Refrigerants: The Blood of the Refrigeration Cycle

Good Day Folks!

Today, allow me to share my thoughts and knowledge regarding refrigerants.

With today’s great importance of refrigeration and air conditioning systems, you might have stumble or even heard from someone about words like Freon wherein it is always followed with the word leaking and harmful to the environment. Well, Freon is a type of a refrigerant.

WHAT ARE REFRIGERANTS?

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Refrigerants are substances that are used in a refrigeration and air conditioning systems to produce a refrigerating effect (cooling effect) wherein these substances need to boil easily from a liquid state into a vapour state and be condensed from a vapour state into a liquid state in a continuous cycle. And that’s how important refrigerants since without these substances refrigeration wouldn’t be possible and that is the very reason that whenever there is a leaking of Freon or refrigerant in your refrigerator or air conditioning system you would be able to notice that your refrigerating equipment is not functioning well. And for that reason, refrigerants are being referred as the blood of the refrigeration system.

PROPERTIES OF REFRIGERANTS
Since refrigerants are substances, therefore they have properties that make them unique and susceptible for use in the refrigeration systems. These properties are as follows: thermodynamic, chemical and physical properties. So below are the properties of thermodynamic, chemical and physical properties of refrigerants.

• Thermodynamic Properties
  • low freezing point
  • low condensing pressure
  • low evaporating pressure
  • low power per ton of refrigeration (TOR)
  • low volume flow rate per ton of refrigeration (TOR)
  • high coefficient of performance (COP)
• Chemical Properties
  • non-toxic
  • non-flammable
  • non-corrosive
  • non-destructive to refrigerated products
• Physical Properties
  • low viscosity
  • high thermal conductivity
  • easy leak detection
  • miscible with oil
  • reasonable cost

TYPES OF REFRIGERANTS

In today’s setting many refrigerants have been named some of these refrigerants are naturally occurring and some of these are synthetically made. So here are the types of refrigerants.

• HALOCARBON/HALOGENATED Refrigerants
  
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  These refrigerants contain the three elements belonging to the family of Halogens and these are Chlorine (Cl), flourine (F) and bromine(Br). These refrigerants are widely criticized for their role in depleting the ozone layer.

Examples of Halocarbon/Halogenated Refrigerants

Refrigerant Number	IUPAC (International Union of Pure and Applied Chemistry) Name	Chemical Formula
R-11	Trichloromonofluoromethane	CCl3F
R-12	Dichlorodifluoromethane	CCl2F2
R-13	Monochlorotriflouromethane	CClF3

• HYDROCARBON Refrigerants
  
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Some of these hydrocarbon refrigerants are the alkanes, wherein they are very suitable for both the petroleum and petrochemical industry.

Examples of Hydrocarbon Refrigerants

Refrigerant Number	IUPAC (International Union of Pure and Applied Chemistry) Name	Chemical Formula
R-50	Methane	CH4
R-170	Ethane	C2H6
R-270	Propane	C3H8

• INORGANIC Refrigerants
  
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  Inorganic refrigerants are those refrigerant that are non-toxic and environment friendly which are still being used for specific purposes like for air which is used in air-cycle refrigerations.

Examples of Inorganic Refrigerants

Refrigerant Number	Inorganic Refrigerant	Chemical Formula
R-717	Ammonia	NH3
R-718	Water	H2O
R-729	Air	-

• ZEOTROPE Refrigerants
  
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  Zeotropic refrigerants are a mixture or blend of two or more refrigerants of different boiling points. As for zeotropic refrigerants are opposite to azeotropic refrigerants.

Examples of Zeotropic Refrigerants

Refrigerant Number	Composition of Refrigerants with Mass Percentage
R-400	R-12 (50%)/R-114(50%)
R-401A	R-22(53%)/R-152a(13%)/R-124(34%)
R-401B	R-22(61%)/R-152a(11%)/R-124(28%)

• AZEOTROPE Refrigerants
  
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  Azeotropic mixture of two substances is one which cannot be separated into its components by distillation. When an azeotropic refrigerant evaporates and condenses as a single substance with properties that are different from those either constituent.

Examples of Azeotropic Refrigerants

Refrigerant Number	Composition of Refrigerants with Mass Percentage
R-500	R-12(73.8%)/R-152a(26.2%)
R-501	R-22(75%)/R-12(25%)
R-502	R-22(48.8%)/R-115(51.2%)

I guess that would be all for my basic knowledge related to the refrigerants being used in the refrigeration systems.

Much love and respect.

Joseph Ace Tigas | @josephace135
Registered Mechanical Engineer (RME)

References:

1. https://www.ashrae.org/technical-resources/standards-and-guidelines/ashrae-refrigerant-designations
2. https://www.thoughtco.com/definition-of-azeotrope-605826
3. https://en.wikipedia.org/wiki/Zeotropic_mixture#Zeotropic_Vs._Azeotropic_Mixtures
4. Industrial Plant Engineering by Joel A. Mandawe