Lighting Led Fixtures and Lumen/Watt

Lighting Led Fixtures and Lumen/Watt

Lighting Led Fixtures and Lumen/Watt.

There is a variety of different opinions on lighting fixtures performances that sometimes confuse even us, who we considered to be “experts” in lighting. So, I take the opportunity to clear up things.
Anything that interferes between the led diode and final fixture outcome, is considered a loss.
So, when we’re saying we have a passageway led with 205 Lumen/Watt @ 25thoC (at 02/2019 this number is also the top output worldwide for low power SMD led) will we have a fixture with performance of 205 Lumen/Watt? Absolutely not!! This is the case for the following reasons:

1. Luminous flux losses from Led in a visual or cover.
2. Operating temperature losses
3. Power supply losses
4. Differences binning Of Led

Let us now analyze each parameter separately.

1. Optical losses: They are proportional to the visual and/or material that is inserted between the diode and the environment. Losses can be from a minimum of 4-6% to 40% in the case of an Opal Polycarbonate Sheet.
2. Operating temperature losses are something that diode manufacturers work hard enough to improve. Indicative, the leading manufacturers’s led operating at 25o Celsius, reduces 4% of the amount of light attributed.
3. Power supply losses are also a relative number but from our experience a 7-10% are excellent returns.
4. The Binning is the classification of the led manufacturer after production and may have a difference up to 40%!! in the performance of the led (sold even at a lower price than the manufacturer!!)
So, let us do the deeds…

  Losses (A) Lumen-Watt (A) Losses (B) Lumen-Watt (B)
Chip Level 205 205
Binning 205 15% 174
Optical 6% 193 25% 131
Temperature 4% 185 4% 125
Power Supply 10% 166 10% 113
Final Lumen/Watt 166 113





Select Fixtures that are supported by their manufacturer and there’s proof and consistency on their performances…

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