HOW WE TESTED THE KIT

www.luxmagazine.co.uk | November 2010 | 59

LED DOWNLIGHTS LUX RECOMMENDS

Tried and tested – the UK’s top LED downlightsLux magazine doesn’t just recommend products – we take ‘em apart and put ‘em back together. And then, just to make sure, we have them independently tested in the UK’s most rigorous lighting labs.

Selecting LED downlights is real headache. There’s the claims and counterclaims – not to mention spec sheets that make the plot from Lost look like a model of clarity and consistency.

So to help specifi ers sort the wheat from the chaff, we’ve taken the most popular brands of LED downlights and given them a Lux MOT. We examined the quality of the light, the standard of engineering – and then we tested them for output and effi cacy at the industry’s most respected laboratories – 42 Partners in Wolverhampton.

They checked all our downlights on state-of-the-art equipment using best-practice procedures.

Minefi eld When they’ve come through all that, the Lux expert panel of engineers and LED experts is happy to stick the ‘Lux recommendation’ label on them.

So if we say the downlights are Part L2 compliant, that’s because we’ve tested them to make sure they deliver at least 55 lumens per circuit watt – an extremely high bar for LED technology to reach.

Specifying LED lamps and luminaires is a notorious minefi eld so it’s worth remembering a few ground rules.

Our tests were carried out by UK’s leading lighting test laboratories at 42 Partners in Wolverhampton. They were tested strictly in accordance with EN13032 in an integrating sphere (rather than the more forgiving gonio where the LEDs can run cooler) at a stable 25 degrees C, and after 100 hours of lamp pre-conditioning. E� cacy is lower than manufacturer ratings due to losses in the luminaire. We measured the e� cacy of luminaire lumens per watt which includes the driver.

42 Partners 21 Woden RoadWolverhamptonWV10 0AUUK Tel: +44(0)1902 453650richard@42partners.comian@42partners.com

Stick to trusted brands – they have more to lose if the products don’t deliver. Also, if you go on the Internet to fi nd a particular luminaire spec – such as the colour rendering, effi cacy, photometry or colour temperature – and it’s not easy to fi nd, that’s because the manufacturer doesn’t want you to fi nd it.

But don’t believe the sceptics: LED luminaires – at their best – are more than a match for traditional fi ttings. Just make your selection with care.

Our tests were carried out in an integrating sphere

electing LED downlights is real headache. There’s tr

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POWER FACTOR AND LEDS The lowest power factor we measured in our tests was 0.77. But many LED products, especially LED lamps, are much lower than this and can be as little as 0.5. A case can be made that low power factors increase the energy used, with commensurate carbon emissions. With traditional lighting systems, specifi ers have become used to high power factors of over 0.9, and they expect it with solid state lighting. But it costs the manufacturers more to make LED lamps with a high PF of 0.9 – and it creates more fl icker. The debate about power factor is currently raging amongst manufacturers, and if they can’t convince the world that low PFs acceptable, they’ll have to bite the bullet and rework the products.

ENGINE: FortimoRATED POWER: 32 WRATED OUTPUT: up to 2000 lmRATED EFFICACY: up to 63 lm/WCOLOUR TEMPERATURE: 4000KCOLOUR RENDERING: Ra80BEAM ANGLE: 65 degreesPRICE: Around £600OUR VERDICT:

★★★★★

RECOMMENDSBest CFL downlight replacement

PHILIPS LUXSPACE

60 | www.luxmagazine.co.uk | November 2010

LUX RECOMMENDS LED DOWNLIGHTS

This is the state of the art in LED engineering. It delivers 60 lumens a watt, a stonking performance that we have confirmed in our independent tests, making it comfortably Part L2 compliant for use in commercial areas. The optics are superb and the Fortimo engine delivers enough lumens to make it a comparable replacement for a twin 18W CFL downlight. But all this precision engineering comes at a price – one that’ll have to be justified by significant maintenance savings.

