Inline Fan Vent

[mikkymo]

I've just noticed that the inline fan in my bathroom is venting straight into the attic... which would explain the dampness up there. It's also been piped in corrugated duct which was holidng about 500mm of water. Going to repipe it in solid duct and insulate it.

Can I put my exhaust vent in the soffit? The closest position I can put the vent in places it right over the middle of the opening bathroom window - is this a no-no?

I can run the exhaust duct a further 800mm to clear the window, but I figure the shorter the run the better?

 

[mikkymo]

Also, the existing in-line fan has its inlet vent right over the bath - is this ok?

 

[David937]

It shouldn't be a problem if you don't intend on keeping the window open when the fan is in use. Also, if there is a trickle vent, I would keep this closed. You need to replace the air the fan extracts - the usual way to do this is by a gap under the door.

When I did something similar a couple of years ago, I vented the fan through the roof using a replacement tile made specially for the purpose because it was too difficult to reach the soffit. Might be another option for you to consider?

Shorter is definitely better and minimise the use of bends. The fan should be at the highest point in the system to avoid any possibility of water getting into the fan.

 

[mikkymo]

From reading up online, having the inlet vent over the bath is fine as the fan itself is outside of the 'Zone' requirements (i.e. IP ratings) so that's ok.

Looked at the roof vents and they look like a great job, but I'm always wary of putting holes in the roof, especially since the pitch isn't very high on our bungalow. I ended up running the duct a little further so the soffit vent isn't in front of the window.

The only issue is that the fan is louder than it was. The added restriction of the extra duct and the soffit vent has increased the sound quite a bit. No problems with vibration - just the whoosh of the air.

Any ideas how to quieten it down? Quick google search of reducing the sound from an in-line fan gives me 2 pages of cannabis growers asking for advice on how to hide their grow boxes from the Rozzers... lol!

 

[David937]

I ended up running the duct a little further so the soffit vent isn't in front of the window.

The only issue is that the fan is louder than it was. The added restriction of the extra duct and the soffit vent has increased the sound quite a bit. No problems with vibration - just the whoosh of the air.

Any ideas how to quieten it down? Quick google search of reducing the sound from an in-line fan gives me 2 pages of cannabis growers asking for advice on how to hide their grow boxes from the Rozzers... lol!

Did you use circular duct? As you say, the noise is caused by the resistance. Apart from changing the grilles to something with less resistance or increasing the size of the ductwork (to lower the noise level), there isn't a whole lot you can do. What fan is it? I had a Vent Axia ACM100 with about 2m of flexible duct on each side and even with the restrictive roof vent and flexi duct, you could barely hear it from the bathroom. Some of the less powerful fans aren't man enough to cope with long lengths of duct.