Luminotécnica – What is it? Architecture, Calculation and More!


You have probably heard about lighting engineering before, and we’ve even covered lighting engineering here at Total Construção. But, supposing that you have never read anything about this term before, and that you have not even heard about it, you need not despair, we are here just to explain what it is about.

Here we will cover everything you need to know about lighting technology, something so important nowadays for architecture and civil construction, even having specialization in this area on the part of architects.

So, ready to leave here knowing everything about lighting? Well then just follow the reading!

What is luminotechnics?

Every journey begins with a first step, and our first step will be to go over with you what, after all, is luminotechnics.

Do you know that lighting you have both indoors and outdoors? Well, that lighting is not placed there by chance or without being properly thought out, studied and calculated, in fact it is only there precisely because of the lighting technology.

The light in each room must be planned for that specific room, and not just put there anyway. It is necessary that the form of lighting, the type of lamp and luminaire that will be used, as well as its power, quantity, distribution and controls be properly thought out for each environment exclusively, all of which is linked to the electrical project of the work.

Examples of public lighting From left to right we can see examples of lighting from the worst to the best

The importance of light for lighting technology

According to physics, the condition of existence in an object or living being is related to the emission and reflection of light, that is, just for that reason we can already have a notion of how important light is. For environments, both internal and external, this importance is also relatively high

Below we will understand a little better about this importance.

The light outdoors

Perhaps you have heard the term light pollution before, and it fits perfectly with what we are trying to explain to you here. Using lighting systems irrationally can cause harmful damage to the environment, and especially if we are talking about external environments here. Examples of this are:

  • Plants may end up not blooming due to “shortened nights”;
  • Animals can feel disoriented, and this will directly influence their reproduction and migration;
  • Excessive and unnecessary consumption of electricity.

If you still don’t quite understand what we want to get to, look at the image above again and reread this part. Not yet? Calm down, let’s explain the image to you:

Examples of public lighting Notice this image again

The first and second situations of the image show inefficient systems, this because there is a scattering of light, that is, the light is being directed upwards and this is not its focus of illumination.

The third and fourth situations of the image, on the other hand, represent efficient systems that direct the light downwards, that is, to where it really should be, illuminating the path for people and also for vehicles.

Do you now understand the importance of planning and lighting technology? It is essential to know how to plan the use of lamps, accessories, luminaires, as well as the calculation behind the lighting technique that provides the correct use for a certain area, and do not worry, we will properly address this calculation below.

Indoor light

The importance of lighting technology is not exclusively for outdoor environments, it also plays a very important role in indoor environments. We will also base ourselves on the image above, and tell you that this same example can be reproduced in an indoor environment, because, depending on what you want, you can reproduce any of the four situations, and not all will be wrong. Again, it all depends on what you want for the specific environment. Let us approach this image again to exemplify the importance of lighting technology in indoor environments.

The first and second situations cannot now be considered inefficient, because, if your environment has a white ceiling and a relatively low ceiling height of, say, 2.5 meters, this will cause the light that is thrown upwards reflect well on the ceiling and provide good lighting for the entire environment. Of course, something like this should not be done in a hurry or without proper planning, but you can already have an idea how, depending on the location, there are several different lighting options.

The third and fourth situations are more everyday, but they also represent the range of possibilities with lighting effects that you have for the most different environments thanks to lighting technology. In the fourth situation, for example, it is a more targeted lighting, where you want to redirect the lighting to a specific point, and the third situation is also to a specific point, but a little broader. Remembering that none of these examples should be used to illuminate an entire environment, for this purpose there are other lighting options that must be taken into account.

Example of luminotechnics in indoor lighting Take a good look at all the lighting sources in this indoor environment, for sure they were all previously thought and contained in a project!

Color and temperature in lighting

At first it may seem that color and temperature are not related, but it is a mistake to think so. The lighting technician foresees this type of interaction between color and temperature, which we will explain below.

It is important that you keep in mind that, every lamp that you are even considering using has a color temperature, it is as if each lamp model emits a light that has a specific color. These colors are based on the colors that are emitted by the sun, that is, the supreme natural light that governs all life as we know it. In this we can exemplify the white light that is seen at noon, while the yellow and orange light are seen more at dusk.

Conventionally the color temperature is given through Kelvin (yes, damn North Americans and their measurement systems), which can vary between 2000 to 6100 Kelvin. So that you can better understand:

  • Yellow light is considered a “warm light”, its color temperature is generally 3000 Kelvin or less;
  • White light is considered a “natural light”, and its color temperature is between 3000 and 6000 Kelvin;
  • Blue-violet light is considered a “cold light”, its color temperature is 6000 Kelvin for more.

Relationship between temperature and color To better understand the relationship between temperature and color

“Okay, but what does this have to do with lighting technology?”

