Everything on lumen
What do you pay attention to: lumen or wattage?
When you used to choose a lamp, it was a lot simpler than it is now. You looked at the wattage and the fitting and that's how you chose your lamp. Manufacturers thought that by indicating the wattage they gave an indication of the light output. That is not how it works. The wattage says something about the energy consumption, not about the light output. Do you want to know how much energy a lamp uses per second? Then you look at the wattage. But when you want to know the light output of a lamp, you look at the number of lumens. With lumens we express the light intensity per wattage.
When you compare different types of lamps such as an incandescent lamp and an LED lamp with the help of the wattage, it is actually comparing apples with pears. A LED lamp is much more energy-efficient than a light bulb, so the wattage is much lower. How to compare an incandescent or halogen lamp with an LED light? Then you look at the number of lumens. Lumen is the amount of light that a lamp emits per wattage. The more lumens you have, the higher the wattage and vice versa. But that, of course, is limited within 1 type of lamp. Otherwise you will come back to the apple and pear story.
To see the difference between different lamps clearly, look at the table below. Here you can clearly see the difference between a light bulb and LED light. For the same number of lumens, you need a lot more power with an incandescent lamp than with an LED lamp. With a light output of 136 lumens you have enough of a 15 watt LED lamp. For a 15 watt light bulb, you get only 90 lumens in return.
|Wattage||Light bulb||Halogen lamp||Energy-saving bulb||LED lamp|
|15 W||90 lumens||119 lumens||125 lumens||136 lumens|
|25 W||220 lumens||217 lumens||229 lumens||249 lumens|
|40 W||425 lumens||410 lumens||432 lumens||470 lumens|
|60 W||710 lumens||702 lumens||741 lumens||806 lumens|
|75 W||935 lumens||920 lumens||970 lumens||1055 lumens|
|100 W||1340 lumens||1326 lumens||1398 lumens||1521 lumens|
Lumen and lux
Do you want to compare different lamps and do you want to know what the light output is? Then you now know that you do not have to look at the wattage. But then we are not there yet. To make things even more complicated, we have another term: lux. Lumen and lux are often confused, but certainly do not mean the same thing. The number of lumens indicates how much energy a light source radiates in all directions, so the total amount of light from your light beam. An important difference between lumen and lux is that lux takes into account the area over which you distribute the light.
Lux is the amount of light that ends up on a certain surface. When you distribute a light source of 100 lumen over 1 square meter, that light illuminates your surface with 1000 lux. But do you spread the same number of lumens over 10 square meters? Then the light source illuminates your surface with only 100 lux. When you need a certain brightness for a room, such as at a workplace in the office, you can better look at lux. For example, a standard of 500 lux is used for a workplace. So when the number of lumen remains the same and the lux is raised, the light is more bundled and visual tasks are easier.