Cooling Fan

[rdnyva]

Should I put my fan over the tank or over the sump. Is it more effective on either one of those places?

[Uncle Salty 05]

Over the sump is hidden and will accomplish the same thing.
Just be prepared for increased evaporation.

[4bruceinc]

I have a canopy and my fans are attached to the opening in the back

[ca1ore]

Absent aesthetic concerns, a fan to accomplish evaporative cooling is most effective in whichever place has the lowest ambient humidity.

[Uncle Salty 05]

Can you send a pic?
It sound like you are just moving the air around and not truly removing it from the canopy.
A more efficient way to go is to seal the rear opening as much as is reasonable, maybe a sheet of plexiglass on a hinge. Then then have computer fans in both the ends of the canopy blowing in, and a larger fan in the center of the top blowing out.
This truly will remove all heat and cool the tank via evaporation.
That is the way I did my old fixture in my avatar and with 3-250 MHs and 4-96 watt PCs I got zero heat transfer to the tank.

[4bruceinc]

My canopy is vented on the sides and the top.

[Uncle Salty 05]

Perfect, just replace the vents with fans.

[4bruceinc]

Here is a pic of the fans.

[4bruceinc]

Perfect, just replace the vents with fans.

Got it - will do. Thanks for the guidance.

[Guygettnby]

i prefer to have a fan mounted over the display tank and not the sump for several reasons. the biggest reason being the heat from the metal halides. i found having a fan blowing over the top of the display in between the water and the halides made a bigger difference then in my stand over the sump.

[rdnyva]

Good points all around. especially the one from Guygettnby. The heat from the lights are definitely a reason to put the fan on the display. I have LEDs which lessens the concern but they still put off some heat. My original question was - is it more, less, NA to have your fan over the display or sump.

I have a clip on fan on the back of my canopy angled so that the breeze hits the front inside of the canopy and exits at the rear of the opposite side. I will keep it this way because I want the heat from the light out of there as much as possible.

So now I ask, would there be any benefit from having an additional fan on the sump? Is twice the evaporation favorable?

[Uncle Salty 05]

If the enlosure around the fixture is as sealed as possible (a lens between water and lights) and air is being both pushed in and pulled out little or no heat will be transferred to the tank.
Looking better is just icing on the cake.:hb2: