MINI-SPLIT

installed a one and one-half ton ( 1 1/2 )MINI-SPLIT last year
around november in my estudio upstairs
kept the place cool
now were into the heat of all heat season
the air is refreshing but after mid-day gets warm in here
i know the room is big like 60 square meters with a 3 meter cement slabed (loza) cieling
so what is happening that the loza gets hot and transfer the heat thru and mix with the cold air
the loza wins

what i am asking
can the MINI-SPLIT be upgraded with a larger compresor
or even a higher capacity fan without buying a larger unit

thanks

chico