Mains halogens

[Grumps]

Dopey question of the day....

Are mains halogen lights dimmable (using a standard light dimmer)?

[Guy King]

The message from "Grumps" contains these words:

Halogen lamps rely on being quite hot to stop them blackening inside. If you run them at very low dimth for a long time they may darken. However, by how much and how soon I have no idea - suck it and see.

[Andy Burns]

I have a 5x50W ceiling fitting that is too bright for normal use, so it spends most of the time on ~30-40% brightness, I've not had a single bulb blow in it so far, unlike the usual tales of frequent replacement, I just took a bulb out to inspect it, and no "soot" visible ...

[Andy Hall]

Yes you can, but make sure you leave plenty of headroom on rating - e.g. don't run 5x50W lamps from a 250W dimmer - use a 400W dimmer instead.

Even better, use a quality dimmer with soft start such as an MK4500 series and the bulb lives will be increased substantially.

[Grumps]

Thanks. It's early days, but we're trying to find a pair of wall lights. So far we have found two that we like. Both have 4x40W bulbs. One uses halogens (mains), the other uses normal filament bulbs. Obviously, this is going to be bright at a total of 320W, so will need a dimmer. Is a halogen brighter than a normal bulb (Watt for Watt)?

[Andy Hall]

Have a look at the comments on olour temperature at

[The Natural Philosopher]

Yes. They have a slightly higher switch-on surge, so a higher rated dimmer is preferable.