Should I leave the air conditioner ON or turn it OFF when I am not in the house?

Theoretically, by leaving the AC running set at a comfortable temperature, means that the air conditioning unit will not have to operate that hard. On the other hand, if you turn it off when you leave and turn it on when you get home, the air conditioner will consume more energy either for cooling or heating. However, in practice the AC should be turned off. You might think that it is a waste of energy to turn on and off the air conditioner, but this saves you a fair amount of money and helps the air conditioning unit to operate more efficiently. It might seem that the AC consumes more energy to cool or heat the room, but actually the air conditioners run most efficiently when they are operating at full speed, rather than operating at lower speed all day in order to maintain a constant temperature.