Our 40'X35' sound-stage studio A has a dedicated HVAC system, and it's low noise! We achieved that by replacing the old ducting system with a newly designed tube that pushes and receives air quietly.  Not only can you hardly hear the system moving air, the equal-sized "in" and "out" registers makes the transfer efficient, which in turns makes heating and cooling fast while cutting down on energy costs.
We all have been in locations where it's very hot or freezing. Sacramento Media Center's staff wanted to make sure that the first upgrade was making Studio A comfortable.  The best part, no one realizes the system is working because it's so quiet.