Standard incandescent light bulbs are among the most profligate energy consumers available, turning more than 90% of the energy they consume into heat rather than light. These old-school bulbs are inexpensive and cast a pleasingly warm light, but their days are numbered.
Compact fluorescent lamps (CFLs) are gradually taking their place. Although they’re more expensive, the cost is coming down and dimmable versions have become available. Bulb life is much longer and, more important, CFLs deliver much more light per watt of electricity than incandescent bulbs.
More recently, light-emitting diodes (LEDs) have emerged as another option. The cost is still well above that for CFLs, but LEDs last a very long time.
Are they worth the extra expense? That’s the question posted by George Lee in a recent Q&A post at GreenBuildingAdvisor, and the topic of this week’s Q&A Spotlight.
“I am renovating a 100-year-old home entirely,” Lee writes, “and I’m buying electric supplies right now. Are LED recessed lights worth it? Or should I buy standard recessed light fixtures and buy LED bulbs later?”
Lee is working on a shoestring budget. The house was in such poor repair he was forced to gut it and make extensive repairs. It has no heat, and the banks won’t loan him a dime. Keeping costs down is a high priority.
So don’t waste your money on LEDs
Forget the LEDs, advises GBA senior editor Martin Holladay. “Right now, the best LED lamps have approximately the same efficiency as the best CFLs, but they cost about 10 times as much,” Holladay says. “Although LED lamps should last longer than CFLs, you won’t see any savings from switching to LEDs — unless the labor cost for changing out a lamp is very high (for example, if the lamp is on a hard-to-reach billboard).”
If Lee goes for reflector-style CFLs in the fixtures, Holladay recommends he read a 2008 report from the Pacific Northwest National Laboratory that includes specs on 16 different lamps.
But LEDs have some advantages
Adam Flowers wouldn’t be so quick to dismiss LEDs. “I’m going to have to respectfully disagree with the previous post,” he writes.
Manufacturers such as and offer LEDs that are superior to CFLs, he says. “To be specific, these are not light bulbs, but LED-designed recessed lights,” Flowers says “Obviously you have the longer rated life (50,000 hours in a reputable LED compared to maybe 10,000 in a CFL), but there are a couple of other aspects worth considering.
“The top-notch LED lighting products will be dimmable, while that feature is very costly on CFL products. And light quality (Color Rendering, Color Temperature, direction of light, etc) will be noticeably better under an LED fixture.”
Flowers says that while CFLs are far more efficient than incandescents, “they still convert 20-30% of their energy into heat, so there’s the cooling load consideration.” In addition, CFLs contain small amounts of mercury. LEDs don’t.
And the cost difference may not be that significant, says Henri du Pont, who identifies himself as the owner of a company that makes LED products. The best CFLs now cost between $10 and $15, he says, while a good LED is now only about twice that. Rebates may be available, lowering the cost even further. (At its website, Cree offers an energy savings calculator comparing the cost of burning a 65-watt incandescent with a life of 2,000 hours to a 12-watt LED with a 50,000-hour life, concluding the $130 LED fixture pays for itself in less than 18 months.)
“You must also consider use or ‘burn time,’” he adds, “and if instant on at full lumen output and color temperatures are concerns… I can tell you the only reason to go with CFL is if you just don’t have the funds.”
Or, just skip recessed fixtures altogether
James Morgan has yet another idea: don’t use recessed light fixtures at all. “They are the least efficient lighting formal regardless of lamp type,” he writes, “in most situations, incandescent, LED and CFL all deliver better performance in other fixture styles such as ceiling-mount, pendant, track, and floor and table lamps.”
Also, recessed lighting fixtures are a common source of air leaks into attics, Morgan adds. If they are installed, “you need to be obsessive about air-sealing.”
Our expert’s opinion
GBA technical director Peter Yost had these thoughts:
The short answer on residential LEDs is, buyer beware. Problems with heat dissipation, color quality, and flicker persist in the less expensive LEDs, so you really have to pay for the better performing LEDs. And some key performance metrics — Correlated Color Temperature (CCT) and Color Rendering Index (CRI) — don’t work well with LEDs at all.
It’s hard to imagine being on a really tight budget and finding room for LEDs, given how fast the market is evolving, how untrustworthy too many manufacturer’s claims are, and how metrics need to catch up to this still rapidly developing technology.
Here are my recommendations:
- Don’t buy anything that you have not actually seen in operation—your eye is still a better judge on the light quality LEDs generate than the metrics we currently have for them.
- Expect to find better quality with higher cost.
- Use to compare and select LEDs.
- Use to better understand LEDs.
In terms of equipping a new home for more efficient lighting in the future, I’d like to tell you to get set up with that will work with both efficient LEDs and CFLs, but it is not clear whether this will become the standard residential fitting as lighting efficiency standards continue to get tougher.