Ans. Running air conditioners for long durations will decrease their efficiency to a great extent. The duration that an air conditioner should run for depends on a lot of factors like:
The temperature outside
The setting on your thermostat
The size of the air conditioner
The state of the air conditioner
The size of the home
The quality of the insulation
Under average circumstances, running the air conditioner for 15-20 minutes is ideal in mild temperatures. In some cases, the air conditioner might cool the house in less time or vice versa. This might indicate that the size of the air conditioner is not proportionate to the size of the house.