FAQ: LED terms you should be familiar with
Acquiring new lighting can be a more complicated process than one might think. Are you, by way of example, acquainted with all the illumination terms in the datasheet or on the packaging? No? Then you are not alone! For that reason, we will look into a number of these terms in this week’s blog post.
What does candela mean? And is CRI important to me? We are frequently asked about the significance of various illumination concepts and, therefore, we have chosen to elaborate an FAQ to remove possible doubts.
Lumen is the unit of luminous flux and measures the amount of light emitted from a light source. In other words, the higher the lumen output, the higher the light output.
If you are in need of LED modules for your home, you must beware of not choosing luminaires with a high lumen amount. One example could be our kitchen luminaire NS33, which emits 357lm.
If you, on the other hand, have to illuminate a storage building, you would prefer a luminaire with a high lumen output. That could be our powerful LED luminaire NS64, which emits as much as 39,000lm.
Watt is the illumination term for power consumption, which means that the higher the Watt, the higher the power consumption.
When replacing traditional lighting with LED, you would not be the first to look for a LED bulb with the same power consumption as the halogen bulb it has to replace. However, Watt merely is an indicator of the power consumption, which means that the energy efficiency itself cannot be read from the Watt.
By way of example, our 7W LED downlight NS14 corresponds to a halogen bulb with 50W.
Lumen per Watt (LPW or lm/W)
Accordingly, you would not be able to measure the energy efficiency from neither lumen nor Watt. By contrast, you would need to look at lumen per Watt, which is measured by dividing the lumen output by the amount of Watt consumed by the given luminaire. In this way, a high LPW is equal to an energy efficient light source.
Our most energy efficient luminaire is our LED tube OS0029. With a lumen output of 2,850lm and a power consumption of 15W, the luminaire has an energy efficiency of 190 LPW. In comparison, an incandescent bulb emits 10 LPW.
The Kelvin scale measures a light source’s colour temperature on a scale from 1,000 to 10,000 K. Warm light, which could be the light from a candle, has a low Kelvin amount of 1,200 K, whereas cold light, which could be a clear blue sky, has a high Kelvin amount of 10,000 K.
Consequently, the Kelvin amount is important in relation to the given atmosphere you would like to create. If you are about to illuminate a restaurant with cosy and intimate lighting, you should be looking for luminaires with a low amount of Kelvin. If you, on the other hand, have to light up a museum, where the light has to be as realistic as possible, you would want a luminaire with around 5.000 K.
The vast majority of our products can be customized in relation to a specific Kelvin amount. As an example, our LED panel NS60 comes with either 3,000, 4,000, or 5,000 K.
Colour rendering (CRI)
If you, by contrast, are interested in how well the colours are rendered, you should pay attention to the luminaire’s CRI. CRI indicates, how the colours are rendered in a given room on a scale from 0 to 100.
With regard to indoor lighting, there is a general minimum requirement of CRI80, but for outdoor use, it might be sufficient with less than CRI80. However, if the lighting is to be installed in an operating room or in a restaurant kitchen, you should consider light sources with CRI90+.
As it is the case with most of our products, it is possible to opt for a higher colour rendering. One of our luminaires with the highest colour rendering is our track spot NS70 with CRI90+.
MacAdam indicates a luminaire’s colour stability on a scale from 1 to 10, where 1 is the target value. For that reason, a high MacAdam is equal to an impure light, whereas it is almost impossible for the human eye to distinguish between the lighting if it has a low MacAdam of 2 or 3.
Most of our products come with a MacAdam of 3, and several of these can be upgraded to a MacAdam of 2. An example could be our linear downlight NS17.
Candela describes the luminaire’s luminosity in a given direction and is used to calculate the lumen output. However, you would rarely be in need of looking further into candela.
Lux indicates the amount of light exposed to a given surface. In other words, the lux amount depends on the room as well as what is placed in the room. In Denmark, there is a minimum requirement of 500 lx for offices, and especially in Europe, there are specific regulations for lux amounts.
How can we help you?
Do you have further questions with regard to illumination terms, or do we have to elaborate on anything? Then do not hesitate to contact us! Our LED experts are ready to help you.