Corsair power supply fan placement

Hello, I recently purchased the 2018 version of the RM750X and I only now realize this power supply is forced into hybrid mode without a switch which is a problem if I want to have the fan facing downwards based on what I have read the past couple years from Seasonic.

The power supply will mostly stay in Fanless Mode as most modern systems run in low loads. As hot air rises naturally, mounting the power supply with the top cover facing UPWARD (towards the direction of the motherboard) will ensure optimal heat dissipation when the fan stands still.

https://seasonic.com/how-to-position-your-power-supply

Aris Mpitziopoulos (amazing reviewer) also had something to say about this specific power supply

it'd be great to see Corsair implement a button for toggling the semi-passive fan mode on and off. That'd allow us to test the fan any time we wanted. Plus, it'd let us install the PSU with its fan facing downward, and not worry about heat building up inside the enclosure and damaging the electrolytic capacitors.

https://www.tomshardware.com/reviews/corsair-rm750x-v2-psu,5585-12.html

As far as I can tell Corsair doesn't have any advice on this topic. In this specific NZXT H500 case which way should I place the power supply? Follow the advice above and let the heat radiate up into my video card or turn it upside down and let it cook?

My previous power supply even from 2012 had a switch for the hybrid fan mode so this wasn't a problem.

That case has vents on the bottom for the PSU fan. So the correct installation would be to install the PSU with the fan facing the bottom vents that are there specifically for the PSU. On the Seasonic page you referenced, this is under "Power Supply with fan in a bottom mount case" ... "Case with ventilation holes in the bottom". This is, by far, the most common mounting these days in cases.

Heat doesn't really radiate into the case from PSUs anymore and it certainly doesn't with the RM series. If installed correctly (with the fan facing an opening, typically on the bottom of the case), passive heat flow will be out the back and a bit out of the bottom - it won't really radiate to your video card and any residual heat from the PSU casing would be minimal when compared to the GPU, VRM and chipset.

When the fan engages, air is pulled through the bottom and exhausted out the back. Again, when installed correctly, the PSU really doesn't impact nor is impacted by case temperatures. If you do, for some reason, install the PSU with the fan facing upwards, it'll still work ... but the air used to cool the PSU will come from your case interior rather than from the room. Because of the heat produced by your components, this will be warmer than outside air, which is why is is less desirable. Also, when the fan isn't engaged, heat will, at some level, passively radiate out of the PSU into the case. Neither situation is ideal but the PSU won't "cook" either.

That case has vents on the bottom for the PSU fan. So the correct installation would be to install the PSU with the fan facing the bottom vents that are there specifically for the PSU. On the Seasonic page you referenced, this is under "Power Supply with fan in a bottom mount case" ... "Case with ventilation holes in the bottom". This is, by far, the most common mounting these days in cases.

The advice is separated based on the hybrid fan setting, you're reading the section with hybrid fan mode OFF. Seasonic recommends the fan facing up with hybrid mode enabled and this is what the corsair PSU is forced to use.

The advice is separated based on the hybrid fan setting, you're reading the section with hybrid fan mode OFF. Seasonic recommends the fan facing up with hybrid mode enabled and this is what the corsair PSU is forced to use.

If that's how you want to do it, go for it. The proper way to install it would be with the fan facing down.

Case in point - did you happen to see the Verge build? He installed his PSU that way - facing up. And it was a hybrid PSU. One of many, many, many issues with that build that was noted over and over and over and over again.

If your case has bottom venting, we usually recommend having the fan face down like DevBiker said so that it can get fresh air.

Thank you.

If anyone else stumbles upon this thread with the same questions I had, jonnyGURU provided some more details about this question in a duplicate thread I made on another forum here: https://linustechtips.com/main/topic/1002207-corsair-power-supply-fan-placement/

That's because it's not a problem.

 

 

 

You're worried over nothing.

 

 

 

This particular Corsair PSU is not made by Seasonic. You can mount it fan pointing down.

 

 

 

Ever since HardOCP reviewed the original RM and it failed in their incubator which has no airflow when the PSU fan is not operating, Corsair has made sure the thermistor that operates the fan is on the main PCB in an area that is the hottest when there is no airflow.

 

 

 

HardOCP review: https://www.hardocp.com/article/2013/11/13/corsair_rm750_750w_power_supply_review/

 

 

 

Corsair blog: http://www.corsair.com/us/blog/rm750_and_850_thermal_issue/

 

 

 

Corsair forum: http://forum.corsair.com/v3/showthread.php?t=123484

 

 

 

A lot of PSUs put the thermistor for the fan controller on the top of either the primary or secondary heatsink, which is closer to the fan than the main PCB. So while this is good at capturing the temperature of incoming air, it's not good at measuring the temperature of the air closest to the main PCB.