I've been considering the fan placement in my case, as a few people probably have after the Bit-Tech article. I bought a few fans from the marketplace here, and have been debating how to best place them for cooling my system. I've obviously read a the article on this site and done a bit of research elsewhere on the internet and still can't come up with a straight forward solution as my system isn't the generic, 2 fans in, 2 fans out with an air cooler set-up. For a start, the cooler is an Antec Kuhler H620, which is doing a great job of cooling my CPU but is recommended to be used as an intake, obviously this isn't ideal. With some systems you can just run them as an exhaust without much issue but the 2nd consideration is that my graphics card uses a Twin Frozr II cooler which doesn't exhaust the air out of the case, raising the ambient temperature. Using the fan on the cooler as an exhaust would then be pulling the warm air from the graphics card through the radiator, which I don't imagine would be a good thing! So the idea I have come up with is below in the crappy diagram: The theory being the cool air from the front is drawn in, will mostly pass over the graphics card and then be drawn out of the side of the case by the fan in the side panel. The warm air from the radiator (cpu never really gets above 50c under full load) would then be extracted out of the top of the case before it gets chance to reach the rest of the components. The PSU pulls in it's own air from the bottom of the case and vents it straight out the back. I feel like I must be missing something totally obvious though as I've not seen anyone else using a similar arrangement. Any advice or alternative suggestions is greatly appreciated. FYI the other possible fan placement is a 120mm (don't think it will fit a 140mm but it might) fan in the floor of the case in front of the PSU and I might be able to squeeze a fan in the 5 1/4 bays with cable ties but I am not 100% sure, would also require me to move my dvd drive and reroute some cable tidying.
Rear fan on the radiator should be an exhaust ideally yeah- you don't want to be drawing air through the hot rad & then dumping it into the case; if needs be or if possible, you could try to run 2 fans on the rad in a push-pull arrangement, that should shift enough air to compensate for the heat coming off the gfx card. Side panel should be an intake as it will do very little as an exhaust- these kind of fans don't function very well trying to draw a vacuum/heat from something, but do extremely well directing air onto something ( like the gfx card ). That seems to be conventional wisdom as I understand it at any rate..
Side fan as an intake to supply the GPU as I think it currently are being drained of air, you could turn the PSU 180 degrees and make it an exhaust, but the side really needs to be an intake as the front one is not that effective and intake. I have the first CM 690 myself so if yours is like it there are a lot of obstacles between the fan and the main "chamber" Assuming that your CPU fan blows upwards I would think that the rear intake is a bit of a loss as the air would hit the side of the cooler. But if you make these changes you would have the same setup as I, bare that my GPU is an exhaust.
I'd change the top 140's so that they push a column on cool air down, and change the kuler to an exhaust so that they can take the air from the column. Also the column will hit the back of the gfx pcb, cooling that.
I have the same case and the same number of fans (although slightly different sizes) - I have: 140mm front intake 120mm side intake over gpu 120mm base intake 140mm roof exhaust 120mm rear exhaust So my suggestion would be to move one of the top exhausts to the side as an intake, flip the rad around to act as an exhaust and move the gpu exhaust to the base to intake (the reason I've suggested this is that afaik a 140mm fan wouldn't fit in the base but would in the side)
Thanks everyone, some good ideas and good points made so far. I can't put a 140mm in the side panel as I have the windowed version which will only take 1x 120mm, but I have a few spare fans I could shuffle around to make a config similar to the ones discussed above. The idea of having a column of cool air blowing down and switching the radiator fan to exhaust is also really intriguing, I hadn't thought of doing that. I think I might have to take a few of the ideas from on here, test them and see which one works best for temps. If anyone else has any ideas/comments that would be great.
Having the roof fans as an intake would be a thermal dynamics fail; hot air rises, trying to push it downwards and then exhaust it through a single fan ( on the radiator ) would be horribly inefficient. Having the PSU as an exhaust may or may not make much difference since it's right at the bottom of the case.