On Apr 10, 11:27 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:
No, not a loop.
The "laptop coolers" are about 10"x9"x3/8" with two very thin, quiet,
medium-speed fans that draw air into the narrow case and vent it out
one of the long sides.
When one is placed upside down on top of a IIgs case, hot air is drawn
upward through the case lid and then exhausted gently backward (or
forward if you are cold ;-), where natural convection ensures that it
will not reenter the IIgs. The hot air withdrawn is replaced by cool
outside air coming in from all the other holes in the IIgs case (most
of which are on the bottom). The power supply will be in a sea of
cooler air, with the slight pressure differential providing assisted
convection cooling.
Ah, OK, so the "laptop cooler" exhaust is at 90 degrees to the intake,
that makes all the difference. My mistake, I thought they had axial
flow. I have to disagree on the utility of the bottom vent holes,
though- they are there, but effectively negated by the metal RF
shield. Someone wasn't clear on the concept of convective cooling-
the big vents need to be on top, as the volume of the hot exhaust air
is greater than the volume of the cool air coming in the bottom...