Are LED lights a significant source of UV?

[Andrew Lenz Jr.]

Incandescent bulbs are a minor source of UV.

Fluorescent bulbs are a major source of UV.


But what about these new-fangled LED lights?


Andrew

 

[Mike Labbe]

I'm a huge fan of this technology. Our shop and house have been converted to LED, and there are many programs out there to do this for nearly free. ($2.50 per bulb, any size, is the current offer from our electric company's partners) The old bulbs produce mostly heat, with very little light. The LED bulbs produce the same light, at the desired 3000k, for a fraction of the wattage/electricity. For example, we replaced our 50w halogens with 7w LED bulbs - and they're brighter! They're also a lot cooler. Halogens run up to 327F, while these run at about 110f.

The packages claim that they don't fade art, etc. They also advertise that they won't attract insects, due to the lack of UV light spectrum. (interesting for a patio fixture)

These are interesting claims, and while I bet they are mostly correct - it would be nice to see some scientific evidence to support it. From what I've learned on the forums from experts such as Hugh, there are multiple factors that can cause fading. The UV light happens to be one of the largest.

Rob Markoff will probably have a better answer and has done a lot of research on this topic.

Mike

PS: Here are a couple boxes from spares I have sitting around the house. One of them has such a claim.

 

[Andrew Lenz Jr.]

Thanks, Mike.

I decided to poke around the web a bit and found this:
http://www.residentiallighting.com/what-light-sources-will-fade-artwork-and-fabrics
where an expert (Randall Whitehead, IALD) claims that there is less UV put out by fluorescent lights than traditional incandescent lights:
"The worst culprit is natural daylight, followed at a distant second by incandescent and finally fluorescent."

This is contradictory to what I've learned over the years. I believe Mr. Whitehead is mistaken in his "expert answer".

I searched more and found this from a research company:
http://www.nouvir.com/pdfs/MuseumLighting.pdf
which states on page 8-8 :
"Fluorescent lamps faded the ISO samples only 10% less than sunlight."
Though this document appears to also be a sales piece.

Also, from the Northeast Document Conservation Center:
https://www.nedcc.org/free-resource...-environment/2.4-protection-from-light-damage
"Fluorescent lamps are inexpensive to use but the commonly available versions emit significant UV radiation."

Here's another from a library cataloging forum:
http://www.librarything.com/topic/142309
"Tungsten incandescent lighting, on the other hand, produces insignificant amounts of UV energy, as the majority of its spectral response is in the green and yellow spectrum, along with significant amounts of infrared energy--heat."
and
"LEDs do not emit UV or IR radiation and the light does not generate heat (although the conductor box does)."

Also from that page and poster Django6924:
"... LED lamps, which emit no infrared nor UV radiation ..."

At least Mr. Whitehead (whom I can't trust) and Django6924 (who seems to know what he's talking about) and the NEDCC agree on no UV from LEDs, so I think we're safe.

Confirmed the answer to my own question, I guess.

Andrew

 

[Rob Markoff]

UV light is only ONE of the causes of fading. ALL light causes fading. Damage from light is cumulative and irreversible.

LED lights are cooler (so in close proximity they are less damaging heat wise and they are not a significant source of UV light because of how they work.)

However, do not think that things will not fade because they are illuminated with LEDs or that because LED lighting is used that conservation grade glazing is not necessary.

Here is a link to an article you may find useful. https://www.dropbox.com/s/yq9kf8o2qa9fc0y/What Causes Fading article.pdf?dl=0

 

[Andrew Lenz Jr.]

Yep, I know it's not just the UV portion of the light spectrum, I tell my customers that all the time. That's why the (visible) light was greatly dimmed when I went to look at the Book of Kells at Trinity College in Dublin in 1995.
:thumb:

Thanks for the link, Rob, I'll certainly check out the article. :smile-new:

Light is quite a complex subject and fading even more so.

Andrew

p.s. And, yes, I know, I know. I still need to just do it and break down and take the CPF test. Darn work keeps getting in the way!