Hi

Just finished a small attic build and have 6" intake from bathroom ceiling as loft gets very hot in summer/cold winter so looking for stable air intake.

I have the 6" fan on a variac and have reduced it to 60% but the noise in bathroom is very noticeable.

It is not fan noise but the 'whoosh' movement of air.

Anyway to reduce this ??

Cheers

filter on the end of the intake is the only realistic option, that will silence it completely

Build a baffle box. It will make your fan less efficent, but it does help muffle that 'woosh'..

hi stealth, how do you make one of those?

Ah come on, it not rocket science.

Fit a box at midway point on your intake ducting.

Build the box out of 1/2 inch ply and baton, marine ply would be good.

Cut 2x staggered 6 inch holes either side of the box.

Fit the ducting into the box and tape around the holes.

Make sure the box is air tight.

The picture says it all really mate

Build a small box - cut some holes for the ducting - gaffer tape it all up and shabang

Also - the bigger the box, the less the 'woosh'.

Never seen that before peeps, will give it a go tomorrow. Was also toying with the idea of poking holes in the ducting so some of the sir will be drawn from loft and majority from bathroom ?

Baffle makes sense though, might just gaffer up a big cardboard box

Cheers

dont forget to report back.

larger/oversized ducting helps reduce air speed, and thus noise also, go a couple of sizes bigger at least

I fucking like that fella iv thought of loads of way over the years but not that one
top idea mucka

it's all down to the speed of the air. so if you build a box with a massive intake hole, the air going into it'll be travelling slowly, and the noise at the mouth of the ducting wont be heard, because it's inside the box. you'd need to have the ducting that would be open to air, much larger than the ducting on the fan side though, otherwise the air will have to move at exactly the same speed as the on the fan side, and you'll still get a wooshing noise at the mouth

Makes sense scraglor, no point in having same in/out of box imo. Will see if i can get 10" grille and only need 1 metre of ducting. Do they sell it by the m ?

Or i may just leave the ducting in loft and get the intake as near as possible to the 6" hole without any noise, it will no doubt still draw the majority of air through there

Will let you knoe how i get on.

Cheers