Jeff, no because the equipment rack is basically the return-air vent for the room and by the time that air returns to the a/c unit inside the garage (other side of the house) it's cool due to the length of the run to get back to the unit. I did that five years ago whenever we built the room and it hasn't had any issues so far.
Personally I'd be of pulling any moist air in from under the house myself ... I'd try to use conditioned air if possible.
Thanks, I'm a thinking sound advise. Don't know why I'd worry about conditioned air.. I try , but my home is basically a gift to my power company even with efforts to contain it!
Maybe I'll just install a damper/diverter for the summer in the return air and vent it to the attic