Refrigeration & Air Conditioning
The fundamental reason for having a refrigerator is to keep food cold. Cold temperatures help food stay fresh longer. The basic idea behind refrigeration is to slow down the activity of bacte- ria (which all food contains) so that it takes longer for the bacteria to spoil the food.
An air conditioner can change the temperature, humidity or general quality of the air. More specifically, an air conditioner makes your home cooler, by drawing heat energy out of the house and transferring that heat to the outdoors, then replacing the air inside your home with cooler air.