Air conditioners generally cool the air 15 to 20 degrees. 80 degrees in return should be 65 in supply. 70 degrees in return should be 55 in supply. If the a.c. is in that range it is working fine and doing all it is going to do. If you need further help, reach me via phone at https://www.6ya.com/expert/thomas_092728000e6acb79