"Morgans" wrote in message
...

"Kyle Boatright" wrote

Double? Naah. It expands, but doesn't double. Boyle's law (PV=NRT) is
based on absolute temperature, which is measured in kelvin. Kelvin is
Celsius plus 273 degrees. Guessing now, if the air temp went from 300k to
350k (or about 80F/27C to about 160F/70C) you'd see volume increase by
(350/300 -1) = 1/6th = about 17%...

OK. I have always heard the approximate rule for good cooling is double
the intake size for the exit size. Guess it doesn't transfer to
expansion.
--

Maybe the velocity of the exit gasses are less. This would cause them to
need more area.

Danny Deger