Velleman Compact fluorescentlamps(CFL) - Manual (Page 2)

Comparison with incandescent lamps
Lifespan
The average rated life of a CFL is between 8 and 12 times that of incandescent lamps. CFLs typically
have a rated lifespan of between 6.000 and 10.000 hours, whereas incandescent lamps usually have
a lifespan of 750 hours or 1.000 hours.
CFLs produce less light with aging. The light output decay is exponential, with the fastest losses being
soon after the lamp is first used. By the end of their lives, CFLs can be expected to produce about 70–
80% of their original light output.
Energy efficiency
The chart shows the energy usage for different types of light bulbs operating at different light
outputs. Points lower on the graph correspond to lower energy use.
For a given light output, CFLs use 20% to 33% of the power of an equivalent incandescent lamps.
Cost
While the purchase price of an integrated CFL is typically 3 to 10 times higher than that of an
equivalent incandescent lamp, the extended lifetime and lower energy use will more than
compensate for the higher initial cost.
Starting time
Incandescent lamps reach full brightness a fraction of a second after being switched on. As of 2009,
CFLs turn on within a second, but may still take time to warm up to full brightness. Some CFLs are
marketed as "instant on" and have no noticeable warming‐up period, but others can take up to a
minute to reach full brightness, or longer in very cold environments.