Of course, we wouldn’t just throw that information on your lap and that’s it. It is important that you keep in mind that the color temperature influences the lighting technique, more specifically, the use of each lamp in each environment, depending on what you want to achieve.

For lamps between 2800 to 3000 Kelvin

These lamps are perfect to give a feeling of coziness to the environment, being more used residentially, in bars or in sophisticated restaurants. Basically, they can be used for any environment where you want to feel a sense of comfort and tranquility.

On the other hand, it should not be used in work environments, considering that its light induces relaxation even to sleep, and does not match this type of environment, which requires a faster pace of work and production.

For lamps between 4000 to 5000 Kelvin

These are the stimulus lamps, the ones that help you maintain an accelerated work rhythm, that is, this one is ideal for offices, gyms, kitchens, and other environments and similar places whose rhythm is accelerated.

And it is clear to have a sense of its opposite, that is, that this is not the adequate light for rooms, rooms, spas, and other places that transmit a more relaxed environment and need that the light transmits the same.

How the calculation is made for lighting engineering

Okay, now is the time to teach you the calculation behind lighting technology, you will see that it is not something difficult to be understood. First of all it is important to define that the NBR ISO 8995 is the one that defines, in Brazil, the necessary guidelines for indoor lighting, that is, this is the NBR that you should always have under your arm for this type of service.

And of course, before we go straight to the calculation and the numbers, below is a list of topics that must be taken into account before we can actually perform the calculation:

  • The color of the surrounding environment, such as the wall, floor and ceiling, given that lighter colors favor the reflection of light in the environment;
  • The type of luminaire also directly influences, because, depending on its shape, it will distribute the luminous flux to the environment in a different way;
  • The environment that is being illuminated and what it will represent, being that a work environment and a rest environment need a different lighting;
  • If there is a natural light that can be used in the environment, then it is necessary to know how to use it to the maximum;
  • Energy consumption, as well as color temperature (as we talked about above), are also topics that must be taken into account when calculating the lighting design.

Okay, already focusing specifically on the calculation, we will use aid again NBR ISO 8995, which stipulates the necessary amount of light for each environment. So that you can understand how the calculation is performed, let’s first understand the meaning of each of its variables.

lm = Total luminous flux in the environment in question

lux = Total amount of light in the room

So, according to NBR ISO 8995, the total amount of light, targeting specific tasks in an office, is:

  • Environment for archiving, copying and circulation of people: 300 lux;
  • Environment for writing, typing, reading and processing data: 500 lux;
  • Technical drawing environment: 750 lux;
  • A project station that is assisted by a computer: 500 lux;
  • Reception: 300 lux

The formula that you can use in order to know if the desired lamp is the ideal one for that place is:

lm / Area = lux

Want an example to better understand? Well then, let’s go!

Calculation example for lighting engineering

Let’s assume here that you are an architect, and you are building a shed for all your interns to work with technical drawing. This shed will be 30 meters long and 25 meters wide, in this situation, how many light fixtures will you need to light the room?

In order to answer this question, you must already have in mind how many lights you will use and what type they will be. For example, 25 high Bay luminaires that each have 14,490 lumens (lm). Is this quantity enough to reach 750 lux, taking into account that the building will be used for technical design? Let’s calculate:

  • First we calculate the total area of ​​the shed to be used

Area = 25 x 30 = 750 m²

  • Now we calculate the number of lumens when using all 25 lamps

lm = 25 * 14,490 = 347760 lm

  • And finally we can calculate the total amount of lux for this project

lm / Area = lux

347760/750 = 463.68 lux

That is, the number of luminaires will not be enough, considering that they will cover only 463.68 lux, and the space needs 750 lux for this specific function.

This is a pre-dimensioning that can assist you in lighting engineering, and the ideal is to always be with the NBR ISO 8995 under your arm and a duly trained professional at your side.

Other precautions when choosing lamps

In addition to always paying attention to color and temperature, as stated above, there are also other factors that you must take into account when choosing the right lamps for each type of environment.

  • The type of location where you will use the lamps: whether it is commercial, home or industrial;
  • Economic factors, depending on how much you can spend on your lamps;
  • Reasons for decoration, pay attention to your lamps to match the rest of the environment;
  • And ease of maintenance is another factor that you should also take into account here.

The best thing to do here is to take a look at the lamp and lamp manufacturers’ catalog, so you can make a better decision during your choice.

Okay, now you already have a good idea about lighting technology, right? Of course, you are not yet an expert in lighting, but at least you are leaving here with more knowledge than you had a few minutes ago, or at least we hope that this is the case.

Always remember to have a professional duly trained in lighting technology, only then you will not have any future problems involving poor lighting of your location. And, if you want to know a little more about what a lighting project consists of, and even where you can take courses specifically for this area, just check out our article on the topic, right here on the site!

Are there any doubts about the topic? So be sure to ask us in the comments below, we will be ready to help you!