Almost all of us have an Air Conditioner in our home. The demand for ACs is likely to increase in the years to come.

Also, since 1990, there has been a massive increase in the level of Indoor Air Pollution. A continuous decline in air quality has spurred many people to invest in Air Purifiers.

Both these appliances help to clean the indoor air.

But the tool which enables them to purify the air is what we call a ‘Filter’.

In this post, we will cast some light on the various types of filters used in Air Conditioners.

Usage Of Air Filters – An Overview

India homes 11 out of 25 most polluted cities in the world.

Millions of people in the nation’s capital and other North Indian cities wake up to a blanket of thick smog. It compels the strongest of people to stay indoors.

Since 1990, there has been a massive increase in Indoor Pollution also. As we spend most of the time indoors, the chances of inhaling polluted air are higher!

It clearly describes the need and utility of air filters.

Let us understand its utility in a nutshell:

The filters improve the performance of an AC unit as they remove the dust and other airborne particles from the air. These particles block the passage of air which hampers the cooling.

The filters in an Air Purifier removes the smallest of the particles from the air, which may affect the health in the long run.

MERV Rating

Before we discuss the various types of filters used in an AC unit, let us have a look at MERV Ratings.

MERV stands for Minimum Efficiency Reporting Value.

It defines the potency of the air filters.

According to ASHRAE (American Society of Heating, Refrigerating and Air Conditioning), the minimum MERV for air filters is 6.

Also, 16 is the ideal MERV Rating.

MERV Rating

%age of the particles removed


20% of the big particles


20-69% of the large particles


85% of the large particles and 50% of dust


90% of the large particles and 70-90% of small particles


can absorb tiniest of the particles

What Are The Different Types Of Filters Used In An Air Conditioner?

1. Washable Air Filters

As the name depicts, these filters can be washed and reused.

Instead of replacing them, you take them out and wash the dust out of them.

These are environment-friendly.

Electrostatic Filter is an example of washable filters.

2. Electrostatic Air Filters

This type of filter is used in Daikin AC models in India.

It removes the dust particles through an electrostatic charge.

It consists of multiple layers of vented metal through which the air passes. The air molecules get charged as they pass through these layers.

The dust particles remain attracted to the static charge and stick inside the duct line until we clean or wash it.


  • They have a lifetime warranty.
  • They can remove dust, pollen and other airborne impurities.
  • They are cost-effective.
  • You are in charge of how often these filters are to be cleaned.
  • They are eco-friendly. So, it doesn’t add to the garbage landfill.


  • These filters require routine cleanings.
  • You have to pay more while you install these filters. But, its benefits help you to recover the money spent.

3. Disposable Air Filters

These are the air filters which you need to replace or dispose of at regular intervals of time.

For example, Fibreglass Air Filters.

4. Fibreglass Air Filters

These filters are very effective in protecting your AC unit from the large particles but are less efficient in improving air quality.

These are rated between 1 and four on the MERV scale.


  • It protects the AC unit against the damaging particles.
  • These are the least expensive among all the air filters.


  • They do not improve air quality.
  • These are generally avoided if anyone in the family suffers from allergies or other breathing problems.

5. Nano Silver Filters

Indian AC brands like Voltas and Bluestar comes with this type of filters.

It has been known from the times of ancient Greece due to its anti-bacterial properties.

Nano Silver Filters release silver ions which deactivate the bacteria. They not only kill bacteria but also inhibits their growth.

Manufacturers claim these filters can remove more than 600 types of bacteria.


It is beneficial to remove pet dander, pollen, dust, bacteria and viruses. It disinfects the air up to 99.99%.

6. Polyester And Pleated Air Filters

These filters are abundant in surface area and have more fibre per square, which make them more efficient.

The pleated air filter is tighter than a fibreglass air filter.

They remove 45% of the air pollutants in your home.


  • It is cost-effective and durable.
  • It is large. So, it traps more particles.


Since these filters are tighter than the fibreglass filters, your HVAC system will work harder to pull the air through the unit. No doubt, the quality of the air increases, the HVAC system will lose some of its efficiency.

7. High-Efficiency Air Filters

HEPA Filters are the best examples of these filters.

These filters are the most effective in removing the pollutants from the indoor air.

HEPA Filters

These filters have a MERV rating between 14 and 16.

These filters can remove 99.9% of the air pollutants inside the home.

They can remove even 0.3 micron-sized particles. And improve the performance of the AC unit.


  • These are highly efficient filters.
  • They reduce the electricity bills by improving the efficiency of an AC.
  • They remove even minute of the particles from the air.


They are a bit more expensive than the other filters.


Remember, you don’t always need an air filter which has the highest MERV rating to get the best indoor air quality.

It depends on the level of pollution in the locality where you live as well as on the indoor air quality.