Do LEDs really run cooler than T5s?

[STiTCH87]

I've heard from many people that LEDs are praised for running so cool and being efficient in power usage over T5s, yet every time I look for info online regarding this subject, everything points to saying that T5s run cooler and are more energy efficient.

Which is true? Any documentation to back this up?

 

[badlands25]

I'm hearing that they run cooler. But the cost of led fixtures are through the roof. The initial purchase of these fixtures start in the 2-300$ and up to the 1k$ range depending on the tank size. I have seen a few diy builds on the forums here if you are handy you could probably build one yourself.

 

[Edward]

could you site your sources?

I misread your post at first. They do run hot, that's why you need a heat sink.

 

[STiTCH87]

Well I DO plan to build one myself this summer whether they run hotter or cooler or more or less effecient IDC simply because they look better and I love shimmer to boot.

http://www.lumiversal.com/upload/T5 v. LED.pdf
That's my source claiming LEDs runs hotter and are less efficient and what not. But it isn't specific on what LEDs were used nor the application of the lights.

 

[Jocko]

Yeah I'm sure the numbers they are giving are not false, but they are certainly choosing which numbers to show in order to make their point. For instance the more amperage you run through an LED, the less efficient it will be. So I'm sure the numbers in that doc are with the LED being run at max. Which almost nobody does in real life. And I think this is based on really old LED tech too.

Just to give a single example, that doc says "The measured efficacy of a 14 Watt T5 fluorescent lamp was 96.7 lm/W, while the measured efficacy for the best performing LED lamp was only 78.5 lm/W." The current state-of-the art for most people is the CREE XP-G emitter. According to CREE, the XP-G when driven at 350mA puts out around 135 lm/W. Even when driven at the max of 1.5A, it still does 92 lm/W.

So I'd say at the very least, with current LED technology, is at least pretty much equal. So one might base their choice on other factors.

 

[STiTCH87]

Like better coloration and a nice shimmer. =]

 

[DoctaQ]

leds are more efficient than t5s for the spectrums they normally produce, t5s also need reflectors because they emit light in every direction, vs leds which emit light in one direction

led drivers can also be more efficient than ballasts, depending on usage and setup

leds dont produce much heat, and of that heat very little of it goes into the tank, aside from going into the room where the tank is

im running about 22w over a 24" metal plate and its barely warm..cooler than a laptop surface

 

[STiTCH87]

Sounds pretty good to me. Right now when I run my 4 T5s totalling 98W my tank gets pretty warmed up. I'll have it at 76.5, run 2 T5s and it'll hit 77.5 then another 2 T5s will hit 78.5 and up. Granted the last 2 T5s are daylights so IDK if different spectrums produce different heat, but lately i've only been running one aqua blue and one 50/50 and keeping the other two off because one, I hate daylight bulbs but cant afford to replace my aqua pink that burnt out, and 2 it runs warm. Hoping LEDs will keep it cooler atleast a degree or two. I never wanna see my tank above 80 this summer if I can help it.

 

[aiaman]

Unlike your current fixture, heat is dissipated thru the heatsink which the LEDs are attached to. There should be no heat directly to your tank.

 

[labnjab]

We have 16 3 watt XR-E crees on our 10 gallon and the tank temp stays at 78 with no fan or ac. They do shoot a lot of heat through the heatsink, not nearly s much as our halides on our 75 gallon do though (they peak at around 200+ degrees). I measured the temp of our heatsink after several hours of running and it was roughly 120-130 degrees so I'll probably add a fan to the canopy soon to help keep that temp down.

 

[aiaman]

I have 2 pc fans mounted to the heatsink w/no heat, cool to the touch

 

[labnjab]

I have 2 pc fans mounted to the heatsink w/no heat, cool to the touch

I'll have to add some fans. I was on the fence about using them when I built the fixture, some people said to use them, some said they wern't needed, but now my canopy needs to be rebuilt, the woods warping and the glues melting due to the heat ::

 

[STiTCH87]

If you angle mount a few fans it should blow off the heatsinks nice and keep it cool. When I build mine i'm using buckpucks so I can wire one fan per 12 LEDs to keep it cool. I currently have a 6 fan strip mounted to my tank and during testing it dropped my 29g from 81 degrees down to 76 degrees within 4 hours of constant run in a non-ventialted room.