Different Types of Air Filters Used in Air Conditioners and Air Purifiers | Explained!

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Air conditioners and air purifiers have become common in India. So, it is essential to know about the different types of filters used in these air conditioners and air purifiers.

Different Types of Air Filters in Air Conditioners and Air Purifiers

Due to the scorching heat, air conditioners have taken an important place. On the other hand, the increasing air pollution calls for air purifiers.

However, before getting into the different air filters, let us have a look at what an air filter is.

What Does an Air Filter Mean?

An air filter is a fibrous and porous device that traps suspended solid, liquid, gaseous particles in the air. These particles can be living, non-living or organic, and in-organic. 

These particles can have a diameter of less than a micron or can be more than a hundred microns. You will find these air filters in AC and air purifiers.

Moreover, air filters are of 2 types active or passive. The active one directly acts on the air pollutants and destroys or deactivates them.

On the other hand, the passive ones capture the pollutants using a filtration panel. These prevent those particles from freely drifting in the room.

However, to get the best results, both active and passive air purifying methods are ideal.

The MERV Rating

MERV is the Minimum Efficiency Reporting Value. It is basically a measurement scale that rates the air purifiers’ particle filtering capacity.

This concept was developed by the American Society of Heating, Refrigerating and Air Conditioning Engineers or ASHRAE.

Nowadays, almost all air filter applications use this scale for measuring the effectiveness of the air filters. 

The table below shows you the different MERV Ratings for different particle sizes.

The MERV Rating Particles’ Size in Microns Pollutants Applications
From 1-4 Above 10.0 micron Dust, pollen, sand, fabric fibers HVAC units
From 5-8 10.0-3.0 micron Spores, pet dander, aerosol mist, mites HVAC units
From 9-12 3.0-1.0 micron Particulate matter, vehicular smoke, lead and humidifier dust HVAC units (hospitals and sensitive workplaces)
From 13-16 1.0-0.3 micron Oil droplets, bacteria, smoke, paint pigments, bacteria OT and Sensitive care unit
From 17-20 Below 0.3 micron Viruses, carbon dust, bacteria, smoke Pharma labs, Pathology research center, electronics

Types of Air Filters in Air Conditioners

In air-conditioners, air filters are essential. It removes the dust particles and plays a vital role in the functioning of the appliance.

Types of Air-Filters in Air Conditioners

If there is no filter then this dust and debris obstructs the air passage and hampers the cooling. Moreover, the efficiency is reduced and affects the electricity bill.

However, with an air filter, you do not have to deal with these problems. Make sure that you clean these air filters by professionals and change them after every 4-6 months.

Electrostatic Air Filters

An electrostatic filter removes dust particles through the electrostatic charge. The magnetic charge effect attracts some debris and other dust particles.

These remain attracted due to the static charge till these are washed and cleaned.

You get plenty of advantages from these electrostatic air filters.

  • Easy cleaning
  • Reduces dust, pollen, and other pollutants
  • Offers lifelong warranty

However, cleaning must be done consistently. This will provide you with undisturbed service for many years.

In India, you find it in Daikin air conditioners.

Nano Silver Filter

This is known for the anti-bacterial quality from ancient Greece. In other words, the Nano Silver Filter is a synonym of anti-bacterial technology.

nano silver filter

It directly attacks and destroys bacterial cells and chemical compounds.

Moreover, when Titanium dioxide is exposed to ultraviolet, it creates electrons in the excited state. 

Later on, this reacts with Oxygen and results in the superoxide ions. Then it reacts with water vapor and produces hydroxyl radicals. 

Superoxide and hydroxyl ions are a great combination in destroying bacteria.

Pleated Air Filters

These air filters are made up of pleats, as evident from the name. It is efficient due to the large surface area and more fiber/sq. 

It traps more particles and removes the odor.

On the other hand, this type of filter is a very durable one and cost-efficient as well.

Benefits of Air filters in Air-Conditioners

  • It provides a longer lifespan to the AC. Therefore, you are relieved of the extra system replacement cost.
  • Easier to clean.
  • Clean and pollution-free indoor air.
  • The AC offers great energy efficiency.

However, before buying an air filter for your AC, just check whether it meets your needs or not. Therefore, before selecting make sure,

  • You select the size according to your AC.
  • The brand value, to get the most out of warranty.
  • Choose a high-efficiency filter. Avoid buying mid-grade filters.

Types of Air-Filters in Air Purifiers

With the increase in air pollution, the need for air purifiers has become a must. There are two types of air purifiers, active and passive.

Active: Here, the air is purified by ionization. The ions are negatively charged through ionization. As a result, the pollutants get attracted to the surface. Moreover, there might be a possibility of Ozone release as well as a by-product.

Passive: Passive air purification depends on air filters. It permanently removes the dust particles and pollutants from the air.

Note: To know more about Air Purifiers, you can also refer to our article Air Purifier Myths Debunked!

Benefits of Air Filters in Air Purifiers

  • Traps respiratory infection-causing viruses and bacteria.
  • It captures mold spores, small particles, and bacteria and helps people who has asthma and other lung allergies.

Different Types Of Air Filters

HEPA Filters

The High-Efficiency Particulate Filter is the HEPA Filter. This technology has been in the limelight since World War II.

