I think Lude is right....

Subject: I think Lude is right....
Name: Celstk855
Date: 5/22/2001 2:34:45 PM (GMT-7)
IP Address: 210.84.108.203
In Reply to: It wasn't that simple posted by ludicrous
Message:

The counter current concept is the go....
The coolest air coming in from the bas where the HS is hottest and leaving from the top where the HS is cooler...the greater DeltaT at the base would offset the lower DT at the top...more so than the other way 'round.
the turbulence idea of Tides has some merit, but it doesnt take into acocunt that increased turb means increased airflow resistance and possible slower velocities..hence offsetting the benefits of the turb.

I recall this discussion a couple of years ago ...wonder if it in the archives...