Air purifier buying guide: Know all about air purifier types, features and filters to choose the right one for your home

That’s where air purifiers come in as a practical solution. An air purifier is a device that actively filters out pollutants, allergens, and harmful particles, letting you breathe easier indoors. If you’re ready to make your home a cleaner, healthier space, an air purifier could be just the answer. But how to find the right air purifier according to your needs and usage? Our comprehensive air purifier buying guide has all the answers for you.

What is an air purifier?

An air purifier improves indoor air quality by removing contaminants and pollutants. It draws in surrounding air, passing it through filters that capture harmful particles, gases, and odours. Commonly used in homes and offices, air purifiers reduce allergens like dust, pollen, and pet dander, while also eliminating smoke, mould spores, bacteria, and viruses.

By continuously filtering the air, these devices create a healthier environment, especially beneficial for people with allergies, asthma, or respiratory issues.

How does an air purifier work?

Air purifiers employ various filtration methods to clean the air, including High-Efficiency Particulate Air (HEPA) filters, activated carbon filters, UV-C light technology, and ionisation.

We will talk about these filters in detail in a later section of our guide. First let's understand how an air purifier works step-by-step.

Air intake: The air purifier pulls in air from the surrounding environment through a fan or suction system.

Pre-filter: Some air purifiers have a pre-filter that captures large particles like dust, hair, and lint. This pre-filter helps prolong the life of the main filter by preventing it from getting clogged too quickly.

Main filtration: The air passes through the main filtration system, which typically consists of one or more filters. The most common type of filter is the High-Efficiency Particulate Air (HEPA) filter, which can capture particles as small as 0.3 microns with high efficiency. Other types of filters, such as activated carbon filters, UV-C light filters, or electrostatic filters, may also be used depending on the purifier model.

Particle capture: As the air passes through the filter, particles such as dust, pollen, pet dander, mould spores, bacteria, and viruses are trapped within the filter media or neutralised by the purification technology.

Clean air released: The purified air is then released back into the room, free from harmful contaminants and pollutants. Some air purifiers may have additional features like ionisation or UV-C light treatment to further enhance air quality by neutralizing or killing pathogens.

The air purifier continues to cycle and clean the air in the room, maintaining a healthier indoor environment for occupants.

Also read: Best air purifiers under ₹5000: Top 6 smart investments for improved breathing

Check out this air purifier by Coway

Who should buy an air purifier?

Air purifiers can be beneficial for various individuals and settings, but their efficiency can vary based on factors such as health, location and other specific needs. Let's explore who should consider buying air purifiers and whether they are efficient in both urban and suburban settings.

Who should consider buying an air purifier?

Individuals with allergies and asthma: People with allergies or asthma can benefit greatly from air purifiers, as they help remove allergens such as pollen, dust mites, pet dander, and mould spores from the air, reducing the triggers for allergic reactions and asthma attacks.

Smokers: For individuals who smoke or live with smokers, air purifiers equipped with activated carbon filters can help remove smoke particles and odours from the air, improving indoor air quality and reducing the smell of tobacco smoke.

Pet owners: Pet owners may find air purifiers helpful in managing pet-related allergens and odours. Purifiers with HEPA filters can effectively capture pet dander and hair, while activated carbon filters can help eliminate pet odours.

Residents of polluted areas: People living in areas with high levels of outdoor air pollution, such as urban centres or regions near industrial sites or highways, can benefit from air purifiers. These devices can help remove pollutants like particulate matter, volatile organic compounds (VOCs), and nitrogen dioxide, providing cleaner indoor air.

Individuals with compromised immune systems: People with weakened immune systems, such as the elderly or those undergoing medical treatments, may benefit from air purifiers, which can help reduce the spread of airborne viruses, bacteria, and other pathogens.

Is it efficient in both urban and suburban settings?

Urban Regions

In urban areas with high levels of air pollution from traffic, industrial activities, and other sources, air purifiers can be highly efficient in improving indoor air quality. They can effectively capture particulate matter, vehicle emissions, and other pollutants, providing relief for residents who are exposed to polluted outdoor air.

