In order to convert lumen into lux, you should know that in order to get 1 lux of light, 1 lumen should light 1 square meter. This means, that if you use an 6w LED light bulb, which has an output of 600 lm, and if you manage to light exactly 1 square meter with all the lumen, and without any other lost light, than you have achieved 600 lx lighting.In actuality, things are not so simple because light disperses and it is very difficult to measure exactly how many lumen are being emitted without a light meter. Also, when measuring your lighting, you should keep in mind that the size of the room as well as the purpose of the room is the norm of the lighting is measured in different places.
In most work spaces, the light’s norm is measured on the work table/desk, which is usually up to 80cm, while in the rooms where no work is expected to be done, the light norm is usually measured on the floor. Here are several examples:
- Lighting for halls and conference rooms - 500 lx
- Lighting for shops for food - 400 lx
- Lighting for shops on self serving – 300 lx
- Lighting for classrooms – 300lx
- Lighting for doctor’s cabinet – 200 lx
- Lighting for kindergartens – 200 lx
- Lighting for service rooms of theaters, movie theaters and schools: 150 lx
- Lighting in laundry rooms - 100 lx
- Lighting of stairs in public buildings - 75 lx
- Lighting in rooms for sleep in kindergartens – 75 lx
- Lighting for stairs in residential buildings and hotels - 50 lx
In order to find out if your lighting is in accordance to these requirements , add up the lumen output of all lights (the lumen is marked on the LED lamp's packing). The sum of all lumen must be divided in the number of square meters of the room (including the walls and ceiling) and if the result is close or larger to the norms, then you have definitely covered the lighting standards.
Here is an example for how to measure the light without a light meter, as well as how many LED lamps you need for a room of 5x5 sq.m and 3m ceiling with a minimum norm of 100lx and to be sure that the lighting is enough.
- first calculate the square meters of the floor, all walls and the ceiling
the result (110 sq.m) is multiplied by the minimum norm for lighting of laundry rooms (100lx)
The final result is 11,000 which is amount of lumen from all lamps used
as we know, a 20W LED lighting has an output of about 2200lm, so you can easily calculate that you will need 5 LED lighting products of this type.
Calculated this way, the lighting will definitely cover all standards and norms for your needs, but won't be the most economic one, because if you use LED lamps with reflectors instead, you will need only half of the power.
