Here's a 1989 2.5-Ton Heil High Efficiency Air-Conditioner at my Aunt's next door neighbor's house. It is very quiet. It has a Copeland Reciprocating compressor and uses R-22 refrigerant. The unit is tied into a 1996 70,000 BTU Lennox WhiperHeat 80% efficient gas furnace. It's a nice system. Enjoy!