CFLs and Choice

November 26th, 2010 by Potato

One of the downsides of new, more efficient lightbulb technology (CFLs and now LEDs) is a nearly paralysing amount of choice. No longer do you go down to the store to grab any old lightbulb, evaluated on at most one or two dimensions (wattage, occasionally long life or a bluer hue). Now there are dozens and dozens of varieties of CFLs.

Many of them attempt to tackle the unfortunate downsides of CFLs in one way or another: instant-on*, dimmable, 3-way, outdoor temperature tolerant — all the sorts of things one never had to worry about with incandescents. Plus with a series of phosphors rather than simply heating an element up, you get to pick your colour temperature and overall spectrum. Unfortunately, I think that’s one of the more important aspects of a CFL for giving good quality light, and it’s one of the only measures that’s not listed on the box. I’m pretty sure we’ve got a spectrophotometer at work to produce graphs like this one below, and I must say I’d be sorely tempted to buy a dozen CFLs and plot out their spectra if someone were to fund such a study. Wayfare says it’s just another way for me to try to get away from writing my thesis, but I think it would be a valuable contribution to society.

Spectrum of a typical fluorescent tube at the hospital

Unfortunately, I’m a pretty technical guy, and even I’m not sure I could translate such a graph into a useful buying decision of whether I’ll qualitatively like the light output of my bulb, so maybe there’s a good reason for that information not being widely available.

Another “problem” with CFLs is that they last so damned long. As far as my experience tells me, they last forever (haven’t had one burn out yet, though the oldest is only just coming up on ~7 years old now). So it’s becoming such a very infrequent event that I actually haul my butt down to the store to buy a CFL, as the last holdout incandescents die. The last time I had to buy a lightbulb was over a year ago: even if I did manage to make a good decision last time, I can’t remember which model I bought, and even then the selection I’m facing is almost totally new and revamped in that time. They even have lightbulbs now that I don’t know how they work (these CFLs with LEDs in the base for “nightlights” — but I didn’t take the time to find out if they needed a special base/switch, or how the LEDs are lit up if the switch is off, and now my curiosity is killing me. Is there a tiny capacitor/battery in there to power the LED while the circuit is closed??).

And unfortunately, there are bad CFLs out there, so it’s important to make this choice well. There are a few left behind in the Toronto house from the landlord or previous tenant that we just don’t like: they’re slow to come up to full brightness, and the light is very “harsh”. Conversely, the Ikea ones we had put in the kitchen of our old house we didn’t like for being so “warm” as to cast everything with a sickly yellow pallor (the colour depth really didn’t seem very good).

* – which are the ones I ended up settling on, and have to say I’m quite disappointed in. Instead of having a 1-2 second delay before the light comes on, it does come on instantly, but only at ~20% brightness, and then very gradually warms up. I prefer the slight delay and then coming on at ~70% brightness of more normal CFLs. Once it finally warms up the quality of the light seems pretty good though.

2 Responses to “CFLs and Choice”

  1. Rez Says:

    The delay in hitting 100% brightness is what bothers me. We put CFLs in the bathroom, but in the morning they would take way too long to warm up so I’d be brushing my teeth in near-darkness most of the time. Eventually we swapped them out for incandescents and put the CFLs in the kitchen.

  2. Potato Says:

    I don’t know if it’s still the case (since there’s been so much evolution in the CFLs), but I find that the larger ones (not “big”, but no the “mini/micro” ones either) that aren’t instant-on are not bad for that kind of use — they take about 1-2 seconds before they produce any light, but the come on at about 70% brightness, and seem to finish warming up within a minute. We had some chandelier-style lights (really small bulbs, small base, 7W) for our old bathroom and they were terrible: like you said, you’d still be in the dark after 2 minutes of brushing your teeth.

    Still, for how often you use the bathroom (or closet, etc) lights, I think incandescents are fine.