Tuesday, September 7, 2010

CFL's and You...How I Save $300 a Year

OK, you knew it had to happen sooner or later.  Time for that age-old stereotypical discussion of incandescent vs compact fluorescent bulbs (CFLs).  And we'll throw in LED lights for good measure, too.  In fact , there is so much to discuss, we’ll break this up into a two part series, with a cost analysis of CFLs and discussion of light quality in part I, and a further discussion of CFLs and introduce LEDs in part II.

I showed earlier this week how switching just 5 light bulbs save me $124 annually. And you can get eight 13 watt GE CFLs for only $7 at Amazon!

Almost everyone knows that CFLs use much less electricity, and depending on where and how they are used, might last several years longer than incandescent bulbs. Further, since they are more efficient than incandescent bulbs, they produce much less heat - a double bonus for the summer months.

But even with all of these pluses, you need to avoid some common CFL pitfalls and understand a few properties of the bulbs to get the most out of them.



And you CFL hold-outs out there - take note!  In just a couple of years traditional incandescent  bulbs will begin to be phased out in the USA due to some 2007 legislation.  Beginning in January 2012, the legislation begins a phase-in period in which 100 - 150 watt incandescent bulbs will no longer be available for purchase.  Over the subsequent two years, the phase-in continues down to 40 watt bulbs.  (Side-note, specialty bulbs like plant lights, and bulbs outside the 40-150 watt range are exempt). 


So consumers have a choice – stock up on cheap incandescent bulbs, or make the energy efficient switch now.  From a financial standpoint, as we'll see, it generally makes sense to make the switch as soon as possible, especially with frequently used lights.

But there is more to the decision than finances.  In fact, there are generally four questions that come to mind when considering CFL’s.

  • Initial cost
  • Quality of the light
  • Aesthetics.  i.e. ‘what’s with that spiral look??’
  • Safety
  • Dimming - most CFL's can't be dimmed, and those that can are limited
This discussion will cover financial considerations and light quality of CFL’s.  Part II will cover safety concerns of CFL’s, and review where LED bulbs stand in comparison.

Initial Cost

The cost component can be quantitatively evaluated, and it is easy to determine that in most applications, compact fluorescents make good financial sense and have a quick payback.  I showed earlier this week how switching just 5 light bulbs save me $124 annually.  And with current prices, you can get eight 13 watt GE CFLs for only $7 at Amazon.

In general, the best chance of getting a quick payback is installing CFLs in high use locations where lights remain on for extended periods.  Porch lights, ‘coach’ lights outside (keep in mind some CFL's may not start below 0 or -10 degrees - check the specs), high use lamps, etc make the best choices.

The worst choice for a quick payback is installation in pantries or bathrooms where lights are turned on and off frequently.  CFLs don’t always handle frequent cycling well, and may suffer a premature death.  One casual ‘fact’ I’ve observed is that CFLs that don’t immediately turn on (i.e. have a second or two delay after flipping the switch) seem to handle demanding places like pantries the best.

Quality of Light

Historically, CFLs have had a bad rap for having a “harsh” light.  This accusation is often made for two reasons, both of which can be accounted for with a small amount of knowledge and taking care to read the packaging.  The two reasons:
  • The bulb may produce more light (lumens) than expected
  • The light may be a bright white light, especially when compared to “warm” incandescent bulbs. 

Both points are discussed in detail below.

Light Color

When considering light color, the most important step is to purchase the correct bulb.  Most people are used to habitually purchasing ‘soft white’ incandescent bulbs, but what does that really mean, and how does that translate to CFL’s?  Terms like “soft white”, “warm light”, “daylight”, and “cool light” are all descriptors that relate to the color temperature of the emitted light.  Color temperature, usually measured in degrees Kelvin (K), represents how warm or cool the procedure light appears.  People generally prefer “warmer” light in living spaces, and “cooler” light in work spaces like workbenches.

As mentioned, color temperature is precisely measured in Kelvin.  Lower numbers mean a “warmer” or more yellow/red tinged, and higher numbers are “cooler” white light.  Most ‘soft white’ incandescent bulbs are 2500 K – 3000 K, which is what the typical homeowner is used to.

CFL bulbs can now match the color temperature of typical incandescent bulbs, with some varieties measuring as warm of 2600K (though they are generally rated as 2700K).  Of course, you can also buy cooler colored CFLs for workbenches, arts and crafts areas, or other applications where a pure white light is needed.

CFL Brightness


Many CFL’s are marketed with a “replacement” wattage as compared to incandescent bulbs.  For example, a 12 or 13 watt CFL may be labeled as a “60 watt replacement”.  While that often gives a general idea for the amount of light produced by the bulb, it is best to read the label and find the amount of lumens produced.  Lumens is a more accurate way to determine the light produced.  This is important because one brand of CFL marketed as a 60 watt bulb may produce more light than another, and that amount of light may  be more (or less) than you intended.

Related to brightness, it is important to note that many CFLs take 30-90 seconds to reach full brightness.  There are “instant on” varieties of CFLs, but even then, it is a sure bet that full brightness will not be achieved for that 30-90 second range.  Some bulbs also may take a second or two to produce any light at all.  Some brands are worse than others – for example Ikea CFLs seem to take longer to turn on than most others.
  
In general, I’d recommend that you start by buying only one or two bulbs of a given brand and style, and then test them out to see if they are suitable.  When you find one that you like, make a note of the brand for future buying reference (and please leave a comment here with your recommendations).

Dimmable CFLs


Note that most CFLs cannot be placed on a dimmer.  Those that can are significantly more expensive (usually three to five times more expensive), and their 'dimable' range is not as wide as incandescent bulbs.  There is definitely still plenty of room for improvement here.

Check back later this week for Part II about CFLs and LEDs, where we’ll talk about other CFL facts and safety considerations, and introduce LED bulbs.

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