PDA

View Full Version : Heat Issues W/ T5 How Can This Be?


Waterbury Guy
04/23/2008, 08:00 AM
I've recently switched from 220W PCs to 220W T5s on my 55 in a canopy with no fans. For a few weeks in the summer my tank would get too hot with the PCs. The temps here in VT this week have been in the mid seventies and my tank is already hitting 86 degrees. My PCs were about 6" above the water, my T5s are about 3" above the water. I thought T5's ran cooler than PCs. Anyone else using T5s have heat issues?

GSMguy
04/23/2008, 08:15 AM
have you added any new pumps to the system? how is your heater being controlled?

1watt of PC creates the same heat as 1 watt of t5 or 1w of halide. so in essence your lights create the same amount of heat.


What T5 did you get? does it have active cooling?

Poisonus Yeti
04/23/2008, 08:24 AM
<a href=showthread.php?s=&postid=12392762#post12392762 target=_blank>Originally posted</a> by GSMguy
1watt of PC creates the same heat as 1 watt of t5 or 1w of halide. so in essence your lights create the same amount of heat.

That statement is far from the truth. All goes back to efficiency of the lamp. Any energy that is not released in the form of light will be in the form of heat, noise, etc.

I'd suggest moving the lamps a little higher. Two to Three more inches above the water can make a big difference. Either that or increase the amount of evaporation by adding some fans.

luke33
04/23/2008, 08:55 AM
Add some fan's to blow on the endcaps on each end, should take care of the problem just fine.

laud
04/23/2008, 09:34 AM
<a href=showthread.php?s=&postid=12392825#post12392825 target=_blank>Originally posted</a> by Poisonus Yeti
That statement is far from the truth. All goes back to efficiency of the lamp. Any energy that is not released in the form of light will be in the form of heat, noise, etc.

I'd suggest moving the lamps a little higher. Two to Three more inches above the water can make a big difference. Either that or increase the amount of evaporation by adding some fans.

There was an entire thread dedicated to this and the scientific minds came to the conclusion that 1w =1w and it does not matter how efficient or inefficient, the heat will be the same.

I agree that raising the lights will decrease the heating of the water, but you will lose a higher percentage of necessary light than wanted. Try adding a ventilation system to blow the heat out of your canopy. You may have a higher evaporation rate than before, but you will help dissipate the heat without light loss.

Waterbury Guy
04/23/2008, 10:53 AM
It's a Tek t5 retro fit. No active cooling that I know of. I think I may need a new canopy as there isn't much room in there for fans

ReefRockerLive
04/23/2008, 10:53 AM
Yes, no matter the efficiency of a bulb, if it has 250w it will throw out the same amount of heat. The only reason that T5 bulbs may seem to run cooler is because of the larger surface area compared to a MH bulb.

GSMguy
04/23/2008, 11:19 AM
<a href=showthread.php?s=&postid=12392825#post12392825 target=_blank>Originally posted</a> by Poisonus Yeti
That statement is far from the truth. All goes back to efficiency of the lamp. Any energy that is not released in the form of light will be in the form of heat, noise, etc.

I'd suggest moving the lamps a little higher. Two to Three more inches above the water can make a big difference. Either that or increase the amount of evaporation by adding some fans.


LINK?

Waterbury Guy
04/23/2008, 11:20 AM
So I suppose it could just be that it's 2-3" closer to the water than my PCs were.

ErikS
04/23/2008, 11:35 AM
There was an entire thread dedicated to this and the scientific minds came to the conclusion that 1w =1w and it does not matter how efficient or inefficient, the heat will be the same.
More like a fact than a conclusion...................unless you've found a convenient way to destroy energy.

Watts are watts, light = heat. Closer to the tank is the likely cause, less energy being dissapated into the surrounding area & more going into the tank.

