A refrigerator keeps food cold by pumping heat from inside its cabinet into the surrounding room. A refrigerant absorbs heat as it evaporates in the indoor coils, then releases that heat as it condenses in the outside coils. A compressor helps keep the cycle moving.
The refrigerant absorbs heat inside
In the evaporator coils, low-pressure refrigerant absorbs heat from the refrigerator and changes from liquid to vapor. Removing heat lowers the temperature inside the cabinet. [1]
The compressor and condenser send heat out
The compressor raises the refrigerant’s pressure and temperature. It then flows through condenser coils outside the insulated compartment, where it releases heat to the kitchen and returns toward a liquid state. That is why the back or sides of a working refrigerator can feel warm.
A repeating cycle moves heat
After passing through a narrow expansion device, the refrigerant’s pressure drops. It cools and can absorb heat again in the evaporator. The cycle repeats as the thermostat calls for cooling. A refrigerator moves heat; it does not destroy it.
Why does the kitchen warm slightly?
The refrigerator releases the heat it removed from its interior, plus some energy used by its compressor, into the room around it.
Sources and evidence
- U.S. Department of Energy — Refrigeration Units Research Paper ↗
Describes a vapor-compression refrigerator cycle in which the condenser releases heat and the evaporator absorbs heat inside the refrigerator.
- U.S. Department of Energy — Refrigerator Technical Support Document ↗
Defines the compressor, condenser, and evaporator roles in household refrigeration.
Sources consulted: 15 October 2026. Written with AI assistance and checked against the linked references; not independently reviewed by a subject specialist. Sources do not endorse this article. See our editorial policy.
Revision: Initial publication; the explanation was checked against linked institutional, medical, or scientific references. This article was prepared with AI assistance and has not received independent expert review.