This question was answered by firstname.lastname@example.org.
The reader who asked this question is looking to change all the T5 lighting at an indoor bowls club, and is confused by all the different variants available for providing a 500 lx level of lighting at the bowling green. (This is specified by the National Governing Indoor Bowling Association.) The club has been offered a 1200 x 600 5000K 50W panel, described as having a diffuser which is omnidirectional and anti-glare.
The simple answer – and the correct one – is to engage someone who’s an expert in lighting technology to find and specify the best equipment for your circumstances. Unless you are an expert in such matters, there is no way that you can negotiate the labyrinth that is the current marketplace for LED panels. And here’s why.
The light market is completely unregulated. Yes, fixtures still need to be electrically safe to use and fit for purpose, but there is no standard for lighting performance. Before the arrival of the LED we ‘knew’ what to expect from light sources, because every manufacturer built their T5 lamps, for example, to the same performance standard. And, because of that, end users could have some kind of guarantee as to how things worked. Some fixtures were better than others, of course, and the cheapest fixtures usually didn’t perform as well as those that had proper optics built into them – but at least we knew what the lamps were doing.
Let’s deconstruct the description that our reader was given: 1200 x 600. 5000K. 50W. Omnidirectional. Anti-glare. It all sounds reasonable and plausible, but what do we actually know?
We have the physical size (1200 x 600), which is useful.
We have the colour of the light (5000K), so we can judge that this is a cold white light which may have been selected by the manufacturers out of choice, or simply because the colder white LEDs provide more light than the (often preferred) warmer versions (3000K to 4000K).
We know how fast the meter will go round. It’s a 50W fixture. But is that a reasonable figure, or not?
We’re told that the light output of the fixture is ‘omni’ directional, but that just means that the light is generally falling out of the front, which is what you expect in the first place.
But we’re also told that it’s anti-glare. Is this at odds with the ‘omni’ direction just described? And why hasn’t the manufacturer stated its glare characteristics? If it really does have decent glare control, you’d expect to see ‘UGR19’ somewhere. This is the universal glare rating – and it’s an important metric.
But what don’t we know?
We don’t know how much light the fixture is providing. There is no lumen output figure. We don’t know the rated life of the fixture. How long before you need to replace them? We don’t know what the deterioration in light output is over time (and this is becoming a serious issue with cheap LED panels). Does it need to be a fire-rated panel? There’s no indication here.
All in all, this reads like the description from an internet-based operation for a very cheap fixture that will fail early. As a colleague of mine says in this very context: buy cheap, buy twice. (Note that this judgment is based solely on the information supplied by the reader.)
Here are a few tips to avoid buying twice:
- Know where (and who) you’re buying from. I always insist on knowing where to find the physical premises of a company, and Google maps is great at checking whether 13B Acacia Avenue is an office building, or the garage to someone’s bungalow.
- Find someone to trust. If you can’t afford to get independent advice, then go along to your local wholesalers and talk to them. Can you trust them? Do they seem to know what they’re talking about? (Bear in mind that anyone who is selling to you is more interested in hitting their sales targets than necessarily giving you the best answer.)
- Try to find the website of the makers of the fixture, not just the product seller. If you can’t find it, walk away. If you find it and it doesn’t impress with any technical information on the products – walk away.
- Never buy unless you have a full set of technical data on the product you’re looking at.
- DON’T BUY CHEAP. The biggest problem we face in the LED world is the idea that you can buy well by buying cheap. No, you can’t.
Personally I use UK-based companies as gatekeepers of good product. I know that their reputation is important to them and I trust them because of that. If you know someone who can offer you free and independent guidance, please consider them as your first stop. Otherwise, write a specification brief of what you’re looking for in terms of the lighting performance and get your supplier to confirm IN WRITING that the solution they are proposing will satisfy that brief. You may like to get legal support, too – because you might end up having to threaten someone with legal action.
If you’d like to ask a question about lighting, write to our Application Editor,
John Bullock: email@example.com
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