Note: the Lamp by Luminous Flux

You are one of those who takes the first fluorescent lamp on the shelf, without giving too much attention to what is written on the back of the Pack? Know that on the reverse side there is as important as the information you get in front of the Pack as the power comparison of fluorescent lamp with bulb. Get a lamp with a higher wattage thinking why she illuminates more often can be a big mistake.

For you to understand better the lamp packaging via ListofledLights, we will show you how important it is to check the luminous flux and luminous efficiency, information listed on the back of the Pack. Right now we open a parenthesis to explain what is flux and luminous efficiency.

The luminous flux is the amount of total light emitted in all directions by a light source, expressed in lumen (lm). Already the luminous efficiency, also known as energy efficiency is the ratio of the total luminous flux and the power consumed, measured in lumen/watt (lm/W). The power is not an index of efficiency, but rather of energy consumption.


The standard ENCE (National energy conservation Label), which ranks the lamps through a range of efficiency, also regulates what information must be disclosed on the packaging of the products. Leandro Barros, Golden Lamps lighting consultant, believes the ENCE reflects a “culture that ‘ inherit ‘ the incandescence where people have always bought and sold lamps by power, but this should change.”

As an example we will use the compact fluorescent lamp of the traditional line of Golden, 30W, voltage 127V. We will explain what information the verse and what is the impact on your purchase.

On the face of the package, we have the lamp warranty information and her duration, indicated based on average residential use 750 hours per year (the average life is of 6,000). As the norm, in the bottom left we have the information that serves as the basis for many consumers: how much power it consumes compared to an incandescent.

This model consumes 30W, the equivalent to an incandescent to 110W. The luminous flux of a fluorescent needs to be equivalent to the incandescent power determined in accordance with the new standard ENCE, which will enter into force in July this year.

In our case, the fluorescent 30W model is equivalent to 110W incandescent, which has to be of 1671 the 1835 lumens (lm) luminous flux.

And it’s on the back of the packaging we found information that proves the equivalence.

The model I have has luminous flux in lumens, in 1701. Another index that can be taken into account in the quality of light is the luminous efficiency, which shows how much she brightens per watt, expressed in lumen/watt (lm/W).

In the next post, we will highlight other information that the packaging of the lamp contains, and what these indexes influence the product.

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