Chemical Properties of Refrigerants in Air Conditioning
Chemical properties of refrigerants are used to select the suitable refrigerant type according to the air
conditioning application. Chemical stability, reactivity, inertness, toxicity are several important chemical properties of refrigerants
and we will see how chemical properties vary according to the
different type of refrigerants.
Important chemical properties for refrigerants in air conditioning
Following chemical properties are discussed in detail in this tutorial.
Chemical stability, reactivity and inertness of refrigerants
Flammability and combustibility
Toxicity and Hazardous properties
Solubility in water
Effects to commodities due to leakages
How refrigerants should be selected according to the chemical properties
Non-reactive or less reactive
Inflammable
Refrigerant should be non-toxic or less toxic
Should not be soluble in water
Zero or minimum effects to commodities
Chemical stability, reactivity and inertness of refrigerants
A good refrigerant chemical should be stable and less-reactive. Also, these refrigerants should not involve in reactions which generate
toxic or harmful chemicals which are capable of doing injuries to humans.
Refrigerants should not react with pipe materials. If refrigerant react with pipe material, pipe will get corroded or damaged with time.
It will cause leakages of refrigerants to the outside. Leakages of refrigerants will increase the maintenance cost of air conditioning equipment.
Reactions such as polymerization, corrosion or etc. should be avoided.
Ammonia has higher reactivity potential compared to
other refrigerants. As an example ammonia can react with copper pipes.
To avoid or minimize the reactivity, use stainless steel for pipelines.
Flammability and combustibility
Flammability of refrigerants is a significant chemical property to decide the safety of people and properties around the refrigerant space.
Hydrocarbon based refrigerants have higher flammable possibility.
Low flammable refrigerants should be used to avoid fire accidents. If a flammable refrigerant has to be used, apply a flame-retardants.
Though refrigerant is not flammable, still that refrigerant can be combustible at more severe conditions. It means that,
though refrigerant does not readily catch the fire at room temperature, but if extreme conditions (like high temperature) are provided,
refrigerant can catch the fire can make conditions more worse.
Toxicity and Hazardous properties
As other chemicals, an extreme care should be given when a refrigerant is chosen because this physical property directly affects to the
health of human lives. Toxicity of the respective refrigerant should be zero or minimum. Ammonia is a toxic refrigerant and Freons are considered as safest
refrigerants.
Solubility in water
Refrigerant chemicals should not dissolve in water or
solubility of refrigerants in water should be less in water as a physical property. If refrigerant chemicals and water soluble in each
other, solid ice can be formed during the refrigeration cycle at low temperatures.
Effects to commodities due to leakages
In industrial scale, foods or other degradable items can be affected due to contamination with some refrigerants like ammonia.
