canopy fans

[ellisz]

Well, I have my 2x250 MH/T5 retro fixture and the canopy is built but I am trying to decide on fan placement.

I had originally planned on putting the fas in the back but I only have about an 1.25" between the back of the canopy and the wall. I thought this might be a problem with pulling salty air out and messing up the drywall?

So now I am thinking of putting them on the top. With the lights being about 12" off the water, I can't see on top of the canopy when it is on the tank, but I worry about light escaping. Any thoughts on this?

I am also planning on using 2 80mm PC fans ran of a 9v AC/DC plug. They seem to move a good bit of air and should not be real loud. Not sure how long they will last but I don't need them anymore anyway.

Any thought?

 

[brndfrb]

Have the fans blowing air into the canopy not out of the canopy.

 

[ellisz]

hmm, most of what I have read says to blow air out. I guess I will have to try and see. Do you think 2 80mm fans is sufficient or would one work?

 

[brndfrb]

I have two 250's on my 65 gallon tank and they are both blowing into the canopy. I have two 4 inch fans on it.

 

[sumphead]

yup, B they should be blowing out. Air will find a way in. The idea is to remove heat. By blowing in you run a higher risk of cooler air creating cool spots on your bulbs. Halides require a higher working temperature to reach optimum performance. This per Dave at Coral Vue.

R-

 

[ellisz]

Is 4" fans the norm here? Should I even bother with my 3" fans?

I am using a piece of peg board for a piece on the back. I was hoping this would help with heat dissipation. I am sure light will get out too but I figured I would give it a shot

edited for spelling

 

[brndfrb]

I think 3 inch fans will be ok. I just got 4 inch because they are bigger. You will just have to put them on and if you have heat issues than you may want to get another 3 inch or get a 4 inch.

 

[ellisz]

I cut the holed for the 3" fans tonight. Hopefully I will get this thing primed and start heat testing