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For an air purifier to effectively clear a large room of allergens and visible dust, it requires a few key aspects. It must have a powerful fan, excellent filtration system, and a recommended room rating to match your large space.

We have found the best air purifiers for large rooms, and have assessed them according to these criteria:

Filter SystemSpecial FeaturesCoverage AreaAnnual Costs
Does the product use a true-HEPA filtration system to remove the maximum amount of allergens?Does the air purifier offer smart features, air quality sensors? Auto mode? Sleep mode?What size room has the unit been designed to clear (in square feet)How much does the unit cost to run per year? How much are filter replacements?
alen breathesmart 75i large air purifierrabbitair minus2a product whiteaeramax100 product 2blue pure 121 large roomcoway airmega 400 product
PRODUCTAlen BreatheSmart 75iRabbit MinusA2Fellowes AeraMax 300Blueair Blue Pure 121Coway AirMega 400
CADR RATING347 overall

350 overallNot specified (2 – 4 air changes per hour)
FILTER TYPES Pre-filter, true-HEPA filter, carbon, antimicrobial, ionizer True-HEPA, pre-filter, activated carbon filter True-HEPA, carbon, antimicrobial, PlasmaTrueHEPA-style filter, pre-filter, carbon filter True-HEPA filter with carbon, pre-filter
COVERAGE AREA (SQ FT)350 – 1300700300-600600-7001560
PRICE POINT $ – $$$$$$$$$$$$$$$$$$$$$$$

🏆 AirHonest Top Pick – Alen BreatheSmart 75i Air Purifier

alen breathesmart 75i large air purifier

AirHonest Award: Best Air Purifier For Large Rooms


  • Customizable filters 
  • Auto mode
  • Air quality indicator
  • Customizable front panels

First on the list is the Alen BreatheSmart 75i, a large unit which caters to rooms up to 1300 square feet when using the highest fan speed, and 350 square feet on the lowest fan speed. True to Alen style, there are multiple front panels to choose from, to customize the color of the unit to suit your home’s aesthetic. While this is a sizeable unit, it has a shallow depth so it can be tucked reasonably inconspicuously into rooms.

The filtration system offers versatility, as you can choose from four different filter systems, (allergies/dust, heavy odor, pets, and VOCs/smoke/odor). Each option provides true-HEPA filtration and an antimicrobial layer to kill bacteria and mold. 

Each filter has a 12-15 month lifespan depending on usage and the level of contamination in the air. The replacement filters are expensive, even when changing them only once a year. However, considering that the air purifier will take care of a whole house or large apartment, the cost seems justified. There is also an ionizer, but it can be switched off with the press of a button, so there’s no need to worry about ozone if it’s a concern for you. 

5 fan speed options offer quiet operation on the first two settings and audible-yet-effective operation on the highest setting. By many accounts, this is considered a quiet air purifier, ideal for sleeping and quiet homes. The fan speeds are switched automatically when the Auto mode is selected, according to the quality of the air as determined by the sensor. 

Five different colors indicate the quality of the air at all times if you wish to monitor it. Another great feature is that the operation lights can be switched off, great for bedrooms and people who are sensitive to light. 

The Alen BreatheSmart 75i is a high-priced air purifier for large rooms, with an excellent filtration system.

Pros 👍
✔ Quiet operation
✔ Effective filtration
✔ Lifetime warranty

Cons 👎
✘ Reports of short lifespan
✘ Large and bulky
✘ Reports of “clunky” noise

View Alen BreatheSmart 75i Air Purifier on Amazon

RabbitAir MinusA2 Air Purifier

rabbitair minus2a product white

AirHonest Award: Best Large Room Air Purifier for Pets


  • Customizable filters 
  • 6-step filter system
  • Remote control 
  • Auto mode and sleep mode

Our runner-up is the very popular RabbitAir MinusA2, another low-profile model that can be wall-mounted or tucked neatly into the room. Like the Alen BreatheSmart above, the MinusA2 offers four different filters (germ defense, odor remover, pet allergies, and toxin absorber). Each one includes the BioGS True-HEPA filter, which removes the standard 99.97% of allergens as small as 0.3 microns, but it also has an antimicrobial treatment to kill mold and bacteria. 

There’s also a pre-filter, medium filter, charcoal filter, and customizable filter layer. This is a great line-up which clears almost all allergens and reduces asthma and allergy symptoms. There is also an ionizer, but it can be turned off to avoid any risk of ozone being released into your home. 

