Saturday, 12 December 2009

CFLs are good, but not that good

Compact Fluorescent Lamps, usually billed as energy-saving - or long-life - bulbs, are certainly worth having. However, as BBC Radio 4's "More or Less" pointed out this week, manufacturer's claims do exaggerate. The rule of thumb adopted by their association is that an incandescent light-bulb's wattage should be divided by 5 to give the equivalent CFL. Thus 12-watt CFLs are marketed as the equivalent of a traditional 60-watt bulb. In fact, for various reasons the conversion factor is nearer 4. A US technical body believes that 3 is more realistic.

One should also remember that bulbs should be disposed of safely


Anonymous said...

There are also issues regarding these compact fluorescent bulbs when use in vivarium for reptiles.

Anyone who knows anything about herptology knows that reptiles need a source of calcium (cuttlefish bone or some other mineral containing calcium) and Ultraviolet light type "B" commonly referred to as UVB. The amount of UVB produced by these bulbs varies considerable across manufacturer and even across bulbs marketed by the same manufacture.

Looking at the SAD (season affective disorder) website; it give an "A to Z list of recommended SAD light manufacturers", while more expensive than ordinary compact fluoresents, these are of benefit to people with this condition during the winter months.

Frank H Little said...

Thanks for that, anon. It gives me the opportunity to plug CAT's EcoStore, which is where I bought the 25W "bio bulb" which gives a good approximation to daylight, and by which I am typing this message.