MR16 Halogen to LED

[F]

I'm thinking about swapping our MR16 halogens for MR16 LEDs but am not sure if the transformers might need changing.

The current downlighters, bought around five years ago from Screwfix, have a transformer for each lamp and have 12v 50W 36° beam lamps installed. I'm looking at the 4W cool white version at

Can I do a straight swap with the lamps, or is it more complicated?

Is the LED I'm looking at a suitable swap? I realise it's a 120° beam compared with 36°, but it's for the kitchen so the less focussed effect might be better?

And is there a supplier with better lamps and/or prices than LED Hut?

Removing the downlighters in favour of fluorescents etc isn't an option.

TIA

[Lobster]

F grunted in news: [e-mail]:

I was in the same position a few months back and was humming and ha'ing over (a) whether to do it at all; and if I went ahead, (b) whether to swap from 12V to 240V.

There's stuff all over

warning you that your old transformers may not work with LEDs, but I'm not sure what the level of risk is, ie, are thet just arse-covering against a miniscule risk? Dunno.

I couldn't find any info at all about whether 12V or 240V LED systems were preferable, by whatever criteria. In the end, I went for 240V; I retained my old Screwfix downlighters, binned the 12V connectors and transformers, and bought half a dozen GU10 connectors

to convert my downlighters.

The lamps I bought were (I think)

(or internet-price.html); warm white option. They're 120-deg beam as well; we have 6 of them in the kitchen. Have to say I'm delighted with them so far - the light quality and brightness is fine, SWBO isn't whinging at all; and providing they last as long as it says on the tin, they'll be faultless IMHO.

Dunno. But FYI there are zillions of 5-10% discount codes floating around that you can use on their site; also they give cashback via quidco and topcashback.

[Andrew Gabriel]

They're probably 20-60W transformers. IME, they cut out with a 10W load, but there's no harm trying.

You don't say how many lights you have, but another option would be to run them all off one transformer. 5 should work, and 4 might, if the transformer is a 20-60W one.

To be honest, I would replace with GU10 mains fittings, and use the GU10 mains versions instead.

It's cheaper, and there is more choice of options. This is typical when looking at GU10 instead of MR16 LEDs.

They also have a 5W one:

However, I couldn't see any specs for any of their lamps, so comparing performance is not easy. I suspect none will match the output of a 50W MR16 (although they may get closer to the lower output of a 50W GU10).

[F]

It's interesting that both you and Lobster have come up with the change-to-mains option. I hadn't thought of that as I had it in mind that 12v lamps lasted longer but, I suppose, that will only apply where there's a filament involved.

If I get the GU10 mains fittings do I just connect the flyleads straight back to a (fairly large) junction box? If I do, do I use 1.5mm twin and earth or, bearing in mind the low load, something a lot thinner?

If I go for the multiple-lamps-on-one transformer option, what cable do I use there?

[Andrew Gabriel]

IME, they sometimes have a short flylead, or sometimes a connector mounted on the frame but spaced away to avoid heat damage (which won't be an issue for the LED lamps). This second type can take the T&E directly.

Open backed ones will give you longer lamp life due to better cooling. However, if the ceiling has to be fireproof or ventilation sealed, then you can't use those and will need a fire rated fitting.

Fittings which hold the lamp around the front ring and have a flying lampholder can take longer more powerful lamps, which if used in fittings with a fixed lampholder to hold the lamp would hang a bit below the front bezel.

You could use regular T&E, but make sure you don't get it cross- connected to the mains circuit by mistake. You could use 2-core mains flex. You should probably use mains rated cable of some type as it will be in the ceiling space with mains cables. Long lengths of the low voltage cable may interfere with radio reception, because of the high frequency AC output of electronic transformers.

[MM]

Is it worth all the hassle and expense of changing? Personally, I've never liked downlighters. I grew up in the 1950s and still prefer the old-fashioned pendant light in the middle, with table lamps where necessary. I'm stuck with my halogen downlighters which seem to be the only form of lighting that builders install nowadays. I switch them off whenever I can. Curiously, the builder used pendant lights for the sitting room and for each of the three bedrooms, yet installed downlighters everywhere else, even in the downstairs guest toilet (I ask you!).

