The total amount of time it takes for a central air conditioning system to remove heat and humidity from your home is dependent on factors such as the outdoor temperature, the total square footage of your house, and the insulation behind your walls. The latest energy-efficient central air conditioners for sale on the market are engineered to decrease the temperature of a four-bedroom house by a total of 10 degrees Fahrenheit every three hours. A standard air conditioner is designed to maintain a temperature in your house that is 20 degrees less than the outdoor temperature.