Some designers and architects have a love-hate relationship with light-emitting diode (LED) lighting systems. While they are innovative with great potential for energy-efficiency, they represent a major paradigm shift for the design community, and their true reliability and lifetime is not generally known. However, most designers and architects are moving out of incandescent toward LEDs. And the Energy Independence and Security Act (EISA) ban on 100-watt incandescent light bulbs, scheduled to take effect on Jan. 1, 2012, will only serve to push more people towards the LED category in the coming months and years.
We asked Jeff Cunius, an engineer at CSL (Creative Systems Lighting), to give us an update on the latest LED developements.
Where are you seeing the most significant advances being made with LED sources and fixtures?
We are beginning to see LEDs with higher junction point temperatures. These LEDs can get up to 150 degrees Celsius, which is extremely hot. For architects and designers, a higher temperature means that they will be able to increase the light impact, ultimately decreasing the amount of LEDs needed to light a space—effectively lowering energy costs even further for building owners.
Do you feel that lumen efficacy improvements are keeping pace with expectations?
Yes. LEDs will only continue to get better. Three years ago when we started using LEDs, we were getting 25-30 lumens per watt. With all of the advancement of junction temperature, we are now seeing up to 100 lumens per watt. At CSL, we are value engineering all of our current LED Eco-Downlights, in order to reduce market costs while keeping the same light output. We are also working with a new heat sync material, which will double the light output from our current LED Eco-Downlight. Our goal is to introduce them to the market at the price point of our current LED Eco-Downlights.
There have been some complaints that LEDs are not as reliable as some manufacturers claim on their labels. Is that still the case today?
We have seen competitor claims that state the raw lumen output of the fixture instead of the net lumen output (after all losses). This can be misleading to customers who are not familiar with these terms. CSL will only publish net lumens, because it is the true measurement of light exiting the luminaire.
Any final advice for anyone considering LED lighting?
Designers and consumers should realize there are differences in the quality of the fixture and LED light bulbs manufactured. Low-end products may cost less for the consumer, but do not have the same light output as high-performance LEDs. For example, large hardware chains sell a lot of decorative fixtures with LEDs, but they are far from the light output of the same fixture with an incandescent lamp installed. This is how they keep their costs low. So, I would advise them to look for high-performance LEDs with at least 50,000 hours of life or more, 70% lumen maintenance and a minimum of 85 CRI.