It helps you in removing the radioactive particles from the air. As a result, it reduces the danger of respiratory disorders.

HEPA Filter

It is ideal in today’s world where there is so much pollution.

The HEPA filter is capable of removing 99.97% of air particles. Note that even the tiniest one cannot escape it.

Moreover, this air filter is so efficient that doctors even recommend it to patients suffering from lung diseases.

Besides, this can also soak cigarette smoke and odors.

Moreover, the best part of the filtration is that it does not throw the contamination back into the air.

Carbon Adhesive Filter

Carbon Adhesive Filter consists of activated carbons that are tiny pores. This facilitates the removal of pollutants.

However, these cannot function on their own but along with other filters.

The activated carbon filter removes smoke, chemicals, foul odors, gases from the air.

Generally, people have a misconception that houses and rooms have no pollutants and have no chemical content. However, there are a lot of contaminants inside your room.

For example, you find a lot of chemicals in furniture, oil paints.

On the other hand, pet odor, moisture. These make things uncomfortable inside, and the best ventilation system fails to remove such pollutants.

In such a case, activated carbon is the most effective.

However, it is not that effective, when it comes to dust particles or other tiny organisms.

Ultraviolet Light Air Filter

These filters act like destroyers. The UV Light destroys the enemy (bacteria). Besides, it annihilates viruses, molds, and yeast.

Thus, this cleaner is useful in hospitals where there are more cases of infections, diseases. 

However, it fails to remove dust, solid particles, or allergens in the air. These air purifiers effectively remove cigarette smoke, foul odors, chemical fumes, and other such particles.

Catechin Filter

It is an antioxidant that belongs to the flavonoids chemical group. It comes with medicinal properties.

Catechin filter

Moreover, catechin filter is efficient enough to fight the virus and kill bacteria. It is capable of removing smoke odor, pet odor, and pollution. 

Besides, the microscopic bacteria and viruses are eradicated.

Moreover, it is a durable one, and with proper maintenance and cleaning, the filter lasts for one decade or more.


This filter is like a layered filtration or double filtration. Basically, it acts like a wall that stops the larger particles from entering the primary filter.

As a result, there is less load on the internal filter.

Eventually, the filter’s lifespan increases, and therefore, it lowers the cost in the long run.

As it acts as armor, it takes the first blow from dust, pollen, and larger debris, hair furs. Therefore, the capacity of the filter increases.

You get this in one piece or come attached to the carbon filter. Moreover, it can be washed and reused.

The Anti-bacterial Filter

From the name, it is understood that this filter kills and destroys bacteria present in the air. It is like a crumple carton that is similar to a mesh.

Anti bacterial filter either comes in one-piece or with HEPA filter.

These filters destroy anti-allergens and dust-mite. It is a nemesis for micro-organisms that are spread all across the room.

Moreover, these filters use ultraviolet rays to kill germs and bacteria.

Photocatalytic Filter

The photocatalytic filter makes use of photocatalysis to purify the air. It works when the ultraviolet light falls on titanium dioxide.

As a result, the electrons get released.

Photocatalytic filter

These electrons react with the water molecules in the air. As a result, it creates hydroxyl radicals.

Now, these hydroxyl radicals act as the primary weapon to attack the enemy that are the pollutants. Then it neutralizes the contaminants and makes them non-toxic.

This entire method is called PCO, which is Photocatalytic Oxidation. It helps in killing air pollutants and is safer.

It removes a lot of air irritants that cause lung infections or sore throat. Besides, it eliminates viruses, bacteria, and mold.

Vitamin C Filter

This Vitamin C filter, besides being a filter, is a therapy as well. It is a potent antioxidant that nullifies the free radicals in the skin.

Vitamin-c Filter in air conditioner

Due to these free radicals, there is aging in the skin.

However, Vitamin C revitalizes the aging skin. Along with it, it makes your skin gentle and soft thus, acting as a stress buster.

The Anti-VOC Filter

VOC is Volatile Organic Compounds. People around might be sensitive to VOC as it might cause headaches or nausea.

Basically, these are carbon-containing compounds that have been emitted out of pesticides, paints, or new furnishing at home.

However, this might have a long term effect on your health.

If there is poor ventilation and you are staying indoors, then it can be harmful.

The poisonous gases have no escape route and circulate inside the room for an extended period.

anti bacterial filter

This might affect your health. You might have a runny nose or watery eyes.

However, in such a case, an Anti-VOC filter makes a difference. It eliminates impurities and eliminates hazardous gases.

PM 2.5 Filter

The PM here refers to the particulate matter and the 2.5 refers to less than 2.5 micrometers.

This PM 2.5 filter filters these extremely tiny microparticles. It has a Polytetrafluoroethylene membrane that decreases friction and wears and tears.

pm 2.5

This membrane has also been used on non-stick pans in order to capture these particulate matters. It has now been a benchmark to gauge industrial hygiene and workplace safety.

This membrane is applicable in gauging the air quality through the EPA test method

This PTFE is basically a soft flexible material that comes with 2.0-micron pore size. This is efficient to capture 2.0 micrometers of particles.

Final Words!

Air filters thus are an essential part of AC and air purifiers. It protects us from harmful particles and increases the efficiency of the machine in the long run. 

However, just check everything before buying any of these appliances.


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