If anyone is considering adding a CPU fan exhaust pipe, consider this roof-drainage "flexipipe" available at Lowes and Home Depot. funny what you can come up with when you have caught the SPC bug.
http://www.gutterworld.com/product.asp? ... =flexelbow
it will bend in any direction, and can be shortened/expanded like an accordian. the big end ('female' ?, lol) is big enough to strech over a small HS fan (about 70 mm square is viable). If you need to fit it around a 60 mm fan, wrap the fan first with some screen-door weather stipping for a good seal. if you cut the large end off, you could possibly stretch out the accordian over an 80 mm fan with a little work.
home depot also sells a matching 2 5/8" x 3 5/8" mounting bracket that the small ('female') end of the pipe slides over. the mounting bracket has 4 screw holes which will allow you to mount the pipe perpendicular to a case side, rear case venting, etc. the opening is about 2" x 3" which is approximately the cross sectional area of an 80 mm fan! (the circular blow chamber of the fan, not external dimensions).
an example application: the achilles heel of this nifty little HTPC case http://www.dansdata.com/images/atc620/backopen560.jpg
is poor air circulation. but, it sports a rectangular vent section in the back! imagine the processor with a 'normal' square block HS and a 60 mm fan on top pointing upwards being vented out the back of the case with a simple 90 degree bend of the flexipipe. if i ever do this, I WILL post pictures
ghetto stylin' at it's best
- your cost... $4!