Hood Fans...

[MPDBullitt]

I have a tall hood on my 90 with 2-250w metal halides in large reflectors.....i have not installed any types of fans anywhere yet. I am getting up to about 81 degrees by the end of the photo period. I'd like to add some fan(s) to my hood to help a little bit but i can't decide the best way to do it.....

1. pc style fans in the top exhausting up and out
2. pc fans in middle back exhausting against wall or blowing in and bouncing off front door
3. a small wally world fan on center brace blowing towards front bouncing off front door

idk....chime in please.

 

[stlcard]

if it were me i would do pc fans on left and right of the hood. 1 in and 1 out. This will create a current of airflow across your lamps. Is the hood open in the back or have 4 sides?

the above will be more dramatic of impact if it is on all 4 sides, but none the less effective either way

 

[Blindside]

I just have one in the middle blowing towards the lid. Works for me. I dont worry about the temp until its 82 for a few hours. But I hit 81 all the time.

 

[Grendel0501]

My frag tank hits 82-84 on the hottest days, and I don't see any problems.
It has lots of evaporation, but thats all I notice.

I use pc fans on my main tank. I have 2 in the canopy and 3 in the stand. The ones in the stand die randomly, because there is little fresh air that gets down there.

 

[MPDBullitt]

the hood is open in the back. Highest temp I have seen is 80.9 so far. I know that's acceptable, was just trying to avoid a 3 degree swing.

 

[BigBoi5680]

I have an 8 bulb 80W ATI fixture that was definitely NOT designed to be placed under a canopy, however I modified my canopy so that the fixture hangs underneath it. I knew the heat would be trapped underneath so I took 6 pc fans and made 3 cut-outs (2 on each end of the canopy sides and 2 on the top directly above the fans in the light fixture and they are turned so that one side pulls air IN through the canopy and the other side transfers trapped (hot) air out of the canopy on the end where it exits the light fixture! I have yet to get above 78 degrees under there.....