Fixit: More details about light bulb comparisons

A recent column compared the cost of the constant operation of a compact fluorescent light (CFL) to a traditional incandescent light. Several readers took issue with the answer, asking:

"Why compare a 15-watt CFL bulb to a 60-watt traditional bulb? That's not an apples-to-apples comparison; no wonder the CFL came out ahead."

Or:

"Why give such a long life to CFLs in the formula? They don't last that long. So that makes the formula you used wrong."

And:

"CFLS can't be used outdoors. So why even compare them to regular lights?"

Here are the answers to those questions:

• CFLs do last a long time, longer than incandescent light bulbs. But quality varies widely from manufacturer to manufacturer. Quality bulbs often cost more than the lower-quality ones sold at many stores. For the best bulb performance, look for the Energy Star label or a manufacturer's guarantee. Remember to keep your receipts, and don't be afraid to return a bulb if it fails prematurely.

• Not every CFL will work in every application. Cold-weather operation is difficult for CFLs, although some CFLs are now rated for outdoor use. You'll have to look for them. But the question that prompted the original comparison concerned indoor lighting, where cold typically is not a concern.

CFLs not the last word In 2007, when federal legislation mandated efficiency standards for light bulbs, it looked like that would be the end of incandescent bulbs. The notoriously inefficient incandescent bulbs didn't meet the standards; the CFL did. That sparked the worry that we'd all be forced to buy and use CFLs, and that the government was banning incandescent light bulbs.

Not so fast. What actually happened is that the new standards spurred manufacturers to improve incandescent bulbs to produce more light and less heat and meet the standards.

Meanwhile, the CFL is far from perfect and is but a steppingstone to the future. It, along with the incandescent light bulb, will be knocked off store shelves by lighting innovations coming soon. Stay tuned.