Know the right questions to ask about LED lighting
Customers are being bamboozled by misleading claims about LEDs. Don’t get caught out – learn how to tell a good-quality LED from a poor-quality one.
For universities with CO2 targets to meet and a steep maintenance burden to reduce, LED lighting looks like a potential saviour. The long life, high efficiency and compact size of LED lighting are making it a must-have option for university premises. Yet the LED industry has become something of a ‘Wild West’. Customers are being caught out by unscrupulous suppliers.
“With little regard for regulation, an alarming number of newly-formed ‘lighting’ companies are now promoting LEDs,” comments Simon Shenton, Head of Lighting Design at Tamlite Lighting. “At best, through lack of knowledge, at worst, knowingly, these companies are boasting misleading energy-savings figures and lifespans. This means that the burden falls on the purchaser to ensure they’re buying good-quality LED lighting.”
Knowing the right questions to ask about the LEDs you’re buying can be the difference between a successful lighting installation – and one that’s completely unfit for purpose.
1. What’s the Colour Rendering Index (CRI)?
“Good colour rendering means that the LED light source reproduces colours accurately, so reds look red, blues look blue, and yellows look yellow,” says Tamlite’s Simon Shenton. “An LED product with a low Colour Rendering Index (CRI) will make some colours look great and some colours look terrible.”
Tip:The minimum acceptable CRI is 80 for Health & Safety requirements where people are present for long periods of time.
2. What’s the colour temperature?
“An ideal light source mimics daylight in terms of warmth and colour,” says Tamlite’s Simon Shenton. “However, an LED on the extreme blue end of the visible light spectrum (in scientific terms: 6000+ Kelvin) will feel Arctic! ”
Tip:Look for a colour temperature of 3500–4000 Kelvin, which will create a comfortable, warm-white colour appearance.
3. Is the light output quoted - the net figure, including losses from the luminaire?
“Some companies may misrepresent the efficiency of the LED, by quoting the efficiency of just the bare LED, rather than the efficiency of the whole unit, including the luminaire,” says Tamlite’s Simon Shenton. “Since, when you slot an LED into a luminaire, you naturally lose some of the efficiency, this makes the energy-savings figures look better than they really are.”
Tip:Always make sure you’re quoted the net figure for light output.
4. Who is the LED chip manufacturer?
Tip:The main manufacturers of LED chips are Philips, Osram and CREE. Other manufacturers are perfectly acceptable, but do ask and then compare.
5. What’s the LED lifespan based upon?
“Many new players in the LED market are not bothering to carry out testing on their products to find out the efficiency and lifespan, so their quoted figures are mere guesswork,” says Tamlite’s Simon Shenton. “If you’re told the LEDs will last for 100,000 hours, beware! This might technically be true – some of your LEDs may still be giving out some light after 10 years’ continual use – but the drop-off in quality of LEDs after about 50,000 hours is such that you’ll want to replace them anyway.”
Tip: When quoted a lifespan, ask what the figures are based upon, and then cross-reference with others.
When meeting with LED suppliers, don’t be afraid to ask these types of questions. Any true lighting professional will be able to provide you with the right documentation to prove their LEDs aren’t just energy-efficient – they provide good light quality, too.
University Business - University Lighting