Bathroom Extractor Fan (No 2)

[MalcyB]

Hi all

Just wanted to see what your thoughts are on having two extractor fans running from the same 3A fuse?

6 months ago I Installed a 4" ceiling extractor fan, ducted via the outside soffit.

They now realise (even though at the time I told them it would not be man enough) that it is not clearing the bathroom of steam, and they keep getting mould appearing on the ceiling.

They have asked if I could install a good inline fan, but to also keep the existing ceiling fan and have them both running at the same time when the light is switched on.

The easiiest way to do it would be to take a new feed from the FCU onto a 2nd fan isolator then to the fan. 

I can't find anything in the regs to say this is a no no, what are your thoughts?

Thanks

Malc

 

[Essex]

There would be no point in keeping the old ceiling fan if it's not extracting.  A good inline fan would do the job and probably a lot quieter.

I would convince them to replace the fan as you would have to cut additional holes in the ceiling and soffit.

 

[MalcyB]

That's my thoughts really. I did say to them when I put the original in, that a bigger one woud be better. Not only that but we re wired the house a couple of years ago and asked them if they wanted an extractor fitting into the bathroom, they said no!

They want to keep both, they are going to do the cutting out of the new vent holes, ducting etc, they just want me to wire this new one in.

 

[D Skelton]

I have to recommend a Solar & Palau 6" silent in line fan. I spec these in both domestic and commercial situations for simple ventilation purposes. You could still vent out of the 4" soffit vent if you used a reducer. I'd also recommend your customer using some insulated ducting for added sound proofing. As long as your internal vent is fitted somewhere above or near the shower then the steam will be no more! These bad boys boast an extraction rate of 500m3/hr as opposed to the measly 80m3/hr you can expect from a bog standard 4" fan.

BTW, I don't work for S&P, I just can't recommend them enough!

 

[MalcyB]

The minimum I've told them to get is 250m3/Hr

 

[Manator]

As its existing adding any additional fan is really easy. However what most people do not understand is the relationship with extraction and heat recovery. I regularly use 12" and 9" fans depending on room dimensions, and still get complaints!

 

[Sidewinder]

Also, you need to remember that no matter how big your fan, unless the same volume of air can enter the room as you are sucking out, then the fan will not remove the volume you require.

It "could" be that there is a lack of make up air, rather than the fan not being powerful enough.

Chuck some calcs at it first to be sure before you spec up the replacement, save you getting egg on your face if it is a make up issue, because, if it is, fitting a larger additional  fan will not make the dramatic difference you are expecting.

I'll second the S&P recommendation though, not that I do much domestic, but, it is the one we have in our bathroom and it works well.

 

[Steve3948]

As above, most either leave the bathroom door wide open, or even open the window thinking that helps !!!!

 

[NozSpark]

Is it just an axial fan.... if so a centrifugal fan of the same size will almost double the extraction rate

 

[MalcyB]

They said that they have the window open as well as the fan, so it is draging air in as well. 

But, they want both fans going in tandem, so who am I to argue?

So I take it no one can see why it would be a problem to have both on the same FCU?

 

[Sidewinder]

I have no issues with them being on the same FCU as long as they fuse spec'd in the manufacturers instructions for both fans is met.

 

[NozSpark]

IMHO the window should be shut

 

[Evans Electric]

Lets keep it simple ....you need to fit a fan that will do the duty for that room  .  Work it out and advise based on that .     I've found the Punto in-line  fans from Denmans to be good  ...in the £50-60 bracket  I think.

The worst fans in the universe are those cheapo in-line things  about the size & shape of a tin of beans  , about as powerful as a wristwatch .    You don't say what you fitted.

To be doubley shure that you are correct in what you advise , measure the room and ask the ventilation rep at your suppliers to recommend .

Also as the Maneater says , I also get complaints that the fan is taking the heat out of the room ,  most people ask for the timer to be set on minimum because of the noise when I want to set it to maximum.    Its there house ...their condensation.

The answer to the losing heat problem is a heat recovery unit  at much more money.

Edit :   Oh yes  feed from same  spur  , not the biggest problem in the world but seperate isolators if you're having the two running ..which I think is a bad idea ...I think the original fan could affect the performance of the new one by dragging air away from it ,  but I know sod all about those things.

 

[SLIPSHOD & SLAPDASH]

Or, does the op mean 2 fans in the same duct ?

 

[Blue Duck]

Or, does the op mean 2 fans in the same duct ?

Hmmm..... 2 fans in 1 FCU okay.... 2 fans in same duct sounds like a bit of a headache why not jus get a decent extractor and explain to the customer how extractor fans work.....

The amount of council properties I go to and there is a ventaxia with h/stat in the bathroom and the walls are black with mould - It made so much noise and came on when ever it felt like it so we got cousin Derek to disconnect it!!! headbang

 

[SLIPSHOD & SLAPDASH]

Hmmm..... 2 fans in 1 FCU okay.... 2 fans in same duct sounds like a bit of a headache why not jus get a decent extractor and explain to the customer how extractor fans work.....

The amount of council properties I go to and there is a ventaxia with h/stat in the bathroom and the walls are black with mould - It made so much noise and came on when ever it felt like it so we got cousin Derek to disconnect it!!! headbang

Doing a job on your patch, Stamford hill common water main replacement.

 

[MalcyB]

Hi all

The new one would have its own ducting and I would put in seperate isolators.

The existing fan is a vent axia silhouette with timer. extraction rate 75 cubic Mts/Hr

The minimum I recomend are the manrose mixed flow inline fans, or similar, extraction rate 245 cubic Mts/Hr. Anything over that then better still.

I do like the look of that Solar & Palau fan.

I have just found out that the tenant is a retired architect so I would have thought he would know all about extractor fans?

 

[Steve3948]

Vent Axia ACM100T above my shower, you can feel the air passing over your body, never had steam or mildue issues

 

[davetheglitz]

Try the TLC website technical section - handy little flow rate calculator!

 

[batty]

Is this a massive bathroom if not a fan that does 500m3/hr  is well over the top.  Do they not have decent heating in the room if they don't condensation will always be a problem no matter what.