into extractor fan unit which I fixed in place with some duct tape and resecured vent duct with tape.So far seems to be working fine.

L'articolo è una serranda di sovrappressione, cioè quando la pressione esterna supera quella interna le alette si chiudono.Questo modello leggero è idoneo, ed è venduto, per canalizzazioni di ventilazione (estrazioni bagni) dove per effetto del Principio di Pascal (Il principio di Pascal o legge di Pascal è una legge della fisica dei fluidi che stabilisce che quando avviene un aumento nella pressione in un punto di un fluido confinato, tale aumento viene trasmesso anche ad ogni punto del contenitore.Wikipedia) se in punto si attua un'estrazione (a esempio al piano di sotto) l'aria estratta non andrà solamente alla testa di camino, ma tenderà a entrare in ogni altro vuoto disponibile (a esempio nel bagno del piano di sopra), con questo economico oggetto il problema è superato.Il diametro si adatta perfettamente alle canalizzazioni da 100 mm.