Our Approach to LED Technology
Planet Lighting has been incorporating LEDs into light fixtures for nearly a decade, with installations across the world. We continue to push the boundaries in what is possible, by sourcing and utilising the brightest, most efficient LED emitters and state of the art driver solutions to maximise overall system efficiency.
We have the knowledge and experience to offer tailor-made, elegant driver solutions incorporating not only all major dimming protocols (DMX, DALI, DSI, PWM, 0-10V, leading and trailing phase edge dimming) but also emergency UPS supplies and solar PV.
LED Lumen Maintenance & Mortality
Comparable Data (product life times)
Unlike an incandescent where the filament snaps, LEDs rarely fail catastrophically. In saying that, it’s worth pointing out that a poorly designed LED fixture has a larger likelihood of sudden failure - correct fixture design is vital in ensuring LED longevity.
What typically happens to LEDs, is over time they become gradually dimmer as the components in the diode degrade. For this reason, the concept of lumen maintenance becomes significant.
L70 stands for 70% lumen maintenance and it’s of importance in LED lighting as it’s been determined as the threshold where the human eye can detect light output reduction.
For a commercial application where the lights are on 10 hours a day 5 days a week, this translates into about 20 years. In a private home, where the light may be on for 5 hours a day every the L70 life span is over 25 years.
Because of their long lives, LEDs are becoming increasingly popular and just about everybody in lighting is now offering LED solutions. What is becoming problematic for many consumers, however, is being able to accurately compare the different products available in the marketplace.
How can a poorly designed LED fixture that is likely to fail or have a short life, be differentiated from one that will last the distance? There are a few key areas in LED design that makes all the difference.
Thermal Management
Effective thermal management is essential in obtaining optimum performance from an LED light source. LED longevity, or lumen maintenance L70 figures are dependent on a solid thermal path to actively and efficiently dissipate heat away from the junction. Keeping LED junction temperature low keeps LEDs brighter longer and reduces the likelihood of catastrophic failures. It also allows installation of the fixture in environments with high ambient temperatures.
At Planet Lighting we take our heat-sinking seriously. Since 2002 we’ve sold over 40,000 LED fixtures and know a thing or two about thermal management.
System Efficacy
Many LED luminaires claim lumens per watt (efficacy) taken straight from the values obtained by the LED chip manufacturer in a lab environment, and do not take into account losses in the fixture itself (reflectors & thermal pathways) and LED drivers.
Once incorporated into a fixture, the system efficacy may well be lower than CFL or other conventional light source equivalents. In the last couple of years, a myriad of LED downlights have become available on the market, but very few manufacturers can offer a total system efficacy taking into account driver losses.
LED drivers is generally not given the attention they deserve. Yet, drivers play an important part in determining overall system efficacy and longevity. What’s the point of an efficient long-life LED if the driver not only is inefficient but will fail within a year or two ?
Planet Lighting base all our data on real life scenarios and provide photometric data and spec sheets for all our LED fittings. Overall system efficacy is another focal point, and we only use efficient drivers with long lifetime and reliability data.
Colour Temperature
A general rule of thumb is that the warmer the colour temperature of the LED, the less efficient it is. There are ways, however, to get a warm colour temperature without compromising too much in terms of efficiency and light output – but you need to know how to! Our motto at Planet is ‘Sky’s the limit’ and although we have a range of standard colour temperatures we offer, we’re happy to explore the road less taken and use our expertise and knowledge to create custom solutions for our customers in any colour -including RGB- or colour temperature.
Planet Lighting Standard Colour temperatures:
- 5300K – Daylight White
- 4000K – Neutral White
- 3500K – Mid White
- 3000K – Warm White
- 2700K – Incandescent White
Colour Rendering Index
Colour Rendering Index (CRI) was developed to assist in evaluating the appearance of colours under different light sources. A high CRI, in theory allows, an object’s colour to appear more natural. For example, by default an incandescent lamp has a CRI of 100, yet it is difficult to distinguish shades of blue and black under low levels of incandescent lighting. This is because an incandescent blub is weak in the blue end of the spectrum. Although, CRI has its limitations it remains a useful tool to compare lights, particularly those of the same colour temperatures (CCT).
The general rule of thumb regarding CRI is ‘the higher the better’. In the LED world, a high CRI typically was achieved at the cost of efficacy (low lumens/watt). Planet Lighting is one of the first LED downlight manufacturers to offer genuine high CRI without compromising system efficacy.
LED Fixture Check List
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LED Life
Many manufacturers don’t offer an L70 of 50,000H. Instead the longevity of the fixture state for example 50,000H– which is vastly different from an L70 of 50,000H as that number refers to the total life of the fixture. It’s also worth noting that some fixtures have an L70 of 20,000H or 30,000H meaning that the longevity of these fixtures will be significantly less than a fitting with an L70 of 50,000H.
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Lumen Output
Check the numbers carefully. Frequently, lumens output values are not converted to real world scenarios and refer to figures obtained straight from the LED emitter in a controlled environment in a lab. Thus, they do not take into account fixture losses. Manufacturers of fittings incorporating warm LED emitters tend to be somewhat liberal in the truth when it comes to lumen output figures, and some may allude to figures obtained from cooler temperatures, which are brighter and more efficient.
Respectable purveyors of LED lighting provide accurate photometric data – at Planet we have IES files for all our LED fittings.
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Efficacy - Lumens/Watt
Efficacy is another area where certain manufacturers chose to be liberal with the truth. Many LED emitters have an optimum efficacy when run at 350mA – and it’s this figure and not a real life scenario which is bandied about. An LED run at 700mA or more will be brighter, but typically not as efficient.
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Drivers & System Efficacy
It pays to check driver life and reliability (MTBF -Mean Time Between Failure- data as well as comparing the efficiency of different products.