Downlights

[Duckfoot1606]

Looking for some guidance on the clearances needed to install LED downlights in a bedroom ceiling, the ceiling void measures 120mm.

Are there any general rules of thumb to consider? I've been told to allow 75mm free space around and above, any comments?.

Thanks in advance

A

[rafletcher]

LED downlighters run cool, so no need for that amount of clearance if it’s not available.

[Ham]

Modern downlight fittings are fire rated, as the electronics in LED can result in fires, where tungsten only blew. As a result, I have used Phillips GU10 bulbs in my old non-fire rated fittings, which are entirely encased in glass, so not susceptible to fire. I personally would chose the same even in fire rated fittings.

[Diver300]

Modern downlight fittings are fire rated, as the electronics in LED can result in fires, where tungsten only blew. As a result, I have used Phillips GU10 bulbs in my old non-fire rated fittings, which are entirely encased in glass, so not susceptible to fire. I personally would chose the same even in fire rated fittings.

I thought that the fire rating was all about making sure that fire in the room below didn't have any way of letting heat and smoke past the light fitting. The smoke and flames from room furnishings on fire will generate far more heat than a misbehaving LED lamp.

[Kim]

Modern downlight fittings are fire rated, as the electronics in LED can result in fires, where tungsten only blew. As a result, I have used Phillips GU10 bulbs in my old non-fire rated fittings, which are entirely encased in glass, so not susceptible to fire. I personally would chose the same even in fire rated fittings.

I thought that the fire rating was all about making sure that fire in the room below didn't have any way of letting heat and smoke past the light fitting. The smoke and flames from room furnishings on fire will generate far more heat than a misbehaving LED lamp.

This.  The reason the tungsten ones weren't fire rated was because TEH RULEZ have been strictified since they were en vogue.  Anyone who's replaced the charred remains of an arcing MR16 connector knows they were far more burny than LEDs.

There's a related rule about light fittings having a glass front in bathrooms (not sure if it applies in kitchens - usually kitchen water's considered a lot less electrically hazardous), so that splashes of water won't cause the envelope to shatter from thermal shock, plunging the user into darkness while showering them in shards of broken glass.  Naturally this will persist long after tungsten lamps are a museum curiosity, and bathrooms are lit by bio-luminescent paint (which will have to be installed behind a glass screen).

[Diver300]

Halogen lights are likely to have the insulation removed behind them so that the smoke and flames can get upstairs faster the lamp fitting won't overheat. LEDs lamps don't need the insulation removed, improving the thermal and fire resistance properties.

In fact, a lot of LED lights are really very thin and can be surface mounted with only a tiny hole in the plasterboard for the wire, while being less than 20 mm deep. The big holes in the plasterboard and the insulation aren't needed.

[tom_e]

In fact, a lot of LED lights are really very thin and can be surface mounted with only a tiny hole in the plasterboard for the wire, while being less than 20 mm deep. The big holes in the plasterboard and the insulation aren't needed.

Hmmm - we happen to be looking at the same situation at the moment.  Got any recommendations?

The recessed options I've been finding often have a low profile, but then specify they need a cover if insulation is above them, and that makes them bigger again.  While the non-recessed options are not as thin as I'd hoped - haven't seen any at 20mm.

[rafletcher]

What I want to find is an IPx4 or IPx5 rated bathroom downlighter that can have the bulb replaced from below in a simple way (as in unscrewing the cover glass) - our current ones have the glass cover masticked to the sealing.

[Diver300]

In fact, a lot of LED lights are really very thin and can be surface mounted with only a tiny hole in the plasterboard for the wire, while being less than 20 mm deep. The big holes in the plasterboard and the insulation aren't needed.

Hmmm - we happen to be looking at the same situation at the moment.  Got any recommendations?

The recessed options I've been finding often have a low profile, but then specify they need a cover if insulation is above them, and that makes them bigger again.  While the non-recessed options are not as thin as I'd hoped - haven't seen any at 20mm.

I was slightly over-optimistic about the 20 mm dimension. The one I have measures at 26 mm at its lowest point from the ceiling when fitted. It contains a base which is fitted to the ceiling with screws, the wires from the lamp are connected to the base, and the whole lamp bayonets onto the base, so there are no fixing screws visible, and no need for a gap between the lamp and the ceiling.
https://www.amazon.co.uk/BIGHOUSE-Plus-Bathroom-Equivalent-Waterproof-Lighting/dp/B09BDXSYFM?th=1

[rr]

Interesting look at downlights , including explanation of fire ratings.
https://youtu.be/sHnY3KQ9MtQ?si=_p4j9W-iz4Y-iPRu