The refrigerant cycle, step by step
Compressor, condenser, expansion valve and evaporator.
- Explain the refrigerant cycle, step by step at engineering level
- Read the numbers that define the behaviour
- Apply the idea to a real vehicle
Overview
Every heat pump and every air conditioner runs the same four-step cycle. Learn it once and you understand both cabin cooling and battery chilling.
In depth
Refrigerant cycle explorer
Trace refrigerant through compression, condensation, expansion and evaporation.
- 1Compression
The compressor raises refrigerant pressure and temperature, turning low-pressure gas into hot, high-pressure gas.
- 2Condensation
The hot gas gives up heat to a cooler medium (cabin air or ambient air) and condenses to a high-pressure liquid.
- 3Expansion
The expansion valve drops the pressure sharply, cooling the liquid well below ambient.
- 4Evaporation
The cold, low-pressure liquid absorbs heat from its surroundings and boils back to a gas, ready to be compressed again.
Key takeaways
- The refrigerant cycle has four steps: compress, condense, expand, evaporate.
- A heat pump and an air conditioner share the same core hardware.
- A reversing valve is what adds heating capability to a cooling-only system.
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