The A/C output temperature on my 2012 Chrysler Town & Country feels diminished, especially in the rear seats' A/C vents. So, I had the refrigerant drained, measured, and topped off (dealership did the work, free of charge), but I'm still unconvinced the A/C is cooling to spec. I have not yet measured the output temperature, but I'd like to know what to expect in a "well-functioning" system.
From my research, it appears that a vent output temperature of 40°F to 45°F (4°C to 7°C) measured after driving for 10 minutes at 45+ mph would be reasonable on a 85°F (29.4°C) day with 70% relative humidity. Measurement would be taken from a console vent using a precise stick & dial thermometer.
Is this so? Are there tables that would provide better diagnostic guidance? Is there a particular thermometer known to be good at measuring vent outputs?