Canopy fans, blowing out or in?

[seagirl]

Hooking up 2 ice cap fans for the canopy. I run t5's but they are not overdriven so i don't need them blowing across the endcaps, just hoping to help with cooling tank down.

What's more efficient at removing heat, both out, both in, or one each? these will be across the back, not end to end. thanks

[sjm817]

In. This way, you aren't pulling salty air through the fan.

[sebae09]

hes right

[seagirl]

thanks

[mr.maroonsalty]

With two I'd go one in one out keeping preasure equal. I like the idea of moving the hot air on the hottest days as far from the water surface as I can. I use panaflos with a manually operated speed controller, they rock, they're quiet and they don't cost a lot.

[AZDesertRat]

One in one out only gives you the CFM of one fan. Both in with exit holes up high in back or on top works great for me.

[areze]

if your canopy is sealed, then you would need to give it a vent to exit, dont force it to find a crack or youll get lousy movement.

[mr.maroonsalty]

With two high cfm fans you'll need a lot of holes, a lot of light escaping, and there is still the likelyhood of a different path of lesser resistance, this is a bb/dsb issue. With all the holes i'd go two out. One in one out may be the same cfm assuming the fresh air port is large enough w/o any resistence impedeing flow.

[AZDesertRat]

My exit holes are directly over the reflectors so no light escapes at all. Make sure to have exit holes at least equal to the size of the fans if not more. I have two 4" fans blowing in and four 4" holes on top for less resistance.

[Waxxiemann]

I do bascally the same I use 4 fans all blowing inward with some big holes right over my reflectors.