Lumen is a measure of the luminous flux or quantity of light emitted by a source. The higher the lumen the brighter the light. For example, a dinner candle provides about 12 lumens. A 60-watt Soft White incandescent lamp provides about 840 lumens.
In a less rigorous way the lumen can be interpreted as a measure of the total “amount” of visible light at a given angle (usually 30º, 45º, 60º, 90º or 120º) in bulbs, tubes, Issued by a given source.
LED technology has changed the way we should invest in lighting. We must keep in mind that the intensity of the light is marked by the lumens, not the watts.
Until recently, when buying a light bulb, we were guided by the watts. Depending on the room to which it was intended, we chose one of more or less watts, depending on whether we need more or less light. We identified (and still do) watts with luminosity. However, watts only indicate the energy consumed by the bulb. That is the power. Logically, the energy consumed will always go in relation to the light released (more energy, more light), but the amount of light emitted by a light bulb is measured in lumens.
In these times when energy efficiency is one of the top things consider, it is necessary to start thinking not only in watts but also in lumens. We must seek maximum light efficiency and LED lamps are the ones that give us more lumens per watt consumed.
LED: more lumens, less watts
LED lamps are the ones that give us more lumens per watt consumed. A 60W incandescent bulb produces approximately 800 lumens (a light efficiency of 13 lm / W), while a compact fluorescent lamp only needs 20W (40 lm / W) to give the same lumens. If we want to replace that 60W incandescent bulb or 20W fluorescent with an LED, we should look for an equivalent in lumens, not in watts. In this case, an LED bulb of only 8W could give us those 800 lumens we need (100 lm / W, 3 times as much as a compact fluorescent of light efficiency). Multiply those watts saved by everything that consumes in a large store or a parking lot monthly and we will have an idea of the amount of electricity we can save.