RECOMMENDS

Best halogen downlightreplacement

PHOTONSTAR LASER LITE

ENGINE: Cree XPGRATED POWER (LUMINAIRE ONLY): 9.1WRATED OUTPUT: 577-770 lumensCOLOUR TEMPERATURE: 3000KCOLOUR RENDERING: Ra>80BEAM ANGLE: 12 degreesPRICE: TRADE £76OUR VERDICT:

★★★★The 55-luminaire-lumen-per-watt metric of Part L2 is not an easy bar to reach, especially in a warmer colour temperature, but the Laser Lite – with the new Cree XPG engine at its heart – hits it comfortably. The narrow beam angle of 12 degrees helps get more of the light out of the luminaire, giving a better LOR (see Tech Briefing, page 96) but this is a difference of only a few percentage points. A lot of product for the price.

www.luxmagazine.co.uk | November 2010 | 61

LED DOWNLIGHTS LUX RECOMMENDS

BEST FOR COLOUR RENDERING PROJECTION LIGHTING

ALPHALED ARTIST

ENGINE: Xicato ArtistRATED OUTPUT: 400 lumensCOLOUR TEMPERATURE: 3000KCOLOUR RENDERING: Ra98BEAM ANGLE: 70 degreesPRICE: Around £75LUX VERDICT:

★★★★This downlight is all about the colour rendering. The highly impressive Xicato Artist module delivers an awesome Ra98 – confirmed in tests by our colleagues at the UCL labs. This makes the AlphaLED Artist more than a match for halogen – and perfect for demanding retail apps.

WHAT SPECIFIERS SAY: I like this product range and its a�ordability. It’s been the product that has brought LED lighting within a reasonable budget for general lighting.

I’m currently using it in a hospital project where we would have used low voltage halogen before.Kevan ShawDesign Director KSLD Edinburgh

BEST VALUE OSRAM LEDVANCE

ENGINE: 9 Golden Dragon LEDsRATED POWER: 13.5WRATED OUTPUT: 680 lumensCOLOUR TEMPERATURE: 3000KBEAM ANGLE: 36 degreesPRICE: Around £100LUX VERDICT:

FIVE MORE TO CHECK OUT

★★★You don’t get much for £100 these days but for this price Osram’s LEDVance gives a great balance of power, efficacy and colour temperature for the price tag. The warm 3000K colour temperature makes it a good alternative to low voltage tungsten halogen while using a quarter of the power.

BEST OUTPUTACDC HURRICANE 50 (formerly Evolution II)

ENGINE: Xicato/ACDC RATED POWER: 20WRATED OUTPUT: up to 1,000 lumensCOLOUR TEMPERATURE: 3000KCOLOUR RENDERING: Ra>80BEAM ANGLE: 40 degreesTRADE PRICE: £95LUX VERDICT: ★★★

If you’re looking for high output in a small package then this is your baby. The well-engineered Hurricane 50 can be mounted in a 100mm diameter format and has an innovative liquid-cooled heatsink that gives up to 1,000 lumens with a decent efficacy, a respectable CRI and a warm colour temperature.

WHAT SPECIFIERS SAY:ACDC Evolution Devil Cree XPE (9 LEDs)The ACDC Evolution is the first I have seen that begins to match the quality of light produced by tungsten halogen. Colours are well rendered and e�ciencies are

good. The only downsides are the depth required to accommodate the heat sink and the cost.Kevin Theobald IALD MSLLKevin Theobald Lighting Design

BEST FOR FUTURE PROOFINGEXLED SOLARA AEON 32-3-S

ENGINE: Bridgelux Helieon 1200RATED POWER: 20 WRATED OUTPUT: 1040 lmCOLOUR TEMPERATURE: 3000KCOLOUR RENDERING: Ra82BEAM ANGLE: 32 degreesPRICE: Around £175LUX VERDICT: ★★★We’re fans of the Bridgelux Helieon LED module as it has a great balance of price and performance, and has allowed a swathe of OEM manufacturers to enter the market. Best of all, you can change it like a lightbulb. This downlight has good colour rendering and efficacy for the price.

BEST FOR DIMMING JOHN CULLEN POLESTAR

ENGINE: AmbientDimRATED POWER: 8WRATED OUTPUT: 402lmCOLOUR TEMPERATURE: 3000KCOLOUR RENDERING: Ra84BEAM ANGLE: 10-35 degreesOUR VERDICT:

★★★★Aimed at residential applications, this product is engineered to have the look and feel of low voltage halogen. The colour rendering is comparable to halogen but best of all is that the Polestar’s engine, the AmbientDim, has been designed to warm up when it dimmed, where colour temperature will fall to 2664K.

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LUX RECOMMENDS LED DOWNLIGHTStr

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