6 Greatest Air Purifiers for Asthma — Say Goodbye to Coughs and Wheezing!

Last updatedLast updated: July 25, 2021
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According to World Health Organization, 235 million people currently have asthma, a non-communicable disease whose symptoms include wheezing and breathlessness. The significant risk factors are inhaled substances, chemicals and particles which trigger allergic reactions and reduce air circulation to the lungs by inflaming and narrowing the bronchial tubes. This review will guide you on selecting the best air purifier for asthma which utilizes HEPA and carbon filters to trap airborne particles that trigger allergic reactions and worsen your disease.

We assessed some essential factors that should be considered to get the safest and most reliable air purifier. Among the features we analyzed is the type and number of filters because they determine the effectiveness of the air purifier. We also reviewed the output and amount of space it can cover to decide on its clean air delivery rate. Finally, we evaluated the dimensions of the air purifier for space assessment and easy storage.

This review includes a comparison table ranking the best air purifier for asthma models based on their features, strengths, and drawbacks. It is followed by the detailed product descriptions and an in-depth buying guide that explains the importance of the essential features and provides examples of the particular models that embody them. We sum up this comprehensive review with answers to the most frequent questions and a summary of our best three picks.

Top 6 Air Purifiers for Asthma 2021


Coway AP-1512HHEditor’s choice

  • Number of filters: 3
  • Filters type: washable pre-filter; odor carbon filter; HEPA filter + bipolar ionizer
  • CADR: 246 (dust); 240 (pollen); 230 (smoke)
  • Coverage area: up to 360 sq. ft.
  • Dimensions: 16 x 18.3 x 9.6 inches
  • Warranty: 3-year limited

More features: air quality indicator; auto mode; 1, 4, 8, 12 hours timer

Coway AP-1512HH air purifier is a valuable investment with tons of features and technology which deliver an impressive performance.

It utilizes four mechanisms of air filtration consisting of a washable pre-filter which captures large debris, an activated carbon filter which absorbs and eliminates odor, a true HEPA filter for trapping finer particles, and a bipolar ionizer which discharges negative ions to attract and remove dust particles. This combination of filters ensures the air in your room is clear of contaminants, microbes, and allergens.

In addition to the three low, medium and high-speed settings, this air cleaner features eco-mode for efficient consumption of energy, and an automated mode which selects the best speed based on the level of air pollution detected by the integrated sensor. Air quality is indicated by three lights – blue, purple and red – with blue standing for clean air and red showing a high level of contaminants. When the filters need replacement, a filter change indicator light will notify you.

The timer can be used to schedule the unit for one, four, eight, or 12 hours for smart energy consumption.

This Coway model has a CADR rating of 246 for dust, 240 for pollen and 230 for smoke, which can effectively purify small and medium rooms of up to 360 square feet. It has also been certified by AHAM, CARB and Energy Star.

The purchase comes with a three-year warranty. Buyers praise the performance and efficiency of this air purifier; only a small fraction has been mildly concerned by the slight rise in temperature when it is running.

Why are we impressed?

  • High CADR rating
  • Varied operational timer
  • Air quality indicator
  • Auto mode function
  • Quiet operation

What negatives must you be aware of?

  • Slight rise in temperature
  • Pricey
RELATED: 5 Best Air Purifiers for Mold Removal – Reviews and Buying Guide

AeraMax 300Best Air Purifier for Allergies And Asthma

  • Number of filters: 2
  • Filters type: carbon filter; true HEPA filter + Aerasafe Antimicrobial Treatment + PlasmaTrue Technology
  • CADR: 191 (smoke); 196 (dust); 188 (pollen)
  • Coverage area: up to 600 sq. ft.
  • Dimensions: 8.1 x 16 x 25.1 inches
  • Warranty: 3-year limited

More features: four speeds; AAFA certified

One of the best ways to objectively determine the safety and effectiveness of a product is through the set industry standards and certifications. AeraMax 300 is an impressive air purifier going by its UL-listing and various certifications by AHAM, CARB and Energy Star. The AAFA has also stamped its approval of this model as the best air purifier for allergies and asthma by awarding it the Allergy and Asthma Friendly certification. It has also been proven to effectively trap and filter the airborne influenza virus through its special high-performance mode.

