Luminous efficiency: what it is and why it is important
A significant part of the success of a lighting project is related to the installation’s ability to adequately illuminate the environment while considering the energy consumption necessary to achieve that. The correct way to measure this parameter is through luminous efficiency, which is based on the relationship between luminous flux and consumed power.
This article delves deeper into the meaning of this concept. By reading the text, you will better understand what luminous efficiency is, know why it is so important that this concept is present in lighting projects, and understand how it is used.
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What is the concept of luminous efficiency?
When a layperson seeks information about lighting, it is common for the evaluated concept not to be the most suitable. In many cases, the variable appreciated is only the consumed power, and this is largely due to a genuine concern about the observed expenditure. However, this leads to a mistaken analysis, and the results obtained tend not to be those desired.
Therefore, the correct procedure during this evaluation would be to analyze luminous efficiency precisely. It is a much more comprehensive attribute that can provide more assertive data regarding the evaluated lighting equipment. This is possible because to arrive at the correct calculation of luminous efficiency, it is necessary to consider another variable besides power: luminous flux.
This attribute refers to the amount of light emitted by the lighting source, that is, how much light the luminaire can radiate. Luminous flux is measured in lumens, and from this measurement, the power of the evaluated equipment, measured in watts, must also be considered. With the relationship between these two attributes, we arrive at the value of luminous efficiency, resulting in the quantity measured in lumens/watts.
However, the analysis can be much more objective if we consider the practical aspects of luminous flux since there is no need for calculations since the value is already informed by the manufacturer. Thus, luminous efficiency can be understood as the amount of energy required to provide the indicated luminous flux. That is, how much energy is spent to achieve the desired lighting.
What is the importance of knowing the concept of luminous efficiency?
There are several aspects according to which it is necessary to know the concept of luminous efficiency well. Furthermore, different people interested in the luminous aspect need to understand this concept. One of them is the professional responsible for lighting projects, especially large areas such as logistics warehouses, for example.
Without mastering these concepts, it will be challenging to meet the requester’s requirements for a project satisfactorily. It is impossible to determine precisely what should be the ideal set of luminaires for a particular environment. Moreover, the quality of the service provided can be significantly compromised without this technical framework.
Other significant impacts of these technical information are the users of the environments illuminated by the designed project. It is worth noting that it is not the concepts that directly affect these people, but the consequence that comes from this type of project. Poorly lit environments or those with insufficient wavelength lighting can cause visual loss.
It is also important to observe compliance with work safety regulations. The immediate effect comes from the possibility of work accidents. In addition, there is a clear indication regarding workplace illuminance in ergonomics aspects of labor laws. Illuminating these locations with adequate luminous efficiency is, above all, complying with the law and ensuring environmental comfort for employees.
How should luminous efficiency be used in lighting design projects?
As previously mentioned, luminous efficiency is a variable of great importance in the development of projects for lighting environments, especially in industrial and large warehouse settings. It is through this attribute that the ideal choice of technology to be used can be made. All of this will reflect on the quality of the project, considering aspects such as resource savings and implementation costs.
It is precisely with luminous efficiency as a reference that the type of luminaire should be chosen, for example. As technology evolves, new types of lighting emerge and efficiency increases. When high-pressure luminaires based on mercury vapor are used, it is possible to achieve around 55 lumens/watt. There are also mixed luminaires, with an efficiency in the range of 30 lm/W.
Next on the list, another option that was widely used over time were metal luminaires. The reason for their widespread use in the past was precisely higher luminous efficiency, which could reach up to 90 lm/W. Their only competitor for many years were luminaires made of sodium vapor, which despite having considerable efficiency, needed to use reactors to have their initial ignition process carried out.
Finally, LED technology emerged, revolutionizing the market due to its high efficiency compared to traditional methods. In terms of economy alone, rates higher than 60% can be achieved with energy consumption. In addition, its lifespan is extended, as there are no gaseous components in its constitution. Thus, the luminous flux is maintained even after years of use.
Completing the list of benefits of LED technology, we can cite its high durability due to strong resistance to impacts. In addition, it has a quick response time, and because it has no chemical components in its manufacture, it is considered environmentally sustainable. A project that uses this type of lighting can be considered an environmental partner.
Luminous efficiency is a variable of great relevance in lighting projects. Contrary to what many think in the market, it is not the power of the luminaire that indicates its most appropriate use. The reason for this is that, in addition to energy consumption, the luminous flux must also be considered in the evaluation. In this way, it is possible to reach a common denominator regarding how much light a luminaire can emit in relation to the total energy consumed. This type of analysis leads to the best possible cost-benefit ratio.
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