How long should the AC run when first turned on?

Question

Setting is on Auto and set to 82 degrees. Air has been on for 1 hour and a half and has not gone off.

air is central heating and air in a mobile home. We just replaced the filter with a new 30 day one. Water was collecting on bottom and coils getting moist. Need help.

Answer 1

The AC will run until the temperature drops to your set point. If it is hot and getting hotter outside, the system may have a hard time pulling the heat out and keeping up with the increased heat load.
The test you should try is to take a good thermometer and measure the temperature of the air going into the return duct, and measure the temperature of the air coming out of the supply duct. You should see a drop of 20* +/- 2 degrees. If you don't have this differential, you need your system serviced.
Keep Kool

Answer 2

You didn't mention if your talking about a central (whole house) a/c unit or an individual room air conditioner. In either case, if the unit has been running for an hour and a half and you have the temperature set on 82, something is very wrong. If it's a window unit (individual room a/c unit) check to make sure that the coils haven't frozen up and that cold air is blowing. If it's a central a/c unit, it's service call time. These types of situations will not repair themselves, don't delay, bite the bullet for the service call and hope for the best.