Suburban Regions

While suburban areas generally have lower levels of air pollution compared to urban areas, they are not immune to indoor air quality issues. Air purifiers can still be beneficial in suburban settings, particularly for individuals with allergies, asthma, or sensitivities to common indoor allergens like dust mites and mould. Additionally, air purifiers can help remove pollutants brought indoors through open windows or ventilation systems, ensuring cleaner air for occupants.

Also read: Best air purifiers under ₹3000: Elite 10 choices to enhance air quality

Check out this air purifier by Honeywell

Types of air purifier filters

A single filter cannot eliminate all the pollutants and allergens from the surroundings. It takes a combination of filters for efficient optimal air purification. Here are the 5 most common air purifier filters or filtration stages and their uses.

1. High-Efficiency Particulate Air (HEPA) Filters

HEPA filters are made of tightly packed layers of fine fibers arranged randomly. They can capture particles as small as 0.3 microns with 99.97% efficiency. This makes them excellent at trapping common indoor allergens like dust mites, pollen, pet dander, mould spores, and fine particles. HEPA filters play a crucial role in improving indoor air quality and offering relief to those with allergies or asthma.

2. Pre-Filters

Pre-filters are made from coarse mesh or fibrous material that captures larger particles like dust, hair, and lint before they reach the main filtration system. By preventing clogging of HEPA and other filters, they help extend their lifespan. Pre-filters also enhance the overall efficiency of the air purifier by reducing the strain on the main filter.

3. Activated Carbon Filters

Activated carbon filters are made from a porous form of carbon that has been treated to increase its surface area and adsorption capacity. Activated carbon filters excel at removing gases, odours, and volatile organic compounds (VOCs) from the air. They effectively absorb smoke particles, cooking odours, pet odours, chemical fumes, and other gaseous pollutants, leaving the air smelling fresher and cleaner.

4. UV-C Light Filters

UV-C light filters use ultraviolet light (around 254 nanometers) to disinfect the air by destroying the DNA of bacteria, viruses, and mould spores. These filters are highly effective at eliminating airborne pathogens, offering an extra layer of protection against illness-causing microorganisms. Commonly used in healthcare settings and areas requiring high hygiene, UV-C light filters help ensure cleaner, safer air.

5. Ionic Filters

Ionic filters emit negatively or positively charged ions that attach to airborne particles, causing them to become heavier and settle out of the air. Ionic filters can be effective in removing particles from the air, particularly ultrafine particles. However, they may produce ozone as a byproduct, which can have adverse health effects and may require regular cleaning of collection plates.

Check out this air purifier by MI Xiaomi

Types of pollutants and air purifier filters to effectively remove them

There are several types of air pollution and each requires a different air purifier filter to effectively eradicate them. Here's an overview of common types of air pollution and the corresponding filters used in air purifiers:

1. Particulate Matter (PM)

Particulate matter consists of tiny solid or liquid particles suspended in the air, including dust, pollen, mould spores, pet dander, and smoke.

Filter type: High-efficiency particulate air (HEPA) filters are highly effective in capturing airborne particles as small as 0.3 microns with a high-efficiency rate of 99.97%.

2. Volatile Organic Compounds (VOCs)

VOCs are chemicals emitted from various sources such as paints, solvents, cleaning products, and furniture. They can cause short-term and long-term health effects.

Filter type: Activated carbon filters are ideal for removing VOCs and other gaseous pollutants. The activated carbon adsorbs the VOC molecules, trapping them within the filter.

3. Smoke and odours

Smoke from cigarettes, wildfires, or cooking, as well as unpleasant odours from pets, cooking, or household chemicals, can contribute to poor indoor air quality.

Filter type: Activated carbon filters are effective in absorbing smoke particles and neutralising odours, helping to improve air freshness.

4. Bacteria and viruses

Airborne pathogens such as bacteria, viruses, and mould spores can cause respiratory infections and other health issues.

Filter type: UV-C light filters and HEPA filters with antimicrobial treatment are commonly used to kill or capture airborne bacteria and viruses. UV-C light damages the DNA of microorganisms, while antimicrobial-treated HEPA filters inhibit the growth of bacteria and mould.

5. Allergens

Allergens include pollen, dust mites, pet dander, and mould spores, which can trigger allergic reactions and asthma symptoms.

