LED Foyer Lighting

[Brian]

I've been asked to recommend some energy efficient lighting for a foyer/public space. The current units are halogen-lamped wall uplighters on dimmers putting out around 700 lumens each.

 

If I go CFL it looks like I can get away with something around 15W each but they ain't going to dim.

 

If I go LED it looks like 10W units will do it but does anyone know of any reasonably priced 10W LED wall washers that can be dimmed on normal leading edge dimmers?

 

The energy cost saving will be around £10/year per unit so there's not much point fitting units costing £250 each.

[adam2]

Are you seeking replacement lamps for existing fittings ? or complete LED fittings ?

 

Retrofit LED lamps that are said to work on standard dimmers are now becoming more readily available. I haved used them succesfully on D0m3stic dimmers.

[gyro_gearloose]

The energy cost saving will be around £10/year per unit so there's not much point fitting units costing £250 each.

There are dimmable LEDs out there, but a quick Google shows that they cost anything from £20 upwards. Philips make some 17 Watt dimmable LEDs, but they list at £35!

[patrick_keys]

I've been asked to recommend some energy efficient lighting for a foyer/public space. The current units are halogen-lamped wall uplighters on dimmers putting out around 700 lumens each.

 

If I go CFL it looks like I can get away with something around 15W each but they ain't going to dim.

 

If I go LED it looks like 10W units will do it but does anyone know of any reasonably priced 10W LED wall washers that can be dimmed on normal leading edge dimmers?

 

The energy cost saving will be around £10/year per unit so there's not much point fitting units costing £250 each.

 

I've designed LED systems and drivers for a number of projects, and this isn't as simple as it should be. The fundamental problem is that LEDs require some kind of Pulse Width Modulation to dim them - maintaining a constant current through the LED (or constant voltage if using LED tape with resistors). If you remove (or chop) the mains voltage using a conventional dimmer, you need to be able to recover sufficient energy from the mains to run the PWM system. It's quite difficult to do, which is why there aren't many mains-dimmable LED fixtures.

 

Ultimately a better solution is to change wiring to use low voltage (12 - 48V) and a dedicated LED driver. There are a number of drivers around that accept a 0 - 10V control input (or better, DMX). The problem of course is that there aren't many suitable housings for a 'roll your own' solution.

 

The LEDs themselves aren't a problem - my current project is using LEDs so bright that I had to use welding glass to look at them, and they weren't even running close to full power. I would love to design a proper nice-looking wall mounted LED fixture complete with DMX control - but can't compete with China on cost.

[Brian]

Hi Adam,

 

I'd happily take a lamp if I can find one. The current lamps are 70W G9 capsules in an ES based adaptor.

 

I've seen the 7W Magaman parts but they're only 400 lumens and seem a bit picky on the dimmer used to drive them.

[adam2]

I have had good results with the "TCP" lamps sold by international lamps. (phone 01279 442266, ask for Chris Stigwood)

 

12 watt, ES base, 800 lumens, warm white, dimmable, about £10 each.

The payback time is probably a lot less than a year since not only electricity is saved, but also the money spent on the existing lamps.

 

I have no connection with Internationbal lamps, except as a customer.

[Brian]

Thanks Adam, looks like they've got some nice LED lamps (and nice to know they're still in business after all these years).

[Don Allen]

In Perth, Western Australia, we have a Nelson Dimmable CFL for $20 (11.58 pound) that actually works. It wont dim to zero, but looks ok for most of the range.

[Tomo]

The 'nicest' dimmable LED retrofit I've seen so far is this Osram:

Aurora 6.5W LED 230V GLS Osram

 

The main reason it's good is the change of apparent colour temperature as it dims, from 100% down to around 40-30% or so it's a reasonable facsimile of a tungsten.

It's the only retrofit I've seen so far that tries.

 

However, it's only rated at 260lm so probably not bright enough for your install.

[J Pearce]

Would you be willing to go to a wireless system? Change your dimmer switches for normal switches or fish keys and then use a wireless remote to adjust the lighting levels (assuming they are on wall plate dimmers, not hooked into a bigger dimming system?).