Lights off!

Yesterday I was zapping my TV when something caught my attention. I stopped at the Discovery channel while the program "Mythbusters" was on. The days theme was: what is less energy consuming - to leave the lights on permanently or to switch them off each time you leave a room?

In order to find out the answer to this long standing domestic question, the hosts of the show tested a range of different lamps, from classical tungsten lamps, to modern coil neon units, LED assemblies, fluorescent bulbs, and so on. They left each kind of lamp running for one hour and measured the amount of energy spent by each one. After that, they measured the energy spent by switching on and off each kind of lamp, and thereafter calculated the equivalent time of continuous usage that that would correspond to.

The results were not so astonishing to me, and confirmed an opinion that I have been finding oftenly reported on the internet. The energy spent by switching on and off a lamp varied from the equivalent of 0.36 seconds of continuous usage of a classic tungsten lamp to a maximum of 23.3 seconds of a modern coil neon unit.

When testing durability of the same lamps, they found out that the most modern lamps would support the stress of being switched on and off oftenly (for domestic standards) for a period longer than 4 years. Therefore, the argument of sparing lamps does not hold to the test.

This means that, in terms of domestic economy and global environment, it is worth switching off the lights when leaving a room, unless you're intending to come back in less than a minute.

:-)
(Sorry to the usual portuguese readers, but I thought this particular theme could be of interest to a broader international audience; therefore I wrote this one in english)