Russell Kent wrote:

In short, the higher the delta T, the better.

BTW, this is a major argument *against* oil/water heat transfer systems: the
oil radiator has a *much* higher delta T than the water radiator even with the
oil's heat added to the water.

Mike Wills responded:

As I recall from discussing this with Fred Moreno, the lower delta T is more
than offset by the fact that the oil/water cooler transfers heat much more
effectively than a conventional air/oil cooler. That is for a given amount of
heat transfer area (core size) the oil/water core will transfer much more heat
than the oil/air cooler. Unfortunately I cant locate the email he sent me
which gives hard numbers that show this.

Mike,
I'm uncertain what Fred means by the statement that the "oil/water cooler
transfers heat much more effectively than a conventional air/oil cooler."  Even
if I agree with that statement, recall that once the oil's heat is in the
coolant you must then transfer it to the air via a water/air cooler.  So the
proper comparison should be between an oil/air cooler versus an
oil/water-water/air cooler system.  I can't imagine how the latter could be more
"effective" than the former.  I'm sticking with my original statement for now.

Russell Kent

 
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