Just thought I'd post this for all to read. It started by my looking on a web site at a bunch of altered cases. Cases altered to make the systems within cooler. Many cases had a grill covering a fan on the side of the case relative to the position of the CPU. It occured to me that that kind of set up would bring in cooler air to the whole case but not necessicarily directly to the CPU, a lot of re-circulating of heated air within the case would still get to the CPU. I decided to try an experiment. I removed the door from the "component side" of the case, I traced its size onto a sheet of cardboard and then cut it to size. Next I figured where the CPU would be in relation to that sheet of cardboard. I cut out a circle there and the duct taped a tube there. The tube was a can of orange juice with the metal top and bottom removed. I sized the tube so that when the cardboard sheet was put in place of the metal door the tube would be right over the CPU fan / heatsink combo. Once I had it lined up properly I tested my computer with both the metal door and with the cardboard door with the "blow hole". I expected the temperatures to be much lower with the tube because at least 90%+ of the air the heatsink's fan put onto the heatsink would come from outside the case at room temperature. With all other factors being as identical as possible here are the results I got:
Conditions.........................| Blowhole....| No Hole
-----------------------------------|------------------|-------------------
Idle 10 minutes................. | 37c/98f.......| 39c/102f
-----------------------------------|------------------|-------------------
Need4Speed 4.................| 39c/102f......| 43c/109f
10 minutes running
-----------------------------------|-------------------|------------------
SiSoft Sandra burn in.......| 40c/104f.......| 45c/113f
15 minutes running
5 degrees celcius / 9 degrees ferenheit under heavy load. No water blocks, no pelitiers, not even an extra fan!
Hope it helps someone.
Conditions.........................| Blowhole....| No Hole
-----------------------------------|------------------|-------------------
Idle 10 minutes................. | 37c/98f.......| 39c/102f
-----------------------------------|------------------|-------------------
Need4Speed 4.................| 39c/102f......| 43c/109f
10 minutes running
-----------------------------------|-------------------|------------------
SiSoft Sandra burn in.......| 40c/104f.......| 45c/113f
15 minutes running
5 degrees celcius / 9 degrees ferenheit under heavy load. No water blocks, no pelitiers, not even an extra fan!
Hope it helps someone.