We slip in Tawas and have AC on our 321 which was installed (presumably) when it existed on the Chesapeake. Fresh water intake is under the starboard aft cabin (valve, filter, 580gpm pump). All of the primary components are installed at the forward end of the port cockpit locker. The main vent being above to the right of the fridge. Secondary vent is installed in the aft cabin. Agree in MI it's not a necessity, but it certainly is a luxury and gives us some peace of mind when leaving the doggos on board when we go into town.
Only grief... the condensation from the condenser coils fills a drip pan which is routed to the forward end of the bilge by the bilge pump pickup. This makes it literally impossible to have a dry bilge with the AC on.