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Unread 03-26-2004, 06:50 PM   #15
Gooserider
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Join Date: Jun 2003
Location: North Billerica, MA, USA
Posts: 451
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Quote:
Kronchev:
with a single fan chevette heatercore I dropped 5-6C by adding a second fan NEXT to the fan I had on it...not on the other side, NEXT to it. pretty awesome IMO, I think the flow from the one cancels the deadzone from the other
Not really. What you did was place two fans in series, which (almost) doubles the static pressure of a single fan. Because you had a higher SP, the airflow was greater. The standards for fans are that putting fans in series keeps the same free air volume, but increases the maximum static pressure. Putting fans in parallel increases the free air volume, but keeps the same pressure.

However, putting two fans right next to each other is usually much less efficient than the theoretical maximum. The first fan feeds turbulent air into the second fan, reducing it's efficiency and causing increased noise. It would be much better if there was an inch or two worth of shroud between the fans so that the air from the first fan has a chance to straighten out and become non-turbulent before it enters the second fan.

According to what I've read, of the three possible arrangements of two fans and a rad, and assuming there are few or no airleaks between the fans and the rad, the best is one fan on each side of the rad (push / pull). Next is two fans pulling, followed by two fans pushing. In each case, having a 1-2" shroud between the fans, and between the rad and the fans will improve the airflow, and reduce the noise level.

BTW, a shroud is the ONLY way to effectively kill the "dead spot" on the rad face. (and a little rad like the chevette needs all the help it can get!)

Gooserider
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Designing system, will have Tyan S2468UGN Dual Athlon MOBO, SCSI HDDS, other goodies. Will run LINUX only. Want to have silent running, minimal fans, and water cooled. Probably not OC'c
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