Today it was warm, 90+ degree. Turned on the AC and it was slow to cool down. Drove about 50 miles and it slowly cooled the car down. I then stopped for about 20 minutes, then started off again and the AC started cooling like it was brand new. Why?

What would cause this?

Haasman

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'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)