Refrigerators—as well as air conditioners, heat pumps, and other appliances that produce "cold"—use basic refrigeration principles to extract heat from the air. Here's how they work:
To remove heat from the air, a compressor pushes a refrigerant through copper tubing between two sets of coils: one a condenser and the other an evaporator. With a whole-house air conditioner, the condenser is located outside and the evaporator is mounted on top of the indoor air-handling unit. With a portable air conditioner, dehumidifier, refrigerator, or freezer, both the condenser and evaporator coils are part of the appliance. As the refrigerant moves from condenser to evaporator, it changes from a high-pressure, high-temperature liquid to a low-pressure, low-temperature vapor and liquid. This low pressure cold liquid "boils" in the evaporator coils, absorbing heat from inside the refrigerator or area to be cooled and turns into a cool low-pressure vapor.
This cool vapor is removed from the evaporator by the compressor and is then compressed into a high-temperature, high-pressure vapor and pumped into the condenser. In the condenser, the high-temperature, high-pressure gas gives up its heat as cooling air moves through the condenser coils and then returns to a high-pressure liquid. This cools even more as it moves to the metering device in which it then again becomes a low-pressure, low-temperature gas and liquid to begin the cooling process over again.
Confusing? Here is the bottom line: When a liquid boils it absorbs heat. When a vapor cools it releases heat and returns to a liquid state. This physical process is repeated over and over.
This complete refrigeration system is called a "sealed" or "hermetic" system and should only be repaired by certified professionals.
|
