Perry Mick wrote:

I measured the finned area of my rad this morning, it's about 12 x 14 x 1.25.

If we simplifiy that to flat plates at 1/16" spacing, there would be 16
surfaces per inch for 14 inches, or 224 surfaces, sized at 12 x 1.25. So
total area is 224 x 12 x 1.25 = 3360 sq. inches. Double that number for both
sides of the fins exposed to air, or 6720 sq. inches.

I have 2 ft. of duct behind the fan to put this surface rad. Originally I
thought 30 tubes, but at 3/16" per tube that is only 5.625" wide. So I'll go
with a 12" width of tubes, or 64 tubes. That would be an area of 12 x 120 =
1440 sq. inches. (Actually about pi/2 or 1.5 times that since the exposed
surface of the tubes is a half-cylinder). Then I put in 60 fins around the
inside spaced at 2" apart, and sized 2" x 12", for a total area of 1440 sq.
inches, then double that for both sides exposed. You end up with a total of
1440 + 2 * 1440 = 4320 sq. inches.

Yes it is slightly less than what I have now, but I think it may work,
because the coolant is running inside much longer tubes, spends more time
there, and the airflow over the big fins is much higher and less restrictive.

Perry

The bumps will be in the direction of the air flow. Use more tubes and rotate
them 90 degrees.

Paul Lamar
 
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