Noisy inbuilt backdraught shutter

[johnm6543]

Dear All

First post so apologies if this has already been answered or I've raised it in the wrong place.

I've just replaced my ensuite extractor fan and ducting - run is 5 mtrs - due to the previous vent hose being full of water! I've fitted a Manrose CF100T due to it's ability to move the air over the 5 mtrs, which I assume the previous one couldn't. It had also only been vented in to the soffit area, so I've fitted a standard grille vent to the soffit and connected the new ducting to it. All good to start with.

However, I've now found the the inbuilt backdraught shutter in the fan clatters about in the wind, which comes flying up the nice new non watery ducting. Can anyone suggest a way of making the shutters fit more tightly, so as they dont move about so much?

Thanks

John

 

[ricicle]

Did you fit insulated ducting and/or make sure the ducting runs downwards towards the vent ?

 

[SaladFingers]

They do that. When there's the fan is not running and there is no air flow, a draught of wind will make them clatter. Any attempts to restrict their movement may make their ability to become somewhat restriced to open with intended air flow.

Edit: just realized you're backdraught is fitted inside, not outside, though some may apply.

 

[Scoby_Beasley]

I'm assuming your ducting has to go "up" into the loft area to come "down" through the soffit? As ricicle has said ducting should run down for its length, ideally, to let the water run out of the external vent.

We once had a noisy, when off, extractor. I made a stand off baffle to block the wind, which usually came from the same direction when the fan "clattered". Problem solved!!

 

[johnm6543]

Thanks for the replies.

The ducting only goes up at the point where it enters the loft and then travels flush with the joists and down at the soffit. I'm getting loft insulation done tomorrow and the duct will then be insulated and under boards, so hopefully that will stop any water build up. The previous duct had been run on top of the boards - not insulated - and did go up and down a wee bit as I remember.

With regards to the shutter, I suppose the solution is to restrict the amount of air getting in to the ducting from outside. Some sort of shutter on the vent grille - similar to kitchen wall fans which have a shutter open/close cover - would be good.....

 

[Scoby_Beasley]

You should really take the duct up as quick as possible then a gradual slope down. Long cable ties (looped together??) to the roof trusses can achieve this. The steam will condense rapidly whatever you do as hopefully your bathroom is a hell of a lot warmer than your loft space.

You can buy cowls to fit over the external fan vent. Just need to find out which way the wind blows when the back draft vanes clatter and fit accordingly.

 

[johnm6543]

Thanks again. I will slant it down a bit and at least I know that any water will go out the vent now rather than spill on to the soffit.

Got fed up with the noise and took the shutters out the fan. No clattering now but a bit too much wind and noise from the road ect coming through the duct. I've had a look at things like the Icon 15 and the vent axia VA 100 - both had shutters on the front - but because of the 5 mtr run I need a centrifugal fan. Any 100 mm mechanical shuttered centrifugal fans out there?