DOE Shedding New Light on Old Fluorescent Tubes

It’s just basic human nature, this urge to fit in, be part of the crowd, to latch on to the new and the trendy.

And what’s the trendy herd bleating about today? It’s LED (light emitting diodes), a fashionable, environmentally popular lighting source that purports to be everything the fluorescent tube is not.

LEDs are associated with the modern and hip, illuminating everything from TVs to iPads to the desert sky above Las Vegas. Fluorescents are viewed as a throwback to a time when cool, white tubes hummed and buzzed above soda fountains and Rambler dealerships.

LED replacements are the latest green cause celebre due partly to the physics-defying efficiencies claimed by manufacturers. This is especially true with the calls for LED replacements for T8 fluorescents, which is the standard overhead lighting in most public buildings. How do these LEDs really measure up with their fluorescent counterparts? Not well, according to a U.S. Department of Energy performance test (available at http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/t8_replacement-lamps.pdf).

The DOE tested a dozen LED four-foot tubes designed as direct replacements for the T8 fluorescent. Their conclusion: “LED T8 replacement lamps performances fall far short of fluorescent benchmarks. To provide equivalent light output to fluorescent T8s and also save energy, LED T8s will need to become two to three times more efficacious than they are today.”

That’s right; LED T8s would have to at least double their efficiencies to match today’s fluorescent tube in both luminosity and energy savings. How did the herd become so enamored with LED’s promises?

Many LED comparison tests are conducted against incandescent lighting, which is something of a dinosaur in today’s workplace, or they’re matched against CFL (compact fluorescent) bulbs designed for home use.

And when head-to-head tests are done with fluorescent tubes in commercial settings, the manufacturers claim they use less electricity, but conveniently overlook luminosity. In other words, it takes more than twice as many LED tubes to replace each T8 lamp, thus requiring much more energy.

LEDs do have their place, and we often employ them with fluorescents when working with commercial clients. LEDs emit light in a specific direction, which makes them ideal for task lighting, refrigerated cases and retail displays. But they’re not efficient conveyers of ambient light, which means they’re not a good alternative for overhead lighting.

The LED T8 replacements cost about 10 times their fluorescent rival. LED proponents claim their longer-lasting bulbs (50,000-plus hours) offset the initial costs, but like their claims of energy efficiency, these don’t stand up under scrutiny.

The same DOE report cited above states: “Unlike for conventional light sources, there is no standard life rating method for LED T8 lamps. The products are too new to have long-term operating data available.” Fluorescents have a documented operating history and manufacturing warranties are offered for up to 36,000 hours. Fluorescents that meet or exceed LED life spans are available in Europe, and we expect them in the U.S. market soon.

The final argument in the LED vs. fluorescent debate: fluorescents contain mercury. This is a problem with CFL home use bulbs, which should always be recycled. That’s not the case with T8 commercial tubes, which contain such tiny amounts of mercury that they are EPA-approved for disposal in public landfills. (Even though safe for landfills, Clear Energy recycles all T8s removed in our retrofits.)

If your company is considering a lighting retrofit, then please do your homework, or consult with professionals who value facts over trends. It may not be fashionable, but it will be better for the environment and your shareholders. And it might just keep you from stepping in the stuff left behind by the herd. 

Paul Hill, co-founder of Fayetteville-based Clear Energy, is an engineer with more than three decades of experience in energy innovation. He holds three lighting-related patents, and has a fourth pending. He can be reached at [email protected]