Loss of LED Intensity Over Time? LED vs. T5 - Two topics in one...

schooleyosis · Oct 30, 2013

I've been pondering the thought of how much intensity or color shift do LED's lose over time. I bought 2 cheaper LED fixtures almost 2 years ago and when I had one of them replaced under warranty a completely new unit was sent back as a replacement. The color shift from the new unit to the old unit was very noticeable... The new fixture had the same amount and brand of LED's as the original fixture running next to it, just in a different layout. I don't think that would have changed the color spectrum.

So my question here is. Has anyone ran LED's long enough; let's say 2+ years, and measured the PAR from day one until now? I am curious if the PAR results are the same? I am also curious if your LED's have shifted in the color spectrum?

And, on a completely different topic, which I was going to post a new thread for but will just discuss here as well, since I'm on the subject. I'd like to compare the cost of running and changing out T5 bulbs versus having to replace a whole LED fixture or LED's after lets say 3 years due to loss of PAR and/or color shift. I say this because it would appear that after 2 years of running my LED fixtures I know the color spectrum has shifted greatly. PAR results I have no clue so I can't comment on that.

I do know that you have to replace the T5 bulbs at least once per year though which is a little expense each year but can add up to a big expense over 10 years. But I am curious as to the lifespan of LED's over a 10 year period as well, as replacing the fixtures every 3-5 years can get very expensive, especially if you are running AI's, Radion's, etc... Don't most LED companies say they are good for 5 years?

Let's not talk about the costs savings of how energy efficient LED's are here... We all already know about that and how much you can save if you switch to Geiko! LOL

Let me know your thoughts! :thumb:

NeveSSL · Oct 30, 2013

Out of curiosity, which LED units are you using?

I'm thinking the LED itself will pose a significant difference in how much change there is. Specifically, I would expect less change and shift from a Cree LED than from a Bridgelux or no-name LED. However, that may not prove to be actually true.

Brandon

schooleyosis · Oct 30, 2013

They are from reeffiltration.com. Good point.

pelagic · Oct 31, 2013

all the LEDs lose the intensity over time, they usually has 50% intensity left after you powered them for 30K to 50K hours.
however, the key to make the LEDs last longer is to have a good heatsink/fan for the fixture.
The lower the temperture, the longer the chips last.

pelagic · Oct 31, 2013

here's some more info about the life span of the LED from Cree

Q:
Why is the life span of an LED measured as lumen depreciation?

The life span of an LED is vastly longer than that of incandescent, fluorescent or HID lamp sources, generally lasting 50,000 hours or longer. Although the LED never really burns out, product life span is measured by lumen depreciation.
The Illuminating Engineering Society's (IES) current standard for calculating the life of an LED as the point at which the LED reaches 30 percent lumen depreciation.

Remember, a 100,000-hour rating is not equivalent to lamp life rating. LED life is rated where it has reached 30 percent lumen depreciation. At 100,000 hours an LED would still be operating, but at a decreased lumen output.

also here's a good post about the LED life span
Lifespan of Cree LED | BudgetLightForum.com

Dowtish · Oct 31, 2013

Good info Cheng!

schooleyosis · Oct 31, 2013

Really good info. Thanks for sharing.

My fixtures must be really cheap because it had several burnt out LED's in it!!!

pelagic · Oct 31, 2013

schooleyosis said:
Really good info. Thanks for sharing.

My fixtures must be really cheap because it had several burnt out LED's in it!!!

There are few possible reasons for it, cause LED usually don't die that easily

1. The humidity and the salt, if you spread the anti-moist spray(eg: H2OFF spray anticorrosion ,Lubricates, Protects, Penetrates & Displaces Moisture), or add a clear acrylic cover between the water suface and the fixture, it should help
2. Make sure you have a good fan/heatsink to take away the heat.

Good luck.

schooleyosis · Oct 31, 2013

I'm switching to T5's. LOL Good info though. I'm pretty sure the moisture got to the fixtures in the canopy.

pelagic · Oct 31, 2013

schooleyosis said:
I'm switching to T5's. LOL Good info though. I'm pretty sure the moisture got to the fixtures in the canopy.

T5 is nice, I am too lazy to change the bulbs so I have LED and Plasma. lol

schooleyosis · Oct 31, 2013

I need to come check those out!

McAllyn · Nov 1, 2013

My T5's will be roughly $120 per 9-12 months... That's a new chinese fixture every year. Pretty sure I'll switch over to LED sooner rather than later.

Mac

schooleyosis · Nov 1, 2013

You can buy both of my old fixtures for less than what it will cost me to change out all 8 4' bulbs!!!! LOL

Dowtish · Nov 1, 2013

McAllyn said:
My T5's will be roughly $120 per 9-12 months... That's a new chinese fixture every year. Pretty sure I'll switch over to LED sooner rather than later.

Mac

Bill-
Start buying them spaced out over a few months. Only change out 2-3 at a time and date them once installed. This way you dont have to acclimate when you add new bulbs and it doesnt hit your wallet so hard all at once. I ususally had mine spaced out to where I changed them every 9 months, but only 2 at a time spaced out over 6-8 months total. Since you are on the same rotation, just buy 2-3 and let 2 bulbs run for 2-3 more months then replace them then and so on.

schooleyosis · Nov 1, 2013

I wonder how expensive it will be to replace everything that gets burnt down when the Chinese fixture catches fire in your canopy????

NeveSSL · Nov 1, 2013

Well, if you replace it staggered out, its really not too bad. Just replace one piece of furniture 2 at a time spaced out over 6-8 months and you're good.

Brandon