What is a Refrigeration System


Refrigeration systems, built on thermodynamics and fluid mechanics principles, play the essential role of maintaining temperatures between two different points. An ideal refrigeration system extracts heat from a particular area and rejects it to some other point, achieving the desired temperature.

The refrigeration system works under thermodynamic principles, involving different steps, including compression, condensation, expansion, and evaporation. This step-by-step process leads to heat absorption from the targeted area and then releasing it to another specified place.

Function of Compressor in Refrigeration System

Function of Compressor in Refrigeration System

The compressor is considered the most important part of any refrigeration system.

It increases the pressure on the refrigerant, thus elevating its temperature.

The compressor works on the mechanical compression principle, converting low-pressure and low-temperature vapor to a higher scale and supporting efficient heat rejection.

Piston, diaphragm, rotary, reciprocating, and centrifugal compressors are some of the prominent types of compressors commonly used nowadays.

They are unique to each other due to their working principles and their feasibility for various applications.

Selecting the right refrigerant compressor is crucial as this is where the gas refrigerant is converted to liquid, helping it pass through the whole system.

Related products: scroll compressor, rotary compressor, semi-hermetic compressor, refrigerator compressor.

Function of Expansion Valve in Refrigeration System?

Function of Expansion Valve in Refrigeration System

The critical role of the expansion valve in refrigeration systems comes during the transition of high-pressure liquid refrigerant to low-pressure gas.

The expansion valve plays the role of a throttling device between the condenser and the evaporator, causing a decrease in pressure and temperature.

An expansion valve ensures efficient heat absorption in the evaporator by providing precision control over the refrigerant flow.

There are different types of expansion valves used in refrigeration systems: Thermostatic Expansion Valves(Danfoss, Emerson, Sporlan, Saginomiya), Electronic Expansion Valves, and Capillary Tubes.

The Role of Condenser in Refrigeration System?

The Role of Condenser in Refrigeration System

The refrigerant absorbs heat in the compression phase, which is subsequently discharged through the condenser.

The process involves transferring heat from the refrigerant to an alternate medium, such as air or water.

This occurs as the high-pressure gas travels through the coils or tubes of the condenser, causing the surrounding air or coolant to assimilate the heat.

The condenser ensures that the system is ready to repeat the refrigeration cycle and helps elevate the system’s cooling capacity.

With different applications and advantages, air-cooled and water-cooled condensers are popularly used nowadays.

Purpose of Evaporator in Refrigeration System

Purpose of Evaporator in Refrigeration System

Evaporators in the refrigeration system play a crucial role in the cooling process.

This is achieved by removing the heat from the water, air, and other materials used in the whole system.

When the low-pressure liquid-gas mixture enters the evaporator, it faces a lower-temperature environment and gets cool.

Different types of evaporators, like air-cooled and water-cooled, are generally used in refrigeration systems.

You can use both depending on the specific application’s nature. Understanding the role of the evaporator is essential to know the dynamics of refrigeration systems.

Function of Solenoid Valve in Refrigeration System

Function of Solenoid Valve in Refrigeration System

A Solenoid Valve is a controlled flow device that helps regulate refrigerant flow throughout the system. It works under an electromagnetic field to either allow or block the passage of refrigerant. In simpler terms, the solenoid valve acts as a gatekeeper for the refrigerant flow.

Not only for flow control, a solenoid valve can also be used to ensure the safety and maintenance of the system in case of any power outage or system malfunction.

Oil Separator in a Refrigeration System?

Oil Separator in a Refrigeration System

Lubricating oil is used to ensure the smooth function of the compressors. This raises the problem of oil getting mixed with the refrigerant. Here comes the use of oil separators in refrigeration systems to ensure that all the oil is separated from the refrigerant and fed back to the crankcase.

The oil separator generally functions based on gravity and centrifugal force principles. As the refrigerant-oil mixture enters the separator, the centrifugal force generated by the rapid rotation of the separator causes the heavier oil droplets to separate from the lighter refrigerant.

What is a Filter Drier in a Refrigeration System?

