For sale, four 24-unit hot/cold air conditioners, all convertible by remote except for one. They are working and have excellent cooling. The reason for selling is moving to an apartment that already has air conditioners. 2 air conditioners are the new energy-saving freon system. 2 air conditioners are the large compressor system with American compressors. Note: The one with the remote conversion does not have the heating function working, according to the technician, due to the conversion. If it's reverted to normal switches, the heating will work. I converted it when I bought it new.