Riverside Cottage 9

[Tim Lamb]

Two threads going on LED lighting! Here's a third:-)

Construction is approaching first fix electrics and I have little idea how to arrange the lighting.

Wall lamps in our existing house have gradually morphed from twin 25W incandescent candles to 5W LED replacements. Because of relatively low ceilings the kitchen has twin 9W fluorescent recessed circular units with opaque diffusers. 5 units give a barely adequate light level. (daylight better than warm white).

I have found something similar in an LED version (SKU DL-SLIM-12W)

Because I plan to use wet underfloor heating upstairs, there will be a layer of Rockwool insulation on the ceiling plaster board leading to concerns about overheating the light fittings and associated power supply units.

Any thoughts? Is there a low profile surface fitting with a wide beam angle?

Is there an on line calculator for domestic light requirements?

[Andy Burns]

From what I can see the SKU you found is similar to some chinese specials I got from eBay, toolstation have started selling them (round/square, cool/warm, small/med/large)

They're barely thicker than teh plasterboard, so no holes in insulation, I've located the external PSU remote from the fitting, mine have PIR foam directly above, no problem with heat, but is only 6W

The edge lit design (ring of LEDs firing inwards to edge of a glass disc, with a pattern of dots on a diffusing filter) gives a wide beam, I have one 5-6" inch downlighter that easily covers a 5x6' area at floor level.

[John Rumm]

Flat panels may work quite well - high omnidirectional light output. E.g.

There are plenty of sites with recommended lighting levels for different tasks.

I don't know if there is one that can translate a require level into numbers and positions of fittings etc, but there may well be.

[Tim Lamb]

That is the sort of fitting I am considering. However, the life discussed in the other threads, seem to be compromised by elevated temperatures. The underfloor heating will run at up to 50deg.C and be spaced 200mm above with perhaps 150mm of Rockwool insulation between.

Meeting fire regulations also needs checking.

Fly proof gets it full marks from the boss:-)

>

[Tim Lamb]

Yes. I doubt that would pass senior management scrutiny but interesting that there is a surface mount adapter. All these LED lamps appear to rely on a separate plug in driver which raises questions about life/reliability and makes me very nervous about committing to something which may be unavailable next year:-(

I must make more effort to look. The one I found wanted ?80 for a handbook!

[PeterC]

Good range at Ledlam, recessed or surface-mount, no separate drivers, some dimmable.

[Andy Burns]

They look like external driver to me ...

[Tim Lamb]

They look interesting Peter. First issue is getting stuff accepted by the management without first finishing the installation.

4 x 80W dimmable ought to light a fair sized kitchen. Ta.

[Tim Lamb]

Me too. But I was just expressing anxiety about replacement life. The ones fitted in our present kitchen are 22 years old and replacement tubes are on the shelf at Homebase etc.

I think I will have to consult with electrical outlets to find what the professionals are using.

[Andy Burns]

I fitted the drivers remote from the lights, so I didn't need access into the flat roof if they need replacing, all that's in the lights themselves are LEDs, so any similarly rated constant current driver should work.

[Tim Lamb]

Most of the fittings I have looked at have a short lead with a push fit connector. The drivers are then loose laid on the plasterboard or screwed to a nearby joist.

CPC do an LED downlighter with a finned heat diffuser but this would be in the ceiling void at an unknown but elevated temperature. I am beginning to think surface mount with a remote common driver might work best.

>

[Andy Burns]

Mine had a twist-fit, but I chopped it off and soldered two longer wires direct to the LED strip inside.

Mine is a porch roof, so there's rigid insulation directly above the plasterboard, in order to leave an air-gap below the plywood deck, I just used a holesaw to make the cut-out and draw in some cabling for the

12V side and the actual driver is mounted on rafters in the garage.

I left mine on for 12 hours to see how hot it got, and "not very" was the answer, but it's only a small 6W one, not 80W(?) you're looking at, I'd think four of those would light a barn let alone a kitchen!

[PeterC]

I hope '80W' is the equivalent, say about 12W LED!

[Tim Lamb]

In message , PeterC writes

Yes.:-)