My computer sits on my desk and imo i would never set a computer on carpet.
Bottom mounted psu on carpet.
Deciding on whether to mount your psu either facing up or down depends entirely on a few factors namely case design airflow with other fans and the power supply unit itself.
Extra cables are easier to manage as they lay on the bottom.
This is typically at the bottom of the case in most modern chassis designs.
In my case i get cool air for the intake and the hot air goes out the side of the case.
To figure out whether your psu fan needs to point up or down start by looking over your pc case.
Psu s mounted on the top have to draw air from inside the case.
Hot air rises and cool air you get the point.
When intel designed the atx form factor the power supply fan was designated as the primary case fan.
The carpet will block the airflow to the psu and in worst cases if you have no psu fan filter installed then the small fiber particles from the carpet can get deposited inside.
On a correctly oriented bottom psu it pulls cool air from the bottom and blows out the back.
Being placed at the top of the case a power supply could.
Avoid placing case on carpet for bottom mounted psu with fan down never put your computer case on the carpet when you have a bottom mounted psu fan facing downwards.
This means that they will run a bit hotter than a psu that is mounted on the bottom which draws air from outside the case.
My psu is mounted in the bottom of my case a tj07.
A bottom mounted psu keeps the psu cooler not the case.
Determine where the psu is intended to fit.
A top mounted psu is like a 2nd exhaust fan but if you want it to run cooler go with a bottom mounted psu.
Once you ve located where the psu will sit check the case for any grills or vents directly beneath this location.