Originally Posted by Duality92
This is the foam I have that I will be using mostly : 87035K54 SKU on McMaster-Carr.Warning: Spoiler! (Click to show)
Super-Cushioning Ultra-Conformable Antistatic Polyurethane Foam Sheets
Temperature Range: -20° to 180° F
Cell Type: Open
For Use Outdoors: No
Density: 1.4 lbs./cu. ft.
Pressure to Compress 25%: 0.3 psi (Ultra Soft)
Protect sensitive equipment from damage. In addition to providing gentle cushioning support, these sheets conduct static electricity away with a surface resistivity of 1011 ohms. They are commonly used for packing and insulating. Foam has open-cell construction, which allows water, air, and gases to be absorbed.
While all foam will have some noise dampening characteristics, not all foam will have the same amount of it. I used 7mm AcoustiPack sound deadening foam
to reduce the sound coming from my present rig and it is very effective. Beside blocking sound transmission, it's denser mass also damps case vibration, which is where a lot of computer noise comes from. The only noise I hear from my computer is the gentle swoosh from air being drawn through filters (and I can barely hear that from three feet away when my room is dead silent, which is almost never). Even that sound can be reduced, or even eliminated, by reducing the speed of the air going through the filters (more fan and filter surface area will allow the same total airflow with less airspeed).
Fan positioning also determines how much sound one can hear. I have two fans on the front of my case and one on the side. Besides extra sound being generated by the filters, the sound from both have a pretty direct path to my ears when I'm setting at my desk three feet away from them. The rear exhaust fan, however, is pretty much silent, even if cranked up all the way mostly because the sound has to almost do a 180° turn to get to me (not being filtered is also a factor).
Performance PCs is coming out with an even thicker foam (12mm; also, more expensive) that will come by the foot in up to 54" sheets so I'm going to wait until the case I'm building ist pretty mnuch finished before ordering any