Bathroom extractor fan installation

[Grenage]

Hi again,

I've been sorting out the loft, removing boards, replacing the upstairs lights, and laying loft insulation. It's horrible itchy work, so I don't really want to go up there again any time soon; a good time to do anything else I might need to get done. This leads to... an extractor fan in the bathroom.

I figured that a ceiling-mounted unit running off the lighting circuit was a good way to go. I'm not sure if it's going to be on a timer or humidity sensor yet, but my main issue is where to vent the air. I thought the soffits would be ideal, but they are far too narrow to take a 100mm vent - so I support I'm left with either the fascia above the soffits, or through the tiles.

I think the fascia is just PCV, but there might be some wood behind it. It's a dropped fascia, so getting to it from the inside is going to be a nightmare. Would a vent tile be the best way to go? I'd probably need to hire a roofer to install the tile.

My other concerns are draughts coming back through the vent and into the bathroom, so would I need a vent with flaps to only open against the force of outward extractor fan air? I assume one normally mounts the fans to a rafter, then makes sure the pipe angles downwards to the vent, to stop water ingress or condensation?

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Bit of a long one; sorry!

 

[foxhole]

Why not go thru the wall with wall vent?

 

[JohnD]

if you use a rectangular duct, or add a rectangular elbow to it, it may fit.

 

[Grenage]

Hi there, than you for your replies.

I find the wall fans a bit unsightly, that's my main reason. Cheers for the tip on the rectangular vents, I didn't know they existed, so I'll have a look around. Hopefully the fan will be powerful enough to stop the steam flying straight back into the soffit.

 

[JohnD]

http://www.screwfix.com/p/manrose-rectangular-flat-channel-1000mm/14118

http://www.screwfix.com/search.do?f...om=&priceTo=&priceFilterOn=&_requestid=284483

if you fit one of these ducted fans in the loft, you will find it quieter and more powerful than the ordinary wall extractors. Some are two-speed.

 

[Grenage]

Hi there,

Unfortunately that second link didn't work, but at least you've given me an idea of what I can look at. The soffit would be a bit of a bonus, as I can access it from the bathroom window.

Thanks again!

 

[JohnD]

I was looking at inline fans, for example http://www.screwfix.com/p/vent-axia-acm100t-in-line-extractor-fan/53730

there are several at different prices. The Vent-Axia currently seem to get better reviews than the Xpelair, though I thought they were usually comparable.

 

[foxhole]

Hi there, than you for your replies.

I find the wall fans a bit unsightly, that's my main reason. Cheers for the tip on the rectangular vents, I didn't know they existed, so I'll have a look around. Hopefully the fan will be powerful enough to stop the steam flying straight back into the soffit.

Often identical in appearance wwith ceiling unit.

 

[Grenage]

I guess so, although it's less obvious and quieter if it's out of the way.

Regarding the vents and the rectangular ducting (which looks like a viable option), something like the aforementioned elbow joint would work well with it:

http://www.screwfix.com/p/manrose-elbow-90-bend-100mm/96549

and

http://www.screwfix.com/p/manrose-r...m_mmc=AffiliateWindow-_-DeepLink-_-Na-_-58258

My only thoughts now are getting an exit vent that will fit the rectangular channel. Assuming I find one, what the chances of locating one with hinged flaps, to stop the wind screaming up and into the bathroom?

 

[foxhole]

If the fan is inline then it should have a non return flap built in, then you can use any type of vent which fits.

 

[Grenage]

That I did not know, good news. Hopefully it won't vent out and get blown straight back into the soffits!

Thank you kindly for setting me straight.

 

[Grenage]

Hi chaps,

Just to say thank you for your input; I've bought all the kit, and it should arrive this week. If I may ask one further question, Foxhole suggested mounting the in-line fan from the rafters with springs (in another thread). Would such springs be bungee cords, the kind used on roof racks etc?

 

[jj4091]

I can't see where he said that but I would say no, because they deteriorate with age. I think he probably meant compression springs between the base of the fan & whatever it is mounted to.

 

[Grenage]

Hi there; thank you for your reply.

I did wonder about the perishing over time; I can get hold of some long expansion springs which might do the job. It would be handy to suspend it, as it will be out of the way of all the insulation!

 

[JohnD]

my preference is to mount it on a thick piece of ply, padded with carpet or similar.