The MinusA2 clears rooms up to 700 square feet, more than enough for a large master bedroom or small apartment. Light sleepers will be pleased to know that this is a quiet unit that won’t keep you up at night, especially when the lowest fan speed is selected. 

What’s more, there is a sleep mode that automatically switches to the quietest fan speed when low light is detected by the light sensor. However, the indicator lights will not switch off, which can be distracting for light sleepers. 

The MinusA2 offers the features you’d expect from such a price tag, such as Auto mode, air quality sensor, and filter change indicator. The medium, BioGS, carbon and customizable filters need to be replaced every 12 months, and the pre-filter can be washed and reused. Considering the number of filters you get, the annual cost is pretty reasonable.

Pros 👍
✔ Low profile design
✔ Effectively reduces allergy symptoms
✔ Quiet operation

Cons 👎
✘ Bright indicator lights
✘ Ionizer may produce ozone
✘ Not great for cigar smoke

Fellowes AeraMax 300

fellowes aeramax 300

AirHonest Award: Best Air Purifier For Large Rooms, Asthma, and Allergies


  • Antimicrobial-treated true-HEPA filter 
  • 4 fan speeds
  • Auto mode 
  • Carbon filter for removing odors

Our third product is the Fellowes AeraMax 300, a more affordable model than the first two, but with a smaller recommended room size, 300-600 square feet. 

This unit has some great certifications, including an Energy Star Rating, AHAM certification, and Asthma and Allergy Foundation of America Certification. It has a similar aesthetic, with a rectangular shape and reasonably shallow depth, with a small control panel down the side. 

The filtration system has four steps, carbon pre-filter, true-HEPA filter with antimicrobial treatment, and PlasmaTrue technology (an ionizer). However, the ionizer can be turned off. The filter style is ideal for removing allergens such as mold, pet dander, and pollen as they are destroyed by the antimicrobial treatment. 

The smart sensor detects when the air is contaminated, and switches the fan speed accordingly, (there are 4 fan speeds, including Aera+ which is similar to “turbo” mode). The true-HEPA filter needs to be replaced once a year, and the carbon filter should be replaced every 3 months. The yearly cost is reasonable, but not cheap by any means.

Pros 👍
✔ Protects against cold and flu
✔ Aera+ mode clears airborne allergens quickly
✔ Great value for money

Cons 👎
✘ Lights cannot be switched off
✘ Ionizer may produce ozone
✘ High fan speeds are loud

View Fellowes AeraMax 300 on Amazon

Blueair Blue Pure 121

blue pure 121 large room

AirHonest Award: Best Air Purifier For Large Room And Dust Removal


  • Custom-color external pre-filter
  • Carbon filter
  • Polypropylene filter kills bacteria 
  • One-touch control button

Coming in at number four we have the Blueair Blue Pure 121, a unique air purifier with a cubic shape. This unit is suitable for rooms from 600 to 700 square feet. It will completely filter a 620 square foot room 5 times an hour, which is a great rate for clear, allergen-free air. It’s not exactly small or compact, but you can change the color theme to better suit your home.

The pre-filter is a visible filter that wraps around the exterior of the unit and comes in customizable colors (blue, pink, black, yellow, and grey/white). Inside the unit sits the HEPA-style filter and the carbon filter. Note that this is not a true-HEPA filter, however, it is extremely effective.

It combines a polypropylene particle filter (naturally antibacterial) with Blueair’s HEPASilent Technology which uses an electrostatic charge to ensure particles stick to the filter. While this is technically an ionizer, all of the potential ozone (of which there are extremely sparse amounts) is kept locked away and will not be released into your air. 

Another excellent feature is that the air inlet is 360 degrees around the unit, as opposed to one side, like many other units. This makes it easier to find a place for the unit. What’s more, the fresh air outlet is at the top of the unit, which also makes placement easy. 

This unit is a lot more minimal in operation than the others, as it has one button which changes the fan speed (there are 3). You won’t find auto mode, sleep mode, or air quality sensors here. While this may be a “con” for some, for many people, this is preferable, as they simply want an effective air purifier that requires minimal control on their part. 

The colored pre-filters are machine washable and are super affordable to buy, so you can switch up the color at your leisure. The HEPA-style and carbon filters (in one bundle) need to be replaced every 6 months and have a pretty high annual cost.

