Refrigerant is a key material that ensures the operation of refrigeration and air conditioning systems. Its function is to absorb, transport and release thermal energy, which allows the desired temperature level to be maintained. The refrigerant undergoes changes of state (from liquid to gas and back again) as it flows through different parts of the system.
How does refrigerant work?
Evaporation: The low-pressure liquid refrigerant in the evaporator absorbs heat from its surroundings as it turns into a gas.
Compression: The gaseous refrigerant is compressed by the compressor , which increases its temperature and pressure.
Condensation: The high-temperature and high-pressure gas in the condenser releases heat while turning back into a liquid.
Pressure reduction: The pressure of the liquid refrigerant is reduced through the throttle valve and returns to the evaporator to restart the cycle.
Refrigerant selection
Choosing the right refrigerant depends on the needs of the specific system and application.
System type: E.g. household refrigerator, industrial chiller, air conditioner or heat pump .
Environmental considerations: Preference for low GWP and ODP (ozone depletion potential) refrigerants.
Operating parameters: Pressure and temperature range required by the system.
Safety considerations: Fire hazard, toxicity and system stability.
Maintenance and handling
Regular inspection: Regular maintenance of the system is essential to avoid refrigerant leaks.
Compliance with environmental regulations: The refrigerants used must comply with current regulations (e.g. the EU F-gas Regulation ).
Proper disposal: Recycling or safe disposal of used refrigerants is necessary to protect the environment.
Example: Comparison of refrigerants
| Refrigerant type | GWP value | Advantages | Disadvantages |
|---|---|---|---|
| R-410A | 2088 | Effective, widespread | High GWP, harmful to the environment |
| R-32 | 675 | Lower GWP, energy saving | Minimal flammable risk |
| CO₂ | 1 | Environmentally friendly, cheap | High pressure system required |
| Ammonia | 0 | Very efficient, low cost | Toxic, corrosive |
Environmental impacts
Ozone Depletion Potential (ODP): Older refrigerants such as CFCs and HCFCs significantly damaged the ozone layer, so their use was restricted.
Global Warming Potential (GWP): The use of refrigerants with low GWP significantly reduces the impact on climate change.
New directives: Regulations in the European Union and other regions are promoting the spread of low environmental impact refrigerants.
Summary
Refrigerant is essential for the operation of HVAC systems and plays a crucial role in the efficiency, safety and environmental impact of the system. Choosing the right refrigerant and regular maintenance not only ensures a longer lifespan, but also contributes to sustainability and reduced environmental impact.