school energy&environment

Lighting

The European Union has ruled to gradually banish all incandescent bulbs (which regards the production of new bulbs) with the following schedule:

• from September 2009, the production of 100 W incandescent light bulbs  or more, and all the bulbs  with frosted or opal glass is prohibited;
• from September 2010 the production of  75 W incandescent light bulbs is prohibited;
• from September 2011 the production of  60 W incandescent light bulbs is prohibited;
• from September 2012 the production of  incandescent light bulbs of all powers is prohibited.

Exception is made for incandescent light bulbs made for specific purposes  (e.g.  refrigerators, ovens, etc).
A 100 watt (W) incandescent light bulb produces the same amount of light as a 20W compact fluorescent bulb;  this means that the two bulbs emit a similar luminous flux (measured in lumens, lm).
The  lumen/watt ratio indicates the lighting efficiency of a light source. While 100W incandescent light bulbs are characterized by a modest lighting efficiency (14 lm/W), because about 80% of the electric energy is transformed into heat and only the remaining 20% into light,  20W CFLs have a much higher lighting efficiency (60 lm/W).
The more efficient operating mechanism leads to a decrease of up to 80% in the consumption of electric energy for an equal luminous flux.
Low consumption light bulbs cost slightly more, but their average life span is remarkably longer than the traditional light bulbs  (10,000 hours vs. 1,000  hours of the incandescent light bulb).
Replacing the incandescent light bulbs can be a great advantage, the higher cost for  purchasing the same is however recovered in a very short amount of time.
Other initiatives:

• turn off the lights if they are no longer needed;
• regularly clean the lighting equipment : the dust, greasy smoke and vapours of the kitchen can decrease the amount of emitted light up to 20%.