Bathroom extractor and cooker hood on same duct?

[chrisevans1001]

Hi there,
The builders installed our bathroom extractor and cooker hood into the same duct. This is causing problems with mainly kitchen cooking smells going into the bathroom instead of outside!

I'm trying to find a solution but most people are commenting it is better to have two ducts for two fans. I'd love to do this as a simple method but it will not work as there simply isn't any room to run another.

The ducting is also horizontal running along the back wall and out of the property. I bought a backdraught shutter for the bathroom fan (where the duct starts) but it seems it was more designed for vertical operation as the shutters just remain open.

Any suggestions?

Thanks,

Chris

 

[Taylortwocities]

You need backdraft shutters in both duct runs.

Untitled

• Taylortwocities
• 27 Feb 2015
• 2

Most backdraft flaps are designed for horizontal fitting, so not sure why you have a problem.
http://www.tlc-direct.co.uk/Products/BG4BS.html

 

[chrisevans1001]

I discovered I had it the wrong way around! That's why I had the problem. :-p

However, I can't have backdraught fittings on both as the cooker hood immediately connects to the main run. There is no space for one. I tried the backdraught fitting just in front of the fan before the main run and it worked fine... except the kitchen fan is so powerful it forces a lot of air out of the small gaps in the joints for the flaps.

 

[JohnW2]

However, I can't have backdraught fittings on both as the cooker hood immediately connects to the main run. There is no space for one.

I would not have thought that was a problem in terms of your main issue. A backdraft shutter in the feed from the hood fan would obvioulsy not stop kitchen smells getting to the bathroom.

I tried the backdraught fitting just in front of the fan before the main run and it worked fine... except the kitchen fan is so powerful it forces a lot of air out of the small gaps in the joints for the flaps.

If you're say that the hood fan is still managing to push some kitchen smells past the shutter into the bathroom, does it not have a lower 'fan power setting' you could use?

Kind Regards, John

 

[chrisevans1001]

Sadly not. I tried all 4 settings, even the lowest setting blows a considerable amount out to outside and into the bathroom (even with the backdraught shutters closed... which works relatively well but a lot of air gets past none the less).

 

[JohnW2]

Sadly not. I tried all 4 settings, even the lowest setting blows a considerable amount out to outside and into the bathroom (even with the backdraught shutters closed... which works relatively well but a lot of air gets past none the less).

Fair enough. If there's space, and if it doesn't restrict flow from the bathroom too much (it shouldn't), you could try putting two backdraft shutters 'in series' in the feed from the bathroom. If that could be done, it ought to further reduce the amount of air being forced into the bathroom by the hood fan.

Kind Regards, John

 

[jj4091]

Have you broken into the main run with a T or a Y? Perhaps a Y might help along with your shutter.

 

[chrisevans1001]

It joins the main run with a T from the cooker hood. I thought a Y would be beneficial but the ducting is flat and I can't seem to find a Y type of that?

 

[jj4091]

Is this one the wrong size http://midselec.co.uk/polyvent-300-y-piece.html?gclid=CIa337i_gMYCFS2WtAodRDQA2A

 

[Iggifer]

I suppose at least it's not bathroom smells getting into the kitchen! That would be waaaaaay worse