Does keeping AC on 24 save electricity?

A common misconception is that leaving your air conditioning system running continuously twenty-four hours a day saves more electricity than turning it off or adjusting the temperature, under the assumption that starting the system up requires a massive surge of power. In reality, letting your AC run continuously when no one is home or when you are asleep wastes a tremendous amount of energy by cooling an empty house against continuous thermal transfer. Modern air conditioning compressors consume energy proportional to their operating time, so letting the system cycle off or raising the temperature setpoint reduces total runtime hours and lowers your electricity bill. You can optimize efficiency using a programmable thermostat. You can verify savings when restricting unnecessary daytime runtime reduces your monthly utility consumption.