There have been times in the summer when my car is in my driveway all day in 100-degree weather, and combined with the sun, it must be 140+ degrees in my car. Can it damage or shorten the life of my car’s air conditioning to immediately crank the A/C to full blast and Max A/C on the coldest temperature right when I turn the car on in order for it to cool off as fast as possible? I’m wondering if it can work it too hard or if any components can wear out fast from forcing suddenly changes in temperature.

  • I know one who had a stone impact on his windscreen and did as you suggest - the very cold air caused thermal shock and cracked the screen all the way across... Otherwise not really no.
    – Solar Mike
    Commented Feb 13, 2018 at 6:43
  • Max A/C switch usually means recirculate 140° cabin air, which means you won't want that turned on right away; but after a few minutes. Also opening the windows a few inches for a few minutes too. Commented Feb 13, 2018 at 16:41
  • 2
    My $0.02 worth: if it were a problem, I'd think car manufacturers would build in some sort of delay on the A/C.
    – BillDOe
    Commented Feb 13, 2018 at 21:03

1 Answer 1


I live in a very hot climate. There is no issue in turning on a properly-functioning A/C to its maximum setting at startup.

Turning the A/C on activates the refrigeration cycle, which at startup will have the same load on the compressor regardless of the temperature setting selected.

This is part of the reason why the cooling effect isn't instantaneous, rather gradual, as the low-side and high-side pressures and system transients work their way out.

  • Do you have any sources on this? Commented Feb 23, 2018 at 14:38

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