Importance of auto-clean feature in air conditioners explained

Many ACs today come with an auto-clean feature, which uses complex mechanisms to get rid of unwanted dust, dirt and other particles inside the AC. If you’ve ever been curious about how the auto-clean feature works, here’s a quick breakdown for you.  

How the auto-clean feature works in ACs

Auto cleaning or self-cleaning air conditioners use the cooling mechanism of the AC itself to clean dust, debris, and other dirt that accumulates inside the machine. Usually activated on a timer, the auto-clean function kicks in and starts freezing the heat exchanger. Once it’s cold enough, water vapour in the surrounding air freezes solid around the heat exchanger, forming a thin layer of ice.  

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This ice traps dust, dirt, and even microbes such as mould. When a certain amount of time has passed, the heat exchanger coil heats up and the water melts away, carrying the dirt with it. This water is then drained automatically. 

The internal temperature does drop significantly during this process so the air flow to the room is usually stopped while the auto-clean cycle is completed. 

Self-cleaning filters

While this process cleans and dries out the inside of the AC, some ACs take things a step further by cleaning the dust filter as well. This dust filter is present in the indoor unit on split ACs and on the front panel of window ACs. Its purpose is to filter out dust and microbes in the air while warm, untreated air is being drawn into the AC for processing. 

These filters are quite large and can get clogged quickly in dusty environments, or even when you have furry pets. In a humid environment, the dust and fur that’s trapped in the filter can grow mould and attract microbes, serving as a source of contaminants. 

The normal process of cleaning these filters involves powering off the AC, and manually accessing the filters and vacuuming or washing them. Some modern ACs get around this problem by including a brush mechanism that runs along the surface of the filter and cleaning out accumulated dirt. This dirt is then dumped into a waste bin which the user can later dump. 

​​Effectiveness of the auto-clean feature

Both processes clean out accumulated dirt and microbes and help improve not only the quality of air that you’re breathing, but also the life of the AC. This is because accumulated dust and dirt impedes airflow and reduces the effectiveness of the heat exchanger. Additionally, the number of maintenance visits required to keep your AC running in top form will be significantly less. 

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Do note that auto- or self-cleaning technology is not a substitute for routine maintenance. That last is still required, and it’s best to follow the manufacturer’s guidelines for doing so. 

An AC with a built-in auto-clean function will always be preferable to one that doesn’t have it. Most ACs will be able to auto-clean the heat exchanger, but it’s usually only the expensive ones that have a self-cleaning dust filter. However, a self-cleaning filter, while convenient, isn’t nearly as useful as a self-cleaning heat exchanger as dust filters are generally easier to access and clean.