“Warm white LEDs donate mostly bluish light” – “Luminaires with permanently installed LEDs are ecologically unacceptable”: Two allegations from last week’s agency reports that mislead LED buyers because they are so wrong.
The integrated, mobile “hue go” LED light from Philips is actually blue – but only if it is adjusted to this color. (Photos: W. Messer)
The industry portal “licht.de” referred a few days ago to a widespread dpa report on “the right lighting in the autumn”, among other things, which was to be read here:
“Right light color: Although there are already warm white LEDs, mostly they donate bluish light. “This is disadvantageous for the eye, because the quality of vision suffers,” says Wunsch. ”
The Heidelberg light biologist, Alexander Wunsch, has been quoted as saying that he has been arguing against the alleged EU incandescent light bulbs for years and apparently is not up to date with LED technology. Since the dpa times would rather have previously informed about the special interests of the Nordbadeners. What is behind this absurd assertion?
In fact, white semiconductor light is mostly generated from originally blue-lit LEDs – similar to those you see at the top of the blog. For this purpose, they are coated with a yellowish fluorescent envelope, which provides “cold” to “wames” white light by means of luminescence conversion, depending on the composition and density. The higher the color temperature, the higher is the proportion of blue light wavelengths and the LED is “colder”.
Light bulbs also have a blue light component
“Warm white” LEDs with about 2700 Kelvin have usually only a very small blue part, donate so surely no “bluish light” – apart from dubious, untrustworthy products with deficient “Globe Top”. With “extra-warm-white” LED lamps, the radiation energy in the blue spectrum can be even less than 450 nanometer wavelengths compared to conventional incandescent filament lamps, which are also somewhat “cooler” with increasing power. For example, the spectral diagram of a clear 60-watt Osram “light bulb” – with a steady increase in the direction of infrared, which provides much heat instead of visible light:
And this is the curve of an even brighter 9,5 W LED lamp with similar light color:
The little blue hill on the left does not appear as a “bluish light” in the overall picture, nor is it necessary to worry about the fearful “blue hazard” effect in normal circumstances.According to the Stiftung Warentest test, a negative chronobiological effect is also not to be expected. On the contrary, the effect of this LED lamp on the “sleep-wake rhythm” was quantified in a current comparison with “90% of incandescent light”; The “sleep hormone” melatonin is therefore less suppressed than from one of the old Stromfresser. Similar low percentages are found in almost all current, “warm-white” LED lamps.
The light color is hardly distinguishable: a “warm white” LED filament lamp (left) and a traditional 60 watt “light bulb”.
If, on the other hand, you want to keep your melatonin within the limits of your work, you are better served with “neutral-white” or “cold-white” lamps between about 4000 and 6500 Kelvin. Depending on the culture and light taste, such lamps are even more popular than the LED retrofits sold with us in Central Europe with incandescent lamp-like color temperatures.
The “vision quality” mentioned by Alexander Wunsch does not in any case suffice as long as such lamps have a decent color rendering index and you do not stare directly into the light source for a longer time (but you should not do that in the case of desired favorite incandescent lamps).
Are permanently installed LEDs “ecologically unacceptable”?
One of the permanently installed LED modules of a “massive” / Philips pendant light. So what is according to “German environmental aid” ecologically questionable.
Just as questionable appeared to me a dpa-AFX-message sent over the weekend on the ecobalance of lamps with permanently installed LED modules. As is well known, they are also offered more and more in hardware stores and discounter stores. In this widely published article, Philipp Sommer, the circle economy expert of “Deutsche Umwelthilfe eV”, is named as a source. Despite the low energy consumption, such luminaires are of considerable concern because the LED lamps can not be exchanged:
“This is a difficult thing: when the lamp is broken, the whole light comes on the trash. The environmental balance is naturally clouded. ”
The industry should be “wherever possible, stay with pears. For classic ceiling lights, for example, the exchange of the lamp should remain possible. ” In fact, LED retrofits (in the photo on the left, a selection in the specialty shop – rack) are unbeatable in terms of replacement – in the case of defects or higher demands on the quality of the light, they can be replaced ruck-zuck.
Unfortunately, however, they also have a few conceptual disadvantages: They must also be able to cope with the space limitations of old socket types or partly very compact incandescent and halogen lamp designs, but should at least be as bright as their predecessors, Luminaire housing without sufficient heat dissipation and therefore dieprematurely, do not often cope with existing transformers and / or wall dimmers. In the medium term, the LED industry would not do itself and us therefore a favor if it would “stay with pears”.
Integrated lighting usually last longer
For integrated luminaires designed for LED modules (in the PR picture on the right “Hatha Wall” wall luminaires from QisDesign), the cooling concept, power supply, circuit, binning, dimming etc. can be adapted to the new technology (See point 8 in this article). Even fans of extreme brightness can find here their hot- lumen lumens in up to four- or even five-digit meetings.
Above all, commercial customers do not have to deal with old “bulb” or spotlight shapes for a long time with the LED conversion, but instead opt for a complete integrated lighting solution. And they do so because they can and must: The investment in such fixtures is first of all more expensive than the simple LED retrofit exchange, but is paid for in the long term – through more flexible control options, more problem-free operation and longer service life.
Integrated “PolaronIQ” wall and ceiling luminaires from Trilux.
The LEDs themselves are not the achilles heel
And if something breaks, then it is usually not the “lamps” (referred to as LED modules or chips) by the “German environmental aid”, but rather components of the pre-electronics electronics. Serious LEDs from the renowned manufacturers can easily handle much more than 25,000 lighting hours and a million switching cycles, while other electronic components often fail much later, depending on the quality and heat load. Although now more and more integrated luminaires are replacing the LEDs thanks to standardized (“Zhaga”) connections, it should nevertheless be unnecessary, because the weak spot is located elsewhere.
A grain of truth is therefore in the “environmental aid” memories: who buys cheap, badly designed and processed LED complete lights, which after a short time give up the spirit, is actually ecologically questionable. At least ten to 20 years they should be able to cope without complaint, so that the electricity savings due to the high efficiency is large enough to turn the initially negative ecological balance (due to more elaborate production, higher material, packaging and transport expenses, etc.).