I jumped on the CFL bandwagon from the early days and much of the same issues that plagued these devices then are still very prevalent today. Early on the biggest problem was with CFL’s turning into crispy critters, one such erupted so quickly the putrid toxic smoke overcame my wife in a few seconds and cutting the electric supply did not extinguish the fire. Many such fire incidents followed, some resulting in serious damages and thus putting an end to even considering CFL’s for many years to follow. CFL’s are prone to ignition and premature failure in applications where the ambient temperature falls below 60°F. CFL’s require several minutes to achieve full light output making them worthless for any application requiring instant full output such as emergency lighting system. The biggest issue with both CFL’s & LED’s is that the “measured” light output does not coincide with the amount and/or spectrum of light perceived by the human eye nor does the light itself traverse the same distance as that of other light sources. In areas where a 60w incandescent lamp provides sufficient illumination, the same application typically requires a CFL with a minimum 100w equivalent output. Light travel distance is another point of concern since a 60w incandescent will provide an acceptable light level at a distance roughly 30% greater than what a 100w equivalent CFL is capable of. The latter may seem inconsequential in the typical residential application but commercial buildings designed around incandescent lamps often cannot be changed to CFL’s without requiring a complete lighting re-design and often adding numerous additional fixtures. In applications where the fixture height exceeds 20 feet, a 150w equivalent CFL does not provide sufficient floor-level illumination as is accomplished with a 100w incandescent. Typical high-bay applications require replacing a single 100w incandescent with three 42w (150w equivalent) CFL’s which means adding two additional fixtures and consuming 126w of utility power – no ROI is possible. LED”s are even further limited on the production of light that is usable to the human eye, the distance at which the light carries and the usable beam width. A typical intermediate bay height application requires two 120w LED fixtures using a total of 240w utility power at a cost of $1240 as compared to a single 250w HID fixture costing $175 – with an actual energy savings of just 14w, one will never see an ROI. I don't know about others but my clients want to see real ROI figures and data based on their application to support those numbers.
My CFCs have done reasonably well. . .approximately 5 years per unit, as promised. As they age, the spectrum does shift and the output decreases slightly, but not enough to cause a replacement before an actual failure. I think the issue is that I am so accustomed to the tungsten light spectrum that nothing else looks right. I remember when florescents came into widespread usage in the home that the older folks like my grandparents complained about it. (Seems the chief complaint was in the kitchen where meat always looked bad long before it was.) When we tried the LED bulbs in the dressing room, all the on-camera people complained about how their make-up looked goon there but awful on camera where the lighting was different. I think that once the brightness issues are resolved and the LED bulbs come into widespread usage, these complaints and issues will fade.
Dave, I'm going to tease all engineers here: don't blame the light for not being able to match colors to dress.
Enough teasing. CFCs have not lived up to their life expectations and are not as bright. I'm tired of the smoke and mirrors about them (smoke especially, when they fail). Add to that they are hazardous waste and cannot be thrown away in the kitchen trash makes them unappealing to me.
I hope the spectrum of the white LED lights can be adjusted so they aren't as "fuzzy" as Dave pointed out.
I plan to continue purchasing visible-light heaters for the foreseeable future.
In the early 90's, fully electric molding machines were breaking into the US mostly in imported machines from Japan and Europe. These machines were low cost to operate compared to their hydraulic brothers, but they were high cost for purchase. At the time, you could buy an identical tonnage hydraulic machine for half the cost of a full electric machine. Fast forward to 2011, and electric machines are pretty much the same cost as hydraulic machines. There is no reason not to purchase electric. The lower running cost is usually enought to justify an ROI for the new investment and bring aging plants in the 21st century.
I'm all in favor of being kind to the environment, but I also like to see it pay off. For example, my new central air conditioner uses less than half the energy of the 26-year-old one it replaced last summer. Payoff is calculated at 6 summers and if it lasts as long as the previous one, it will pay for itself 4 times over. That's a good deal.
On the other hand, changing from incandescent bulbs to the new LEDs has not been as successful. My den had four 100-watt bulbs in the ceiling fixtures. I replaced them with LED bulbs rated at 30 watts' worth of light using only 4 watts electricity. A great savings on electricity, but it is simply too dark in the room. Replacing 60-watt bulbs with two of these 30-watters should have worked well in the bedroom, but, similarly, what works on paper may not work in the field. The light is fuzzy, I can't see detail, it doesn't work as a reading lamp, and it does something to color perception that makes me unable to match colors to dress myself.
For now, I'll have to go back to the CFC bulbs and stock up on 100-watters before they vanish. It seems like a primitive solution to a problem that should have been solved long ago.
I think the experts' advice around taking a holistic approach when evaluating options is a great takeaway. The bottom line around energy-efficient anything is that it has to make good business sense. That evaluation can only be accomplished by taking a long view and evaluating the sum total of requirements--not just by blindly hopping on the green bandwagon.
It's amazing how energy consumption awareness has changed in just a few years. I wrote an article on energy efficiency in plants in 2008 and it was a new topic. Plant operators were just getting around to looking for ways to save energy. Until then, energy costs were so low, consumption wasn't an issue -- nor was the concept of green. Funny how rising energy costs can focus the mind.
Festo's BionicKangaroo combines pneumatic and electrical drive technology, plus very precise controls and condition monitoring. Like a real kangaroo, the BionicKangaroo robot harvests the kinetic energy of each takeoff and immediately uses it to power the next jump.
Design News and Digi-Key presents: Creating & Testing Your First RTOS Application Using MQX, a crash course that will look at defining a project, selecting a target processor, blocking code, defining tasks, completing code, and debugging.
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