Home appliances can be divided into several categories. Through the use of computers and microchips, it is now possible to design fully automated homes. All appliances are interconnected and under the control of one computer. Kitchen Equipment Large kitchen appliances include refrigerators, freezers, ranges and ovens, dishwashers, trash compactors, and waste-disposal units. Some, such as freezers, may be kept outside the kitchen because of lack of space.
Refrigerators often contain freezer compartments as well as ice-making machines.
Refrigerators and freezers generally operate on a compression system of cooling. In a frost-free refrigerator, refrigerant gas is compressed by a compressor and transmitted to condenser coils where it is pressurized, cooled, and liquefied. In liquid form, the refrigerant then passes through an expansion valve and returns to a gaseous state in the evaporator coils. The refrigerant absorbs heat as it changes from a liquid to a gas, and the temperature of the inside of the refrigerator is lowered. The condenser fan forces heat into the room, and the evaporator fan circulates the cooled air in the freezer compartment.