Halogen beam widths, wattage, transformers and IP ratings

[Pete Verdon]

Unless anyone has any better ideas, I'm going to replace the horrible light fitting in my bathroom with some halogen downlighters.

The room is 3.2m x 1.7m. I'm thinking of fitting three lights, equally spaced down the middle of the room. Most of the bathroom type fittings seem to be 35w - I want the room to be fairly bright and I guess 105w overall is probably enough. However, 35w bulbs only seem to be available in 36º beam widths and smaller. Although I'm using downlighters (because I prefer "hidden" fittings for a bathroom) I don't really want a "spotlight" effect. I'm concerned that such a narrow beam might leave parts of the room in shadow - although I have no real experience on which to judge it. What do you think?

60º beam bulbs are available at 50w. This is too much for TLC's fire-rated bathroom fitting, although I still haven't established whether I actually need fire-rating upstairs. I also wonder whether 3x50w will be too much for a fairly small room. As I said, I have no experience of these lights.

I note that the fire-rated fittings also need "cool fit" bulbs, which further limits the choice.

Another variable in the choice of lamps and fittings is that my ceiling is 2.5 metres high. I believe this puts it outside the zones, so I could choose a non-IP-rated fitting. Not sure this is sensible though in a steamy bathroom.

Finally, is there any particular reason to prefer either a single transformer powering all three lights, or an individual transformer for each light?

Cheers,

Pete

[robgraham]

My bathroom is remarkably near the same size in all planes - just a tad longer. It's north facing with a single window, so needs to be lit well. The lighting was all installed before any of this IP rating malarky came along.

I would be concerned about the narrow beam width of the halogen downlighters giving you pools of dark and light - ie the lack of general light spread. In the days of incandescents this was never a problem and who wants CLFs in a bathroom.

At some point I'm going to have to face the same quandary as I have a

60W incandescent downlighter near the door, and a similar one in an uplighter on the wall above the bath. At some point I will run out of replacements ! The basin at the far end from the door is lit with a cluster of 10 x 10w halogens which also spread light well.

Rob

[<me9]

Fit a 2D or similar IP rated fitting to the ceiling. It will give a much better light and last longer, and be cheaper to run.

[Adam Aglionby]

2D fluro gives better light than halogen, for a totally new value of better perhaps. 2D lamps are pretty good efficiency wise but feel they should really be restricted to stairwells and carparks, personally.

At 2.5m throw, 36 degree will be fine, will also gain from reflectance off the walls. Lamps are liable to be still available for at least the life of the installation

Seperate trafo for all lamps keeps the 240V out of any of the hazard zones, Mode are a good brand.

Might consider seperate wall mounted light by mirror.

Cheers Adam

[Pete Verdon]

It's immaterial, as I don't like that sort of fitting. I have something similar at the moment (although with a single incandescent inside it) and don't like it.

OK. Bear in mind I'm not especially interested in illumination at floor level - if the bottom of the cone only just covers the floor, presumably there will be quite a lot of space outside it at, say, chest level. It's true that there will be reflection from the walls.

I'm not sure I understand. The transformer(s) will be above the ceiling in any case; the question is whether to have one next to each light fitting, or a single one next to the central fitting (since that's where the power is) and 12v cables to the fittings either side.

The mirror itself incorporates a pair of small fluorescent tubes, so I'm covered there.

Pete

[pcb1962]

3 x 50W will not be too much, I have a room 5 x 2m with 10 x 50W, it's nice and bright but not over-bright.

[The Natural Philosopher]

Well I don't like protusions in bathrooms. Of all the bogs and baths here, all have 50W KV spots, and all are to an extent shadow casters unless you put in about 25W/sq meter, except one room that has a central

60W incandescent luminaire. Its fairly low profile, and does a better job.

. When the bulb goes it WILL get a CFL, as its a bugger to change and the light quality is adequate to read Tolkien in the bath with ;-)

[NT]

If I were lighting the bathroom anew I'd go for linear fluorescent as the main source. These work great _if and only if_ the many common gotchas are avoided.