Fixed Speed vs. Inverter Air Conditioners - What’s the difference?

When deciding what type of air conditioner to invest in for your home or business, there are many factors that need to be considered.

Within those, it is understanding whether you would benefit more from a fixed speed system or an inverter system air conditioner.

These are the two main types of air conditioning technology on the market and so it’s important to know their differences in terms of performance, energy efficiency and capabilities.


Although a fixed speed system and an inverter system share many of the same functions, the compressor motor technology inside the unit that’s used to cool the incoming air differs greatly. Below we explore how and the benefits they offer.


In this article we cover:

  • What is a fixed speed air conditioner?
  • What is an inverter air conditioner?
  • Understanding the differences and benefits



What is a fixed speed air conditioner? 

Fixed speed air conditioners, which are also referred to as non-inverter, are built with a single-speed compressor motor that has a start/stop operation.


This means that when the desired temperature has been reached, the compressor motor turns off automatically, and only restarts when the temperature passes a set threshold. To put it in other words, fixed speed air conditioners operate at full or no capacity. In some countries, its popularity is waning as the trend for inverter air conditioners continues to grow but fixed speed systems still stand as an excellent solution to climate control needs. 


What is an inverter air conditioner?

Inverter air conditioners use variable-speed compressor motor technology and, unlike the start/stop operation of a fixed speed air conditioner, they are able to adjust the compressor speed in tune with temperature fluctuations.


So, when the air conditioner reaches the desired temperature, instead of switching off the compressor motor, it works in a low power mode that keeps it running. By doing so, an inverter system can operate continuously with a minimal load while providing constant temperature and increasing indoor comfort. 


Understanding the Differences


When comparing a fixed speed unit with an inverter unit, as mentioned above, the functions that both types of system offer are practically the same.

The main difference lies within the compressor motor and the impact that it has on the efficiency of both the cooling and heating performance, and the energy consumed. In fact, the type compressor motor has implications for efficiency, noise and also costs, things which need to be considered when purchasing or replacing an air conditioner.



In terms of efficiency, an inverter air conditioner is the most energy-efficient option, one of the main reasons driving their increased demand.

The variable-speed compressor technology means the unit adjusts the motor speed rather than switching it on and off, thus reducing the amount of power needed to start the system up.



Though both types of air conditioners are capable of running relatively quietly, an inverter conditioner does have the advantage over fixed speed units.

The start/stop nature of fixed speed air conditioners means sound levels are inconsistent and more noticeable during operation. If noise is a deal-breaker for you, whether for concentration or disturbed sleep on hot nights, then an inverter type is what you need because it reduces operational noise to a minimum. 




The upfront cost of a fixed speed air conditioner is lower than that of an inverter unit, making it the ideal choice for those on a tighter budget, or for sporadic use throughout the year. However, if you live in a location where temperatures fluctuate greatly, an inverter is more cost-efficient for use in the long run. 



An important factor to consider, there are two things to be aware of when choosing which type to buy. Regarding the type of system, a fixed speed air conditioner has more chance to incur issues because of the start/stop operation. That said, when thinking about repairing costs, the inverter is generally more expensive because of the greater number of parts in the compressor. 


So, depending on budget, frequency of usage, and the costs and convenience of maintenance, fixed speed and inverter air conditioners make the ideal choice. 


Explore our residential air conditioning range here, and see how our expertise can be applied to your business here.


ꟷ Hitachi Cooling & Heating Australia ꟷ