Filter type: HEPA filters are highly effective in capturing allergens, providing relief for allergy and asthma sufferers by reducing exposure to these airborne particles.

6. Formaldehyde and other chemicals

Formaldehyde and other volatile chemicals can be emitted from building materials, furniture, and household products, posing health risks.

Filter type: Some air purifiers use specialised filters designed to target specific chemicals, including formaldehyde. Activated carbon filters are also effective in adsorbing a wide range of volatile organic compounds (VOCs), including formaldehyde.

Also read: Best air purifier brands in India: Complete comparison guide, top 9 picks

Check out this air purifier by Fulminare

Features to look for in an air purifier

Pre-filter: Catches large particles like hair, extending the lifespan of internal filters. Can be washed and reused for sustainability.

Air quality monitoring: Constantly monitors room air for specific pollutants, automatically adjusting settings for optimal air quality.

Adjustable fan speeds: Offer customisable purification and room cooling. Most purifiers provide 2-5 speed options, plus Turbo Mode for extra power.

Antimicrobial treatment: Prevents bacterial and microbial buildup on purifier filters, maintaining cleanliness and hygiene.

Remote control: Enhances accessibility, allowing users to adjust purifier settings from a distance for convenience.

Portability: Handles and castors improve purifier portability with multi-functional wheels and handles for easy movement.

Filter replacement indicators: Alerts users when filters are clogged, ensuring timely replacement for continued purification effectiveness.

Humidity regulation: Filters out allergens, mildew, mould, and dust while regulating moisture levels in the air for comfort and health.

Timer: Automatically switches off the purifier after a set time, offering convenience and energy savings.

Certain air purifier models may offer extra features like WiFi connectivity, integration with mobile apps, portability wheels, display dimming, and more. Availability of these features varies by purifier model.

Also read: Best air purifiers under 20000: Top 10 purifiers delivering clean air in budget

Check out this air purifier by Phillips

How to choose the right air purifier for your space?

Here are a few factors to consider before investing in an air purifier:

1. Size of your room

To select the right air purifier, measure your room size. Look for Air Changes per Hour (ACH) ratings. ACH (Air Changes per Hour) indicates how many times an air purifier cycles the air in a room hourly. Higher ACH ratings signify higher efficiency.

2. Buying price and maintenance cost

Air purifiers entail two costs: initial purchase and maintenance, including electric consumption and filter replacements. Costs vary based on quality and filter lifespan. Ensure your budget accommodates ongoing maintenance.

3. Energy efficiency

Consider the energy consumption of your air purifier before purchasing. Larger units for big spaces consume more energy. Continuous operation, especially at high speeds, increases energy usage.

4. Real time air quality tracking

A real-time air quality tracking feature is essential in an air purifier. It enables you to monitor its effectiveness and adjust settings accordingly. Devices with this feature often have automatic modes to adjust speed based on pollution levels, ensuring continuous protection.

5. Clean Air Delivery Rate (CADR)

CADR (Clean Air Delivery Rate) is an objective measure of an air purifier's ability to remove contaminants. It verifies the accuracy of area coverage and effectiveness against pollutants like dust, smoke, and pollen. Higher CADR ratings indicate greater efficiency in cleaning the air.

6. Placement

Calculate the square footage of your space to determine the appropriate size and placement of your air purifier. Ensure the purifier's square footage rating matches or exceeds the room's area. Place HEPA or carbon filter purifiers 2-3ft. away from walls for proper airflow. Position ionic filtration purifiers centrally for optimal 360-degree output.

7. Noise level

When selecting an air purifier, the noise level is an important factor to consider, especially if you plan to use it in bedrooms or quiet spaces. Look for purifiers with low noise levels, typically measured in decibels (dB). Quieter models, operating below 30 dB, are ideal for minimal disruption, especially during sleep.

Also read: A head-to-head comparison of Dyson air purifiers and other top alternatives available in the market: An analysis

Check out this air purifier by Qubo

Where to place your air purifier?

Selecting the right spot for your air purifier significantly enhances its efficiency and performance, potentially boosting effectiveness by up to 20%. When placing your purifier, identify the areas in your house or office with the highest pollutant concentration and ample airflow.

Check out this air purifier by Coway

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