How Does a Refrigerator Drip Pan Make Water Evaporate?

How Refrigerators Work

• Refrigerators work not by producing cool air, but by removing heat. This is done due to the expansion properties of gases. When gases expand rapidly, heat is pulled in from the surrounding area. In a modern refrigerator, a liquid refrigerant circulates through the cooling pipes. At one point, usually inside the freezer, the coolant passes through an expansion valve where it is transformed into a gas and cools the compartment. The gas is then pumped down into a compressor where it is transformed back into a liquid. The cool air in the freezer compartment makes its way down into the refrigerator through vents and cools that chamber as well.

Refrigerators and Water

• Because the air inside the refrigerator is cooler than the outside air, whenever you open the refrigerator, warmer air can enter the refrigerator and condense on the walls inside. Water also appears inside a refrigerator during the defrosting process. As the ice inside the freezer compartment melts, it drips down through a drain pipe in the freezer and into the refrigerator compartment.

Refrigerator Drain Pans

• The drip pan in a refrigerator is positioned directly underneath the cabinet. A drip hose in the bottom of the refrigerator compartment leads down to the drip pan. These pans are usually made out of tough plastic. A grill in front of the refrigerator gives access to the pan so that it can be removed for cleaning and emptying.

Drip Pan Evaporation

• The bottom of the refrigerator usually houses the coils for return part of the cooling system. The pipes in this area are warm because the coolant inside has been absorbing heat in the freezer compartment. This warming helps to heat the water in the drip pan below. As the water is heated, some of it is converted into vapor, which escapes into the atmosphere. Refrigerator drip pans are also constructed so that they are very long, which keeps the water inside shallow and allows for easier evaporation.