The definitive low-energy GU10 lighting thread

[E36GUY]

It'll be the lux level as stated earlier in the thread. The amount of light offered over a distance will be decreased significantly. They will 'look' as bright but LED does as it's such an intense light source but the level of light say, 2M away from the lamp will be where the shortfall lies.

[anonymous-user]

I was looking to replace a blown halo GU10 light in a corner of a utility room, and decided it needed more light so thought I'd test one of the direct replacement luminaire LEDs.

As I'm too lazy to re-cut the existing GU10 downlight fittings hole and install transformers, I went for a 240v with 65-70mm cut out fitting as below.



12w, c900lm, 50 degree, 3100k. £34.80 inc vat

1.) Fitting (using some spare wago connectors), took c 5mins . Which is not bad, as I've often spent several minutes trying to fit new GU10 bulbs
2.) Light colour - more yellow than I expected. Will have a look at their Neutral White (3700k)
3.) Light spread - very good
4.) Amount of light - very good, much brighter across whole area. Could believe it's 2x brighter than GU10 halo it replaced.

Summary - not cheap, very bright, very easy to fit. Depending on long term, could be very good for those wanting high levels of light, and are,like me, too lazy to make new cuts out, use transformers etc.

[baxb]

E36GUY said:

PeterTTT said:

E36GUY
Whats you view on CRI and LED lights? Is it an important factor in choosing LED Lights?
Thanks
Peter

Absolutely! CRI is Colour Rendering Index. In LED this tends to be higher with warm white colours but essentially, the higher the CRI (to 100 max), the better real colours look under that light. Reds, Blues, Greens etc will all look more lustrous under a higher number. A lower number has a noticable blanching effect on these types of colour. Next time you go to the butcher, notice the meat is presented under a pink light. This red end of the spectrum makes your beef look dense and bloody. It's a trick!

Of late I have noticed lighting hungry businesses like hair salons rightly changing to LED to save energy and money but then getting it all wrong by being all lit up with cool white temperatures. As an industry that deals heavily in colour, this shows how little attention is being given to the lighting as this is completely the wrong colour for them to be working under. A lady's (or gents if that's your thing) hair colour will look completely different as soon as they step outside. Hopefully better under the higher CRI of daylight but notwithstanding, hair salons should give consideration to this.

Most white LEDs start as a blue light chip then a phosphor (the yellow you see over the top) is applied which changes the colour. LEDs up to a CRI of around 80 will have started life as blue. 90+ CRI will have started life as Red (with the phosphor added) and tend to be more expensive.

For most people, 80 CRI would be more than adequate.

The other thing to mention here in addition to CRI is Macadam Elipse. Briefly, this is a measure of how closely matched one LED's colour will be to another in terms of colour temperature. The higher the number of steps, the less match you are likely to get so even if lamps state 3000k temperature, you could see a variation +/- 500K which is visible to the eye if a higher step is in place.

This is will be especially noticable from products at the lower end of the market such as GU10 LED retrofits and cheaper down light fixtures. Not to look directly at but you will likely see different shades of white when they 'cone' onto a wall. Case in point below:



Architectural lighting companies will/should employ LED with a lower step Macadam Elipse thus a more consistent output. And that is what you pay for and the explanation to those wondering why company a is more expensive than company b for what the layman assumes is a similar product.

Bit late to this, but I was manning our company stand at Lux Live last week (big lighting expo) & spoke with a number of component suppliers as well as manufacturers & it was very interesting to hear that there is a market now for all grades of led chip, we manufacture commercial products (led panels, high bay lights, non-corrosive fittings etc) & choose from specific 'bins' to get colour consistency with products. The bins we choose for our panels have a tight spread (under 200 kelvin) to give good uniformity & consistency but are more expensive as a result, the bin corresponds with the position on the sheet the chips are 'printed' to. Some bins will have a wider range (500k+) & others are rejected altogether.

Actually they are not, as nowadays some manufacturers will take the cheapest chips they can & use them in their products regardless of colour consistency or uniformity because cost is the overiding factor in product 'development', but if it means they can bring a 600x600 panel to market for under £35 they will. So with a combination of low grade led chips & cheap labour (another subject, but certainly up to last year there were 'children' working in some chinese factories a collague visited - as his western face walked in the room quite a few of the staff cleared off out of the other door sharpish !) you can bring a product to market for 25% of the cost of a decent quality product. To put a PH slant on it i'm not comparing a Ford Mondeo with a Rolls Royce but rather a 2nd hand ratty Tata Nano with a Ford Mondeo !

[markbigears]

Brendan, I saw this was on last week at Excell, was I mainly commercial? Anything took your eye from the domestic market?

[baxb]

I didn't get much of a chance to look around, they cost a fair but to exhibit at so I am on stand the whole time bar the odd 5 min comfort break. My technical manager did have a look about but it was more to see what was out there for lighting controls, domestic is not really our thing (you need Guy for that !) so didn't spend any time looking at domestic/residential stuff.

