From what I understand is most cases are designed to intake from all sides and exhaust out the back panel only. (Somtimes the top as well). The side panel DEFINITY an intake. That is blowing fresh cool air directly onto the CPU, Northbridge, Southbridge heatsinks. Those normaly don't have fans they will be cooled by the side panel fan. This should creat a flow of air starting at the front panel moving accros your Hard drives hits the motherboard and is accelerated from the fresh air from the side panel fan intak and then exhaused out the back.