How Air Purifier Works – A to Z Details

Before we get into the details of how air purifier works, we must know about why air purifiers are needed. 

Air Purifiers have become the need of the day especially in highly polluted cities in India. In some areas even if the outside air seems to be fine, the dust, smoke and other harmful particles that affect our health are usually part of Indoor Air Pollution and not outdoor. 

There’s a reason we all must know how air purifier works because these devices can purify the indoor air and create an environment of fresh air around us.

Sources of Indoor Air Pollution

But there are many types of pollutants present in the air. Moreover, there are many types of technologies used by various air purifiers.

So, the common question arises in our mind, ‘How do Air Purifiers work’

In simple words, the air around us is sucked and passed through the filters that are present in the purifier device, trapping all the pollutants, which allows clean air to pass through it. This is how air purifier works.

Need of Understanding Purification Process

It is necessary to understand the Basic working model of air purifiers and the exact purification process of each technology used

Because the causes of air pollution are different after every 500 meters. And if you want pure air at your home, you need to understand the pollutants present in your area as well as the best technology to tackle this pollution. 

So, let us first analyse the type of air pollutants present indoors.

“ Indoor air is two to five times dirtier than outdoor air. And in few cases, it’s up to 100 times dirtier – Full of pollutants harmful for human health”

Environmental Protection Agency (EPA), USA based Agency

Many scientists have proven that 80% times it is the polluted indoor air that harms our respiratory system more than the outdoor air and the sad part is, it is the most neglected fact and is never taken seriously.

The main reason for it is the air concentration. If highly concentrated air stays in a room, it can severely affect your respiratory system.

This is why you should know how air purifier works. Given below are the pollutants and its sources.

Various Air Purifiers have different technologies to tackle each of these pollutants. So, let us analyse the working model of air purifier by analysing processes going on at the back end.

How Air Purifier Works?

Air purifiers basically consist of fans or pairs of fans designed in an aerodynamic shape which create a low pressure area during its functioning. 

This low pressure area results in the suction of air present in the room which is further released after purification. 

After suction of air from the room, it is made to pass through a filter or pair of filters made of various materials specially designed to remove specific pollutants present in the air. 

Other technologies like Ionic, UV filtration, Plasma cluster technology also act on the air at this stage of filtration after which purified air is released back in the air. 

But the most advanced and safe filtration is by using True HEPA Filters. Therefore you must use an air purifier that contains True HEPA Filter.

The whole process of Air Filtration happens with an average speed of around 400 meter cube air purification in 1 hour (depending upon the type of filters and technology used in purification process)

Basic Working Model of Air Purifiers

Basic Working Model of Air Purifiers

This was the basic working model of all Air Purifiers used in earlier times. But its simpler working would give you a clarity on how air purifier works.

Now, due to various advancements, different air purification technologies are used to enhance the quality of air by removing life threatening pollutants, but the basic mechanism remains the same.

Types of Air Purification Technologies and How do they Work

1. Basic Filters or Pre-Filters

Low end air purifiers contain basic filters which restrict the passage of coarse particles through the filter. This is a very basic mode of air filtration or pre-filtration process which acts as a first filter to the room air which is then forwarded to further air purification processes

These filters are usually part of the air purifiers which are used in heating or cooling systems fitted between air return ducts and the furnace. Its major work is to prevent damage to the furnace due to dust and dirt build-up.

Basic Filters or Pre-Filters

Only the large particulates get trapped into this pre-filter as this filter is just for the purpose of damage prevention for the internal parts and other main air filters from the large sized pollutants.

Material used in making these filters is usually foam, fiberglass, synthetic fibers or even cotton. (Type of material may vary based on the need of purification levels). 

Denser the filter, lesser is the area for air passage and more is the air purification obtained.

2. Activated Carbon Air Filter

Activated carbon air filters are obtained from plant materials like wood, coconut shells or coal which act as natural activated carbon filters

These carbon filters consist of small pores between the carbon atoms which act as a micro filter for pollutants. They can even trap chemical fumes, odors along with suspended pollutants in the air.

Activated Carbon Air Filter

Spacing between the carbon atoms acts as unlimited pores on the carbon filter (for efficient filtration). These filters capture particles even smaller than the smallest gaps in the filter material. 

It is highly absorbent and does not release captured pollutants back into the air. Just make sure you change these filters periodically to avoid choking and efficient air purification.

