Thursday, November 3, 2011

Fluorescent Fundamentals

Compact Fluorescent Lights (CFLs) have both friends and foes. I'm a friend, though in the future I see even much promise for LEDs.

This spring I finally replaced the last incandescent in our house. The candelabra-style 40 watt chandelier bulbs were the last to go. It was only when that I found some CFLs that were only slightly bigger (by about 30%) and didn't look totally tacky that I could celebrate discarding the last incandescents. The result is quite passable, though someday LEDs will have enough light output to replace the CFLs. (The highest ouput of any candle-style LED bulb I've seen is only 150 lumens, about equivalent to 15 watt incandescents; they need to triple the output to substitute for 40 watt bulbs.)

In the journey to replace all our incandescents, I've discovered some useful information--and hit a few jogs and bumps in the road as well. So I thought I'd make a checklist of lessons learned.
  1. Always recycle. All CFLs have some mercury content. Some less than others, but every one of them should be recycled. NOT in recycle bins (at least not in Arlington, TX), but at Home Depot and Lowes. Both stores have recycle bins just inside their entry doors. So be responsible, save up your spent CFLs and turn them in! (See also
  2. Be careful. CLFs are glass and can release mercury vapor into the air if broken. Recommendations on cleanup include leaving the area and airing out the room, and very careful disposal of fragments (see more). While I would don my good respirator, I wouldn't go all out with a HAZMAT suit.
  3. Buy EnergyStar. Not all CFLs are created equal. EnergyStar has objective criteria on reliability, bulb-life, warm-up time, quality control, and limited mercury content (read more). Don't buy random CFLs just because they're cheap--you might just get what you pay for! 
  4. Buy efficient bulbs. Not all EnergyStar CFLs are created equal. Divide lumens output by watts input and compare. Upper end bulbs get 65 to 70 lumens per watt. Small bulbs and specialty bulbs are much less. Smaller bulb efficiency goes down because the ballast of every bulb uses about the same level of energy. (But keep it all in perspective: incandescents only get 10 to 14 lumens per watt.)
  5. Use proven bulbs. My own recommendations (having rejected a number of unacceptable bulbs):
    Watts Equivalent
    (incandescent watts)
    Maker /
    Price /
    "100" 23 1600 70 TCP /
    Home Depot
    $21/12-bulb contractor pack
    $1.75 each

    "60"1490064 TCP /
    Home Depot
    $15/12-bulb contractor pack
    $1.29 each

    "40"955061 Philips Energy Saver
    mini twister
    Home Depot
    $8/3-bulb pack
    $2.66 each

    reflector flood
    1575050* Philips Energy Saver
    reflector flood*
    $20/4-bulb pack
    $5 each

    942547* Philips Energy Saver
    decorative candle*
    $10/3-bulb pack
    $3.33 each

    * Not an EnergyStar rated bulb.
  6. Avoid dimmers. "Dimmable" CFLs are less efficient, dimmer, less dependable, and turn on more slowly. They don't dim that well either--they dim a little, but not down to zero, and they maintain a cold bluish tint. So just replace the old dimmer with a standard on-off switch instead.
  7. Avoid CFL flood lights. My experience has been that these turn on slower and burn out faster. The very nature of these encased bulbs involves a small tight enclosure, which tends to decrease performance and lifespan. The best I've found are noted in the chart above, and I have a handful of these deployed. Consider instead using standard CFLs in some fixtures--they may yield as much light as the reflective floods. An even better solution for floods and spots are LEDs as they continue to become more cost-effective: they are perfect for floods and spots since their output is intrinsically directional.
  8. Avoid tight enclosures. Overheating dims and shortens the life of CFLs.
  9. Avoid photocell controls. Photocells that work with incandescents don't work with CFLs, and those designed for fluorescents may not work very well either. Instead, use a timer designed for fluorescents. This may include replacing a simple on-off switch with a programmable timer-switch for the front porch, which can even allow for a varied programmable setting each day.
  10. Avoid colors outside the 2700K to 3000K range. 2700K is close to an incandescent. Above 3000K looks bluish.
  11. If a CFL doesn't fit, consider a new shade or globe. I've had several fixtures that needed a slightly different shape globe or lens. In each case, the new one ran about $7, which was quickly recaptured by the very first CFL used (which is projected to save a total of about $77). For example, a 2-light fixture with 100 watt bulbs replaced by 23 watt bulbs burning 8 hours a day (= 1/3 of the time) produces savings for a year = 2 x 77 watts saved x $1/watt x 1/3 of the year = $51.33 per year. So the payback period = $7 globe cost / $51.33 per year savings = 0.14 year x 12 months/year = 1.6 months! (In most cases, fluorescents can even pay for a replacement fixture in a reasonable amount of time.)
  12. Be bold and put in swirly CFLs even when they're visible. They have an interesting "architectural" feel. A bathroom vanity light designed for "globe" bulbs looks just fine with swirly bulbs. New and edgy.
  13. Buy new light fixtures with CFLs in mind. Don't want to see a swirly bulb? Then choose a fixture where the bulb isn't exposed. Whatever the style, make sure there's adequate clearance for CFLs, both in height and at the base.
  14. Do NOT use CFLs in the refrigerator. Because of mercury content and poor cold temperature start-up, the fridge is no place for CFLs. Look to LEDs instead.
Now is the time
Go ahead buy a big 12-bulb contractor box--it makes it easy to go through the house and change everything out. They are economical, and you'll keep a good bulb on hand when one burns out. The big boxes also use less total packaging than smaller packages, and the boxes (the ones from home Depot) are 40% recycled and fully recyclable.

And those seemingly-incredible claims on the box stating a savings of $1,104 (for 23 watt CFLs) or $660 (for 14 watt CFLs) are in fact credible. Take the 23 watt bulbs: my rule of thumb says $1/watt saved x 77 watts saved = $77 saved per year x 12 bulbs = $924 total. The manufacturer's math is more detailed and with slightly different assumptions, but my rule of thumb serves to verify their claim--we're in the ballpark together.

So even if your incandescents aren't burned out, you're wasting tons of energy and money by waiting until they burn out to change them. What about those seldom used bulbs--like in the attic? Think of it like this: suppose it has half its life left. It was probably rated to last 1/4 of a year (if burned continuously), so it has 1/8 of a year of burn-time left. If you keep it till it burns out, you will have burned up a total of: 100 watts x $1/watt per year x 1/8 year = $12.50 worth of electricity. So stop the bleeding and replace it with a $2 bulb that will save you money every time you turn it on.

There's another reason to change them all at once: you'll observe a clear, measurable change in your monthly electric usage compared to a year ago. If you change them little by little, the difference will be there, but harder to see.

What to do with displaced incandescents?
Should you give away those half-burned incandescents? Only to your worst enemy. Sad to say, but just throw them away. (If anyone has a better use for them, let us all know.) If they were wasting your money, why waste someone else's? Why waste energy--for the nation? We need to reduce our national footprint for the sake of our national security and our future generations' energy needs.

If you want to give something away, buy two big boxes of CFLs and give one away. Take it to Mission Arlington or your local charity. Or give it to a friend as a not-so-gentle hint. Tell them you're giving them "over $1,000"!

Coming soon: a follow-up on Fluorescent Objections!

"Let your light shine before men so they may see your good works and give glory to your Father in heaven." -- Jesus (Matthew 5.16)

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