Featuring a four-step filtration system with True HEPA filter, carbon filter, AeraSafe antimicrobial treatment, and PlasmaTrue technology, this air purifier is well equipped to remove dust mites, mold spores, tobacco smoke, pollen, odor, and other allergens from your surroundings. The AeraSafe antimicrobial treatment sterilizes the HEPA filter to prevent breeding of harmful microorganism while the innovative PlasmaTrue technology traps tiny contaminants through ionization.

The integrated AeraSmart sensor automatically detects air quality for impurities, and then the auto mode selects the right speed from the four available settings ranging from low speed for quiet operation to turbo mode for faster and thorough filtration.

A blue light illuminates when the air purifier is running, and you can select the settings from a control panel at the front of the unit which also features a child lock for additional safety.

Despite its portability, AeraMax 300 provides broad coverage of large rooms that range from 300 to 600 square feet. It has a CADR rating of 191 for smoke, 196 for dust, and 188 for pollen.

What stands out?

  • Expansive coverage
  • Effective against influenza virus
  • Integrated sensor and auto mode
  • Quiet operation
  • Control panel with child lock
  • Compact size and lightweight

What cons did we manage to find?

  • The blue light can’t be dimmed
  • The unit itself and the filters are pricey
RELATED: 5 Best Air Purifiers for Mold Removal – Reviews and Buying Guide

Winix 5500-2Best HEPA Air Purifier for Asthma

  • Number of filters: 2
  • Filters type: carbon filter; HEPA filter + PlasmaWave Technology panel
  • CADR: 243 (dust); 246 (pollen); 232 (smoke)
  • Coverage area: up to 360 sq. ft.
  • Dimensions: 14.9 x 7.8 x 23.6 inches
  • Warranty: 1-year limited

More features: filter replacement indicator; LED light auto dim; timer

The Winix 5500-2 is among the products made by Winix, which also makes humidifiers and de-humidifiers, so you can be sure that the manufacturer is well conversant with air freshening and filtration.

This air purifier utilizes three steps of filtration to get rid of most of the contamination; True HEPA filter which traps 99.97% of dust mites, pollen, and the shedding of fur and feathers by pets which can cause hypersensitive reactions, activated carbon filter with advanced odor control, and an ozone-free PlasmaWave filter unique to Winix purifiers, which decontaminates chemical gases and neutralizes allergens by releasing hydroxyls into the atmosphere.

There are four settings of low, medium, high, and turbo to adjust the speed of the fan, three timers of one, four and eight-hour intervals. There are three operation modes consisting of a built-in smart sensor that detects the amount of air contamination, auto mode which automatically adjusts the speed of the fan for optimal filtration, and sleep mode for quiet running at night. An LED light changes light to blue, red or yellow to indicate the current air quality, and auto-dims to suit the current ambiance.

This model has a high CADR rate of 243 for dust, 246 for pollen and 232 for smoke, which makes it one the best HEPA air purifiers for allergies and asthma, with protective coverage of up to 360 square feet.

The purchase comes with a one-year warranty. A couple of customers had issues with the LED light getting stuck on one color which they fixed by pressing the reset button for a few seconds.

Why did it make our list?

  • The thorough three-stage filtration process
  • Four fan speed settings
  • Decent coverage
  • Scheduling timers
  • Built-in smart sensor
  • Sleep mode

What is not ideal about it?

  • Malfunctioning LED light
  • Short warranty cover
RELATED: 8 Effective Air Purifiers for Your Whole Home — Big or Small!

Oransi Finn OVHT9908Best Air Purifier for Large Rooms

  • Number of filters: 2
  • Filters type: HEPA filter; carbon pre-filter
  • CADR: 140
  • Coverage area: up to 400 sq. ft.
  • Dimensions: 7 x 10 x 22 inches
  • Warranty: 10-year limited

More features: includes two extra pre-filters; electronic controls; LCD display

Although it has a CADR rating of 140 and can effectively purify large rooms of up to 400 square feet, Oransi Finn OVHT9908 has a slim tower shape that is ergonomically designed to fit in small spaces.

