From inside (document excerpt):
24ANA1 Infinityt 21 Series Air Conditioner with PuronR Refrigerant 2 Through 5 Nominal Tons (Size 24 To 60) Product Data INDUSTRY LEADING FEATURES / BENEFITS Energy Efficiency S 14.5–21 SEER/11.1–15 EER New Aesthetic Design S WeatherArmor Ultrat Cabinet Baked on powder paint Steel louver coil guard Color matched ceramic coated cabinet screws Extra Quiet Operation S Silencer System IIt for sound as low as 72 dBA Quiet mount split post compressor grommets Exclusive Silencer Top design Electronic ECM ball bearing outdoor condenser fan motor Forward-swept condenser fan blade Compressor sound hood Laminated steel compressor mounting plate the environmentally sound refrigerant Carrier’s Air Conditioners with Puronr refrigerant provide a collection of features unmatched by any other family of equipment.
The 24ANA1 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. Reliability, Quality and Toughness S Two–Stage scroll compressor S Field–installed 16 cu. in. filter drier S Back–seating service valves S High pressure switch S Low pressure switch S Internal pressure relief valve S Internal thermal overload Controls and Diagnostics S Infinityt control (Dedicated A,B,C,D only) S Utility Interface Connection S Up to 18 point diagnostic capability Applications S Long line — up to 250 ft. total equivalent length. See Long Line Guideline for more information. S Low ambient (down to 0_F) with complete Infinity system. Limited Warranty S 10–year limited warranty on compressor S 5–year limited warranty on all parts MODEL NUMBER NOMENCLATURE 1 N 2 Product Series 24=AC 2 N 4 3 A A Product Family A=RES AC 4 A N Tier N=Infinity Series 5 A/N A Major Series A=Puron 6 N 1 SEER 1=21 SEER (Nominal) 7 N 2 Cooling Capacity 8 N 4 9 A/N A Variations A=Standard 10 A/N 0 Open 0=Not Defined 11 A/N 0 Open 0=Not Defined 12 N 3 Voltage 3=208/230 1 13 N 0 Minor Series 0, 1, 2. ISO 9001:2000