HOW TO RECOGNISE A GOOD LED DOWNLIGHT
1. THE LED COLOUR TEMPERATURE MUST BE 2700K
When buying LED Downlights for your home, you want the same warm, ambient feel you are used to getting from halogen and incandescent lamps. ‘Warm white’ sounds ideal – but it‘s just a description, and not a very accurate one. To get the effect you want it‘s much better to look for the actual colour temperature, which is measured in Kelvin (K). To recreate the warmth of halogens and incandescent lamps you need a rating of 2700K. Both lamps shown here are described as ‘warm white’: the bottom one is 2700K and the top one is 3000k.
2. CHOOSE AN LED WITH A CRI OF 95+
Colour Rendering Index (CRI) The CRI tells you about the ‘quality‘ of light you‘re getting. It‘s a measurement of how well the light source will reproduce the true balanced colour range of the objects it illuminates.
So if you have a lovely brown leather chair or bright cushions and you want them to look their best, you need a high CRI score.
Traditional halogens and incandescent lamps have a CRI score of 99 out of 100, which means we are all used to an exceptional quality of light.
Most LED downlights have a CRI score of 80. That‘s fine for many uses in the home, but if you don’t want a 20% drop in light quality when you change over to LED, you need lamps with a CRI of at least 95.
In these images, high CRI lighting brings out the vibrant colours in the child’s play mat and the flooring. They both look just as good under the 99 CRI from the incandescent lamp (left) and the 97 CRI from our 11w LED Bulb (right). But the 80 CRI light makes everything look dull and flat.
DON’T DULL YOUR LIFE
See the colour difference in the two images below. The left image appear more vibrant and bright, it’s particularly obvious in the brown leather chair, the red throw and the wooden flooring. The High CRI Lighting in the top image is bringing out the true colours of the items whilst the low CRI LED’s are making everything duller and more sterile. As impactful as it is using images like these, the effects of CRI are far more visual and obvious in person.
3. GET A LIFESPAN GUARANTEE ON THE WHOLE LED LIGHT
When it comes to stating the lifespan of a lamp, LED companies often let optimism get the better of them. A good quality LED chip can last up to 50,000 hours, but the LED spotlight you buy will only last as long as its other components – which essentially means the power supply. Most power supplies have a life of 10,000 – 20,000 hours. At Well-Lit, we‘ve tested a lot of LED products. We‘ve yet to find an LED spotlight that‘s built to last 50,000 hours. What we do find are spots with components that are simply incompatible with the lifespan being claimed. Tip: Make sure the guarantee you get is for the whole LED Lamp and not the LED chip alone. This avoids problems if the lamps fails but the LED would still be functional – as it usually is.
4. CHOOSE AN LED WITH GREAT HEAT DISSIPATION
Without effective heat dissipation to protect the critical components, high temperatures will have a severe effect on performance and reliability. Designing and constructing an effective heat dissipation system requires specialised skills and high quality materials. Cutting corners in this area is a sure way to produce LEDs more cheaply, but at the cost of long-term reliability. As we‘ll see shortly, the capacitors inside the power supply can be particularly susceptible. But for now let‘s find out what good and bad heat dissipation looks like in practice. The first image shows an LED spot that‘s widely available in the UK. The red colour indicates the hottest areas. The heat dissipation system is virtually non-existent, and the generated heat is retained in the worst possible place – in the LED area just under the lens assembly. After just a few hours‘ use, the heat will start to compromise the longevity of the chip. The chances of this LED spotlight reaching its claimed lifespan are remote.
The next image shows our 7w Dimmable LED Spot. The lens area and the base containing the power supply – are blue, indicating that they are much cooler. The generated heat is dissipated to the casing, protecting the critical internal components.
5. CHOOSE AN LED WITH A HIGH QUALITY POWER SUPPLY
Many new converts to LED lighting are disappointed to find their lamps fail completely within a year or two of purchase. When we get these lamps on the workbench, we find the cause is usually the capacitors in the power supply – not the LED itself. These capacitors have a maximum temperature rating of anywhere between 80 degrees C to 130 degrees C. The higher the rating, the higher the cost to the manufacturer – you can probably guess the rest. Continuous operation at the maximum temperature will reduce the lifespan of the product. Operating above the maximum ratings is even worse. Here you can see a range of power supplies we‘ve recently taken out of LED Lamps on general sale in the UK. One good one, the rest a mixture of low cost, poor quality components and even some potential fire hazards.
MAKING YOUR CHOICE
Of course, some of these five differences are easier to check than others. But if the colour temperature and CRI information are present and correct, and the guarantee covers the whole lamp, there‘s a much better chance that the parts you can‘t see are up to standard as well.