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Fluorescent lamps

This post is also available in: Portuguese (Brazil)

A lot of things is spoken about economy in our bills provided by fluorescent lamps. They dissipate 80% less then tungsten ones (incandescents); so, tendency is to think that they’re friend of nature or more environmentally friendly.

But, is it really true? Let’s review some points:

  • Manufacture of incandescent lamps is much more simplified. Also, the quantity of materials is fewer. Fluorescents have electronic circuits that require a lot of energy to being constructed, beyond energy and materials for the fabrication of each component.
  • Fluorescent lamps have heavy metals (i.e. mercury) on their composition. Nowadays, as the selective collection isn’t working (the way it should be) for this type of lamps (although there’s already a process of decontamination of the pipe), they’re still going to landfill, contaminating rivers. Just for curiosity, the quantity of mercury in a fluorescent lamp can make not appropriate for human consumption K liters of water.
  • Fluorescent lamps have a very small power factor (compacts have 0,5). It means that a large room, that uses these lamps, must have a capacitor system (more energy and materials for the fabrication), to correct power factor.
  • In the other hand, incandescents heats a lot. In the truth, they just light because of the heat: the conductor inside the lamp becomes incandescent when it exceeds certain temperature (very high). Using incandescent lamps also overloads the refrigeration system.
  • But its power factor is practically 1. In other words, to correct the power factor of a industry, you would need less capacitors, because the incandescents would help the correction.
  • Fluorescent lamps have longer life than incandescent ones. But it is reduced as you use the switcher, in the same period of time. OSRAM says if you leave the room and will be back in about 15 minutes, it is better not to turn off the light.
  • Fluorescent lamps that use external electromagnetic reactor (necessary for its functioning, that requires more energy and materials to be made) works with 60 Hz (here in Brazil), which causes visual discomfort. The newest ones work with about 35 KHz, that reduces this effect, but they generate more harmonics, so you should install filters (more energy and materials to be made).
  • The cost of the conductors, however, is cheaper, when you use fluorescent lamps (because they drain 4 times less current to generate the same light flow).

Today everybody says that just because fluorescent lamps consome less than incandescent (better efficiency), they’re a friend of nature. But how about other factors that was written above? They consume less, all right, but in terms of ecology, there’s a much bigger impact.

It is obvious the overload that is saved from the electrical system of a country. Imagine what would happen if all fluorescent lamps (20W) become incandescent ones (100W).

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