What is a Filter Drier in a Refrigeration System

Filter Drier is another critical component of a refrigeration system that is designed to remove the contaminants and moisture from the refrigerant.

In the system, it is placed between the condenser and expansion valve and ensures the purity of the whole cycle.

There are two primary functions of filter drier: filtration and dehydration.

Firstly, it acts as a filter, trapping contaminants. Secondly, the filter drier also acts as a dehydrating agent that removes moisture from the refrigerant.

It is essential to remove the moisture as it could cause the formation of ice crystals.

Related products: Danfoss Filter Drier, Emerson EK Filter Drier.

Suction Accumulator in Refrigeration System

Suction Accumulator in Refrigeration System

Sometimes, the liquid refrigerant enters the compressor’s suction line, which is prevented using a Suction Accumulator.

Not only does it prevent the liquid from entering, but also ensures that only the vaporized refrigerant gets into the compressor.

The suction accumulator plays a vital role in protecting the compressor and enhancing the reliability of the refrigeration system.

What is Superheat and Subcooling in Refrigeration System?

Subcooling and Superheat Chart

To represent the temperature variance of refrigerant vapor and liquid, we use the parameters of Superheat and Subcooling.

Let’s explain it separately what is Superheat and Subcooling:


The additional temperature of the refrigerant vapor above its saturation temperature at a given pressure is known as superheating.

Any further temperature increase is considered superheat after the refrigerant vaporizes in the evaporator.


Subcooling involves lowering the temperature of the refrigerant liquid below its saturation point at a specific pressure.

This occurs after the complete condensation of the refrigerant in the condenser—the importance of subcooling lies in guaranteeing that only liquid refrigerant enters the expansion valve.

Refrigeration System and Refrigeration Unit

Refrigeration System and Refrigeration Unit

When you understand refrigeration systems you will understand the relationship between refrigeration systems and refrigeration units and the difference between refrigeration units and condenser units.

All refrigeration units are designed and manufactured according to the principles of refrigeration systems. (Understanding Refrigeration Units – A Comprehensive Guide)

For example, HUBHVACR has small refrigeration units and semi-hermetic refrigeration units, and you can get an idea of what they look like by checking out the page.

Regardless of the type of refrigeration unit and condenser unit, they all must have a compressor, condenser, expansion valve, and evaporator.

If you have very serious cost control then you only need these four basic accessories.

However, such a refrigeration system is unstable.

That’s why we include accessories such as filter dries, suction accumulators, oil separators, solenoid valves, ball valves, sight glasses, etc. in our refrigeration systems.

More Refrigeration Unit Products: Remote condensing units, drop-in refrigeration units, walk-in cooler condensing units, self-contained refrigeration units, indoor condensing units, etc.

Refrigeration System and Air Conditioner Unit

Refrigeration System and Air Conditioner Unit

An air conditioning unit is an upgraded version of a refrigeration system that has very high technology.

This is because the air conditioning refrigeration system has harsh temperature requirements.

Therefore, it depends on the type of air conditioner that determines the accessories of the refrigeration system.

For example, the accessories for a domestic air conditioner and a commercial central air conditioner are different.

Domestic air conditioners pay more attention to energy saving, so they need to use inverter compressors and electronic expansion valves, and these accessories can help the air conditioner get more accurate temperature control.

Commercial central air conditioning focuses more on upfront investment costs, so it uses cheaper fixed-frequency compressors and thermal expansion valves.

However, the total price of a commercial central air conditioner is exorbitant because it has a greater cooling capacity requirement.

For precision air conditioning units, it is again a different range of applications.

Precision air conditioning places more emphasis on the unit’s control of humidity and temperature, so it has a plate heat exchanger instead of the traditional air-cooled heat exchanger in its evaporator construction.

In conclusion, there is a wide variety of air conditioners available, you can check out this article to see the types of air conditioners available or contact HUBHVACR directly to customize the air conditioning unit you need.


In this comprehensive article, we have tried to explain the critical functions of different refrigeration system components.

Understanding all this complex knowledge helps you build a stronger foundation about refrigeration systems, ultimately leading to a better technical person and businessman in the relevant field.

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