Pros 👍
✔ Effectively removes visible dust
✔ Kills bacteria and mold in the filter
✔ Easy to use

Cons 👎
✘ Not a true-HEPA
✘ No auto mode
✘ Reports of chemical smell

View Blueair Blue Pure 121 on Amazon

Coway AirMega 400

coway airmega 400 product

AirHonest Award: Best Smart Air Purifier for Extra Large Rooms


  • Auto, sleep, and eco modes
  • Air quality monitor
  • 4 fan speeds 
  • Washable pre-filter, true-HEPA filter with carbon

At number five, we have the Coway AirMega 400, a boxy unit which changes the air 4 times in a 780 square foot room, and twice in a 1560 square foot room, per hour. The filtration system is simple yet thorough, featuring a permanent, washable pre-filter. The Max2 filter is a true-HEPA filter combined with a carbon filter which reduces at least 99% of VOCs in the air. 

This is a great model for people who want their air purifier to do the work for them, without having to manually adjust the settings. When the unit is set to “Smart” mode, it will change the fan speeds according to the contamination in the air, (auto), and will use the lowest fan speed when low light is detected (sleep). When the air has been clear for 10 minutes, eco mode will kick in to save power. 

The noise level of the AirMega 400 is debatable, as some people find the top two fan speeds to be too loud, while others have marveled at how quiet the unit is overall. It’s safe to say that very noise-sensitive people will likely be bothered by the higher fan speeds, but for everyone else, it’s quiet enough for bedrooms. What’s more, the air quality indicator light can be switched off to reduce light pollution in the room. 

The pre-filter is washable and should be cleaned every 2 weeks, and the Max2 filter should be replaced every 12 months. The Max2 filter replacements are quite expensive, but you get two sets, as two sides of the unit features an air inlet with filters.

Pros 👍
✔ Reduces VOCs
✔ Smart operation
✔ Quiet on lower speeds

Cons 👎
✘ Reports of bad smell
✘ Expensive filter replacements
✘ Higher fan speeds too loud for noise-sensitive people

How To Choose An Air Purifier For Large Rooms 


Many air purifiers designed for large rooms have a large price tag to match. Research the price range of the kinds of air purifiers you prefer, and figure out a budget. Also, take into account the annual maintenance and energy costs. 

Recommended room size

Your air purifier needs to be able to handle the size of your room, otherwise, it will not provide effective allergy relief, odor reduction, and fresher air. Make sure you’re clear on the minimum and maximum square footage the unit can handle. For example, it may have maximum square footage of 700 but clears a 350 square foot room more effectively. 

Filtration system 

The air purifier is as good as its filtration system, so choose one which caters to your particular needs. If you have pets at home, you could choose an air purifier with a true-HEPA filter for dander and carbon filter for odors. Look for at least 3-stages of filtration. For compromised immune systems, look for true-HEPA filtration with antimicrobial treatment to kill bacteria and viruses. 

Noise and light 

If your air purifier will be situated in a bedroom or quiet room, choose a unit with quiet operation and adjustable lights. Make sure the indicator and control panel lights can be dimmed or turned off, and that there is an ultra-quiet fan speed option. Even better, choose an option with a sleep mode. 

Filter replacement costs 

Be clear on the maintenance requirements, how often the filters need to be changed, and how much the filters cost. The conditions of your home and how often you use the unit will affect the longevity of the filters. If you have pets or a particularly dusty home, you might be looking at more regular filter changes.

Frequently Asked Questions

Does CADR matter for air purifiers?

CADR refers to clean air delivery rate and is a measure of how fast the air purifier clears a particular space of certain allergens such as smoke, dust, and pollen. It is used as a measure of how efficient an air purifier is and can be helpful when assessing a unit overall.

However, it’s not a foolproof system as it doesn’t take germs, ozone, and VOCs into consideration. For this reason, it’s better to take the filtration system and tech features into consideration when choosing an air purifier, as opposed to focusing on the CADR rate. Look for true-HEPA filters, antimicrobial treatments, and carbon filters.

What is ACH? (Air Changes per Hour)

This refers to Air Changes per Hour and tells you how many times per hour the air purifier can change the air in the entire room. This is important to take into account when looking for an air purifier for large rooms. For example, the air purifier might be marketed for rooms up to 1500 square feet but cleans such a space twice an hour. Whereas, it can clean a 750 square foot space 4 times.