I have a recently installed Trane XC95 and has been hooked up to my older Lennox A/C unit. They installed a Trane Coil at the furnace when they put in the furnace. My problem: I can hear a loud rush of freon whenever the comprssor starts the A/C cycle. It sound as if I have water hose running at full volume. I never had this sound before. They have checked and adjusted the charge on the freon. I beleive that there is air in the system. When they isntall the A-Coil they forced the freon into the compressor but I don't beleive that the evacuated the system. My concern beside the annoying noise is if air/moiture is in the system will that shorten the life of my compressor? I would like to have the system vacuumed or evacuated and recharged, is the a good solution? As a note there is a TXV on the system and system is cooling fine. Any help would be greatly appreciated.