2006,I have a mini r53 s (supercharged) runs fine but when car stop and AC is on for a wile car overheat

Car is modified has new aluminum radiator and set of 2 fans, it has modified air intake and new coils and spark plugs, everything runs smooth but when car is stop for few minutes with AC on the cars start heating up, as soon car runs again car cools to normal temperature, AC don't cool down air so well.
Could it be frion gas?

My car has 100000 miles.
My car has a manual transmission.