> What do the enlightened readers of PICLIST have to say ? Claiming enlightenment would be, quite possibly, too much, even on New Years day at the very beginning of time as we leave the noughties and launch into the teens, but I have a few thoughts thereon (CFLs and enlightenment, but I'll reserve the latter). _______ Full disclosure: Philips paen follows. No shares or financial interests in Philips - I just tend to like their better products. Extremely good and detailed CFL versus other comparison comprehensive investigation of issues involved. Writer is not anti CFL per se. 60+ screens. http://sound.westhost.com/articles/incandescent.htm#cchar > And what about the toxic material in CFLs ? Mercury is the most quoted toxic material. Levels in modern well designed CFLs are lower than in many older ones (figures available from Gargoyle and/or Philips nee Glowlampen Fabriken (full-circle)). Philips and their apologists (of whom I tend to be one) claim that the Mercury levels emitted from a typical power station when producing 4 or 5 times the energy required to operate a CFL are well in excess of those contained in the CFLs. ie burning coal etc to produce the power to operate an incandescent bulb of equivalent light output to a CFL liberates more mercury than is contained in the CFL. Further, the extra CO2 generated by operating an incandescent bulb is currently considered by some, due to their degree of enlightenment (see above) to be a net disadvantage. Also, I understand that in th USA, but note perhaps elsewhere, yet, CO2 is poisonous and therefore presumably also toxic. Note that this toxin does not emit from nor is contained in the non-CFL but is produced elsewhere as a consequence of its operation. > The CFLs I have purchased do not reach the lifetime touted for them. > Some fail after about 100 to 200 hours. I have not seen a > relationship between brand name / cost and longevity. As a substantial but largely domestic user I have seen some early failures but note that name brand bulbs typically to last for extended periods. Bulbs subject to long periods of operation often have lifetimes in excess of manufacturers claims - sometimes much in excess. When starting a new bulb I usually write the date on its base and I know what sort of usage each location sees, so my lifetime assessments are not entirely anecdotal. NZ & Australia "Consumer" (testing organisation) tests show that light output per Watt varies between brands by up to about 2:1. Usually the Philips "Tornado" (spiral glass) top the efficiency table. I tend nowadays to only buy Philips Tornado CFLs and their longevity is usually good. Philips publish a lumenr/Watt rating on the outer package. This increases with increasing Wattage and is higher for bright-white/daylight blue bulbs than for warm-white. I do not know what range of PFs are produced by various CFLs but typical figures given are around 0.5. It would be entirely doable to produce near unity power factors electronically if the will existed. cost is liable to be an issue. Sample of one: I have a CFL here which has run for about 30,000 hours (probably about 1 month to run to reach this target). It's a Philips "Genie" 8 Watt, 3 small loops, warm white, 53 l/Watt claimed. It operates in our hall light fitting and is operated essentially '24/7'. It was installed on August 12th 2006. 1238 days, 29,712 hours. Turned off sometimes semi-randomly. (Running cost at ~$NZ2/Watt is $16/year 24/7. Turning the bulb off regularly will kill it much quicker, but running it say 12 hours / day would save about $8/year in energy costs which is more than its capital cost, so doing so would arguably save money. And result in a somewhat dark hall even in daylight due to less than inspired house design. Russell -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist