Question about air ducts

Reading through the articles on the front page, this subject has caught my interest. One question though, does the air duct obstruct the air flow inside the case?




If the duct were placed above the cpu fan/hs, the circulating air would have to go below the duct to get to the exhaust fan right? Would that hurt anything?

I understand how ducts pointing at the cpu and gpu would help its cooling, but how does it effect the general air flow?

btw, by air ducts, I only meant to cut a hole on the side of my case and have a cardboard or other material duct to "guide" the air in.

A circular duct would have only a small effect on the airflow. A duct straight onto your CPU fan from the side of your case would lower your CPU temps more effectivly than relying on case airflow.....

I knocked one up from an old KFC drinks cup (plastic). I will get round to doing a proper one yet, although this one is very effective!

Would it help any if at the entrance of the duct you had a fan blowing air in? Or is the duct itself sufficent. Also, how close did you place the edge of the duct to the cpu fan?