Bathroom extractor fan

Hi all, thanks for your replies so far.

I have checked in the loft and the existing fan is in line. I have decided to replace with an inline one now, if there is no permanent live is it just a case of getting one from the lighting circuit? I want the fan to over run on the new one.

Ta

You can't just take a feed from "any random circuit". You need to trace the wiring for the existing fan and determine how the current one is wired.
As already mentioned, you may have a permanent live and someone's fitted a non-timer fan. Or you may find that whoever wired it didn't engage any brain cells and simply wired for a non-timer fan as is the case with ours
What you can NOT do is have a switched live (and probably neutral) through the isolator and take a separate live from the lighting circuit that doesn't go through the isolator. That would leave you with a setup where more is live when the isolator is off than when it is on
If you are currently wired without a permanent live, then ideally you'd replace the T&E from the fan back to the isolator and from the isolator back to the light fitting or switch (depending whether it's looped at light of looped at switch) and replace the isolator with a 3 pole one if it isn't already.

EFLImpudence said:

imntetmi

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Imitation, i assume. This forum is very buggy on mobile recently.

John D v2.0 said:

Imitation, i assume. This forum is very buggy on mobile recently.

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Maybe, but the sentence would then still not be (at least gramattically) correct. For no particularly rational reason, I think I subconsciously interpreted it as meaning "in terms" - since ".... are fairly poor in terms of generating airflow." would make total sense, and is correct English!

Kind Regards, John

'Line' is just a typical choice for the electrical establishment; a perfectly normal word which means something really common that no member of the public would realise meant anything specific - because it doesn't.

Thanks all, I fitted an inline fan in the loft. Works a charm.

That is for your help

Hi, me again. After I fitted the in line fan over a year ago I have a problem with the ceiling around the vent above the shower getting damp and going black.

I want to replace my in line now with a safe none in line extractor, could you recommend me one please?

cheers

Sorry forgot to add it will be zone 1, I don’t have a permanent live so a none timer version please.

room is 8ft by 4ft en-suite.

cheers all

con1_uk said:

Sorry forgot to add it will be zone 1, I don’t have a permanent live

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so you need one. Or just leave your switch permanently on. Or, conceivably, use a timed switch.

What size is your duct?

con1_uk said:

Hi, me again. After I fitted the in line fan over a year ago I have a problem with the ceiling around the vent above the shower getting damp and going black.

I want to replace my in line now with a safe none in line extractor, could you recommend me one please?

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I doubt that being in-line is your problem.
Looking back, I see there are some unanswered questions ... Is your duct lagged ? Is is sealed properly to the intake grill ? Is there a back-draught shutter ? Does the fan have a run-on timer ?
If the duct is unlagged, then it will cool from the cooler air in the loft. There will be condensation on the inside of the duct, and that can run back down and if the duct isn't sealed to the grill, then it could seep between duct and grill spigot - thus wetting the ceiling plasterboard. Not having a run-on timer will make that worse. Also, when not running, air in the duct will cool, and circulate downwards to create a cold spot in the ceiling - thus promoting your damp problem.

So well lagged duct, sealed so that condensation can't leak to the ceiling, a reasonably long run-on time (to clear the damp air after a shower), and a back-draught damper (to stop cold air flowing back) will all help. BTW - there are traps you can put in vertical ducts to catch condensation and prevent it running back down and dripping from the grill.

Also, a flow switch in the supply to the shower would work to prevent people not using the fan by leaving the light off - as SWMBO would be prone to doing. It is "a difficult task" persuading her that the answer to black patches in the ceiling corners is to get the damp out as quickly as possible - rather than nuking it periodically with bleach

Hi, still not done the ducting and had a thought, can ducting from the shower fan be connected to the toilet pipe that already goes up through the roof and out?

no