Silent dimmable halogen spots?

[Mango Bob]

We're having a bathroom fitted with 1.5" (I think!) dimmable halogen spots and the ones the fitters have used buzz infuriatingly

Please can someone recommend a model of *silent* dimmable halogen spot that are certified for bathroom use and directional (i.e. you can lean it in one axis)...the ones we have are chrome and flush with the ceiling but they sound like a power station!

Many thanks in advance - if someone answers today we can get the fitters to change them while they're still here

[Johnny Thunder]

They are making this noise because they have installed low
voltage spots.
Somewhere, there will be transformers driving the spots.
As an example, there may be 3x40w spots, being driven by
a 120w transformer. Running it at maximum like that is ok
but it will hum.
you have 2 options.
Install heavier duty transformers, or install mains spotlights.
If you are going to the trouble of changing the spots, for
moveable type, then I would recommend doing away with low
voltage and going for mains voltage spots.
Johnny.

edit:

Doing away with the dimmer may reduce the humming,
or even stop it.

another edit:

Bathrooms are divided into zones for wiring regulations purposes.
I assume that by using a dimmer, it is situated outside the bathroom.
Johnny.

[Johnny Thunder]

Do you mean something like THIS Bob.
This model is mains voltage.
Johnny.

[Mango Bob]

Johnny you're correct, the dimmer is outside the room. So am I right in understanding that mains voltage spots won't hum...can you get mains voltage halogens? The humming is louder the lower you turn the dimmer.

We want dimmable so you don't have to be blinded when in the bath - but can also have it bright so I wake up in the dingy winter mornings! The lights we have are (I think) dichroic halogens - the ones that have slight green/purple tinges to the light.

Is there no way of having them dim without the humming - surely someone can make a silent transformer?

[Docta teef]

With mains woltage spots only the dimmer will hum but very quietly

[Docta teef]

You may find that this applys to mains VOLTAGE spots as well

[Johnny Thunder]

You will create problems for yourself when you start to alter the voltage or current characteristics of the primary side of any transformer.
This is what a dimmer does.
In more complex circuits, other devices are usually incorporated to combat the side effects of this.
I would not recommend installing a dimmer on a low voltage lighting system, unless the transformer is designed for this purpose.
Johnny.

[theendisnye]

I would go for something more like this http://www.diy.com/diy/jsp/bq/produc...maxBullets=999
the GU10 bulb is a 240V 50W halogen bulb, I have several and they are dimmable and look similar to the 12V versions.

Steve

[Mango Bob]

Originally Posted by theendisnye

I would go for something more like this http://www.diy.com/diy/jsp/bq/produc...maxBullets=999
the GU10 bulb is a 240V 50W halogen bulb, I have several and they are dimmable and look similar to the 12V versions.

Are they suitable for use in a bathroom? the site doesn't say...the spots are in bathroom zone 1 as the room is small and they're near the shower head.

[Johnny Thunder]

Bob, zone 1 is 2.25m from floor level.
I think, if I remember correctly, lighting installed in a ceiling recess is classed as zone 2. I am not sure about this but I will get my Regs out later, check, and let you know.
If that is not the case, then I.P ratings (ingress protection) come into the equation. Off the top of my head I cannot remember the actual rating without checking the Regs again. I think, in this situation, the IP rating changes depending on whether the shower head is fixed or unmountable.
Again I will check.

Johnny.

[Johnny Thunder]

Bob, if your ceiling is 2.25m or lower, then without getting too technical, you want to be looking for a light fitting with some sort of I.P rating due to the fact that the recess for the light is also zone 1.
The IP rating you need to be looking for, is IPx5.
Do not worry about the x digit, this refers to foreign bodies entering the enclosure, ie fingers. If it is a nicely manufactured spotlight you have no problem.
The second digit refers to the entry of moisture.
5 indicates protection against jets of water.
If it does not have an IP rating, it may have a symbol which means the same.
You need to be looking for 2 triangles, each with a water drop inside it.
There are other factors in this equation, but we will be getting technical.
This would involve protection at electricity source, isolating transformers, bla bla bla.
Hope you can understand all of this.

Johnny.

edit:Check THIS link for the codes.
About 3/4 down the page, you can see the symbol I mean.

Johnny.

[Johnny Thunder]

BTW, I am still trying to work out what this has to do with Home Cinema DIY.

[Mango Bob]

Thanks for you responses Johnny!

I didn't feel it was "General Chat" and there's no other building-related forum
Plus I have grand plans to install a big semi-silvered mirror, lcd screen and speakers - so it's a potential home-cinema DIY bathroom

After careful inspection by my girlfriend and the guy doing the installation they think it's the bulbs themselves that are buzzing rather than the transformers?

Does that sound even remotely feasible? Sounds like rubbish to me but I've not been in the loftspace yet to hear them...

[Johnny Thunder]

I suppose it is possible, but I have not come across buzzing halogens.
You said originally that the lower the dimmer, the louder the noise.
That still sounds like the transformer doesnt like the Primary voltage.
As a quick test, replace the dimmer with a normal switch.

Excellent answer btw..........

Johnny.

[Mango Bob]

The transformers themselves (after doing some digging) are purpose designed to be dimmable.

They're described as Micromark 60W dimmable transformers - is there a special dimmer switch type that they're supposed to use. The bathroom guy has just fitted a plain budget dimmer switch.