Explore the parameters of the LED bulb

LED lighting has become extremely popular due to its efficiency, durability and versatility. However, in order to fully exploit the potential of LED lighting, it is useful to have a good understanding and appreciation of the various parameters related to its quality and characteristics. Let’s take a look at the key parameters of LED light that affect its efficiency and application.


The lumen (lm) is the unit of measurement used to determine the luminous flux emitted by lighting.

The higher the lumen value, the greater the luminous flux, which means the greater the amount of light emitted by a given light source. It is worth noting that the lumen value is closely related to the energy efficiency of an incandescent bulb or LED lamp. The higher the luminous flux with lower energy consumption, the higher the luminous efficiency, which translates into energy and financial savings.


Kelvin (K) is the unit of measurement used to define the colour temperature of light. In the context of LED lighting, colour temperature plays a key role in defining the shade of light emitted.

As a temperature scale, the kelvin describes the energy characteristics of the light that an LED bulb emits. The higher the value in kelvins, the cooler the light, close to white or blue, while a lower value indicates a warm light, close to yellow or orange.

Typically for LED lighting, colour temperatures range from around 2700 K to 6500 K. Values close to 3000K indicate a warm colour, which creates a cosy and relaxing atmosphere, ideal for domestic interiors such as bedrooms or living rooms. A value of 4000K corresponds to a neutral light that is comfortable and natural to the eye, suitable for general lighting in various rooms. On the other hand, values close to 6500K indicate cool light, which is more stimulating and suitable for applications in areas that require more concentration, such as offices or shops.

Choosing the right colour temperature depends on individual preference and the nature of the room you want to illuminate. It is worth noting that LED technology makes it possible to fine-tune the colour temperature, which means that we can adjust the lighting according to our preferences and needs. We can create the right mood in the room, provide comfortable working conditions and achieve optimal visual effects.


Lux (lx) is a unit of measurement used in lighting that describes the intensity of illumination on a given surface. It refers to the amount of light that reaches a unit area. In the context of LED lighting, lux is used to assess the brightness and quality of lighting in different areas. The higher the lux value, the brighter the lighting.

Depending on the application and requirements, there are different guidelines for minimum light intensity in different areas. For example, in workplaces such as offices, an average light intensity of 500-750 lux is recommended, while in shops or art galleries, a higher light intensity may be needed to fully display products or artwork.

LED lighting offers a wide range of adjustability and brightness customisation, allowing the light intensity to be fine-tuned to suit specific needs and conditions. The high efficiency and controllability of LED lighting means that high light levels can be achieved while saving energy.


Lumens is used to define the brightness of a light source. It is useful for comparing the brightness of different incandescent bulbs or LED lamps. The higher the lumen value, the brighter the light emitted by the source.

Lux, on the other hand, is used to determine the brightness of lighting in a specific location. This is useful for assessing the level of illumination in a given area and can be used in the context of lighting design, such as the lighting of rooms, workplaces, streets or other areas.

In summary, lumen refers to the total amount of light emitted by a source, while lux refers to the intensity of illumination on a given surface. Lumen measures the luminous flux, while lux measures the brightness of light (intensity) at a given location. Both units are important in the context of lighting to assess the brightness and luminous efficiency of a light source and to ensure adequate lighting in different areas.


The candela (cd) is a unit of luminosity, and luminosity is otherwise known as the flux intensity of a light source. Luminosity defines the magnitude of the visual brightness of light. A candela is the luminous intensity with which a source shines in a specific direction. In 1948, the candela was introduced as a unit of measurement of the luminous intensity of light and replaced the earlier unit of luminosity, which was called the candle.


The CRI, or Colour Rendering Index, is a measure of how truly and faithfully a light source renders the colours of objects compared to a natural light source such as the sun.

The CRI scale ranges from 0 to 100. The higher the CRI value, the better the light source renders true colours. A value of 100 means that the light source renders the colours of objects perfectly, as with natural lighting. For example, a light source with a CRI of 85 will render colours less well than a light source with a CRI of 95.

CRI is important when choosing lighting because it affects how we perceive colours in a given space. For example, in areas where colour fidelity is crucial, such as fashion shops, art galleries or photography studios, lighting with a high CRI is recommended.

For domestic lighting, especially where we perform tasks that require detailed colour discrimination (such as in the kitchen or bathroom), it is also worth paying attention to CRI. Lighting with a high CRI can also improve well-being as it better reproduces natural lighting conditions.

However, it is worth remembering that CRI is not the only criterion we should consider when choosing a light source. Other important parameters include, for example, colour temperature (which determines the ‘warmth’ or ‘coldness’ of the light), light output (measured in lumens) or energy efficiency.

Power Factor

Power Factor is one of the key parameters in lighting, especially for LED and fluorescent lighting. The power factor, expressed on a scale of 0 to 1, is a measure of the efficiency with which a luminaire converts electricity into light.

A high power factor (close to 1) means that the luminaire is efficient in converting energy into light, while a low power factor (close to 0) means that much of the energy is wasted. In other words, the higher the power factor, the less energy is used for other forms of energy, such as heat.

Choosing a luminaire with a high power factor can benefit you in terms of lower energy bills and a lower environmental impact because less energy is wasted. A high power factor can also mean a longer luminaire life, as less energy is converted into heat, which can shorten the life of some lighting components.

However, it should be noted that for domestic lighting, the differences in energy consumption between luminaires with a high and low power factor may not be significant. However, these differences may be significant for large commercial or industrial facilities where lighting is used for long periods of time.

It should also be noted that a low power factor can cause power quality problems in power grids, leading to interference and instability. Therefore, in some jurisdictions, luminaires must meet certain minimum power factor requirements.


A watt (W) is a unit of power in the SI system of units, used to describe the power consumption of a light source, such as an incandescent bulb or light fixture. Traditionally, a higher watt value meant more light emission. For example, a traditional 60W incandescent bulb will emit more light than a 40W bulb.

However, with LED lighting technology, energy consumption (watts) is not directly proportional to the amount of light emitted (lumens). LEDs are much more energy efficient than traditional incandescent bulbs, meaning that they can emit the same amount of light (or more) with much less power consumption.

For example, a 10W LED bulb can emit the same amount of light as a traditional 60W incandescent bulb. Therefore, when choosing LED lighting, it may be more useful to look at the number of lumens (the unit of light) rather than the wattage expressed in watts.

Why is it worth it?

When analysing the savings of using LED lighting, we need to consider several key factors, such as energy efficiency, the cost of the bulbs and their lifespan.

1 Energy efficiency: LED bulbs are significantly more energy efficient compared to traditional incandescent bulbs. In a traditional incandescent bulb, around 90% of the energy is lost as heat, whereas LED bulbs convert almost all the energy directly into light. For example, to generate around 800 lumens (typical illumination for a table lamp), a traditional incandescent bulb uses around 60 watts, while an LED bulb only needs around 10-12 watts.

2 Cost of bulbs: Although LED bulbs tend to be more expensive to purchase than traditional incandescent bulbs, this cost is offset by their long life and low energy consumption. For example, a typical LED bulb can last 25,000 hours or more, compared to around 1,000 hours for a traditional bulb.

3 Running costs: Assuming that the cost of electricity is around £0.6 per kilowatt hour, the annual running costs for a traditional incandescent bulb at an average illumination time of 6h/day is around £123, while for an LED bulb it is around £20.

These figures are, of course, approximate and can vary depending on specific conditions, such as the cost of energy in a particular region, but they show a general trend. Using LED lighting can lead to significant energy and cost savings compared to traditional incandescent bulbs..