Refrigeration systems have gas installed in a series of tubes. . Air conditioning systems use built-in chemicals, but also air from the room or rooms being heated. Gases built into air conditioning units cool air that circulates through the unit; the unit then redistributes the cooled air through the room.
Refrigeration, or cooling process, is the removal of unwanted heat from a selected object, substance, or space and its transfer to another object, substance, or space. Removal of heat lowers the temperature and may be accomplished by use of ice, snow, chilled water or mechanical refrigeration.
A refrigerator is one of our most valuable household appliances. It keeps food and drinks cool, by pushing a liquid refrigerant through a sealed system, which causes it to vaporize, and draw heat out of the fridge. The vaporized refrigerant then is passed through coils outside the fridge (at the back or the bottom).