RM750X fan - is it an intake or exhaust fan?

[giskard]

My case has a filtered air intake underneath the case, which I'm assuming is to bring cool air into the underside of the case, so when fitting my RM750X, should the fan be pointing down to bring in cool air from outside or should it be pointing up into the case?

[LeDoyen]

if there's access to air inside the case (no closed off PSU shroud) it's always better to have the fan pointing up, inside the case.

It prevents heat rising into the PCB when the PSU is tunning passively. Fan up, the PSU runs passive easier (cooler).

Fan down, the PCB will run a bit hotter and the fan will start more often.

Edit : and the fan is an intake, always, i forgot to answer the main question 😛

Edited December 15, 2021 by LeDoyen

[giskard]

9 hours ago, LeDoyen said:

if there's access to air inside the case (no closed off PSU shroud) it's always better to have the fan pointing up, inside the case.

It prevents heat rising into the PCB when the PSU is tunning passively. Fan up, the PSU runs passive easier (cooler).

Fan down, the PCB will run a bit hotter and the fan will start more often.

Edit : and the fan is an intake, always, i forgot to answer the main question 😛

Thanks, there is a separate PSU compartment at the bottom of the case so it would make more sense to site the PSU "upside down" so that the fan sucks in cool air when the fan spins up. 

[LeDoyen]

That's true, but also, if the circuitry stays cool there's no need to spin the fan to begin with 🙂

And also, the case airflow (positive pressure or negative pressure) will always get some air circulation through the PSU when the fan is pointing up.

In the end it's personal preference. either will work.

Fan down can be more noisy since the fan will spin more often, depending on what you are powering of course. Fan up, also depending on what case/fans/fan arrangement you use will be more silent.

There's no wrong way to install it if there's access to air in both positions. You can put it fan down, and if you hear the fan kick in every 10 minutes, then maybe it's time to try fan up.

If it stays silent or don't bother you, it's totally fine.

[giskard]

Thanks again @LeDoyen, I'll leave it as is (fan facing up) then and see how it goes