amcdonald figured it out.....the 92mm fan is blowing in(when it's running). The PSU fan is blowing out. It just uses one housing as the picts show. After the test period, I'll try to reconstruct this duct so the filter is easily exchanged. Right now the filter is hot-glued to the duct. It should last quite a while however, and it's cleanable.
Look....there's a reason not very obvious, why the CPU runs so cool... it's in these
pictures.
The duct is solid aluminum and it's a snug fit on the Alpha end. Heat from the Alpha is transferred into the aluminum of the duct by conduction....and by convection also. If you feel the duct on the Alpha end, it gets warm. This actually makes the duct itself, an extension of the Alpha heatsink. Now look at the power supply in the pictures...it has a 92mm fan drawing air over the hot end of the duct. Also when the duct fan is not running, this same fan is sucking air through the Alpha duct. Remember...the Alpha duct with it's filter is the only way air enters the case. The hard drive fan does the same thing...blows out and sucks it's air through the Alpha duct. Another thing, the air entering the duct and hitting the Alpha is ambient temperature. This computer can be run for hours with normal usage, without the duct fan even running. The CPU never exceeds 36c.
It's quiet. The foam in the pictures is CompUSA acoustic foam. $20 gets you enough to completely line a Lanboy. It's 4mm thick with a sticky backing. Works pretty well and applys easily.
As far as airflow is concerned there is no mixing of exhaust and intake air. It's hard to explain the SilentTec cooling utility.....it controls the duct fan and the hard drive fan. You can adjust it many ways. I'm still trying to get the whole thing down right. I do know those two fans may have to be changed. They wouldn't run much below 1700rpm......but the SilentTec could make them run even slower and quieter.
If anyone wants more explanations or more pictures I'm willing help out anybody trying to duplicate this setup. It works....