What is luminous flux and how to calculate it?

Do you know what luminous flux is? In any lighting project worth its salt, whether industrial, public, or even residential, it is extremely important to plan the number of luminaires, as well as the types that will be used.

When it comes to LED luminaires, undeniably the most recommended for high-level lighting projects, calculating the luminous flux is essential to ensure that the environment has precise and effective lighting.

With that in mind and aiming to “illuminate” your ideas, the team of specialists at AALOK has prepared today’s post, where the following topics will be covered:

• What luminous flux is;
• How it should be calculated;
• The best way to carry out a lighting project for your company or public space.

Ready? Then check it all out below.

Luminous Flux: What Is It?

We know that a well-lit environment provides a range of benefits. In a company setting, lighting is directly responsible for good productivity and employee well-being. In public spaces, proper lighting promotes greater safety.

Regardless of the scenario, lighting planning is the first step to ensure that the LED lighting used in the environment will bring maximum benefits, making the space more comfortable, safe, sophisticated, modern, and so on.

One of the essential points of a lighting project is precisely knowing how to calculate the amount of light needed according to the size of each space.

In this regard, luminous flux is decisive. Luminous flux refers to the total light emitted in all directions by a light source—in our case, LED luminaires.

It is important to keep in mind that luminous flux is not just a “measure” to identify the amount of light. It also relates to the power of luminaires, as well as temperature and distance. The concept is even used to identify characteristics of stars and in astronomy studies.

This light cannot be measured visually; however, it can be calculated using the lumen (lm), considered the unit of measurement for luminous flux.

How to Calculate Luminous Flux

When, during the planning of a lighting project, the appropriate lumen amount for each environment is established, we can accurately determine the number of LED luminaires, among other necessary items, capable of providing the ideal level of illuminance.

Below, check some examples of lumens/watts according to some LED luminaire models:

• 270lm/3W
• 450lm/6-9W
• 800lm/8-12W
• 1100lm/13-15W
• 2600lm/25-28W

The next step is to calculate the lumens for each space in the project. Let’s imagine a room measuring 4m x 3m. You should multiply these two numbers to get an area of 12 m².

To determine the number of luminaires per m² needed, it is necessary to find the total lumens required. To do so, multiply the lux requirement according to the table by the area of the space. Suppose the environment is an office, which according to the table requires 300 lux:

12 × 300 = 3600 lumens

Now, let’s take as an example an LED luminaire with a value of 560 lumens.

The calculation to determine the number of luminaires per m² required is done by dividing the number of lumens needed to illuminate the office by the lumens provided by the luminaire:

3600/560 = 6,42 ≈ 7 luminaires to ensure the efficiency of LED lighting in your project, don’t hesitate. The best choice is AALOK. Click here and request your quote now.