When choosing the luminaire for a given space, it is not only factors such as the type of luminaire or the light temperature that come into play, but also concepts such as lux and lumen. These concepts are essential to ensure the right intensity and quantity of light at each point without the need to experiment with different intensities. In addition, light intensity is a very important factor in architecture and interior design, as it is an element that can completely affect the final result. Therefore, not having the right amount of light, or too much light in a particular place, could spoil all the previous work
In short, it is important to know and understand the concepts of lux and lumen to be able to choose the luminaires with the right intensity for each specific area, but do you know what each one means? These concepts of lux and lumen are still confusing for many users, but at FARO Barcelona we tell you what they are and how they differ so that you can use them to your advantage in your next architectural or interior design project.
What is a lumen?
Lumens measure the luminous flux emitted by a luminaire. In other words, it is the amount of light emitted by a source without taking into account the surface it illuminates, and the higher the lumen value, the more light the source produces. When we talk about indoor lighting, the most common is that the luminous flux is 1100 to 3000 lumens, although this depends on other factors such as the height at which the luminaire is placed or the reach of the luminaire. The lumen concept is also essential for measuring luminous efficacy, i.e. the amount of light a luminaire produces in relation to the power it consumes (lm/W).
What is a lux?
The concepts of lux and lumen are closely related. While lumens measure the amount of light emitted by a source, luxes determine the same amount of light, but are projected onto a surface. Therefore, one lux is equivalent to one lumen per square meter. In short, this measurement is used to determine the total amount of visible light and its intensity over a specific space, normally indicated from the center of the angle, where the luminous intensity is greatest.
Difference between lux and lumen
Once the concepts of lux and lumen are clear, it is much easier to understand the difference between the two measurements. The main difference is that lux measures the intensity of light on a specific translucent surface, while lumen measures the luminous flux regardless of the distance at which the light source is placed or the space it illuminates. Therefore, a 1000 lumen luminaire projecting its luminous flux over a space of 1 m2 would be illuminating this place with 1000 lux, whereas, if it were a space of 10 m2, it would be illuminating with 100 lux.
Taking into account these concepts of lux and lumen, there are recommendations about the most advisable amount of lux not only for each space and room depending on the activity that is going to be carried out but also for each specific point of a place.
That is to say, although there are general recommendations for places such as homes or restaurants, specific amounts of lux are also recommended for specific points such as the following:
- Kitchen (working area): 500-600 lux
- Kitchen (general area): 200-300 lux
- Bedrooms and bedrooms (headboards or reading area): 500 lux
- Bedrooms and bedrooms (general area): 100-200 lux
- Children's room (play area): 300 lux
- Living rooms (general area): 200-300 lux
- Living rooms (TV area): 50 lux
- Study and reading area: 500 lux
- Toilets and bathrooms (general area): 200 lux
- Toilets and bathrooms (mirror zone): 300-500 lux
- Passage rooms (corridor or stairs): 100-200 lux
Knowing these recommendations and based on the particular needs and tastes of the client, our Lighting Projects Department can recommend specific luminaires that meet the specific requirements of the project. Still not sure about the concepts of lux and lumen? Don't worry, at FARO Barcelona we are at your disposal for any questions you may have. If you want to know more about the recommended lux for each room and place, do not hesitate to contact us.