Reefmaniac1
04/23/2008, 12:03 PM
Now the ballast's energy conversion efficiency (or lack thereof) can cause heat issues, but if you have the ballast mounted remotely, then that shouldn't be a problem.

kzooreefer
04/23/2008, 12:19 PM
I also agree that your problem comes from the lights being to close and to the lack of fans. I moved my T5's up so that the bulbs themselves are 7 - 8 inches above the water. Mine also came with 2 fans in the fixture to help dissipate heat. As this spring has been warmer than normal so far, in the mid 70's here in MI, I've had to turn my tanks heater down a lot earlier than usual. Tanks been running 81 during the day and about 80 at night. So the lights are only adding 1 degree. Turned the heater down another couple of notches again this morning as that is the major source of my heating problems.

DarG
04/23/2008, 12:32 PM
Waterbury Guy ... I would suggest cooling the canopy. Without actively moving the hot air out of the canopy the heat given off by 220 watts of T5 or PC is going to end up heating the tank. The only way to help is by installing some fans in the canopy to help move the heat out. Im not sure about the best configuration would be to do this but there are plenty of canopy users who could help. I would assume that using fans to suck cool air in and others to suck it out would probably be most effective. Some of the air also blowing over the surface of the tank water will help facilitate evaporative cooling which will also help with the tank temp. although evaporation will increase some as well.

RyanMKintz
04/23/2008, 01:28 PM
Igree with everybody else, somehow add a fan

Noobie99
04/23/2008, 05:30 PM
Don't they have clip on fans that you could use to help with the heat? It may not be the prettiest thing in the world but it would help.

LPS_Blasto
04/23/2008, 10:02 PM
Power a 12v transformer and use computer case fans to cool it. Computer case fans are cheap and come in a variety of sizes. Even the cheapest bushing models will last a couple years at $3ea.

Use a larger 120mm fan to suck the air OUT. Use a little bit smaller fan on the inlet. An 80mm or 90mm fan would be good for intake. I'd cut a hole in the side and down low for the intake fan/fans. The exhaust hole should be on the top or high in the back somewhere. Heat rises. Bring the cold air in from the bottom and take the hot air out the top.

Or you could just put a 120mm fan on both sides. One intake and one exhaust. Cut them into the canopy so they pull air directly across the endcaps and blow if out the other side. Just keeping your lights cooler can increase their efficiency and life span. If you can keep the lights cool enough, maybe they will last 12 months instead of only 8 or 9 months? Worth a shot anyhow.....

ConcreteReefer
04/23/2008, 11:06 PM
<a href=showthread.php?s=&postid=12392762#post12392762 target=_blank>Originally posted</a> by GSMguy
have you added any new pumps to the system? how is your heater being controlled?

1watt of PC creates the same heat as 1 watt of t5 or 1w of halide. so in essence your lights create the same amount of heat.


What T5 did you get? does it have active cooling?

GSM's right, a watt is a watt is a watt..

DarG
04/24/2008, 08:23 AM
Blasto makes another good point. If your tank is getting that warm the heat in the canopy is not only going to shorten the life of you bulbs but may also be reducing par. You should be able to get 12 plus months from the blue T5's and 18 months or more for the white T5's. But they wont last near that long if the are running too hot. It's looking like I am easily going to get 9 months and probably more from two overdriven "blue" T5's . A Super actinic (UVL) and Fiji Purple. I am cooling both the bulbs and endcaps as well as the water surface very aggressively with two 8" fans and the guts from a floor standing crossflow fan. My tank is an wall with the tank basically in a closet with the wall cut through to the living room. It gets pretty hot in there. My evaporation is close to 2.5 gallons per day. The point is that cooling your canopy well will not only help bring the tank temp down but also improve your lighting output and the life of your bulbs. You can buy good fans that run very quietly.

Poisonus Yeti
04/24/2008, 12:41 PM
<a href=showthread.php?s=&postid=12394041#post12394041 target=_blank>Originally posted</a> by GSMguy
LINK?

It's called the conservation of mass. I don't need to provide a link to something that has been around for ~200 years. If two 75w lightbulbs have the same amount of usable light but one of the lights makes more noise than the other it will have less heat. The other one will have more heat but make less noise. Even though it might not be a significant difference there is still a difference.