HX 650 Installation
In a bottom-mounted configuration, I've seen them mounted with the fan pointing up and with it pointing down (with a vent below the PSU). Some say the vent is to bring air into the PSU, others say you can push air out the bottom. This will be in a Lancool PC-K62 which is on the way. Any thoughts? Thanks in advance.
If you have a solid floor (wood floor, tile etc) then use the fan downwards so that it sucks air from the bottom, the K62 has a vented slot in the bottom for the PSU with a dust filter already on it.
If your using carpet use it facing up sucking air from the case. Less cooling for other system components but it will do.
I have a Lancool Dragon Lord case for my new system. I've also had three other cases with bottom mounted cases. You have two choices with the a bottom mounted power supply.
First, if your case has sufficient ventilation, airflow, and cooling, then you could mount the psu fan side down so it draws in cool air from the opening in the bottom of the case and exhausts warm air out the rear of the case. The idea is that by drawing in its own supply of cool air rather than drawing in warm case air the power supply will be easier to cool and will last longer. However, do not place the case on a carpeted floor, especially deep pile carpeting. The carper fibers will block air flow. A few years ago I made my own pc stand with casters.
Second, you could install the power supply with the psu fan on top. The concept is that the psu would help cool the interior of the case by drawing in warm interior air and exhausting it out the rear of the case. This concept goes back many many years when Intel started making cpu's that ran hot. The cpu's did not have cpu heatsinks or fans. In addition pc cases did not have case fans. In the original atx standards Intel specified that psu's should be placed near the cpu so the psu fan could help cool the cpu. Obviously this standard no longer applies.
The choice is yours to make based on your own specific ventilation, airflow, and cooling situation.
The ventilation, airflow, and cooling in my new Dragon Lord case is excellent so I mounted my power supply with the psu fan on the bottom.
The Dragon lord case has excellent ventilation, airflow, and cooling. Therefore you can mount the power supply with the fan on the bottom and let the psu cool itself. Just remember not to put the case down on a carpet as the carpet will restrict airflow through the bottom panel opening.
regarding cooling other components - If the psu is mounted so that the psu fan is on top, then it helps remove warm air from the interior of the case. Think of it as a secondary exhaust fan. The primary exhaust fans are the ones mounted at the top rear of the case. The primary exhaust fans at the top rear of the case are the ones that are closest to the cpu and actually help cool the cpu.
I believe it its better to mount it fan down to draw air from below the case. That is because it would disturb the air flow. Hot air rises so it would draw the coolest air in the case and expell it out of the back. It could even lead to higher cpu and gpu temps. in a small case.
I have an HAF 932 and tried it both ways but didnt see any difference at all. but i opted for fan down config anw.
slo - minor correction - hot air rises when the air is still. That changes when a forced air system is installed.
I'm glad to see you tested your pc both ways. I was beginning to think I was the only one who did that. My old/backup system is in a HAF 932. My new system is in a Lian Li Dragon Lord case. When I tested both ways I didn't see much difference either.
Originally desktop cases were horizontal cases spread out on a desk or table. We didn't have very many vertical tower cases back then. As previously mentioned there were no cases fans and no cpu heatsinks or heatsink fans. That's why Intel wanted the psu's near the cpu. It was the only way to exhaust hot air from the Intel cpu's that were running hotter and hotter as they became more powerful. The power supplies wound up at the top of vertical tower cases when the horizontal cases were rotated 90 degrees to transform them into vertical towers. The psu was still the only way to remove hot air from a case. That has changed quite a bit. In modern tower cases the top mounted psu has been replaced by multiple 120mm or larger exhaust fans at the top rear of the case.