@ 2005/09/02
The good guys at Kool Solutions were nice enough to send a sample of their CHILL VENT CV-28 Air Duct to try out. This duct is designed to pull cool air from the bottom of the case up to the CPU intake fan, claiming "...a CPU temperature reduction average of 3°C to as much as 10°C." The following animated drawing from Kool Solutions demonstrates how it works:

Comment from Sidney @ 2005/09/02
Joe's analysis in C/W verus case temp is on the mark. However, Chill Vent sucks cooler air from the bottom of the case which in turn gets cooler air from the front panel or any crack around the case (it is not water tight).

Certainly, the shape of Chill Vent is not for any beauty contest, rather it is designed for keeping up the air pressure; hence the large to small to large "chamber" effect. Sadly, Joe did not try out the graphic card temp. Based on my own experience or should I say experiments; larger fan at the graphic card area did not gain benefit.

On theory; good case ventilation may not yield any benefit in using Chill Vent, depending on which spot in the case is being measured. In practice, air temp at CPU fan intake area and below will be the highest unless high end graphic card is used which becomes the hottest spot in the case. If you could agree to this, Chill Vent continues to work well in a well ventilated case.