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.
If you compare different types of lamps, such as an incandescent lamp and an LED lamp on the basis of the wattage, it's actually comparing apples and oranges. An LED lamp is much more energy-efficient than an incandescent lamp, so the wattage is a lot lower. How do you compare an incandescent or halogen lamp with an LED lamp? You look at the number of lumen. Lumen is the amount of light that a lamp emits per wattage. The more lumen you have, the higher the wattage and vice versa. But that, of course, is limited within 1 type of lamp.
|Wattage||Light bulb||Halogen lamp||Energy-saving bulb||LED lamp|
|15 W||225 lumen||300 lumen||900 lumen||1350 lumen|
|25 W||375 lumen||500 lumen||1500 lumen||2250 lumen|
|40 W||600 lumen||800 lumen||2400 lumen||3600 lumen|
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.