Bathroom Condensation Problem

[Gos1]

Hi. Recently fitted a Extractor Fan into my bathroom ceiling and run the vent outside.
After a few months it does not seem to be doing a good job of getting rid of all condensation/stream from a bath/shower
Now have condensation marks on the painted walls which look unsightly . I think i need to upgrade to a larger unit.
The room is 29 cubic metres?
Any suggestions on which model and size??
Thanks in advance

 

[jjpearce05]

http://www.tlc-direct.co.uk/Technical/Ventilation/Ventilation4.html

 

[Gos1]

Thanks, been there, but would like to know other suggestions to models etc, the ones lists seem very expensive

 

[Taylortwocities]

That's because most cheapo fans do not do a very good job!

You may also have other factors that make the fan not work too well:

Some quuestions-

What is the length of the run of duct?
What is the size of the duct?
Is there a good gap under or thru the bathroom door. The fan won't work well if the door fits too well - the fan will be trying to suck on a partial vacuum.
What is the length of time for the fan over-run?
What is the make & model of the existing fan?

 

[Gos1]

Hi and thanks Taylortwocities.
What is the length of the run of duct? - Approx 1.5m
What is the size of the duct? - 100mm
Is there a good gap under or thru the bathroom door. The fan won't work well if the door fits too well - the fan will be trying to suck on a partial vacuum. - pretty good, i'm no carpenter when i fitted the door
What is the length of time for the fan over-run? - No Over-run, just whilst lights are on, which with kids is 23/7 LOL
What is the make & model of the existing fan? Wickes!

 

[Taylortwocities]

No Over-run, just whilst lights are on, which with kids is 23/7 LOL
What is the make & model of the existing fan? Wickes!

OK, there's most of your problem.

Fit a timer fan with an over-run of at least 15 minutes and get a good powerful one with an extract rate of more than 100m³/hr

Alternatively fit a powerful fan contralled by a humidistat, then it will run whenever its moist in there.

Don't go for the cheap option, or you'll be forever scraping mould off the walls and redecorating.

 

[Gos1]

Thanks Taylortwocities
So what you are saying is the fan i have has just not a big enough extraction rate? As because the lights/fan are normally left on for longer then 15 min (Kids for you lol)
Most with a higher rate appear to 35w and have a ducting dia of larger then 100mm (this is the existing size of the duct i have).
Would you or anyone else know of a good, reasonably priced fan that is as power full to do the job but with only a 100mm duct.
Thanks in advance

 

[JohnD]

having it on with the lights is IMO fine

it means it will run not only during and after baths and showers, but also when people are using the WC, washing hands, cleaning teeth, cutting toenails etc

it also avoids relying on people remembering to turn it on.

but get one with a timer if you want

How many showers a day happen, and how many baths? How long do they take?

be aware that wet towels hold a lot of water which will slowly evaporate into the air.

the cheap 100mm fans are not much good, especially if there is ducting, and don't last long Get a Centrifugal fan if you can, they are more powerful and quieter than Axial fans. They are available to fit 100mm duct.

If the duct runs in the loft you can get one that sits up there instead of being ceiling mounted


This one would be good http://www.screwfix.com/prods/98482.../Manrose-In-Line-Centrifugal-32W-Bathroom-Fan

and this one is as cheap as I think you could go http://www.screwfix.com/prods/11442...tor-Fans/Manrose-Centrifugal-25W-Bathroom-Fan

 

[Gos1]

Thanks all
Taken a trip to local B&Q.
Purchased a Greenwood Airvac 115mm kit, £38. It has a 180m/hr 25w output.
Nobody tell me this is no good please
Making existing 100mm holes into 115mm as you are reading this

 

[Gos1]

Hi. Installed the fan, but can not find a permanent live to wire in the timer At present connected both wires i.e L /SW to the nearest downlighter. Any ideas where a permanent live is hiding?
At the pullcord which operates the downlighters/fan just 2 wires, i am asuming these are no good?
Thanks

 

[ban-all-sheds]

//www.diynot.com/wiki/electrics:lighting

 

[Gos1]

Not sure what i'm looking at in relation to my question, may be it's a sunday thing

 

[flameport]

The two wires at the pull cord are live and switched live. You could either connect there, or at the other end of those wires, which is most likely in a junction box concealed out of sight in the ceiling somewhere.

 

[Gos1]

Thanks flameport.
I am asuming with the four connections on the fan, L N E Sw.
The permanent live to power the timer is L?

 

[Gos1]

Having real grief with this, able to get the fan to work with lights by joining both wires L/ LS to same block on downlighter. This way fan comes on and off with lights.
Can not get the fan to run through timer!!!!
I have tried all combinations i.e LS to permanent live at ceiling rose (3 red wires together)
L to permanent live at ceiling rose (3 red wires together)
Help Please!!!