It cleans the air with a four-stage filtration system consisting of a carbon pre-filter, a HEPA filter, an ionizer, and a UV lamp which works with the two extra pre-filters to sterilize the filter, eliminate odor and volatile organic compounds through oxidation. The two pre-filters also serve to extend the lifespan of the HEPA filter by handling the large particles to prevent clogging. An indicator reminds you when to replace the filter.

An LCD display features a user-friendly interface with electronic controls for power, UV lamp, ionizer, and the three fan speed settings. At its highest speed, this Energy Star-certified model only uses 55 watts.

The package includes two additional pre-filters and a user manual, and the manufacturer offers a limited warranty of ten years.

A number of customers struggled with switching on this air purifier when they placed the filter wrongly owing to poor instructions. Some owners also complained of the initial plastic odor when the unit is running, and the blue light that stays on during operation.

What makes it special?

  • Extensive protective coverage
  • Long-lasting filter
  • Compact design
  • Two additional pre-filters
  • Energy-efficient

What cons did we find?

  • Initial odor
  • Blue light stays on
  • Incomprehensive instructional manual
RELATED: 5 Best Air Purifiers for Mold Removal – Reviews and Buying Guide

GermGuardian AC5350WBudget Pick

  • Number of filters: 2
  • Filters type: HEPA filter; charcoal filter + UV-C light technology
  • CADR: 114 (dust); 127 (pollen); 108 (smoke)
  • Coverage area: up to 167 sq. ft.
  • Dimensions: 9.1 x 6.7 x 27.6 inches
  • Warranty: 5-year limited

More features: five speeds; Energy Star certified

The sleek design of GermGuardian AC5350W and its CARB and Energy Star certification provides a stylish and energy-efficient way to improve your indoor air quality for a safe and healthy atmosphere.

It features the trusted HEPA filter which can remove 99.97 of all 0.3 micron-sized allergens, a charcoal filter to keep odor at bay, and UV-C light technology which combines with Titanium Dioxide to filter mold spores and microbes from the air by changing their genetic makeup. This makes it a suitable choice for those looking for the best top rated air purifier for mold and asthma.

It is also one of the quietest air purifiers for asthma with the highest speed setting producing minimal white noise.

The five fan speed settings include sleep mode for silent operation at night. If you are one of the people who might find the blue light a distraction at night, you can get rid of it by switching off the UV-C.

Its CADR rating of 114 for dust, 127 for pollen and 108 for tobacco smoke can effectively purify the air in rooms measuring up to 167 square feet.

It also includes a digital display which allows you to switch between settings, a timer that can be set for up to eight hours, and an indicator which alerts you when the filter is due for replacement.

You might notice a slight odor when you initially use this air purifier, but the smell soon disappears.

What are our favorite features?

  • HEPA filter and UV-C technology
  • Multiple speed settings
  • Digital display
  • Lightweight and compact
  • Inexpensive

What could be better?

  • Initial slight odor
  • Relatively small coverage area

Honeywell HFD-120-QBest Air Purifier for Small Rooms

  • Number of filters: 2
  • Filters type: washable pre-filter; permanent washable IFD filter + electronic ionizer
  • CADR: 100 (dust); 110 (smoke); 132 (pollen)
  • Coverage area: up to 170 sq. ft.
  • Dimensions: 28.7 x 11.2 x 10 inches
  • Warranty: 5-year limited

More features: Energy Star rated; AHAM certified

If you are worried about the cost of replacing air purifier filters annually or after every six months, then you will love the permanent and washable filter of Honeywell HFD-120-Q. This modest model combines three filtration mechanisms; a washable pre-filter for trapping large debris, a permanent IFD filter for eliminating fine pollutants, and an electronic ionizer which fights dust particles by emitting charged ions which attach themselves to harmful airborne particles.

A CADR rating of 100 for dust, 110 for smoke and 132 for pollen allows for purification of small and medium-sized rooms measuring up to 170 square feet. The manufacturer claims the IFD filter can remove 99% of airborne allergens, but mind it can only filter the ones that are at least two-micron sized while the true HEPA filter eliminates 0.3-sized micron contaminants at 99.97% effectiveness. However, this air purifier does an above average purification, and it can either be washed or vacuumed. The permanent filter which can be cleaned regularly makes this model the best air purifier for pet allergies and asthma.

There are three fan speed settings of low, medium and high, and a filter reset light to notify you when cleaning is due. Speed selection, power, and oscillation are accessed by pressing the buttons on the panel.

This air purifier has been certified by AHAM and Energy Star for minimal energy consumption, with the highest speed setting consuming 60 watts of power.

Speaking about the drawbacks, a number of buyers have complained of the oscillating feature malfunctioning.

Why did it make our list?

  • NO replacement filters needed
  • Adjustable speed settings
  • Low energy consumption
  • Quiet operation
  • Inexpensive

What is not ideal about it?

  • Low filtration rate
  • No automated function
  • Malfunctioned oscillation

Things to Consider

With fresh air becoming a luxury in the world today, the need to invest in an air purifier that makes our surroundings free from toxic fumes and harmful particles is more important than ever. People suffering from asthma are particularly vulnerable to allergic reactions. This informative buying guide expounds on the features you should evaluate when shopping for the best air purifier for asthma, and explains how they work to purify air for a clean, allergic-free atmosphere. It also briefly answers some of the most frequently asked questions.

How can a purifier ease asthma?

Asthma causes inflammation and narrowing of bronchial tubes which restricts air to and from the lungs. Exposure to smoke, dander, microbes and allergens can trigger and worsen the symptoms. Since air purifiers work by filtering the air of these airborne particles and cleansing it, it can prevent and alleviate hypersensitive reactions. Filters, such as the gold standard HEPA filter, clean the air of particles that are as small as 0.3 microns at an efficient rate of 99.97%. For perspective on the size of the particles, the width of a human hair strand is 100 microns.

Features to consider while choosing an air purifier for asthma

The following are the certain features which determine the quality and performance of air purifiers.

Filters types

The effectiveness of an air purifier mainly depends on the type and number of filters. Filters can be replaceable or permanent, like the IFD filter in Honeywell HFD-120-Q.
The best top rated air purifier for mold and asthma combines several filters to target various contaminants. A pre-filter captures large particles which can clog the other filters while the main filter traps the fine particles. An activated carbon filter absorbs pet odor, smoke and other gaseous pollutants while an ionizer discharges negatively charged ions into the atmosphere that attach themselves to 0.01-micron-sized airborne particles to remove them.

The HEPA (High Efficiency Particulate Air) filter is considered the standard worldwide because it can eliminate tiny 0.3-micron particles and cleanse the air of at least 99.97% of harmful microbes and allergens while a regular filter, such as the permanent IFD filter of Honeywell HFD-120-Q, has a maximum effectiveness of 99% and can only capture particles that are bigger than two microns.

For the best HEPA air purifier for asthma, consider Coway AP-1512HH or Oransi Finn OVHT9908 which both feature four stages of filtration with a pre-filter, an activated carbon filter, a HEPA filter, and a bipolar ionizer.

CADR level

Clean Air Delivery Rate is a standard testing system by the Association of Home Appliance Manufacturers (AHAM) which measures the effectiveness of a portable air purifier to remove tobacco smoke, dust and pollen pollutants from the air. The CADR rating indicates the volume of air filtered in cubic feet per minute, with a high rating indicating faster filtration and higher output of clean air.

Winix 5500-2 has a high CADR rating of 243 for dust, 246 for pollen, and 232 for smoke. This makes it one of the top contenders for the best air purifier for allergies and asthma.

