T5 vs. LED Heat Question

[Zen685]

How does the heat output on an LED fixture compare to T5s? Right now I'm running a 6x54 watt T5 retrofit setup under a closed canopy with no ventilation. It's worked well for almost 2 years but I have a hard time keeping the heat down in the summer. Would I have the same problem with an LED setup in the same closed canopy?

[James77]

Both are pretty low heat as far as imparting heat to the water, but the same watts of each will impart the same heat into the room. The no ventilation is what is killing you though, all that hot air is trapped in the canopy and is heating the water. You should be actively cooling those T5s as well if you want the best performance and life out of them. LEDs need cooling as well, and putting them in an unvented canopy will most likely lead to problems.

Is drilling and adding fans an impossibility? That would be your best bet and would cool your tank down.

[Zen685]

I need to add fans but I've never done it because I've always had good growth and the tank rarely overheated. This last 100+ degree summer made it a hassle to keep the tank cool so I'm considering my options.

Does anyone know of a good high quality fan cooling fan that won't buzz a lot? The tank's in the living room.

[James77]

On ym past canopies, I simply used a couple 4" computer cooling fans. The ones I used were Noctua NFP12 fans, they are less than 20 dB at full speed, and are powerful. Some fans will advertise a certain CFM, but they have little pressure behind it.

http://www.newegg.com/Product/Product.aspx?Item=N82E16835608004

You can find them cheaper Im sure, just showing the ones I have. You can use any 12v transformer you ahve laying around to power them. Also, fall and winter are almost here, it may not be an issue for much longer.

[swflfisher]

x2 on the cpu fans, they are about as quiet as you can get

[GSMguy]

Just add ventilation.

I like the azoo fans that Drs Foster and Smith sell.

[CaptiveReef]

Over the years I have had T-12 bulbs, Metal Halide, Power Compacts, T-5's, and now LED.

I will say the LED's are the coolest running light source out of all the lighting I have used. No need for a chiller, and the LED's last for 5 years then they drop to 75% output after that. The next light source for reef will be Plasma and that is a whole different story! A Plasma element is the size of a tic tac and it is as brite as the sun!


CaptiveReef :wave:

[v3ngence]

Both are pretty low heat as far as imparting heat to the water, but the same watts of each will impart the same heat into the room. The no ventilation is what is killing you though, all that hot air is trapped in the canopy and is heating the water. You should be actively cooling those T5s as well if you want the best performance and life out of them. LEDs need cooling as well, and putting them in an unvented canopy will most likely lead to problems.

Is drilling and adding fans an impossibility? That would be your best bet and would cool your tank down.

I agree with the rest of your recommendations but good LEDs are over 95% efficient at converting electricity into light, metal halides are around 90% efficient, and the best compact fluorescents are 75-80% efficient.

The percent of energy that is converted into light can be absorbed and used by your tank without becoming heat, thought some light does end up heating surfaces. The percent that doesn't get converted into light is what is directly created as heat by the light. And a 100w LED light will only produce 5w of heat, while a 100w fluorescent light can produce over 20w of heat.

[Zen685]

Here's the canopy I'm working with. My wife wants it to look like furniture so no fans on the front or sides. I can probably get away with fans on the top and back. I'm really leaning towards building 2 24 LED pendants to sit on each side of the center brace. With the canopy being so shallow the LEDs would rest a few inches off the water. I would probably put a fan on top of each heat sink and a couple more on the backside pulling air out of the enclosed space. Do you guys think this would cause a problem? Most of the setups I've seen on here are pendant style hanging in the open.

http://www.reefcentral.com/forums/picture.php?albumid=1856&pictureid=35524

http://www.reefcentral.com/forums/picture.php?albumid=1856&pictureid=35525

[James77]

I agree with the rest of your recommendations but good LEDs are over 95% efficient at converting electricity into light, metal halides are around 90% efficient, and the best compact fluorescents are 75-80% efficient.
.

Right, but the same watts of each will put out the same heat. The higher efficiency may mean you need less watts, which will mean less heat.


The percent of energy that is converted into light can be absorbed and used by your tank without becoming heat, thought some light does end up heating surfaces. The percent that doesn't get converted into light is what is directly created as heat by the light. And a 100w LED light will only produce 5w of heat, while a 100w fluorescent light can produce over 20w of heat.

The light will turn to heat, no matter if it goes into the tank or room. There is not that much that is absorbed by the corals and other animals in the tank. A 100 watt LED and a 100 watt flourescent will create the same amount of heat. The LED may kick off more light with it, but that energy is just temporarily converted.

Here is a recent thread that went into it quite well:

http://reefcentral.com/forums/showthread.php?t=2067082&highlight=heat

[chadfarmer]

make sure you look at the other powered items on your tank also it not just the lights

if the tank was pulled off the wall a little more would help vent too

[Zen685]

If the lights are off the temperature drops quickly. The rest of the pumps aren't putting much heat into the tank.

2 Koralia 4
1 MP40
1 MAG9
1 Skimmer Pump
2 maxi jet 1200

Pulling the tank off the wall is not an option. It's already sticking out into the living room quite a bit. I may duct the back fans to the side to pull in some cooler air.

[James77]

Could you drill several smaller holes in the sides and out a decorative mesh over them, or even a small " fancy" fan cover? I did that on mine, and it still looked good.... But maybe a wife would see it different.....

[Zen685]

I love the idea of the small holes but I presented it to the management and it was vetoed.

[rtparty]

But maybe a wife would see it different.....

There is no maybe when talking about wives and a fish tank. They always see it different...

:lmao: