Different Types of AC Filters Simply Explained

Air filter plays an important role in the energy efficiency and lifespan of an air conditioner. Apart from that, it also impacts the indoor air quality as well. However, they are often overlooked.

If they are not properly maintained or replaced as per schedule, then it can lead to several problems in the working of an air conditioner. And you may have shell out money on professionals for ac repair.

In this article, we have provided information on air filters, their efficiency, maintenance, working mechanism and others.

Functioning of AC Filter

The cool air developed by air conditioner will pass through the air filter before releasing into the ducts or room. The filter will remove dust, grease, smoke and other impurities. When these filters get clogged up with impurities, it obstructs the air passage.

So, air conditioner will consume additional power to deliver cool air flow which results in higher electricity bills. Clogged filters will also affect the delivery of cool air. So, you have to decrease the temperature or increase the air flow unnecessarily. This further leads to additional power consumption and finally higher power bills.

If the filters are not cleared on a regular basis or replaced for a long time, then it can lead to issues with motor and other parts as well. So, it is very important to change (if disposable) or clean (if reusable) once in every 3 months.

Types of AC Filters

There are several types of filters commonly used in air conditioners. We have mentioned them below with a detail description of each type.

1. Electrostatic Filters

They are also called as reusable or washable filters. They contain multiple pleated layers with aluminum frame. When the air passes through the first layer, the friction between the air molecules and filter will create static electricity and charge the physical contaminants positively. As they pass through different layers, positively charged contaminants will attach themselves to the filter. So, only pure air will come out of the final filter layer.

It is designed to trap almost 80 to 90% of the physical impurities like pet dander, dust, smoke, mold spores, bacteria and others that are often present in indoor air. The MERV rating for electrostatic filters is between 1 to 4. They can trap particles that are more than PM 10.

Easy to clean and maintainTakes time to clean the filters
Cost-effectiveIf clogged, they block air flow more than other filters.
Can remove impurities larger than PM 10
Doesn’t need frequent replacement
Improves air flow
Traps 80% to 90% of physical impurities

How to Clean Electrostatic Filters?

These filters should be cleaned once in every 4 to 6 weeks based on the pollution levels or indoor air quality. As cleaning process electrostatic filters is higher, it is recommended to do it when you are free for the day. Don’t do the cleaning process if you are in a hurry or have another appointment. Below is the step-by-step process of cleaning the electrostatic filters.

  • Turn off the air conditioner.
  • Carefully open the AC and remove the air filter.
  • Now pour water in the opposite direction.
  • Use higher pressure for a thorough cleaning.
  • Now rinse the filter using mild soap water from another side.
  • If there are any tough stains, you can use specific cleaners.
  • Wash again with plain water.
  • Drain the excess water and place it under shade for drying up.
  • Once the filters are completely dry, you can replace them in the air conditioner.

Verdict – If you or any person of your family is dealing with allergies, then this is the perfect filter to improve indoor air.

2. HEPA Filter (High Efficiency Particulate Air)

HEPA filters are capable of trapping 99.97% of impurities or pollutants that are 0.3 micrometers in diameter. This filter is specially designed for removing fine, coarse and invisible particles in the air. Some of the pollutants it can remove are pet dander, pollen, dust mites and others. A HEPA filter contains randomly woven fibers (each 0.5 to 0.2 micrometers thick). These fibers are slightly larger than the particles they have to trap.

Can trap 99.97% of pollutantsCannot trap odors, chemicals and gases
Can remove particles more than 0.3 micronsExpensive to replace
Some are washable while some are not

Cleaning or Replacement:

Usually, HEPA filters have to be replaced instead of cleaning. However, if you want to clean it between the replacement period, then there are two different ways to do it. Choosing between these two methods is usually based which type of HEPA filter you have. Usually, manufacturer’s mention as washable or permanent.

If it is mentioned as washable, then you can clean it by rinsing under cold water. However, make sure to avoid touching the filter material. Before re-installing it, make sure to clean it properly. Some manufacturers provide special instructions on how to clean. You can also follow those guidelines.

If it is mentioned as permanent, then you can just clean it gently using a vacuum cleaner to suck out the debris and dust collected in it. Water should never be used for cleaning these filters. Usually, replacement duration of HEPA filter is once in every 6 months.

Our Verdict:

HEPA filters are usually suitable for people who are dealing with sensitivities and allergies, if there is a lot of traffic in a room or if the area is prone to have high pollen content in the air.

3. PM 2.5 Filter

PM 2.5 refers to pollutants that are less than 2.5 microns in size which is 3% of human hair. PM 2.5 filter is specially designed for removing particles smaller than 2.5 microns. Continuous exposure to PM 2.5 pollutants are worsen the health, especially for people dealing with asthma or bronchitis. These pollutants can also help in plaque deposits in arteries and lead to heart attacks.

This filter usually comprises of five different layers. 1st and 5th layer is made from spun-bound polyester material which will filter out large particles. The middle layer which is the 3rd one is activated carbon layer. It will trap particles using adhesion process. The 2nd and 4th layers are made from melt-down polypropylene which will filter out small substances.