MM

[Terry Fields]

I have two fitting here each of which take two 20W MR11 lamps. I replaced these with Philips 4W MR11, partly because they were described as 'transformer independent', which I took to mean that they provide a sufficient load for any transformer to work properly - and they did. Been in service for 18 months (hall and landing) with no problems.

The description on Amazon's web site has now changed and the 'transformer independent' claim has disappeared in a total rewrite that now says these lamps are 240V!

Philips make MR16 which you might like to check out, but they aren't cheap and cheerful. The ones you link to look like they use the 5050 chip, which appears to be about the best that China currently offers - the Philips ones are two single-chip LEDs per lamp.

[Terry Fields]

Apologies, the MR16s are 4 x LEDs per lamp, and the description well down the Amazon page says "The patented intelligent driver enables broad compatibility with existing electromagnetic and electronic halogen transformers."

HTH

[F]

As per my original comment above.

[MM]

I did have a look on Amazon for LED alterntives to MR16 halogen and was shocked by the price of these things. Also, no multipacks.

MM

[Terry Fields]

But you need to look at *lifetime* costs:

Lets say 50W halogens cost 50p each and last for 4000 hours (usually

2000), and a Philips MR16 10W LED costs £25 (they're cheaper than this) and lasts 20,000 hours (claimed 40,000).

In 20,000 hours you're going to need 1 x halogen and five replacements, total £3, or 1 LED at £25. Difference is £23 in favour of the halogens. Is that a good buy?

LEDs use less electricity, so that will have to make up for the £23 extra cost of the hardware, so where is the cross-over point?

£23 @ 8 units per £ = 184 kWh or 184,000 Wh.

But the halogen uses 50W and the LED 10W, difference 40W to the halogen. 184000Wh/40W = 4600 hours to make up the difference, which is less than a quarter of the life of the LED.

But there is still 15,400 hours of life left in the LED, so your net saving in that time comprises 4 more halogens that you would have had to buy (£2) and you're not using another 15,400 x 40/1000 kWh = 616 kWh at 8 to the £, or £77

That's a total saving over the life of the LED of £79.

Note that this calculation has been heavily biassed in favour of the halogen, in terms of longevity and cost, and against the LED on the same grounds. Real savings could be double this.

Additionally, halogens come in one colour temperature, and the LED comes with a choice of three.

Upfront costs aren't everything, and electricity isn't going to get any cheaper.

[MM]

Nope. The real reason is that LED replacements for halogen are a relatively new thing and the manufacturers are fleecing us becase they can. It's always been like that. High cost to begin with, then more and more manufacturers come on board and the price plummets. In two years from now, they'll cost a quid each, not a fiver each.

MM

[Terry Fields]

In two years from now I will have already got my money back, while you're paying through the nose for the electricity for lighting. Your cheap LEDs in two years time will have cost you £shedloads.

All I did above was to calculate the costs of both halogens and LEDs, and showed that even on a worst-case scenario LEDs repay their cost. You can turn this calculation round and work out the cost of halogen lighting while waiting for LEDs to become cheaper, and that's what your cheap LEDs will really cost. It isn't all about purchase price and nothing else.

[Adam Aglionby]

LED comes in a choice of CTs yup, so do halogen for some puposes but LED co lour rendering is at best in the high 80`s, Halogen is 100.

Colour rendering is not LEDs strong point.

[MM]

Recently I bought a set of three bulkhead LED lights for around £3 from a Wilko-like store just to see what they were like. Each one has a diameter of about 6cm and contains 3 LEDs. Needs a couple of AAA batteries. You just stick the thing onto a clean surface.

Bloody horrible light! Dim, blue. Awful.

MM

[Terry Fields]

Jeezuz. Battery powered LEDs are optimised for efficiency, which means 'daylight white'. You can get this in mains-powered LEDs for domestic lighting, but there is also a far wider choice available.

Or to look at it another way...

I bought a cheap torch the other day that had a filament bulb in it it. Needed a couple of AAA batteries. Bloody awful dim yellow light! Dreadful thing it was. It'll never catch on and never replace LEDs.

[alan]

Only if they are running cool. A 10W LED isn't going to run cool in a standard down-light fitting.