Are high power LEDs more reliable than mid power ones?
The evolution of engineering and research on LED lighting fixtures has enabled the use of new materials as well. For so-called mid power LEDs, for example, the use of plastic materials allows to maintain relatively lower costs compared to the use of ceramic based materials for high power LEDs.
But is it really so?
The evaluation, which is also a financial one, in choosing which LEDs to use, should be done in the medium and long term. The so-called mid power LEDs are useful for low power, and from the point of view of the luminous flux. Although they can initially generate the same high power LEDs light, they tend to have an unmatched performance. The most important difference between high power and mid power LEDs is the duration and decay of the luminous flux.
High power LEDs maintain a stable, luminous flow even at high temperatures, so they are said to be ‘codified’. LEDs mounted in outdoor floodlights, for example, can reach junction temperatures of up to 85 degrees centigrade. The luminous flux indicated for mid power LEDs usually refers to a junction temperature of 25 degrees centigrade, while the average temperature that can be reached by LEDs is 60 degrees. The actual luminous flux can therefore be less than the indicated one. Considering 100 lumens of mid power LEDs at a junction temperature of 25 degrees and 100 lumens of a high power LED, such as those used by Niteko, there is a decay of the luminous flux of the first around 15-20%, while the latter will lose about 7-8% at a junction temperature of 120 degrees.
Niteko uses high power ceramic based LED for its products. These (LED high power), on one hand, ensure a constant luminous flux, even at high junction temperatures, while, on the other hand, they can guarantee a longer service life.
Giuseppe Vendramin: Technical Director