Problem No. 2: LEDs flicker and often badly. If you buy an LED replacement lamp and put it in the lighting system in your home or office and it has a dimmer on it, you’re introducing the same nasty flicker that was associated with fluorescents lamps before the electronic ballast. That flicker causes headaches in about 20 percent of the population if you work under it all day. Why would we knowingly put in a lighting system that causes that kind of flicker unless we were in a race to the bottom?
No. 3 is compatibility problems. There are hardly any standards for LEDs. As a result, if you buy an LED and screw it into a fixture as a replacement lamp, there’s no assurance it’ll work on the dimmer that’s connected to it. In commercial settings, the compatibility problems can be significant.
No. 4 is glare. LEDs are extremely bright and they create a unique type of glare we’ve never had to deal with before. The extreme brightness of LEDs has only begun to be addressed as a significant issue. Once again, the exaggerated blue light from LEDs is a big part of the problem due to retinal stress. In 2011, French scientists were the first to express concern by banning LED in schools because of the risk of ocular damage to children under the age of 18. Developing eyes are not naturally protected against the high concentration of blue light. More recently, ophthalmologists have been warned to limit examination light exposure when LEDs are used, for similar reasons.
r: if there are no standards, how can our readers distinguish good LED products from bad?
Benya: Differentiating good LEDs from bad is not easy, and don’t expect that to change quickly. But if you are willing to acquire a few new skills and tools, you can make much better decisions immediately.
When it comes to the color of the LED, consider buying a field spectrometer like the AsenseTek Passport, UPRtek MK350, or one of several meters from Minolta or other companies. Measure the LED you are considering, and compare it to natural light of the same approximate color temperature. Be prepared for a shock at how badly LED lighting compares. Also compare competing LEDs and you will realize how important measurements can be and how bad some LEDs really are. To be blunt, color temperature, or CCT, and color rendering index, or CRI, are no longer good enough to reveal strengths or shortcomings of LEDs. Since Energy Star standards are far too low for my interests, I guess I’d have to say that what few standards we have are probably not good enough.
There are several flicker meters, and flicker can be spotted by the camera on most cell phones. Try recording the light for five to 10 seconds, and often the strobing will be very apparent. As for glare, use your eyes–if it is glaring, you will know it.
There are organizations whose primary interest is independently evaluating LED lighting. Perhaps the most important for commercial work is the Design Lights Consortium, or DLC. DLC was founded by the Northeast Energy Efficiency Partnership, NEEP, a regional non-profit that strives to accelerate efficiency solutions to create lasting change in the marketplace. NEEP founded DLC because utility companies want to give rebates for putting energy-efficient lighting in place but also want to ensure the rebates are given for good-quality products and not junk. There is so much junk and so many lies about how lighting performs!
One of DLC’s main jobs is to make sure products meet minimum standards of quality. But it’s a voluntary standard. You can still buy junk, but a utility company won’t give you a rebate if you haven’t bought something that meets DLC standards. Of course, like anything else, DLC standards are abused. I find companies that claim their products are DLC-listed and they’re not. [Peruse DLC’s Qualified Products List.]
r: What are some of the best and worst LED products available now?
Benya: I am personally not fond of LED replacements for fluorescent tubes. Most LED replacement tubes save energy by reducing the amount of light. Alternately, you can put in a fluorescent replacement tube that uses fewer watts and produces less light, too. But the LED replacement tube will cost $30 to $40 per tube, and the fluorescent replacement tube costs $5. I feel that if you want to save the maximum amount of energy, it is probably better to invest in a new LED luminaire, which is more attractive and 25 to 30 percent more efficient than the best fluorescent.