A fan in another room which sucks the air out of your music room is the way to do it.
Create a vent or vent shaft to your music room. Say some PVC near the ceiling or in the ceiling and suck the hot air out. The vents over the equipment would probably be best.
Small silent computer fans at the ends of the PVC will not be noisy.
My two cents.
Add in some large block of Ice in tubs near your seating position.
