Which is a better placement of fans on a Rad?

[topaimz]

Is it better to pull the air outta the rad

or

blow the air into the rad out the other end?

P.S.
Is it even better if you put 4 x fans?
2 pulling out the air, and 2 blowing in the air into the rad?

[Brandon_Tyler]

First, could enlighten us all on what rad you'll be using?


- Brandon

[Mr. Tinker]

best is push pull by a small margin, and I like push for noise reasons after that, but really, almost no difference in most conditions.

[creidiki]

I believe cathar measured that push is 2% (or less) better than pull with PAs.

In any case, its pretty minimal. With low-restriction rads (PA,BIP,MCR220) it really doesent make much difference, and with high-restriction rads (HE,BIX,Cores) i belive its the shroud thats the most important thing? I could be wrong about that.

[andersson.j]

Fans on both sides
Performs best but it won't be any huge performance boost over fans on just one side. (Unless you have a very restrictive rad and weak fans.) Take a look in Marcis excellent thread A challenge - PA120.3 vs HE120.3 vs PA160. (http://www.xtremesystems.org/forums/showthread.php?t=77260)
2x fans in Push-Pull is of no major benefit over 1x fan in push.

Fans on one side
I havn't done any testing so I'm just speculating on this one, but I'd say it depends on which fan you use and how far from the rad you mount it. Fans have dead spots in the middle but the further away from the fan you measure the more evenly it blows. Hence the further you distance the fan from the rad the less difference push vs pull. Even if you mount them directly on the rad you won't see any huge difference, at least I can't on my rad. The best way to find out what works best for you is to try.

[topaimz]

Just for reference, the rad I'll probably purchase is the PA120.3
and fans, Im not sure about.

[creidiki]

Yat Loons if you can get them. Official recommended fans for PAs :)