Question Comparative thermal testing of intake on top of PSU shroud vs at case bottom w/o shroud?

[dyungim]

This picture is for reference only and doesn't quite illustrate case B) because in that case, there would be no PSU shroud.

Has anyone done comparative thermal testing of having an:

A) 140mm intake fan on top of the PSU shroud located anterior and superior to the PSU

compared to a

B) 140mm fan in the same anterior position, but at the bottom of the case with PSU shroud removed?

https://hardware-helden.de/der-perfekte-airflow/?showall=&start=2 This is the best I could find, but they only tested intake at the bottom of the case. Frustratingly, they did test cases in separate articles that support fan mounting atop the PSU shroud, but they did not place fans there: https://hardware-helden.de/be-quiet-pure-base-500-optimales-lueftersetup/

Fractal Design Define 7 Airflow Guide: Das optimale Lüftersetup

So gelingt der perfekte Airflow im Fractal Define 7. Unser Guide zeigt die optimale Lüfterkonfiguration für niedrige Temperaturen.

hardware-helden.de

Fractal Define 7 Compact Airflow: Das optimale Lüftersetup

In diesem Guide zeigen wir das optimale Lüftersetup und den perfekten Airflow im Fractal Define 7 Compact!

hardware-helden.de

One drawback I could see to mounting on top of the PSU shroud is potentially losing a PCIE slot. Another is that the fan might not be located optimally to have clear airflow over the anterior end of the PSU; i.e. it may overlap horizontally somewhat with the top of the PSU.

I know that front-to-back airflow works fine, but in the detailed testing above, 1 bottom intake, 1 rear exhaust, and 2 top exhaust was superior, and I suspect also quieter (as the fans are physically further away if the tower is sitting on a desk).

Additionally, I am aware of cases like the Corsair 540, but that particular one has a bunch of janky plastic so it's a hard pass. And I am also aware of cases like the Lian Li O11 XL, but I don't want any glass in my case (pets, kids). Also the Lian Li glass panels have a nasty habit of coming unglued and falling off.

 

[BonzaiDuck]

This picture is for reference only and doesn't quite illustrate case B) because in that case, there would be no PSU shroud.

Has anyone done comparative thermal testing of having an:

A) 140mm intake fan on top of the PSU shroud located anterior and superior to the PSU

compared to a

B) 140mm fan in the same anterior position, but at the bottom of the case with PSU shroud removed?

https://hardware-helden.de/der-perfekte-airflow/?showall=&start=2 This is the best I could find, but they only tested intake at the bottom of the case. Frustratingly, they did test cases in separate articles that support fan mounting atop the PSU shroud, but they did not place fans there: https://hardware-helden.de/be-quiet-pure-base-500-optimales-lueftersetup/

Fractal Design Define 7 Airflow Guide: Das optimale Lüftersetup

So gelingt der perfekte Airflow im Fractal Define 7. Unser Guide zeigt die optimale Lüfterkonfiguration für niedrige Temperaturen.

hardware-helden.de

Fractal Define 7 Compact Airflow: Das optimale Lüftersetup

In diesem Guide zeigen wir das optimale Lüftersetup und den perfekten Airflow im Fractal Define 7 Compact!

hardware-helden.de

One drawback I could see to mounting on top of the PSU shroud is potentially losing a PCIE slot. Another is that the fan might not be located optimally to have clear airflow over the anterior end of the PSU; i.e. it may overlap horizontally somewhat with the top of the PSU.

I know that front-to-back airflow works fine, but in the detailed testing above, 1 bottom intake, 1 rear exhaust, and 2 top exhaust was superior, and I suspect also quieter (as the fans are physically further away if the tower is sitting on a desk).

Additionally, I am aware of cases like the Corsair 540, but that particular one has a bunch of janky plastic so it's a hard pass. And I am also aware of cases like the Lian Li O11 XL, but I don't want any glass in my case (pets, kids). Also the Lian Li glass panels have a nasty habit of coming unglued and falling off.

Well, that's a particular kind of case. But when it comes to the PSU, you'd like to effortlessly push tons of air through the 140mm hole so that the built-in fan never turns on for the life of the unit.

I am now experimenting with tightly-sealed conventional cases -- and old ones -- like the Coolermaster 831/832 [submodels] or the HAF 932 or 922. I'm using high-CFM Noctua iPPC 140mm fans already fitted for noise-suppression. I have three -- one for the CPU pusher fan. I've chosen a Delta 120mm 150 CFM exhaust -- these are all PWM fans.

So with attention to sealing all holes except those porting the intake and exhaust fans, you'd like enough pressure to more than sufficiently cool a PSU. And if you use something like my Seasonic Titanium 750, I think they're something like "90+". So they stay cool.

Here's something interesting about ads and news for the HAF 922. I found one on Ebay as "Used" for $100. When I bought mine -- I have three of them with one empty and in a garage cabinet, all from maybe 2010or 2011. I think I paid $80 each plus shipping -- New. Actually, the Ebay offering for a CM 831/832 and submodel same as I"d had since 2007.-- was also holding its new-purchase value that includes a discount -- maybe $150. So after buying one for $150 discounted in 2007, I bought a second one for $150 in 2020.

 

[Timur Born]

What temperatures are you interested in specifically?

If you put the fan closer to the components then it likely benefits these components more specifically than the rest. Position A is closer to the GPU unless you put it all up front. If the PSU is (semi)fanless than its own heat will contribute to the air's heat of a position B fan.

If you put the fan further away from everything (position B) then its air will still be pulled in by the GPU fans, but parts of it may distribute more beforehand or may just be blown out to the back of the case before it reaches the GPU if strong front fans are used.

I own the case in the image, but I use it inverted, so memory dimms and VRM would likely benefit the most (with an AIO pump on the CPU). Position B fans get into trouble with the PSU cables coming out of the back of the PSU.

 

[dyungim]

Well, that's a particular kind of case. But when it comes to the PSU, you'd like to effortlessly push tons of air through the 140mm hole so that the built-in fan never turns on for the life of the unit.

The bottom intake fan is for case cooling, not for PSU cooling.