mithriltabby | Time to research light bulbs... (Reply)

I’ve been talking about doing this research for a while, and now I need to replace some bulbs around Maine Coon Manor, so it’s time to do the research on compact fluorescent bulbs. (The timing of this is largely to do with having had a bulb burn out in the parlor last night, not with the current bizarre legislation proposed to ban incandescent light bulbs and make life difficult for people who need accurate color rendering in their day jobs.) I want to save power, but not at the expense of making the house lighting look harsh. The factors here are brightness, color temperature (which is how “warm” a light looks), and color rendering index (CRI) (which is how true the spectrum produced is to that of natural sunlight). Brightness and color temperature are commonly shown on the packaging, but CRI can be hard to track down.

I’m looking forward to LED light bulbs and eventually quantum dot bulbs, but I hear the CRI of LED bulbs is more in the 60–70 range right now and that they function best as spotlights, rather than ambient illumination. The Incandescent vs. CFL vs. LED Light Bulb Challenge (and related Digg page) has a spreadsheet for comparison.

EnergyStar says that our familiar incandescents generate 870–890 lumens at 60W, 1,190–1,200 lumens at 75W, and 1,680–1,750 lumens at 100W.

There’s a bunch of good data at Ask the Builder. Light Bulbs Alter True Colors says incandescent bulbs have a color temperature around 2750 K, and Light Bulb Color Temperature says that 3000 K will bring out reds, browns, and oranges, 4100 will bring out greens and blues, and 3500 K is a good intermediate. Another site has an article on What CF lamps to use where.

It looks like every bulb sold locally has a CRI of 82, if I can find it at all. TCPI sells theirs under the brands “Commercial Electric” at Home Depot and “DuraBright” at Orchard Supply. Home Depot also stocks Lights of America Fluorex bulbs. OSH also has Satco bulbs and Sylvania Dulux. Lowe’s also stocks the Sylvania. Safeway stocks General Electric CFLs.

The ones I couldn’t find CRIs for were the house brands: Home Depot’s n:vision and Lowe’s Bright Effects. I also can’t find any aggregations of recommendations; Don Klipstein’s page has a bunch of information on CFLs, and his bug report section found flaws in the Lights of America, n:vision, and older GE models. He links to another page of reviews that suggests the Commercial Electric ones are good. The Federal Energy Management Program has some shopping guidelines, and links to the Lighting Research Center, which has extensive details that are far too much for my tired brain to keep track of right now.