Fans blowing in or out?

[10reefman]

I'm building this conopy I'm installing two fans on top,what's better blowing in or out?

 

[beastium]

thanks for posting this. Was thinking the same question.
On one hand IN flow will draw in fresh, cooler air but that air will need to be vented out again.

OUT flow might draw moisture into the fans and I am wondering the difference in rate of evaporation between the two options.

 

[reefiness]

if they're on top I want to say your better option would be blowing out. Being that hot air rises that should mean you get the most bang for your buck pulling that hot air out.

 

[jackson6745]

Definitely blowing out. The moisture will be there regardless, inflow will increase evaporation if the fan is actually blowing on the water surface making the closed canopy even more of a humid environment. I used to always make the fans on each end, one blowing in and the other out for best air exchange.

 

[10reefman]

Thanks for your comments my tank is got acrylic on top then leds. I drilled holes on the sides the back is open 25% so I was thinking blowing in

 

[10reefman]

 

[10reefman]

 

[10reefman]

 

[Smotz]

I have one on the side blowing in and 2 on top blowing out.

 

[pecan2phat]

If I'm going for evaporative cooling like on a nano tank or sump, the fan would blow in over the surface of the water.
If I was exhausting hot air from a cabinet or canopy, then the fans would blow out like everyone mentioned.

 

[jackson6745]

If I'm going for evaporative cooling like on a nano tank or sump, the fan would blow in over the surface of the water.
If I was exhausting hot air from a cabinet or canopy, then the fans would blow out like everyone mentioned.

Warren! :thrash:

 

[Chefjpaul]

nice job on the canopy.

 

[pecan2phat]

Rich :fish:

 

[10reefman]

Thanks, almost finish painting it now