The Utilitech 23W (100W) Soft White CFL (Lowe's) is part of the Lightbulb
test program at Consumer Reports. In our lab tests, Lightbulb
models like the 23W (100W) Soft White CFL (Lowe's) are rated on multiple criteria, such as those listed below.
Claimed life: Claimed life is how many years the manufacturer says the bulb will last based on 3 hours of use per day.
Brightness: Brightness indicates the brightness (lumens) of each bulb after 3,000 hours of life testing, as compared with the brightness of a comparable incandescent.
Efficiency: Efficiency is the comparison of the amount of light (lumens) produced by a given amount of electrical energy (watts). The more the lumens per watt the more efficient the bulb.