Timeguard’s LED Equation

Timeguard’s LED Equation

Andy Douglas, Managing Director at Timeguard asks: “How did buying LED lighting get so complicated?”

It started with looking at the “equivalent wattage” output, checking the price and buying. Then we started to see different designs to choose from so the cosmetics became important. Then the market started to see a few failures and realised that, despite the low power consumption, these devices still needed to be built with guaranteed quality (and that some of those design features were more than cosmetic, they had a technical purpose).

Then with LED lighting extending its reach and being offered for virtually any use, indoors and out, automatic on/off timing became an issue, and we could see the importance of rating switches and drivers to withstand the repeated, surprisingly high, power surges that implies. On top of that, people quite rightly started getting pickier about the quality of the light, the field of illumination and the ambience it created: so the design of the LED array, the lenses and the back plate reflectors assumed greater importance.

A simple choice became a lot more complicated… The short answer is, of course, to go with a trusted brand name. Still, even then you need to check the specification to make sure any integral PIR switches are actually rated for LED and check the small print to see if they are good enough for at least a three-year warranty (which should surely be the industry benchmark by now?).

Watts vs lumensTimeguard-LED-3
We need to stop buying LEDs according to the energy they consume and focus instead on the light they give out (lumens).

We all know that consumption will be low, but people won’t swap to this low energy alternative unless the light is good! Broadly speaking, if you want output similar to an old 60W incandescent, look for around 800 lumens. For the equivalent of an old 40W bulbs, look for 450 lumens. Our LED floodlights deliver over 2000 lumens while consuming only 32W. Instant brightness should be a given.

Do all LED luminaires deliver the same lumens per Watt? No, lumens is the measurement of light output after optical inefficiencies, the wattage is the total power consumed by the luminaire after thermal effects, driver losses. Considered collectively, these loss mechanisms can result in a decrease in efficacy of greater than 30% according to the US Dept of Energy. You can’t do much about heat loss other than to dissipate it effectively, but a manufacturer’s choice of components and the design of the luminaire of optical efficiency can deliver improved efficiency. You could argue that the energy savings are marginal at an individual user level, but it soon adds up for a whole building or business. Of course, you would expect that a manufacturer whose quality control had drilled down to ever last component will also have created a better product overall. The biggest inefficiency of all, is poor componentry or production QA that fails, so that the product needs to be replaced.

“You could argue that the energy savings are marginal at an individual user level, but it soon adds up for a whole building or business.”

Saving a few pennies on a luminaire with a substandard driver or PIR just does not make commercial sense if the kit Timeguard-LED-2fails and the job has to be done twice.

Yes, it’s true that LEDs generate relatively little heat – but even this is potentially a problem for enclosed LEDs in particular in outdoor lighting where the IP rating is generally high to protect the luminaire from the elements, but this also restricts the air flow and cooling to the luminaire. Gradually, and eventually, the heat produced by the LEDs is going to degenerate the LEDs themselves and the electronic components surrounding. So look for proper cooling fins and pins, not just a few holes in the casing.

Another consideration is PIRs. Whether it is providing outdoor security lighting or automating internal lights and HVAC systems to conserve energy, PIR detectors are everywhere. Just when you thought these were products you could sell over the counter without too much thought, out comes a warning about LED compatibility. All LED lamps and luminaires must use a type of driver or voltage reducing circuit as for AC LEDs and this driver or voltage reduction circuit can cause current spikes at switch-on that far exceed the PIR’s normal operating current and shorten the life of the switch in the PIR. Poor power factor of many LED lamps and drivers can also reduce the PIR’s life and can result in false claims of efficiency (Lumens/Watt) by manufacturers.

The LED arrays, lenses and back plate reflectors combine to create the right light ambience; be it a focussed beam, a wide field for security coverage or warmth indoors. Daylight, cool white and warm white are common options. Daylight and cool white are typically used for in or outdoor lighting, warm white is often preferred for just indoor use, although we also chose it for our carriage lantern style outdoor LED light fittings.

Another important point within the design is “how easy is it to install?”, and “how does it look once installed?” The norm is to still use a simple wall bracket which is both practical and lower cost, but the flood is generally then fixed in its direction and not easy to adjust. An option could also be use products with the “pan and tilt” feature built in, such as the Timeguard range of single and twin LED floods (LED100 / LED200, both with and without PIRs) so the installer/user can quickly and simply direct the LED floodlight to the area to be covered and adjust the length of the LED beam through tilting the flood head accordingly. It’s worth noting that these stylish design LED floodlights also offer the simplest installation as they simply plug-in to a pre-wired back case. They really are that very easy to fit.

So how can suppliers make it less complicated? Simple: manufacturers put all the information you need online and readily visible on the outside of the box, and good wholesalers only stock good products.

For more information visit: www.timeguard.com

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