Reciprocating VS Rotary Compressor in AC – How to Choose the Right Air Compressor

The application of air conditioners has nowadays increased due to rising temperatures all across the globe. There are different components of an air conditioner that functions with the cohesion to create a comfortable and cool environment inside a room. One of the main elements of AC is a compressor that contributes to the entire process of cooling. The primary purpose of any compressor is to convert the electric energy into the potential energy that is stored in the compressor air. The presence of a perfect compressor might be a making or breaking deal for the user. In this article, we will be bestowing the working principle of a compressor, its type, and which one you should select according to your preferences.


Working Principle of a Compressor

Air conditioners perform three processes for evaporating cool air into the room. These are:


air conditioner Compressor

The main principle of a condenser is to extract the low pressure and refrigerant gas and compress it. It will convert the enhancing temperature and pressure resulting in the high pressure and hot gas release.



air conditioner Condensation

Next, the fans take control of the process when they blow the cold air to the outside by extracting the hot air from the room. Once the hot air moves through the cooling gas, it then condenses into a lukewarm liquid. This liquid moves through the high pressure to the expansion valve, considerably decreasing the temperature of the warm liquid.



air conditioner Evaporation

The liquid then finally passes through the evaporator coils, where there is low pressure. The warm air from the room blows over these coils through another fan set, resulting in the heat-transmitting reaction. This process cools the air supplied to the room. The refrigerant completes the entire cycle and becomes a low-pressure gas. The machine repeats the whole process for a continuous cool airflow cycle to have a comfortable environment.


Different Kind of Compressors

Now let us take a quick look into the various kinds of compressors present inside an AC with their advantages and drawbacks for each.

Piston or Reciprocating Air compressor

This compressor type compresses down the air with the pistons by moving upward and down inside the cylinders. They are meant for irregular use when the user needs a small air amount and are perfect for workshops, do-it-yourself projects, homeowners, construction workers, and small businesses. If the compressor remains idle for almost one-third of the time, then the reciprocating compressor is the best choice for the requirements.


  • Reciprocating compressors can compress gas with 5 to 10% of the less energy input.
  • It can attain exceptionally high pressure with the multiple set up of cylinder and piston arrangements.
  • Easy to maintain as the shaft and the piston mechanism can be easily disassembled with no problem fixing.


  • The vibration and the noise level is high due to the multiple mechanical moving components present inside.
  • It can release the air only at a high temperature.


Rotary Air Compressor

A rotary air screw compressor consists of two rotors that operate in the opposite direction. The air is trapped in between these two rotors, thus leading to the occurrence of compression. They are perfect for utilization that requires a continuous air supply. These compressors come with a design for performing non-stop and offer a consistent and sturdy airflow. Rotary screw compressors are an ideal selection for industrial and commercial users with continuous air supplying a demand. The compressors are exceptionally reliable and durable in situations where there is a lot of demand.


  • The rotation inside the compressor features moving components, resulting in lesser vibration and noise during operation.
  • Operate in a wide pressure and power range
  • Perfect for industrial and business applications, factories, and offices
  • The outcoming air is not so hot.


  • More expensive compared to the reciprocating compressors
  • Require to use them in a loop for better and durable performances


Comparison between Rotary and Reciprocating Compressors

Now let us check out the comparison between reciprocating and rotary compressors based on different parameters.



The reciprocating compressor implements a piston for compressing the air inside the cylinders and is sent to the receiving tank with high pressure for use. Rotary compressors implement rotors to slide inside and outside the rotor for forming the compression pockets. The primary advantage of the reciprocating compressors is their upfront affordability. Rotary compressors are more energy-efficient than reciprocating ones.


Energy Efficiency

Energy Efficiency

83% costs of the total air compressor are related to energy use, while the machine has only 11% of the total amount. You will see these expenses with a price tag, but you can observe a hike in the electricity cost every month. Thus you should go for a compressor that will be energy efficient and is competent enough to deliver more air with less energy consumption. It is what a rotary compressor in an air conditioner does. The advanced architecture produces a nearly perfect rotor unit seal for enhancing the volumetric efficiency and reducing the energy amount for delivering the air.

Rotary compressors achieve mechanical efficiency of up to 90%, which is not possible in reciprocating compressors. Reciprocating machines operate at high speed, create more heat, friction, and waste energy. On the other hand, rotary compressors perform at decreasing temperature, minimal friction, and higher efficiency.


Duty Cycle

The air compressor is useful only when it is compressing the air. Every AC cannot operate in a loop and requires some downtime. The reciprocating compressor requires 30 to 50% of the downtime for preventing component wear, overheating, breakdown, and oil carbonization. Thus you should always purchase a reciprocating compressor that will be double the CFM mount that the application needs. On the contrary, rotary compressors run at 100% of their capacity for a 24-hour working day with no experience of damage or wear. Since the duty cycle of the rotary compressors is so high, you can install a small machine that will need less power. It means you can have huge savings on the electricity bills.


Life Expectancy

Rotary compressions are highly durable and last for a long time. According to research, they state that the rotary machines come with a lifespan of nearly 100000 hours due to minimal fraction, proprietary air bends, lower operational speeds, and simple engineering. Conversely, reciprocating compressors have less longevity due to high operating speed, complex engineering, and tremendous friction.


Quality of Air

Trustworthy high-quality air delivery is a precondition when it comes to the question of air conditioning systems. Rotary compressors implement highly efficient filtration systems where 1 to 3 mm of carryover oil enters the machine, preventing any damage or contamination of the air conditioner. Conventional reciprocating condensers often include 25 mm of carryover oil. Rotary components come with a reliable delivery of high-quality air that keeps everything downstream, operating for a longer and better life.


Which one to select: Reciprocating or Rotating?

After comparing all the pros, cons, and features, we will suggest picking an air conditioner with a rotary compressor than the reciprocating components. It is intelligent to spend more in the initial stage than lifetime expenses concerning ROI.


Final Thoughts

The usage time of the AC is very significant before deciding which compressor type you want to use. If you are acquiring an air conditioner for the house use, it is better to go with the reciprocating air compressor. However, if you want to install an AC in an industry, office, or shop where people will use it frequently, you should opt for a rotary compressor. Both of them come with demerits and merits, you should consider all your requirements and compare which one will be ideal for you.


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