Bathroom Electrics - Fan hum - white box(?)

[mj62mj62]

Hello,
Thank you very much in advance for your help, I'm very much a noob on this stuff!

We moved into a recently refurbished house and outside of both loo's is a switch for the fan. These switches have a white box beside them that hums, like an electrical transformer or something.

Strangely, the switches are too high up to reach without a chair, so it's not easy to switch them on for a shower and then switch them off again.

What is this white box that is making the humming noise? Is there a way to stop it? Thank You,

Matt

 

[1john]

yes the white box is a transformer. the switches are placed out of reach for a reason, the fan should come on with the light and have a run on timer, if you switch it off after you have showered then you cill not clear the moisture in the air that you have created and could well end up with condensation and mould problems.

 

[mj62mj62]

Thanks John - yes, the fan comes on when there is steam and clears the room, which I agree is a good design.

Is there a way to eliminate the humming noise?

I've also noticed that the box is a bit warm, so it may be wasting electricity constantly!

 

[1john]

transformers do run warm, it's common, and as for wasting electricity, a running fan, iirc, used about 25W and the transformer will be pulling much less (<1watt at a guess) on 'standby'

 

[mj62mj62]

Thanks again John - that is quite good news

That just leaves the question about the hum - is it just a matter of buying a better transformer or is it just something I have to get used to?

I ask because one of them is in the bedroom (en-suite) and it hums all night...

 

[1john]

you could try swapping it out for another one, i dont know how quite loud is for you but transformers do tend to buzz, some worse than others.

 

[mj62mj62]

Is there a really high quality brand or shop I should be looking at?

An internet search turned up too many options and none specified that the transformer is particularly quiet...

Thanks

 

[flameport]

Is there a way to eliminate the humming noise?

Replace the fan with a 230v type, which won't need a transformer.

Not much else you can do - all transformers hum to a certain extent, and the problem generally gets worse as the transformer gets older.

 

[mj62mj62]

Replace the fan with a 230v type, which won't need a transformer.

Sounds like a plan - that is what I'd like to do.

Both of the fans are in extensions, so maybe a full sized fan wasn't possible at installation time. I'll ask the electrician. Cheers

 

[mj62mj62]

The builder's Electrician (not our own) says the ceilings are too narrow and too low to support normal 230v fans. This is because they are in the extension part of the house and the ceilings are fairly low there.

Is this true or are there special 'narrow' fans you can get?

Thanks again! Matt

 

[Steve]

Sounds like twoddle, imo.

 

[londonboy]

What if the fans in zone 1?

 

[TicklyT]

Sometimes a judiciously positioned packing piece under one or two of the fixing screws can true up any slight twists in the transformer case if the surface it is mounted on isn't quite flat. That may be enough to mute a noisy transformer.

 

[securespark]

Or the cabling to the fan will not support an LV fan.

 

[flameport]

What if the fans in zone 1?

230v fans can be installed in zone 1, provided they are IPX4 or better (most are).

As for narrow/too low - not likely. The operating voltage does not have much (or any) influence on the physical size of the fan.