Air Conditioner

[sonzoil]

Have a 2015 Forester. Recently had ac condenser replaced (dealer) due to a leak. Drove the car this weekend in 90-degree weather. The air conditioner seemed to be not consistent in temperature output. Had to have the fan on highest setting and the air never got that cold, that you had to turn it down. Once I was home, I used an infrared temperature thermometer on the air blowing out of the front dash duct. Without the air on, the temperature blew 75 degrees. With the air on full blast the temperature was 58 degrees coming out of the duct. On one of the cyclings on and off, I was able to get a reading of 50 degrees. I could not repeat the 50 degrees temperature, unless I revved the car to 2000 rpm. Does anyone have thoughts on why the temperature would not be consistent? Thanks