AIO Fan Behind/In Front of Rad?

Oceanwave · January 9, 2019

1) I have a rear 120mm AIO (CPU) exhaust. Does it make much difference which side of the rad the fan is on?

2) Would this push/pull setup be OK?

Inside Fan (pushing through) on CPU header (PWM)
Outside Fan (directly exhausting) at fixed low speed

mxk · January 9, 2019

No it doesn't really matter, but having an AIO exhaust air is worse for temps

Ogreclock · January 10, 2019

23 hours ago, Oceanwave said:

1) I have a rear 120mm AIO (CPU) exhaust. Does it make much difference which side of the rad the fan is on?

2) Would this push/pull setup be OK?

Inside Fan (pushing through) on CPU header (PWM)

Outside Fan (directly exhausting) at fixed low speed

Push vs. pull will both have to deal with air resistance due to the radiator, so the differences are almost negligible from what I've heard.

As for the placement of the rad, you would want it where it would get cool air passing through, so either top or front mounting would be optimal.

kevinisbeast707 · January 11, 2019

Honestly it mostly depends on the fans from what I've found. Some fans such as the fractal design hp series make a lot more passing noise when in pull and are quieter in push than in open air whereas some like corsair's sp120 and noctua's p12 either don't really care or sound slightly more pleasant in pull. I would test with the fans that you have but keep in mind that sometimes your placement of the rad can affect other components temperatures.

WoodenMarker · January 11, 2019

Cooler fans are generally optimized for push so having the fan in pull would likely mean worse performance. The difference is usually small unless the fan has a design that's extremely skewed towards push like the Noctua NF-F12 with its stator guide vanes.