From inside (document excerpt):
24ACA3 Comfortt13 Series Air Conditioner with Puronr Refrigerant 1 1/2 To 5 Nominal Tons (Size 18 To 60) Product Data INDUSTRY LEADING FEATURES / BENEFITS Efficiency S 13 — 15 SEER/11 — 12 EER S Microtube Technologyt refrigeration system S Indoor air quality accessories available Sound S Sound level as low as 74 dBA S Compressor sound blanket Comfort S System supports Thermidistatt Control or standard thermostat Diagnostics S TechAssistt with 6–step diagnostics at–a–glance Reliability S Puronr refrigerant — environmentally sound, won’t deplete the ozone layer and low lifetime servce cost.
the environmentally sound refrigerant Carrier’s Air Conditioners with Puron r refrigerant provide a collection of features unmatched by any other family of equipment. The 24ACA has been designed utilizing Carrier’s Puron refrigerant. The environmentally sound refrigerant allows you to make a responsible decision in the protection of the earth’s ozone layer. As an Energy Starr Partner, Carrier Corporation has determined that this product meets the Energy Starr guidelines for energy efficiency. Refer to the combination ratings in the Product Data for system combinations that meet Energy Starr guidelines. S Front–seating service valves S Scroll compressor S Internal pressure–relief valve S Internal thermal overload S Low–pressure switch S High–pressure switch S Filter drier S Balanced refrigeration system for maximum reliability Durability WeatherArmort protection package: S Solid, durable sheet metal construction S Steel louver coil guard S Baked–on, complete coverage, powder paint S Color matched cabinet screws Applications S Long line — up to 250 ft. total equivalent length, up to 200 feet condenser above evaporator, or up to 80 ft. evaporator above condenser (See Long Line Guideline for more information.) Low ambient (down to -20_F) with accessory kit S Warranty Single Phase S 10–year limited compressor warranty S 3-Phase 5-year limited parts warranty 5-year limited compressor warranty 1-year limited parts warranty S S MODEL NUMBER NOMENCLATURE 1 N 2 Product Series 24=AC 2 N 4 3 A A Product Family 4 A C Tier 5 A/N A Major Series 6 N 3 SEER 7 N 3 8 N 6 9 A/N A Variations A=Standard 10 A/N 0 Open 11 A/N 0 Open 12 N 3 Voltage 13 N 0 Minor Series