This seemingly trivial topic – one might think that it suffices to compare figures – is in fact full of catches which you will learn about thanks to the following article.
The basic question is: what are you comparing? Manufacturers want to show off their products as best as possible, so often they display units against which they can cope better. Descriptions may sound similar, nonetheless present completely different parameters. The following list will protect you from comparing apples with pears.
Rated flux of a fitting or rated flux of LED diodes in the fitting?
Always compare the rated flux of a fitting, because only this parameter shows what is the luminous flux emitted by the LED light source mounted within the fitting with regard to losses related to the construction of the fitting. These losses can be up to 30% of the flux of the diodes! Taking the rated flux of the LEDs in the fitting into calculations will help you find out that you need less fixtures and thus you will not provide the required illuminance. See our product cards – they clearly define the rated flux of the fitting and the rated flux of the light source (LEDs in the fitting).
Rated power of a fitting or the power of the light source?
It happens that manufacturers indicate the catalog power of LED sources in the fitting, leaving out the rated power of the fitting. The rated power of a fitting is the power drawn from the electrical grid – larger than the power of the LED source in the fitting – and you will find it in LUMITEAM product cards.
What is the luminous efficacy of the fitting?
The real luminous efficacy of the fitting determines the amount of light (lm) emitted from the light fitting per one power unit (W). For the calculation, use the rated flux of the fitting and the rated power of the fitting. Only these numbers take into account all of the losses generated by the components of the fitting, such as the power supply, optics or glass. The results of our lamps are very good, so we are proud to indicate their true effectiveness.
What is the Ra (CRI)?
This parameter refers to the quality of color rendering. For different rooms there are various established standards, for example: for rooms where people perform office work Ra is > 80. If the decision concerning the choice of fitting is to be taken based on reliable data, you ought to compare fittings with the same Ra (two lights with varying Ra will also have different luminous efficacy).
What is the color temperature of the light?
The color temperature of light is expressed in kelvins [K]. The higher it is, the greater the proportion of blue, which gives the light a cool shade. Typical LED luminaires produce light in the range of 2,700 K to 6,500 K. When comparing luminaires, it is important to combine products glowing with the same color temperature. This is important, because only then it is possible to evaluate the same visual comfort. You might want to consider the fact that luminaires with a higher color temperature have up to 5% higher luminous efficacy; however, then the color of the light is fairly cool (more than 6,000 K).
| 1800-2000K | candle flame |
| 2500K | flashlight bulb |
| 2800K | light bulb in the lamp |
| 3500K | early morning, late afternoon |
| 4000K | fluorescent |
| 5200-5500K | noon, direct sun |
| 5500K | flash light |
| 6000-6500K | cloudy sky |
| 7000-8000K | shadow |
How to interpret the durability of LED luminaires?
The durability of LED luminaires is determined using the LxBy indicator. In the case of LUMITEAM lamps, the lifespan is 100,000 hours at the mentioned L70B50 indicator. This means that after 100,000 hours of burning time, 50% of all LED diodes will be shining with a stream of not less than 70% of the initial value. However, if you change the indicator (for example to L80B20), the lifespan will change as well.
When comparing luminaires, pay attention to details in the descriptions of technical parameters, because they determine whether the lighting will meet your expectations.
