Air Purifier Buying Guide India: How to Select the Right Air Purifier for your Home? (2022)

Most people are uninformed about the importance of indoor air quality. However, according to research conducted by the World Health Organization (WHO), nearly 1.3 million people die due to indoor air pollutants and poor ventilation in India. 50% of deaths in children under 5 years of age are due to poor air quality. Likewise, old people and children are widely affected by air pollutants due to their weak immune systems.
Not many people know, but indoor air can be 2-5 times more polluted than outdoor air, especially if you’re living in a metropolitan city or in a heavily urbanised area. In fact, India houses 13 cities out of the world’s 20 most polluted cities.
Some of the key sources of indoor air pollution are mould, pet hair, bacteria, tobacco smoke, mildew, dust and dust mites, pollens, plant fungi, etc. These air pollutants can lead to various hazardous health problems such as asthma, allergies, and other respiratory issues. As per research, ⅓ of the world’s asthma patients reside in India.
That’s when air purifiers come in!
In this post, we will be explaining what to look for when buying an air purifier for your needs:

Now air purifiers come in all sizes, shapes and types. The basic factors you need to look for in an air purifier are its ability to detect pollutants, clean the air using ideal filters and circulate clean air across the room. Premium air purifiers are capable of trapping up to 99.7% of air pollutants that could enter your lungs or nasal passage, leading to chronic respiratory diseases.
What is an Air Purifier and how does it work?
The air purifier is an air cleaning system that uses a specialized filtering process to trap microscopic particles such as bacteria, pet hair, dust mites, mould, mildew, toxins from sprays, VOCs found in new carpets, and paint and varnishes and so on. Medically, air purifiers are termed effective in reducing allergy symptoms, and asthma and improving your breathing and sleep.
How does an Air Purifier work?
The primary technology used in air purifiers is a “filter”.
- Pre-filter: The web-like structure of the pre-filter blocks large particles.
- HEPA filter: The air further passes from the primary filter to the HEPA filter that blocks PM 2.5 particulates such as damaging bacteria, dust mites, mould, pollens, wood smoke, etc.
- Carbon filter: partially cleaned air passed from HEPA filter further goes through the specially treated carbon filter that effectively removes household odour produced due to cooking, garbage, sprays, cleaning chemicals, etc.
- UV lamp: Lastly, the clean air goes through UV light to kill airborne microorganisms, germs, flu and pathogens such as bacteria, mould and viruses.
The rest of the machine looks after the air inflow and outflow, and its flow rate is based upon the blower function and filter’s ability to clean the air.
In short, it’s all about selecting the right filter.

Air Purifier Buying Guide: How to choose the right air purifier for your needs?
Room Size
Not all air purifiers are made equal; each differs in its power and ability to purify the air. The major factor that affects its ability to clean air is the room size. It is better to choose an air purifier that can efficiently operate in a room that is 20-40% larger than the room you’re planning to use it in. This way, you can run the air purifier optimally on its low setting, with less noise and less energy consumption.
If you’ll be using it in your bedroom, choose a model with low noise level. Make sure to consider the height of the room as well when selecting an air purifier.
Small room up to 155 sq.ft. | Medium room up to 300 sq.ft. | Large room up to 500 sq.ft |
---|---|---|
Perfect for nurseries and small rooms | Perfect for bedrooms | Perfect for large living spaces or large rooms |
Recommended size: Mini Tower or Desktop | Recommended size: Tower | Recommended size: Tower or Console |
You can check the top-selling air purifiers below 15000 here.
Types of Filter
Most air purifiers in the market today use two major types of filters viz. Composite and HEPA (High-Efficiency Particulate Air) Composite.
- HEPA filters are a highly recommended choice for air purifiers as they are best capable of mechanically separating the air pollutants from the air. Good quality HEPA filter removes 99.7% of particulates with less than 0.02 microns in size such as dust, mould spores, pet hair and dander and pollen. Larger the HEPA filter, the more particulates it will be able to trap. The size, construction and material of the filter also play a vital role in its performance. HEPA filters come in various grades, and the ones made for homes generally have H-11 to H-14 grades. The H-13 grade filter is good to use in moderately polluted areas, while the H-14 filter grade is recommended for worse environments.
- Activated Carbon Filters are often used in combination with other filter types, but rarely on their own. Such activated carbon/charcoal filters can absorb gases and odours, thus reducing fumes, smoke or chemicals. These filters work by reacting to the oxygen and thus open up millions of pores that will trap a large amount of odour, chemical and gas molecules. Once these filters are saturated, you need to replace them.
- Antibacterial and Germicidal filters help to remove harmful germs and bacteria. For this, such filters use UV light along with HEPA filters. Mostly, these types of filters are used in day-care schools, labs, kitchens and hospitals to reduce the risk of airborne infections. However, these need to be replaced every 3 to 6 months. Modern units come with an LED indicator that signals that the filter needs replacement.
- Charge Media Filter: In this type, the particle filter works with an electrostatic charge filter to trap particles that are as small as 0.1 microns. These are highly efficient but require frequent replacements.
- Photocatalytic Oxidation (PCO) uses a metal plate coated with titanium dioxide in combination with UV light to oxidize and mechanically break down chemicals. The large chemical molecules break down into the water and harmless carbon dioxide molecules.
- Electrostatic Precipitators work similar to the charged media filters, the only difference is that here the particulates precipitate and gather on the collector plates instead of trapping in filters. You can easily wash and clean these plates and they don’t need to be replaced.
- Pre-filters: As the name suggests, pre-filters are used as an add-on filter before the main filter to collect large pollutants such as dust, pet hair, human hair, etc. Often, these are made from non-woven polyester or foam and are designed to improve the life of HEPA filters or activated carbon filters. Plus, you can even wash these filters.
- Ion and Ozone Generators: These purify the air by dispersing negatively (or positively) charged ions into the air. These ions cling to the particles in the air, making them negatively (or positively) charged, so the particles become heavy and attach to nearby surfaces such as furniture or walls. Such units are found less effective in removing particles of fungal spores, smoke, pollen and dust. One thing to remember is that these air purifiers may produce Ozone gas which is dangerous to inhale.
The important thing to note is that HEPA filters are the ONLY type of air purifiers that meet the EPA standard for safety and efficiency, hence are widely used.

CADR (Clean Air Delivery Rate)
CADR is an important factor to consider that directly affects the performance of the air purifier, as it defines the level of purified air produced by the purifier. It denotes how many cubic feet of air the unit filters in one minute for various pollutant categories such as smoke, dust and pollen.
Choose an air purifier with higher CADR, as it will signify higher purifying capacity.
ACH (Air Changes per Hour)
The ACH denotes the number of times the filter purifies the air of the room it is installed in within an hour. If you reside in a metropolitan city like Mumbai, Bangalore or Delhi, choose an air purifier with a minimum of 4 ACH, which means that it will clean the air fully every 15 minutes.
Indoor AQI (Air Quality Indicator)
All air purifiers with AQI use sensors to monitor the air quality in the room and show you the AQI metrics. These metrics are generally based on PM2.5 particles or overall air quality. The PM2.5 and smaller microscopic pollutants are most hazardous as they can deeply enter into our lungs or the bloodstream to cause various critical health problems.
A few high-end units come with an auto mode function that automatically adjusts speed based on the air quality.
AQI metrics | Related Health Problems |
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0-50: Good | Minimal effect |
51-100: Satisfactory | Minor breathing issues to sensitive people |
101-200: Moderately polluted | -Breathing discomfort to people with heart disease or lung problems such as asthma
-Affects older people and young children |
201-300: Poor | Breathing discomfort to people with heart disease or who are exposed for a prolonged time |
301-400: Very Poor | May cause respiratory impact to the people exposed for a prolonged time, especially if they already have a lung or heart disease |
401-500: Severe | May cause respiratory illness to even healthy people. It can severely affect people with lung or heart disease. |
Bad AQI metrics can cause hazardous effects to your health, hence it is important to choose an air purifier that shows you the current indoor AQI. Another good feature to consider is IoT connectivity or mobile app support. New models from the top brands like Xiaomi and Dyson integrate with your mobile app to allow users remotely control the unit and monitor the air quality in the room.
Check the best air purifier models available for purchase now.

What are the Best Brands of Air Purifiers in India?
Brand reputation plays a significant role in the quality, warranty and after-sales service you will get for your air purifier.
The top air purifier brands in India are Dyson, Mi, Philips, Sharp, Coway and Honeywell. All of these brands provide premium air purifiers to suit different air purification needs, varying in room size, CADR, filtration system used and other add-on features.
You can check the best-budget air purifiers in India under 10000 INR here.
FAQs for Air Purifiers Buying Guide
It depends on the size of the area you wish to use it in, and also on how polluted the room is. Make sure to check the CADR and room size specifications of the air purifier before buying.
Here you can check the top 10 best air purifiers suitable for Indian home needs.
Yes, you can. The power consumption of all the latest models is low and it does not generate heavy electricity bills. Air purifiers eat up 1/40th part of the power of an air conditioner. Moreover, the filter life of an air purifier depends on the air quality and usage.
CADR for the highest speed setting is specified. For low noise, you may run the unit on the lowest setting but it may affect its purifying efficiency.
The lifespan of filters depends on the air quality, their material and construction. Commonly, filters last for about 9 to 12 months with 6 to 8 hours of daily operation.
Yes, indoor air is reported to be more polluted than outdoor air. Most people spend 80% of the time indoors, hence it is crucial to get an air purifier, especially if you have breathing issues or you live in a metropolitan city.
It depends on the speed levels it can reach. Most air purifiers are not that loud, even on their highest setting. Also, most units are very quiet at low speeds.
Filters are very easy to change. Plus, you will find all the instructions in the manual. Otherwise, you can simply contact the customer service team to change the filter.
The frequency of changing filters depends on usage, air quality, and brand with model type. Some air purifiers come with an indicator for filter replacement. For others, you may need to change them every 10 to 12 months.
Best Air Purifiers to Buy in India (2022):