I have spent almost my entire career on a roof or in a house . I recently came in-house with self-contained Trane and McQuay equipment . One of the techs told me Glycol systems are almost 100% efficient . On a roof , I am looking for 30 degrees above ambient for pressures . He told me look at the Glycol temperature for pressures , no add . He said dont worry about subcooling just get 10 - 12 degrees superheat . I dont want to look stupid but i had to admit i did not know . He said i should get 23 SEER with Glycol .
Does this guy know what hes talking about and do i need to go back to school ?