Do Air Conditioners Filter Pollution? Aircon Facts & Myths Explained

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Yes, air conditioners provide us with comfort during warm weather. But do air conditioners filter air pollution and help improve indoor air quality?

This and other popular aircon-related questions are what we will answer below.

Let’s get started.

1. Does using an aircon unit improve indoor air quality?

Whether running the latest energy-efficient AC units or using an older model, the belief that an aircon unit can improve indoor quality is a myth and a misconception.

The truth is that air conditioners do not purify the air nor help improve indoor quality (IAQ).

Instead of purifying air, AC units are designed to cool indoor air temperature and reduce heat in a room.

How do air conditioners work?


While air conditioners come in a variety of types, shapes, and sizes, they all operate on the same basic principle and all have 3 key components:

  • A refrigerant to cool the air
  • A compressor to compress the refrigerant
  • A fan to move the air within the AC unit

For a clear comparison, air conditioners work similarly to refrigerators. Here’s how:

  • An air conditioner unit draws in warm air from inside the room.
  • A fan blows the warm air to an evaporator coil filled with refrigerant.
  • The refrigerant removes heat from the warm air; this process cools the air and transforms the refrigerant into a gas state.
  • The cooled air is recirculated throughout the home while the refrigerant (now in gas form) travels toward the compressor.
  • The compressor constricts the gas-form refrigerant, increasing its temperature and pressure.
  • The gas refrigerant moves toward the condenser located outside of the home.
  • The refrigerant is exposed to the air outdoors.
  • The heat is absorbed from the refrigerant by outdoor air and would return to its original liquid state.
  • The liquid refrigerant travels back toward the evaporator coil.
  • The entire process of cooling the warm air repeats again.

The short video below will also clearly explain how air conditioners work:

So to answer the question: Does than air conditioner provides clean air?

The answer is no – just cool air.

2. Do air conditioners filter pollen and dust?

Aircon units can’t filter chemical and biological air pollution.

However, installing air filters in your HVAC system can remove some physical contaminants from the indoor air, such as dust and pollen.

Air filters can sieve air contaminants for a short duration. However, they aren’t reliable in filtering microscopic and tiny allergens.


Cleaning your AC unit regularly and changing your air filters at least every two weeks can protect you and your family from dust and pollen.

Moreover, air conditioner with HEPA filter (High-Efficiency Particulate Air) and higher MERV (Minimum Efficiency Reporting Values) rating are better able to filter particles and finer air contaminants.


So, do air conditioners filter pollution?

Answer: Air filters, not the air conditioning unit itself, can help clean indoor air.

That being said, most of the top-rated air conditioners in the market today have an air filter located in the return air section of the unit.

3. Does air conditioning clean air of smoke?

We reiterate that the primary purpose of an air conditioning unit is to cool the indoor air and not to purify the air or remove smoke inside a home. 

However, newer AC units have filters and improved features that can slightly purify smoke.

Granted that you keep the filter clean, your AC unit should somehow help reduce smoke particulate in the air.

Now you might wonder:

Does air conditioner work as air purifier?

The answer is they don’t and don’t try to use your AC unit as an air purifier.

4. Is air conditioning harmful to health?

According to some sources, AC units offer relief from the summer heat but can become a severe health risk.

If not properly maintained and regularly cleaned, air conditioners can cause indoor air contamination that contributes to respiratory ailments, colds, fevers, headaches, and fatigue.

So we highly urge you to regularly clean your AC unit.

Do aircon filters stop Covid?

Yes. Air filters of AC units can reduce indoor air pollutants, including airborne contaminants and viruses.

However, according to the EPA (the United States Environmental Protection Agency), the filtration system or AC units are insufficient to protect people from COVID-19.

5. Does window AC bring in outside air?

One of the most common misconceptions people have about air conditioners, especially wall-mounted air conditioners, is they will bring in dirty air from outside.

Hence, some people choose not to use their AC even if it is too hot during days with bad air or if they are currently staying in a city with heavy air pollution.

But the truth is, most window air conditioners don’t pull air from outside.

AC units simply cool, filter, and recirculate the air that’s already inside your home.

There is even a study conducted by someone from China that proves the air coming out of their AC unit is no different in quality from the ambient room air.


But you might be thinking?

“Why do window air conditioners stick outside of your home? Or why do you need to vent your portable air conditioner?”

An AC unit needs a vent to let hot air outside. They serve as an exhaust of hot air rather than a gateway to bring outside air in.

But full disclosure, some AC units do pull air from outside.

Air conditioners with a “Fresh Air Mode” mode will draw in outdoor air.


Final Thoughts

Air conditioners have become a part of our daily lives.

And while they provide ease and comfort during hot summer days, air conditioners do not filter pollution.

Air conditioners also do not purify air but rather, remove heat from indoor air.

But like we discussed above, newer aircon models today are not only energy-efficient and helps reduce energy consumption.

More importantly, they also come with air filters that sieves dust, smoke, and other air contaminants.

Until here and we hope this article has provided you with useful information regarding aircon units and what they can do for you.

If you have more question about your AC, let us know in the comment section below.

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