Canopy fans

[Enzel]

I'm in the process of building a canopy for my tank. I currently have 3x MH and having a fan in there is a must. The plan is having one fan on an end pushing air in and on the other end another fan pulling the air out. I'm currently using one of these on an end of the tank:

http://www.target.com/Honeywell-Tabletop-Air-Circulator-Black/dp/B001R1RXUG/ref=sc_qi_detailbutton

Needless to say, that thing is LOUD. I'm looking to buy 2 large case fans, maybe around 4"+ to be able to carry the heat from end to the other.

Any ideas on which one I can get? I have this link I've been looking at:

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007998%204802%204093&IsNodeId=1&name=$10%20-%20$25

[Enzel]

Bump, anyone? :rollface:

[zachfishman]

Those 120mm fans were what I was going to recommend. You'll just need a 12V DC converter and a bit of simple wiring, but it should work great. You may wish to just put two (or even 3) fans blowing in from one side, as many reefers have noticed that fans positioned to suck hot, moist air out of a canopy tend to die prematurely.

ADD: I don't know how much air flow you'll need (over 100cfm for sure), but mind the dB rating on these fans. There are many models of varying cfm/dB ratios (and many more models at CompUSA - where I bought my Silenx brand fan). If you don't know, the dB scale is not linear, and a fan rated 40dB is in fact ten times as loud as one rated 30dB. In this sense it would probably be better to mount several fans with lower dB than one fan producing the same air flow but rated at a significantly higher dB.

[Korrine]

Would the fans for sale by fish places somehow be able to stand up to moisture better than the hardware store bought fans? I've been wondering that for a little while now.

[Korrine]

for example these vs those?

http://www.fosterandsmithaquatics.com/product/prod_display.cfm?pcatid=14701

[DustinB]

I use 4, 92mm computer fans. 2 of them are rated to a slightly higher cfm, these are on the exhaust side of the canopy. The main thing you want is to have more exhaust than intake. If you run the same flow or have more intake than exhaust you risk trapping some heat in the canopy swirling around.

If it's going to be a completely enclosed canopy I would probably put 2-3 fans on the top right side, then 2-3 on the left side.

[autodave]

I use these:http://www.sidewindercomputers.com/no12ulnonffl.html

You will need a power supply also.Have them pushing air into the canopy to extend the life of the fan.

[snulma1]

on my 4 ft fixture (2x 250w MH) I ran 2 fans on the ends (1 push and 1 pull) then 2 on the top (both pull) since the heat accumulates at the top.