Recessed Lights - Mains versus Low Voltage.

[grumpy rob]

quick question for any sparks out there

We are considering fitting recessed lights into the bathroom ceiling. So far I have been unable to find any benefits of low voltage lights apart from the "whiter light"

Considering the cost of transformers (one per light I'm told!) is there anything I'm missing about the benefits of them?

[JonRB]

Don't know where you get the idea of one transformer per light. 3 or 5 is far more usual.

Whoever kitted out our current house used just about every conceivable lighting standard possible, so I have to keep a stock of standard bayonet, large Edison, small Edison (spots), low voltage halogen (both the two-prong spot type and also the little nipply bulb-type ones used in cooker hoods) and 240v halogen. The latter are the worst - they're bloody expensive and are always blowing.


>> Edited by JonRB on Tuesday 22 November 15:18

[grumpy rob]

aha..

so [url]www.screwfix.com/app/sfd/cat/pro.jsp?cId=101667&a [/url

could run 2 X 50W lamps?

and

www.screwfix.com/app/sfd/cat/pro.jsp?cId=101667&ts=73520&id=51565

could run 3 X 50W?

that will reduce the cost's (which is good) but I still can't see why people would run them over the mains one, and hence no transformers to mount.

[XM5ER]

I've just fitted a load of 240v halogens and the spark just happened to mention (after wiring them up) that the mains voltage halogens last about five minutes and that in the long run it would have been more economic to fit 12 volters. The other issue is, they are not as bright as you would expect so you will need more to light a room adequately.

The next rooms I convert will be on 12 volts.

[sleep envy]

grumpy rob said:

We are considering fitting recessed lights into the bathroom ceiling.

Whichever fittings you decide on make sure they conform with the new building codes for installing in bathrooms.

They will need to be sealed from beneath to stop steam/vapour penetrating into the luminaire and vented from above with the appropriate fixing to dissipate heat build up.
There was a case in the trade that the wrong fittings were used in a shower room, steam shorted the fittings and caused a fire. Insurance company then investigated and voided the claim as they were not the compliant fittings to be used in wet areas.

PS - I'd go with the 12V and a transformer set up as there's more choice on the market.

[grumpy rob]

sleep envy said:

grumpy rob said: We are considering fitting recessed lights into the bathroom ceiling. Whichever fittings you decide on make sure they conform with the new building codes for installing in bathrooms.

I take it that's the Zoning System, all the one I looked at where zone 1 and IP65 which is apprently what is required for bathrooms.

Thanks for all the advice guys, PH's never fails to amaze and inform !

[bga]

XM5ER said:

I've just fitted a load of 240v halogens and the spark just happened to mention (after wiring them up) that the mains voltage halogens last about five minutes and that in the long run it would have been more economic to fit 12 volters. The other issue is, they are not as bright as you would expect so you will need more to light a room adequately. The next rooms I convert will be on 12 volts.

When I brought my flat 2 years ago the kitchen had 8 mains halogen bulbs installed. I've not had to replace any yet.

[JonRB]

bga said:

When I brought my flat 2 years ago the kitchen had 8 mains halogen bulbs installed. I've not had to replace any yet.

Lucky you. I seem to be replacing 1 a month, and we only have one installation of 3 lights!

Incidentally, B&Q are doing a 6-pack for £5 at the moment, which is the cheapest I've seen them.

[sleep envy]

bga said:

XM5ER said: I've just fitted a load of 240v halogens and the spark just happened to mention (after wiring them up) that the mains voltage halogens last about five minutes and that in the long run it would have been more economic to fit 12 volters. The other issue is, they are not as bright as you would expect so you will need more to light a room adequately. The next rooms I convert will be on 12 volts. When I brought my flat 2 years ago the kitchen had 8 mains halogen bulbs installed. I've not had to replace any yet.

It's heat build up that kills the 230/240v halogens. If there isn't sufficient flow of air around the lamp they burn very quickly.

[sleep envy]

grumpy rob said:

I take it that's the Zoning System, all the one I looked at where zone 1 and IP65 which is apprently what is required for bathrooms.

Sounds about right but check with the manufacturer/supplier to be doubly sure.

[speedchick]

For safety reasons you should use low voltage lights in a bathroom, I learned this while working at B&Q, can't remember the full details, but I do remember that bit.

[wedg1e]

In my experience high-power low-voltage lamps are a bloody nuisance; they blow far more often than would an equivalent mains-voltage lamp.
Also, whilst 6 or 8 50W low-voltage lamps set into your ceiling may look nice, in practice the room often seems darker than if lit with a single 60W mains lamp! Not only that, but lying in the bath with a spotlight shining in your eyes is not conducive to a relaxed atmosphere...

[up-the-dubs]

When we had our house extension done we got... ummm... 53 low voltage jobs put in in the kitchen, hall, landing, study and bathroom.

It was 10 years ago, the first bulb blew last month. Fairly impressive if you ask me.

[ultimasimon]

Low voltage halogen lamps require matching to the transformer. People do not realise this. If you run with 4 halogen down lighters rated at 25 watts each then you must use a 100va transformer. For 4 lamps rated at 50w each then use a 200va transformer. Get the idea?

If you put in a lower wattage lamp, you will reduce the life of the transformer.

If you put in a higher wattage lamp, you will dramatically reduce the life of the lamp - and as some have said 1-3 weeks.

The advantage of using downlighters is they give the room a cleaner squarer look and should not cause shadows or blackspots. If you find you have dark areas then whoever installed them didn't use the correct spacing or angles - all lamps come in different angles of coverage. Failing that then the spacing is to far apart.

A correctly matched lamp/transformer package will last as long as a traditional filament lamp. If lamps keep blowing prematurely, then I would change your transformer and match it correctly according to the lamps/wattage on your circuit.

[wedg1e]

ultimasimon said:

If you put in a lower wattage lamp, you will reduce the life of the transformer.

Not sure I see how that works....

[XM5ER]

bga said:

XM5ER said: I've just fitted a load of 240v halogens and the spark just happened to mention (after wiring them up) that the mains voltage halogens last about five minutes and that in the long run it would have been more economic to fit 12 volters. The other issue is, they are not as bright as you would expect so you will need more to light a room adequately. The next rooms I convert will be on 12 volts. When I brought my flat 2 years ago the kitchen had 8 mains halogen bulbs installed. I've not had to replace any yet.

Only passing on the sparks experience, he looks after a local farm shop which has about 220 mains lamps and he changes about 20 per weeks for them (though I'm sure he's exagerating little here). He did say that if you use a dimmer to switch them on and wind them up rather than go straight to full power, they will last considerably longer.

[Pigeon]

wedg1e said:

ultimasimon said: If you put in a lower wattage lamp, you will reduce the life of the transformer. Not sure I see how that works....

Me neither. I strongly suspect it doesn't...

ultimasimon said:

If you put in a higher wattage lamp, you will dramatically reduce the life of the lamp - and as some have said 1-3 weeks.

This will reduce the life of the transformer, by overloading it.

(The overload reduces the voltage to the lamps, so they don't run hot enough for the tungsten-halogen cycle to work properly and they go pop as well.)

Me, I don't bother with incandescent lighting at all. Every bulb in my place is a compact fluorescent modified for longer life.