positioning of extractor fan in bathroom

[alexg]

i am building an ensuite in a loft room which will place it up in the eves...

the vertical walls to each side of the bathroom will be approx 800mm high, before turning up at an angle to meet at the top.

i want to place the extractor so the ducting can flow through to the sofet and therefore be hidden... in order to do this, the extractor head would need to be adjacent to the bath (which I guess is a good thing), well away from the door (again, a good thing), but mounted no higher than 800mm in the vertical section of the wall...

are there any building regs to prevent me from positioning the vent so low in a wall?

thanks

 

[nozspark]

As you live in England then this work is notifyable under Part P of the building regulations and therefore must be done by a competent person (not necessarily registered)..

Do you really want to be taking risks with the lives of the people who are going to be using this bathroom???

 

[alexg]

As you live in England then this work is notifyable under Part P of the building regulations and therefore must be done by a competent person (not necessarily registered)..

Do you really want to be taking risks with the lives of the people who are going to be using this bathroom???

i'm not doing any of the work myself,,, my builder is doing it and all electrics will be signed off by an electrician at the end,,, i'm not into risk taking,,, just trying to work out what is possible and what is not.

thanks

 

[nozspark]

OK...

Personally I would let them design the installation, but let them know your requirements.. Sometimes you will get a "Can't do that" response. It's not that they are being funny with you, it'll just be that it's against the regs or not to a standard that they will be happy to carry out.

OPTIONS

1. It sounds like you are going to need a SELV (12v) extractor fan - the regs don't require them any more, but I wouldn't be happy with a 230v one that close to my bath (even if it's RCD protected - which it should be anyhow)!!

2. Is there anyway you could mount the fan on an external wall (i.e. gable end)??

3. Could you put the fan on the ceiling and either go out through a ridge or tile vent??

 

[alexg]

OK...

Personally I would let them design the installation, but let them know your requirements.. Sometimes you will get a "Can't do that" response. It's not that they are being funny with you, it'll just be that it's against the regs or not to a standard that they will be happy to carry out.

OPTIONS

1. It sounds like you are going to need a SELV (12v) extractor fan - the regs don't require them any more, but I wouldn't be happy with a 230v one that close to my bath (even if it's RCD protected - which it should be anyhow)!!

2. Is there anyway you could mount the fan on an external wall (i.e. gable end)??

3. Could you put the fan on the ceiling and either go out through a ridge or tile vent??

Option 1. of using a 12v fan makes sense, but Option 3. of using a tile vent might also do the trick... i might look into that one now...

thanks

 

[JohnD]

steam rises so put it as high as you can, and the far side of the bath or shower from the door.

Use a hose to take the steam away from this position to your vent.

 

[pbar]

With tile vents, in a lot of cases you can get a replica of your existing tiles, either from the manufacturer, or a general one. Then it's just a case of taking a tile off and replacing with the vented one.
You can also get a Lapvent, which is like a vented tile in that it vents out through the roof, but you do all the fitting from the inside, so no need to mess with tiles.

 

[alexg]

if i go down the route of sticking the fan through the wall at the gable end of the house, it will mean that the fan is at the highest position in the room (which i presume is a good thing), but is directly above the bath...

does this mean that I have to use a 12v fan as it will be classed as zone 1?

thanks

 

[JohnD]

yes and that might be the simplest fit. however you can also get duct fans which need not be on the bathroom wall, they can be anywhere along the duct (so can be well away from splashing risks)

the 12v fans do not seem very powerful to me.

IMO it is better not to put the fan directly above the bath or shower if you can avoid it, as this gives more options for type of fan

 

[nozspark]

Personally I don't find a difference in the power (l/sec) of a 12v or 230v fan and infact on the Greenwood site all their AXS100 range have the same extract rate whatever the voltage...

Just remember that if you use an inline extractor fan then you must be able to access the fan

 

[GaryMo]

does this mean that I have to use a 12v fan as it will be classed as zone 1?

thanks

An IPx4 (most are) 230v fan with 30mA RCD protection is fine for zone 1.

 

[alexg]

Here is a diagram of the bathroom looking back towards the gable end wall.

Untitled

• alexg
• 31 Oct 2008
• 1

The sink will be on the right facing up against the internal vertical wall.

The approx dimensions can be gauged by the doorframe (room approx 3m wide with 1m verticals to each side)

So I guess the question will be... location A, B, or C for the extractor vent?

Thanks

 

[JohnD]

location "A" certainly looks the best place for it, and I can't see any scope for trunking or duct (unless you were to put a mini flat ceiling in the apex of the roof. If you had room for it this would also be a good place to put your lighting too.)

 

[alexg]

well i'm going for position A...

I bought an 100mm Expelair 230vAC timer extractor from Screwfix today... it's IPX5 rated which I believe is good for Zone 1 (ie. above the bath).

Now I just need to sort out an RCD switch... might just leave that one to the electrician to specify...

cheers for the help

 

[hairyben]

Flat 4x2" duct between the roof trusses, down to the void then out the soffit?

Could either mount a surface fan near the top on the angle, or ideally use an inline fan concealed but accessible in the void- this would be quieter.