Therefore, if you are surrounded by bad smell, an air purifier with carbon filter will do the job for you. Also, it would enhance the Air Purifier working.

3. HEPA (High Efficiency Particulate Air) Filters

Air purification strength of HEPA filters is maximum which makes it the most commonly used filter in high quality air purifiers. 

It is made of fiberglass (in most of the cases) which are 99.97% infiltration of pollutants as small as 0.3 microns. Even more efficient version of this filter, that is, ULPA (Ultra-Low Penetration Air) helps in extreme filtration. 

Fact: HEPA air filters were invented in World War II with the motto of removing radioactive contaminants produced as a byproduct of the atom bomb preparation process.

HEPA Air Purifiers are life saviors and one just can’t imagine how air purifier works without a HEPA filter. So, if you have a True HEPA filter with a high purification technology in your air purifier, you can be confident about the good quality of air produced from your purifier. 

Furthermore, HEPA Filters used with a mixture of air filtration technologies can also remove bacteria, germs and viruses as small as 0.02 microns. Some of these Air Purifiers with HEPA Filters can also remove H1N1 Swine Flu virus and Influenza virus.

Check detailed article on HEPA filter including HEPA Air Purifier which is a must read before buying any purifier.

4. UV Light Action

UV lamps are present along with the conventional filters provided above. Role of UV lamps is to kill germs, bacteria and viruses through ultraviolet light action. 

It’s not an alternative to HEPA filter, but it is an add on to kill bacteria and viruses which cannot be tackled with the help of some filters alone. This is also an important add on to kill bacteria and viruses if at all those get trapped by advanced filters inside the air purifier. Therefore using these air purifiers that kill viruses are worth.

If you have a UV Lamp present in your air purifier, then the spreading of illnesses and diseases is completely prohibited which adds a ‘healthy factor’ to the air purifier. Generally Germicidal UV Lamp is used for UV action

UV Light Action

5. Ionizing Purifiers

Ionizing purifiers use different and unique type of technology than conventional filter mechanisms. It can be an alternative to HEPA filter for air purification but it is not recommended if you are buying air purifier for your home or office. 

Ionizers are usually used in larger spaces like community halls, malls, etc whereas HEPA Air Purifiers are mostly recommended for Home, Car and Office Purposes.

Air present around us has a neutral charge (neither positive nor negative). Ionizer creates positive and negative charge in air for the sake of air purification. 

Air ionizer operates by emitting negatively charged ions (anions) into the surrounding air. These negatively charged ions attract positively charged ions like allergens, dust, mould and bacteria.

They react and form a bond which settles at the bottom of the room which can be absorbed in the air purifier with the help of vacuum. 

This process emits ozone gas which is harmful for our body and therefore we can easily inhale the gas if the room is smaller. If the space is larger ozone gets diluted and doesn’t highly affect us. Therefore, Ionizer Air Purifiers are not recommended in smaller spaces.

Are Air Purifiers a Waste of Money?

No. It’s worth investing for a healthy and better life. The current technologies used in air purifiers are capable enough to generate more than 97% of pure air even in highly polluted cities of India. 

The only thing is that you must know which type of air purifier to buy as per air pollution levels in your locality. Now that you know how air purifier works, you must also learn to customize the settings of your purifier. 

These air purifiers are highly beneficial (and we feel are must) for people suffering from asthma and families which have small children, pregnant ladies and senior citizens who are more prone to air borne diseases.

These air purifiers also work best to get rid of pet hairs, smoke and pollen present in your house. 

Ever wondered the reason behind your unnatural coughs or sneezes even when you don’t have any illness, it is because of these pollutants. Therefore, you must know how air purifier works and you must have an air purifier at your place.

Myths of Air Purifier

These are the 7 myths of Air purifiers which are busted today by understanding the working model and functioning of air purifiers (and technologies used in them). 


Hopefully you are now aware of “how do air purifiers work” in purifying the indoor air.

Considering all the must-haves and must-not’s, we have selected the best air purifiers especially for air conditions in India. We must tell you, these are the most trusted & recommended ones. Buying them is truly a no brainier. 

Coway Sleek Pro AP-1009

Coway Sleek Pro AP-1009

Philips AC2887 20 Air purifier

Philips AC2887-20

Dyson Pure Cool Link Tower Wi-Fi-Enabled Air Purifier, TP03

Dyson Tower TP04

If you have any questions, let us know in the comments.

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