inverter ac

Inverter Compressor

An inverter compressor uses a variable frequency drive (VFD) to adjust the compressor’s speed. The VFD takes the incoming AC power and converts it into DC power using a rectifier. The DC power is then converted back into AC power using an inverter, which allows the frequency and voltage of the output to be adjusted.

The inverter compressor has a powerful neodymium magnet rotor that rotates around a stationary stator. The stator has multiple windings, which are energized with alternating current to create a magnetic field. The magnetic field interacts with the magnetic rotor, causing it to rotate and compress the refrigerant.

The speed of the inverter compressor is controlled by adjusting the frequency of the alternating current applied to the stator. The VFD adjusts the frequency of the AC power supplied to the compressor, which in turn adjusts the compressor’s speed. By varying the speed of the compressor, the inverter air conditioner can modulate the cooling capacity to match the cooling demand, resulting in more precise temperature control and energy efficiency.

The inverter compressor operates in a range of speeds, rather than just being on or off like a traditional compressor. It starts at a low speed and gradually ramps up as the cooling demand increases. Once the desired temperature is reached, the compressor slows down to maintain the temperature, using less power than a traditional air conditioner that cycles on and off to maintain the temperature.

The use of a variable speed compressor is one of the main advantages of inverter air conditioners over traditional air conditioners. By modulating the compressor’s speed, the inverter air conditioner can maintain a consistent temperature with less energy consumption, resulting in lower energy bills and a more environmentally friendly cooling solution.

In summary, the inverter compressor in an air conditioner uses a variable frequency drive to adjust the compressor’s speed, resulting in precise temperature control and energy efficiency.

While the inverter compressor can be designed around any refrigerant, R-32 is the best choice thanks to its efficiency and reduced Global Warming Potential. Furthermore the inverter compressor is typically smaller and more compact than a reciprocating compressor (quite similar in weight to rotary compressor though), which makes it easier to install and requires less space in the air conditioning unit. Additionally, the inverter compressor uses fewer parts than a reciprocating compressor, which can also contribute to a lighter weight.


Apart from all the goodiness, there are some drawbacks, lets read them below.

  1. Higher initial cost: Inverter air conditioners are typically more expensive than non-inverter air conditioners. This is because they use more advanced technology, such as the inverter compressor, to provide more precise and efficient cooling. While the higher initial cost may be offset by lower energy bills over time, it’s still a significant upfront investment.
  2. More complex technology: Inverter air conditioners use more advanced technology than non-inverter air conditioners, which can make them more complex to install and maintain (such as PCB issues etc). If something goes wrong with the inverter compressor or other inverter components, it may require a more skilled technician to diagnose and repair the problem.
  3. Potential for noise: While inverter air conditioners are generally quieter than non-inverter air conditioners, the inverter compressor can produce a high-pitched noise that some people find annoying. This noise can be more noticeable in smaller rooms or if the air conditioner is located near a bedroom or other quiet space.
  4. Compatibility issues: In some cases, inverter air conditioners may not be compatible with certain types of thermostats or other components in the home’s heating and cooling system. This can make it more difficult to integrate the inverter air conditioner into the existing HVAC system, which may require additional installation costs or modifications.
  5. More frequent maintenance: Inverter air conditioners may require more frequent maintenance than non-inverter air conditioners. This is because the inverter compressor and other inverter components are more complex and require more specialized maintenance procedures. This can increase the overall cost of ownership over the life of the air conditioner.


The functions of the PCB in a split outdoor unit of an air conditioner can vary depending on the specific model and manufacturer, but they typically in an inverter AC it includes:

  1. Control of the compressor: The PCB helps control the operation of the compressor by monitoring the temperature and pressure of the refrigerant and adjusting the compressor speed accordingly.
  2. Fan control: The PCB helps control the speed of the outdoor unit’s fan to ensure optimal cooling performance and energy efficiency.
  3. Defrost control: In cold weather, the PCB helps control the defrost cycle of the outdoor unit to prevent the buildup of ice on the unit’s coils.
  4. Sensor monitoring: The PCB also monitors various sensors in the outdoor unit, including the temperature sensor, pressure sensor, and other sensors, to ensure optimal performance and prevent damage to the unit.
  5. Diagnostic capabilities: The PCB can also help diagnose any problems or malfunctions in the outdoor unit by providing error codes and other diagnostic information.


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