Key Specifications of a 20-Ton Package Air Conditioner: Cooling Capacity: 20 nominal tons / 240,000 BTU. Compressor Type: Hermetic scroll compressors or Inverter for energy saving. Electrical: 380V - 3 Phase - 60Hz. Gas Type: Usually environmentally friendly (R410A). Design: Integrated unit (Package Unit) installed on the roof, facilitating maintenance.