There was a mix of commercial & domestic products, but also quite a range of component suppliers ranging from drivers to control systems. It's fair to say that at least 95% of all lighting on display was led, I saw one neon lighting stand & one induction lighting stand, no manufacturer had any fluorescent/halogen stuff on display that we could see.

Edited by baxb on Tuesday 25th November 11:00

[Gazzab]

Gazzab said:

I take it back...the quality of light is ok but not great. The brightness is fine and the colour seems ok. But there is something not quite right. I can't quite explain. My son is happy with it though.

Of the 5 bulbs fitted on Saturday, 3 have stopped working and 2 are flickering. Suspect its not the lamps but the driver....

[Matt_N]

Gazzab said:

Of the 5 bulbs fitted on Saturday, 3 have stopped working and 2 are flickering. Suspect its not the lamps but the driver....

I was under the impression that a lot of MR16/GU5.3 LEDs will not work properly on a normal 12v transformer, meaning you have to switch it for something else.

[hairyben]

Matt_N said:

Gazzab said:

Of the 5 bulbs fitted on Saturday, 3 have stopped working and 2 are flickering. Suspect its not the lamps but the driver....

I was under the impression that a lot of MR16/GU5.3 LEDs will not work properly on a normal 12v transformer, meaning you have to switch it for something else.

The mr16 retro-fits are designed to work on 12VDC as supplied by trans. Torridal trans should be fine, they might or might not work on electronics as electronics can have min loads of around 20w, dimming brings more pain as with dimming you're now hoping 3 different set of electronics will integrate.

Gazzab if it's not already I'd try a torridal transformer to feed the track, might evan bring back your dimming if you're lucky, I find the sylvania MR16 LED while not cheap are pretty nice.

[Gazzab]

Thanks but I suspect this will go beyond my electrics knowledge.
There is a grey round unit on the wall that is a transformer (wound?) and this then sends 12v down the wire to power all 5 lights. Could I then open it up and remove the contents and place a different transformer in it? One that can power all 5 lights?

[Alucidnation]

Just get the correct rated LED Driver for all 5.

[Gazzab]

Yeah I would like to replace the transformer. I think current one is torridal. So suprised it's not working but suspect it doesn't deal with the lower wattage. So I guess a suitable electronic one will do and hide it in the current transformer casing. Just need to identify the right driver that will work with 5 x 5w led maps in parallel.

[Gazzab]

Halogens back in. 3 of the LEDs have burnt out and the other two smelt a little like they had started to burn. So all going in the bine. Sadly I can't fit downlighters as it's a loft room without a ceiling as such.

[hairyben]

Gazzab said:

Halogens back in. 3 of the LEDs have burnt out and the other two smelt a little like they had started to burn. So all going in the bine. Sadly I can't fit downlighters as it's a loft room without a ceiling as such.

Mains voltage track such as http://www.toplightco.com/acatalog/HV_Track_Fittin... down the apex can look pretty nice. Wide range of different spotlight fittings can then be plugged into it- and moved/altered/added to as desired. If it's a big attic 3 circuit track allows flexible lighting

[Alucidnation]

Gazzab said:

Halogens back in. 3 of the LEDs have burnt out and the other two smelt a little like they had started to burn. So all going in the bine. Sadly I can't fit downlighters as it's a loft room without a ceiling as such.

Did you fit a proper LED driver in the end?

[smn159]

@E36GUY - sent you a PM at the weekend which you may not have seen, as I'm potentially interested in 8 x ZEP1's

Kitchen being plastered today, so thoughts turn to lighting

[BGARK]

Without going through all 20 pages, where is the best recommendation for GU10s

I purchased 20 from: http://www.ebay.co.uk/itm/10-X-GU10-9w-12w-Dimmabl... All blown within 6 months, pants quality!

Thanks

[markbigears]

Just replaced kitchen with philips master 4.5w and 5.4w. Nice warm white and very bright.

[E36GUY]

BGARK said:

Without going through all 20 pages, where is the best recommendation for GU10s

I purchased 20 from: http://www.ebay.co.uk/itm/10-X-GU10-9w-12w-Dimmabl... All blown within 6 months, pants quality!

Thanks

I'm afraid at £3 a pop this was only ever going to be the case.

[Gazzab]

Alucidnation said:

Gazzab said:

Halogens back in. 3 of the LEDs have burnt out and the other two smelt a little like they had started to burn. So all going in the bine. Sadly I can't fit downlighters as it's a loft room without a ceiling as such.

Did you fit a proper LED driver in the end?

No I refitted Halogens and gave up! I dont know which electronic driver I need and cant find any links to anyone who has done the same. Did read one site where they were concerned about RF in this situation... (ie where its a parallel cable track).

[BGARK]

E36GUY said:

I'm afraid at £3 a pop this was only ever going to be the case.

Yes ok I get the point, so once again who should I use?