What are refrigerants?

Refrigerants are essential components in refrigeration and air conditioning technology. They enable the transfer of heat and are therefore central to the operation of refrigerators, air conditioning systems and heat pumps. This article provides a comprehensive overview of refrigerants, how they work, types, properties and their importance in various applications.

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What are refrigerants?

Refrigerants are special fluids that are used in refrigeration systems and heat pumps to transfer heat. Their properties enable cooling or heating processes. They are essential in areas such as food cooling, building air conditioning and industrial process cooling.

How do refrigerants work?

The way refrigerants work is based on a thermodynamic cycle, which consists of four main steps:

1. Vaporization: At low pressure and temperature, the liquid refrigerant absorbs heat from the environment and evaporates.
2. Compression: A compressor increases the pressure of the gaseous refrigerant, which also increases its temperature.
3. condensation: In the condenser, the hot, gaseous refrigerant releases heat to the environment and condenses back into a liquid.
4. Expansion: An expansion valve reduces the pressure of the liquid refrigerant, causing its temperature to drop. The cycle starts all over again.

To help you understand, the following is an example of how a refrigerant works in a heat pump:

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What types of refrigerants are there?

Refrigerants are used in natural and synthetic Refrigerant divided. natural refrigerants such as ammonia (R717) or Propane (R290) Are more environmentally friendly. Synthetic refrigerants are manufactured industrially and offer a wide range of applications.

Natural refrigerants

Natural refrigerants occur naturally and often have low global warming potential (GWP) and ozone depletion potential (ODP). They are more environmentally friendly but often require special safety measures.

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synthetic refrigerants

Synthetic refrigerants are manufactured industrially and are divided into different groups: chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFO).

Here is a summary table of the most important synthetic refrigerants:

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What are the properties of refrigerants?

The choice of a refrigerant depends decisively on its properties. These influence the efficiency, safety and environmental compatibility of the plant. The following table shows the most important properties of refrigerants and their significance:

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How has the development of refrigerants changed historically?

The Development of Refrigerants shows the shift from natural substances to synthetic alternatives and the return to more environmentally friendly options:

• From 1755: Natural refrigerants Like ether, sulfuric acid, dichloroethylene, ammonia and CO2 Were used. The focus was on technical feasibility.
• From 1929: With the development of CFCS (e.g. R11, R12) moved the surety at the center. The flammability and toxicity of natural refrigerants led to the widespread use of CFCs.
• From 1988: Due to the Destruction of the Ozone Layer (high ODP) were HFKW (e.g. R22, R124, R142b) developed as alternatives. The ozone hole led to stricter environmental requirements.
• From 2000: The focus shifted to Global Warming (GWP). HFKW Such as R134a, R404A and R32 were used, but with high global warming potential. Natural Refrigerants Such as ammonia and CO2Remained in use.
• From 2015: New HFO refrigerant Such as R1234ze and R1234yf were developed. They have a low GWPand are considered a sustainable alternative. Win at the same time propane, ammonia and CO2 Continues to be important as a natural refrigerant.

The graph clearly shows that natural refrigerants are becoming more relevant again despite being displaced by synthetic variants in the meantime. The focus today is on environmentally friendly and future-proof solutions.

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Statutory regulations and standards

Current legal regulations, in particular the EU f-gas regulationLimit the use of refrigerants with high GWP. From 2025 Are refrigerants with a GWP > 750 Prohibited in new heat pumps and split air conditioners. The focus is on promoting natural refrigerants Such as CO2, ammonia and propane, as well as synthetic alternatives with low GWP.

Safety standards such as DIN EN 378 Regulate the safe use of refrigeration systems. For example, operators of refrigeration systems with a filling capacity of ≥ 5 tons CO₂ equivalent regular Tightness checks Carry out. There are also obligations to Professional Recovery and Disposal of refrigerants at the end of the life of the systems.

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Why are refrigerants essential in refrigeration and air-conditioning technology?

Refrigerants are essential because they enable heat transfer in refrigeration and air conditioning systems. They absorb heat at a low temperature and release it again at a higher temperature. Without this process, refrigerators, air conditioners, or heat pumps could not function.

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Which alternatives will prevail?

Future-proof alternatives include natural refrigerants such as CO2 (R744), ammonia (R717) and Propane (R290). They have a low global warming potential (GWP) and meet legal requirements. Synthetic refrigerants such as HFO (e.g. R1234yf) are also considered an environmentally friendly solution.

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How does a refrigerant affect the environment?

A refrigerant has an impact on the environment when it has a high Ozone Depletion Potential (ODP) or Global Warming Potential (GWP) Has. CFCs damage the ozone layer, while HFCs increase global warming. Natural refrigerants such as CO₂ and ammonia are more environmentally friendly and reduce these effects.

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How do you choose the right refrigerant for a heat pump?

The right Refrigerant for a heat pump Depends on the Efficiency, who environmental sustainability And the surety Off. Refrigerants such as R290 (propane) offer high efficiency and low GWP. For this reason, it is the preferred refrigerant if government subsidies are to be claimed. For special applications, CO2or HFO refrigerant Suitable as R1234ze.

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How is refrigerant safely handled and disposed of?

A refrigerant is handled safely by certified professionals With a valid Cold certificate Take care of installation, maintenance and transportation. Starting at certain filling quantities, regular Tightness checksprescribed. At the end of its life, the refrigerant must be properly used recovered and are disposed of by certified companies.

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