Can remove minute pollutantsNot washable
Less expensive compared to HEPA filters

Cleaning or Replacement:

It is not recommended to clean PM 2.5 filter because even after washing it, the pollutant will remain in the filter. And as these pollutants are less than 2.5 in size, they are hard to see. So, you have to replace the PM 2.5 once in every few months or as per the manufacturer guidelines.

4. Anti-Bacterial Filter

This is one the prominent air purifying filters often used in air conditioners. They either come as a single filter or in combination with HEPA filter. As their name implies, they will destroy bacteria and other microorganisms present in the air.

It is designed in a way to kill bacteria and trap dust particles using positively charged elements. This filter contains microscopic pores which are efficient in trapping dust and other pollutants.

Can trap dust, pollen and irritantsShort lifespan
Improves air quality
Removes bacterial, virus, spores and microbes
Improves lifespan of AC
Economical to use

Cleaning and Replacement:

Anti-bacterial filters need frequent replacement. They can be cleaned and reused as well but only for certain time duration or between the replacement schedule. For cleaning, you can just wash them under running water and re-install them after completely dry. You have to replace them once in every 3 to 4 months.

Our Verdict:

This filter is suitable for localities with humid climatic conditions where moisture content is high as it will help in the growth of microbes.

5. Catechin filter

Catechin filters have antibacterial and antiviral properties. Actually catechin is an element derived from green tea leaves. It is applied to every molecule of the filter. When the air passes through it, pollutants like tobacco, pets smell, and gases are removed. It also traps bacteria, microscopic virus and other microbes that pollute the air.

Removes odors and smells of tobacco, paints and others.Expensive
Traps microbesStill more research is required to conclude its potential
Helpful for people dealing with asthma

Cleaning or Replacement:

Catechin is actually an element added to filters. So, you have to check the replacement details of the filter or the instructions provided by the manufacturer.

Our Verdict:

It is suitable for people who deal with breathing problems like asthma. As this element is an eco-friendly material, it is better for atmosphere as well.

6. Activated Carbon Filter

As the name implies, this filter contains activated carbon. It eliminates odors and gases present in the air. It uses adsorption technique which involves chemicals reaction between the pollutants and activated carbon pores. This process will make them to stick to the millions of pores present in the filter. Some of the pollutants it can trap are smoke, gas, paint fumes, odors, and others.

Trapping VOCs and harmful gasesCan trap only chemicals that attract to carbon.
Removes terrible odorShort lifepsan
Eliminates dangerous chemical fumes like ozone, carbon monoxide.Cannot trap bacteria

Cleaning or Replacement:

If the manufacturer has not mentioned as washable, then you should never wash the carbon filter. Usually, carbon filter has to be placed once in every 3 months. If the manufacturer has mentioned as washable, then you can wash it with soap water under sunlight.

Our Verdict – It is suitable for areas where there is a lot of pollution caused by smoke or other bad odors.

7. Anti-VOC Filter

VOC represents volatile organic compounds. They are usually emitted by things like detergents, adhesives, paints, building materials and so on. The main objective of anti-VOC filters is to prevent the recirculation of VOCs into the indoors.

Trapping VOCs and harmful gasesCan trap only chemicals that attract to carbon.
Removes terrible odorShort lifepsan
Eliminates dangerous chemical fumes like ozone, carbon monoxide.Cannot trap bacteria

Cleaning or Replacement:

It is not recommended to clean or re-use anti-VOC filter as you cannot wash away volatile organic compounds. It is better to change the filters every 4 to 6 months.

Our Verdict:

Anti-VOC filters are suitable for offices, paint shops, or areas where the pollution is caused due to gases or chemical fumes.

8. Nano Silver Filter

This filter is capable of removing bacteria, virus, fungi, spores and other microbes. It filters them out by using silver ions. The silver will not only kill the bacteria but also stop further growth of microbes by destroying their inner configuration or absorbing the cells. This filter can remove more than 600 types of bacteria in the air.

Perfect alternative for activated carbon filtersExcessive exposure to silver ions can make the bacteria resistant to it.
Removes bacterial and other harmful microbesEnvironmental concerns are also associated with it
Stops the growth of microbes
Removes pet dander, dust and pollen
Takes less space

Cleaning or Replacement:

They are self-cleaning filters so you don’t have to worry about cleaning. however, you may have to replace them once in every 3 to 4 months based on the usage or as per the manufacturer recommendations.

Our Verdict:

They are suitable for areas where there is a high chance of bacterial growth like humid climatic conditions or if people are dealing allergies.

Few Words to Conclude…

Filters are one of the important components of an air conditioner. If these filters are clogged or have stopped working, then many issues rise within the AC. Filters have direct impact on the efficiency of the air conditioner. So, you have to clean them regularly or replace them as per their schedule to make the air conditioner works fine.

For any questions, write to us in the comment section below. We will reply to them at earliest convenience.