Originally posted by: Zepper
IF I were to run a duct to my CPU fan, I would want the air filtered to help keep the HS clean. (snip) ... Computergate.com has a cheap duct (about $6. on sale recently) and fans and filters can also be gotten from jab-tech and svc but they don't have the cheap duct...
That's a new eTailer for me. They still have the duct, but the photo could be a lot better. I "think" it has a center section similar to a clothes dryer's flexible ducting, with stiff terminations that look like they should match up to 80 mm fans on each end. There is no indication how far it will reach (oops! I hadn't scrolled down far enough! It's there, 15").
One of the manufacturers of cpu heat sink devices sold a short one with a bend in the middle and an 80 mm fan at the big end. The idea, I think, was to move the fan a distance from the actual heat sink, so the central dead spot, under the hub, of fan-directed airflow would be squeezed out by the duct. It wasn't intended to reach all the way to an outside air source, however.
I still like that bottom fan idea, a great deal better than a second front panel intake, with the limitations on intake area involved there (sorry, folks, one of the travails of senior age memory changes -- there is another air ducts thread in which I've included the bottom panel intake fan comments).