Shower extractor fans

[NiceCupOfTea]

We have a problem with our bathroom always being damp, even with the extractor fan on all the time and the window open. I have cleaned up all the mould and I'm painting with bathroom anti-mould paint, but want to beef up the fan. It's a 10 year old Wickes 4" inline extractor fan (20w). It's grubby but not blocked as far as I can see, but I was wondering if I could get something more beefy. A quick look at Screwfix and they're all 20w too, and there doesn't seem to be any point spending 30 quid on something the same.

Any suggestions?

[NiceCupOfTea]

Hmmm, good old TLC direct seem to have come to the rescue:

http://www.tlc-direct.co.uk/Products/SLTD160.html

Looks ideal (also one with a timer) but wants 3 core and earth (presumably for the 2 speed settings, although the timer version seems only to have one speed).

Presumably I could just hook up LA, N, & E from the old fan and it would run at full speed?

Installation intructions here:

http://www.tlc-direct.co.uk/Technical/Ventilation/...

Thanks in advance!

[anonymous-user]

Kill off the old mould first, it'll come back through even with mould inhibiting paint.

[swindler]

Get a 6" fan (with shutters) and set it to run longer after the light has gone out.

[Spudler]

Vent-Axia VASF 100T.
Extreamly quiet too.

[NiceCupOfTea]

Spudler said:

Vent-Axia VASF 100T.
Extreamly quiet too.

Says 21 l/sec which is 75 m3/hour. The one above does 160 m3/hour!

I don't want to make holes in the wall either - plug and play inline fan. I've cleaned as much mould off as I can.

[hairyben]

The problem is your old fan will in all likelyhood be an axial impeller design, which are next to useless at moving air any more than a couple of feet and use of flexiduct further stunts them further. It's a scandle they're evan sold with flexiduct as kits!

What you need is a centrifugal blade design that creates higher pressure, screwfix flog a manrose one for about £50 which'll do the job just fine for a decent sized bathroom and sensible duct length.

[NiceCupOfTea]

hairyben said:

The problem is your old fan will in all likelyhood be an axial impeller design, which are next to useless at moving air any more than a couple of feet and use of flexiduct further stunts them further. It's a scandle they're evan sold with flexiduct as kits!

What you need is a centrifugal blade design that creates higher pressure, screwfix flog a manrose one for about £50 which'll do the job just fine for a decent sized bathroom and sensible duct length.

Like this?

http://www.tlc-direct.co.uk/Products/MRCFD200S.htm...

Is the one I posted above centrifugal? It doesn't say - just sayd "high pressure", and "does the work of 3-4 toilet fans". I just want the beefiest one to clear the steam quickly.

[caziques]

Stop the steam forming in the first place by enclosing the shower.

The more air extracted the more air is pulled under the door, the more steam.

Cured a bad case of mould in one of our bathrooms with the equivalent of a Showerdome.

showerdome.org.uk

[NiceCupOfTea]

Nice idea, but the shower is over the bath.

[hairyben]

NiceCupOfTea said:

Like this?

http://www.tlc-direct.co.uk/Products/MRCFD200S.htm...

Is the one I posted above centrifugal? It doesn't say - just sayd "high pressure", and "does the work of 3-4 toilet fans". I just want the beefiest one to clear the steam quickly.

thats the one, fitted loads of them and only complaint I've ever had is they thought it wasn't working because they couldn't hear it (I fit the fan fitted to roof rafters if poss rather than the bath ceiling/loft floor to avoid noise transmission)

You can get higher rated ones but I've only used them for super long runs or dual room extraction. You need to balance air extraction with the fact your paying to heat that air, and too powerfull may evan cause a draft, proper siting and type will be far more efficient than just bunging in a more powerfull one. If poss site the intake nozzle right over the shower, or close to the shower with the showering zone between the intake and the air source eg door.

Most extractors that I get asked to swap with more powerful ones because they "don't work" are normally the wrong type (as 1st post) or sited poorly (leaving the shower in a dead air spot where the airflow from door to fan misses it).

[NiceCupOfTea]

Cheers! The intake is right over the shower so no problem there. The route the pipe takes has a couple of kinks but not too bad.

Wondering if I can sort the wiring for the timer one - I assume I will need a permanent live as well as the switched. Would want to use the lightswitch as the trigger, but of course that is on a lighting ring and the fan is on the upstairs sockets so don't think that'll work. May stick with the switched one.

[hairyben]

NiceCupOfTea said:

Cheers! The intake is right over the shower so no problem there. The route the pipe takes has a couple of kinks but not too bad.

Wondering if I can sort the wiring for the timer one - I assume I will need a permanent live as well as the switched. Would want to use the lightswitch as the trigger, but of course that is on a lighting ring and the fan is on the upstairs sockets so don't think that'll work. May stick with the switched one.

Fans are normally wired using a 3 core & E from the rose/main lighting junction so you have L, trigger/switched L and N. Taking a feed from the sockets while not necessarily wrong smells like bodge so you'd want to be careful. You can put a switch in for the fan to operate it via the trigger so when you turn it off it'll overun but you're better off doing it properly.

[Jumpy Guy]

On a similar theme, I'd like to vent the air from the shower through the roof

i've heard of problems with condensate coming back down the ducting

anyone had any experience?

[hairyben]

Jumpy Guy said:

On a similar theme, I'd like to vent the air from the shower through the roof

i've heard of problems with condensate coming back down the ducting

anyone had any experience?

You need a condensate trap/drain in the duct.

[Jumpy Guy]

aha, like this?

http://www.tlc-direct.co.uk/Products/BGCT.html

and what is better as the outlet, removing a slate and using a vent type, or a pipe with a hat?

[5potTurbo]

OP: Sorry for the 'hijack', but I too have been wondering what's best for an extraction option - having a bathroom with no windows/external walls.

Jumpy Guy said:

aha, like this?

http://www.tlc-direct.co.uk/Products/BGCT.html

and what is better as the outlet, removing a slate and using a vent type, or a pipe with a hat?

Presumably the condensation trap needs another pipe running out of it to an external point for the water to run out, e.g. through the fascia?

I ask as I have a ceiling mounted Marley fan that needs replacing and I think I'd like to instal an inline fan instead - condensation running back down into the Marley unit has knackered them more than once!

So, can I wire the inline fan to a plug socket, which is in the attic and inturn is controlled by a switch from outside the bathroom door?

Thanks in advance!

[NiceCupOfTea]

hairyben said:

Fans are normally wired using a 3 core & E from the rose/main lighting junction so you have L, trigger/switched L and N. Taking a feed from the sockets while not necessarily wrong smells like bodge so you'd want to be careful. You can put a switch in for the fan to operate it via the trigger so when you turn it off it'll overun but you're better off doing it properly.

That makes sense!

Unfortunately, somebody has wired the fan separately - it seems to run from the same socket as the shower pump with a separate switch inline. The fan only has L & N to it. The bathroom has 4 GU10s (nasty cheap lampholders too) so there's no rose to get at all the cables. Tis tempting to isolate the cable to the fan and rewire it properly from the lighting ring as you say.

[herewego]

Is it possible the shower is being left to run with nobody under it?

[NiceCupOfTea]

Erm, no! Well, it's possible, but it's not happening!;)