light hoods

[von_rahvin]

hello everyone i am new to this board.
I got stupid and bought a large tank. 135 gallon. back to the origional thought, I am going to be using 6 6' VHO and i know these creat alot of heat so i decided to custom make a hood. on each side i put 4 computer case fans. 4 pushing 4 sucking. any other suggestion before i put the lights in?

 

[rlv695]

Von_Rahvin
Welcome to the Best BB on the net..
No i dont think you didnt do a stupid thing for buying a big tank... a big tank will be more stable in the long run,,as for your chiose in lighting... vho is a good way of getting good lighing... the fans are a very good idea... with for 4 bulbs i would go with two 10k... 1 50/50 and last one full actinic,,,,if you have any more questions... please fell free to ask... have a good time..and good luck on your tank

 

[dburr]

I personally would have all fans pushing in. The two fans pulling will pull evaporated water with the air. This will eventually rust your fan moter. Good luck.

 

[mr . salty]

I have only fans pushing IN,And they are rusting...Blowing in,and out is a good idea,and I doubt if one will rust any faster than the other...

 

[von_rahvin]

these are mag fans, they only cost $1, have no ball bearings and no moving parts.
any other suggestions about how i could make the reflector?

 

[javajoe]

A fan with no moving parts? How does it move the air?
Sorry-- couldn't resist... must... be... smarta......
To answer your question-- being a computer tech myself- i would tend to do the same thing- with a computer you want the air to come in the front of the PC case, and exit the back- airflow is what cools the CPU. I cannot see it working any differently here-- and for the price of fans, who cares if you have to replace them every month! (not that they would ever fail THAT quickly...)
I am newbie- still don't have my tank set up- just finishing the stand for my tank now, but from what I have been reading, fans will also increase evaporation, so make sure to pay close attention to that- water evaprates, salt doesn't A side benefit to increased evaporation though is that in addition to cooling the bulbs, increased evaportion will make it easier to keep the water temperature cooler in warmer weather.... doesn't matter if you have air conditioning, but i know our house we don't have central air, and this past summer was a killer!
[ September 28, 2001: Message edited by: Javajoe ]

 

[dburr]

Isn't the idea of a fan to push air directly on a bulb to remove the heat? If it is pulling it would be pulling from the circumference of inside the hood and blow straight out. Would that be enough to cool the lights? I understand about one side pushing, the opposite pulling, but I was concerned about the evaporation aspect.
I will be installing mh lights soon and want to do it the best possible way.
thanx DBurr

 

[von_rahvin]

the idea behind having one side pull and one side push is that it creats a currant of air over the lights, if both sides are pushing in then you have a dead space in the middle, not cooling that part of the bulbs,
well this it what my thermodynamics class taught me . . . course that means it is most likely wrong
personally, i believe there must be a better way out there. just wish i knew what it is

 

[caymanlovers]

Van - you are right. If all fans are pushing in they will never produce as much flow (which is what removes the heat) as your push-pull setup. (Theoretical thermodynamically speaking, push-push will produce more heat because it will raise the air pressure in the hood.)