trapped heat

[jc]

I just got my new 260w PC light fixture yesterday. I added it to the 130w strip I already had. Both of these are inside of a wooden hood. Since the legs would not fit inside of the hood I decided to just lay the new fixture on top of the glass canopy. Wrong move. A few minutes later I heard a loud cracking noise and found one side of the glass canopy had cracked. O.k. so I changed the glass and put a piece of 2x4 at each end of the fixtures. So now the fixtures are 1 and half inches off of the glass, and about 1 inch from the closed lid. The lid is open at the back. Just how much heat is too much? When I opened the lid today I got a blast of hot air in the face. The glass canopy is warm enough to put my finger on it for about 5 seconds before it gets too hot. Can I add a fan to the back of the wooden hood? Does it even matter? I don't want to break my new fixture or another piece of glass.

[JimD]

First off, I would suggest removing the glass top to allow for 'evaporative cooling', You can add a fan or two if needed to control temp if it gets too high, if the hood has no means of ventilation, youre going to build up excess unwanted heat, which, as you found out, isnt good. Keep an eye on your tank temp!

[MikeyBoy]

Absolutely, you should have that canopy vented with fans.
you can buy the fans al Altex Compute supply at 281 and north of Bitters

If there is that much heat in the hood, your raising the temperature of the tank water too........


not good.
If it is that hot, I would not be running it until you get that hood vented with fans.

[jc]

I checked the temp and it is still 79 or 80 which is what the heater is set at. The wooden hood is open wide and the fixtures are warm to the touch, but I guess that is normal. The tank is not totally covered by the glass canopy. There is about 4" strip at the back that is open the length of the tank. I tried to run the tank without the glass canopy once but I got salt spray on the bulb that is near my hang on back skimmer. The skimmer output has bubbles, not alot but enough to leave some salt on the bulb that was about 5 inches from the water. I noticed that the top of the glass was warm, but the bottom nearest the water was not. maybe the glass is blocking heat and I should leave it on?

[jc]

I do want to put some fans on the hood. Should I put one on each end? All blowing in or one in and one out?

[MikeyBoy]

sounds good, that is what most people do.(on both ends)
I think the glass being "Warm" would be considerered normal. Hot would not be.
Those fans will help a ton.

[jc]

I have been to altex before I will check it out. Do they have fans that have ac plugs or will I have to do some wiring? I got some huge fans for a projector my brother and I built, but they are pretty loud. The glass is definately warm but cool on the other side.

[brewercm]

Most of the fans I believe you will need to wire yourself. Just buy a cheap extension cord and cut off the female end strip and your good.

[SBreef]

If you want an a/c fan, they should have a power cord that plugs directly into the fan and wall outlet. If it is a dc fan that you want, you will have to wire it. Low voltage is safer!!

[jc]

My wife had the perfect solution. "just take the top off of the hood". Both of us are short people so we can't see the top of the wooden hood anyway. Now the heat just rises up into the air.

[LoneStar]

My wife had the perfect solution. "just take the top off of the hood". Both of us are short people so we can't see the top of the wooden hood anyway. Now the heat just rises up into the air.

Good deal. If you do decide to install fans later on, I would choose DC. To hook up DC fans, just buy regular computer fans (I use 120mm) and a AC to DC convertor (Like the ones for home phones, routers, small electronics). They have both at Altex. Just clip the end off the convertor and solder it to the fans. Usually you can run up to 4 on one convertor, although I just have two fans on one convertor now.

If you go the AC fan route, they have those at Altex too. The way the AC fans work is there is a special connector on those fans, rather than wire leads coming out. They have a AC cord with the correct connector located next to the fan bin. That way you don't have to worry about soldering on wires to the AC fan (not sure if it has a wall plug on the other side though). ;)