I'm running a nzxt case m59. i installed a second hard drive and got a 5c temperature drop. i just moved it off the carpet onto a particle board desk and it dropped another 5c. It has a fan filter on the bottom but the psu covers it with no air between it. no other holes on the bottom. is that normal for the temp to drop from moving off carpet? does the case gather heat on the bottom and transfer to the carpet? im sitting at 20c cpu temp at idle right now. I'm just using 5 fans, no water cooling. im thinking about adding a fan to the chipset and ram. could it be possible to drop the temp another 5 to 10 degrees with that?
upgrade your cpu fan and make sure the air flow from the back and the sides of your desktop are not blocked from any objects,about the carpet issue,never leave your desktop,laptops etc on carpets,not only they produce heat but also dust is a f...ed up situation so...no carpets hope that helped you.
(1) Yes carpets are bad for increasing the dust inside the computer. Moving onto a solid surface will improve the Air intake to the PSU (Bottom mounted) and PSU will run cooler.
(2) Raising the computer to the top of a desk vs on the floor and on a hard surface (I have mine on Plexiglass). The lower the better, reason: the temperature on the floor is lower than at 3 ft above. This could be negated if under a desk and the hot air expelled from the computer is trapped under desk.
(3) NO you will NOT drop your temperatures below 20 C, Unless your room is less than 65 F. If your Room temp is above 70 F (21C) then your CPU temp of 20 C is incorrect as CPU temp should be about 8 C (At a Min > 4C) above Ambient temp and can NOT be less than ambient.