Science explained

How refrigerators and heat pumps move heat

Refrigerators and heat pumps use a circulating refrigerant and mechanical work to move thermal energy from a cooler region to a warmer one.

TechnologyThermodynamics

Editorial review: August 12, 2026 · Julian E. Marston

Evaporation absorbs energy

At low pressure, refrigerant evaporates while taking in heat.

Compression raises pressure and temperature

A compressor supplies mechanical work.

Condensation releases heat

The hot refrigerant rejects energy to the surroundings.

An expansion device closes the cycle

Pressure drops before the refrigerant returns to the evaporator.

This page explains scientific concepts for general learning. It does not replace laboratory safety procedures, professional engineering guidance, or individualized medical advice.