Coverage area

Besides CADR rating, air purifiers are also rated according to the specific number of square feet they are designed to clean. This is referred to as the coverage area. Using a low coverage air purifier in a large room will reduce its effectiveness.

To identify the most suitable air cleaner based on coverage, measure your designated room including the height and select a model with a higher recommended coverage area than the size of the room. This allows you to operate it on lower speed efficiently and noiselessly while retaining a high output.

Noise level

The essence of an air purifier is for us to have clean, breathable air that can prevent and alleviate our respiratory problems, not add migraines to our symptoms with noise that can wake up the dead.

Air purifiers usually feature multiple fan speed settings with varying noise levels. To co-exist peacefully with them and even sleep soundly as they run, choose a model with adjustable speed so you can select the lower one which is quieter. GermGuardian AC5350W has five fan speed settings, including sleep mode. Its highest speed setting also produces minimal white noise.


Knowing the dimensions of an air purifier will help you calculate the available storage space, and make any needed adjustments to accommodate it. The size will also determine its portability, which makes it easier to move the unit from one room to another.

For instance, Oransi Finn OVHT9908 is seven inches long, ten inches wide and 22 inches long, with a slim tower shape for compact storage.


To know how long you should expect your air purifier to last, look at the length of its warranty as well as other incentives regarding labor, replacement of defective parts and after sale service. Honeywell HFD-120-Q and Oransi Finn OVHT9908 have long warranties of five years and ten years respectively.

Extra features

Extra features complement other functions by providing options for a more powerful performance, easy control, and greater efficiency.

This includes an automatic mode which chooses the best setting for the level of contamination, auto shut-off, ambient auto-dimming light, sleep mode for quiet operation, eco-mode for minimal energy consumption, air quality sensors and light which automatically detect the level of air pollution. Other handy options include adjustable fan speeds, filter change indicator which alerts you when replacement is due, scheduling timer for delayed start, and LED display panel for easy access of controls and display of feedback and other useful information.


Pets have an odor, and they shed fur, dandruff and dander that can trigger allergic reactions. But pets, especially cats, can have an asthma attack from pollen, smoke, mold spores, perfumes, and air fresheners, among others. Since filters eliminate these particles, both the pet and its owner can benefit from an air purifier with HEPA filter which removes 99.97% of airborne particles and an activated carbon filter which absorbs odor and gaseous pollutants, such as Coway AP-1512HH.

Look for models with pre-filters which prolong the lifespan of HEPA filters by preventing clogging, and a filter change indicator to notify you when cleaning or replacement is due. When setting the air purifier up, leave enough space around the air purifier to allow free circulation of air through the filters. Conserve energy by scheduling a delayed start with the timer.

They both have their pros and cons. The best one is the one that suits your purpose, environment, lifestyle, and individual preference. Permanent filters require regular cleaning so someone with a busy lifestyle might find them inconvenient while others will be only glad to save money on filter replacement costs. They are also better for the pollen-laden environment since you can clean them any time. Replaceable filters are suitable for busy people and germaphobes who might worry about recycling pollutants.

Our Verdict

Coway AP-1512HH scored the highest in performance owing to four filtration features, multiple speed settings, high CADR rating, extensive square foot coverage, filter change indicator, automatic mode, scheduling timer, and air quality sensor and light. With the only fault being the minor mild temperature increase when it runs, it is easy to see why buyers are extolling the quality and delivery of this air purifier, and why it was our best air cleaner for asthma.

AeraMax 300 ranked just as high as Coway AP-1512HH, and it was our choice for the best air purifier for allergies and asthma. And we are not the only ones who think so; The Asthma and Allergy Foundation of America awarded it the Allergy and Asthma Friendly certification. This model also offers effective proven against the flu virus, in addition to its multiple filters with sterilization treatment, adjustable speed, high CADR rating, sensor, and a child safety lock.

Winix 5500-2 embodies the powerful performance of the trusted HEPA filter, earning it top rating as our best HEPA air purifier for asthma. Additionally, it has one of the highest CADR ratings and can effectively purify rooms measuring up to 360 square feet.

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