The Definitive Buyers’ Resource

Only the best air purifier reviews. We reviewed top air purifiers to identify the best air purifier for allergies, mold, dust, smoke, pets and more. This site presents our findings. Our buyer’s guide will teach you everything you need to know about air purifiers and how they work. There is too much marketing out there that makes it difficult for first-time buyers. Read each air purifier review at least for the Top 5 Air Purifiers carefully to figure out the most important features you should look out for when buying one, and where to buy it for the lowest possible price.

There are more than 189 hazardous air pollutants according to the EPA. An air purifier will go a long way in helping you purify the air in your living environment.

Air Purifier Comparison

Here is a comparison of the 5 best air purifiers currently on the market:

Alen Breathesmart Winix Plasma 5300 IQAirHealthProPlus Honeywell True Allergen Remover Oransi V-HEPA Max Air Purifier
Full Name Alen BreatheSmart Winix 5300 IQAir HealthPro Plus Honeywell Enviracaire 50250S True HEPA Allergen Remover Oransi V-HEPA Max
Coverage 1100 square feet 350 square feet 900 square feet 390 square feet 600 square feet
Length (Inches) 10″ 19″ 16″ 18″ 17″
Width (Inches) 17.8″ 9.8″ 15″ 18″ 22″
Height (Inches) 26.8″ 24″ 28″ 19″ 8″
Weight (Pounds) 21 pounds 16 pounds 35 pounds 21 pounds 18.5 pounds
Air Changes Per Hour (ACH Rating) 5x if used in 430 square feet space, 2x if used in 110 square feet space 5x 5x 5x 5x
Clean Air Delivery Rate (CADR Rating)
Dust 256 248 450 250 230
Smoke 276 236 450 250 230
Pollen 301 252 450 250 230
Removes Smoke Yes Yes Yes Yes Yes
Removes Pollen Yes Yes Yes Yes Yes
Removes Dust Yes Yes Yes Yes Yes
Removes Pet Dander Yes Yes Yes Yes Yes
Removes Mold Spores Yes No Yes Yes Yes
Removes Germs Yes No Yes Yes Yes
Removes Odors Yes No Yes Yes Yes
Pre-Filter Charcoal Charcoal Charcoal Carbon Activated Charcoal
Energy Usage (Watts) 85 Watts 115 Watts 100 Watts 120 Watts 90 Watts
Warranty Lifetime 5 Years 5 Years 5 Years 10 Years
Shipping Free Shipping Free Shipping Free Shipping Free Shipping Free Shipping
Others 60-day No Questions Asked Return Guarantee Consistently rated #1 Clemson University rated #1
Price $$ $ $$$ $ $$

How to Choose Air Purifiers

The best air purifiers check the boxes in each of the following categories:

  1. Size – room / whole house. The area covered by the air purifier will always be listed. Make sure this is at least as large as the size of the room you plan to install the air purifier in
  2. Noise Level – most air purifiers generate some white noise
  3. Air Changes Per Hour or ACH Rating – This metric indicates how many times the air purifier can exchange the air in a room in an hour. The higher the better – for those with allergies, look for an ACH rating higher than 4
  4. Clean Air Delivery Rate or CADR Rating – This is another important metric which tests the ability of the air purifier to clean out the most common air pollutants including pollen, dust and smoke. The higher the better
  5. Indoor – most air purifiers are meant for indoor use unless otherwise specified
  6. Allergy – read the labeling to see which allergens the air purifier is capable of removing
  7. Energy Star – check the energy rating and the number of watts used. Most air purifiers are very energy efficient and use only about 60W, similar to that used by a typical light bulb
  8. Odor Removal – look out for activated carbon pre-filters. Pre-filters are used to remove larger particles such as hair before they arrive at the main filter. Look for pre-filters coated with activated carbon, which helps absorb unpleasant odors including tobacco smoke
  9. Portable / Weight – instead of buying multiple air purifiers, some prefer to buy a portable air purifier and rotate it from room to room. If this is your plan, be sure to check if the air purifier has wheels or is not too heavy
  10. Filter – is it washable / replaceable? Check to see how much replacement filters will cost as well.
  11. Price / Price Range – this consideration should come after the previous ones. Once you have decided on the features you need, look to get them for the lowest possible price
  12. Warranty – look for at least a 3-year warranty. There are some manufacturers that even offer lifetime guarantees (Alen)

How Do Air Purifiers Work

What is an air purifier and why do we need them? Air purifiers are necessary because of the presence of a variety of air pollutants that find their way into our living environments. Common air pollutants include the following:

  • Pet allergen (0.3 – 100 microns)
  • Dust Mite Allergen (10 – 40 microns)
  • Pollen (10 – 100 microns)
  • Plant Spores (10 – 70 microns)
  • Bacteria (0.3 – 3 microns)
  • Fungi (0.5 – 5 microns)
  • Mold (2 – 20 microns)
  • Tobacco Smoke (0.003 – 0.04 microns)

The following video demonstrates how to build your own air purifier for $25 – of course you are better off purchasing a proper one, but this illustrates how air purifiers work well:

Types of Air Purifiers

First, note that there are natural methods to purify the air in your home, such as with air purifying plants.

However, air purifiers are needed for a more thorough removal of all air pollutants. Different types of air purifiers remove various categories of air pollutants and contaminants in different ways – here are the major ones:

HEPA Air Filters

HEPA stands for High Efficiency Particulate Air – HEPA air filters remove up to 99.7% of all particles that are 0.3 microns small – these include pet allergens, dust mite allergens, pollen, plant spores and fungi, but do not include extremely small particles such as germs or smoke. However, HEPA air filters can also be treated with agents to kill bacteria and germs as well.

The other thing to note is that HEPA air filters have to be changed occasionally in order for them to remain effective.

Ion and Ozone Generators / Electrostatic Precipitators

Also known as electrostatic precipitators, these types of air purifiers work by creating charged particles. Through electrostatic attraction, these charged particles attract airborne pollutants and cause them to adhere to a surface. Note that this does not in fact remove the airbone pollutants. Rather, it creates spots on the floor or wall, where these coalesced particles reside.

The disadvantage of ion and ozone generators is that they produce ozone, which may have harmful side effects, particularly for those prone to breathing problems.

Antibacterial Air Purifiers / Germicidal Air Purifiers

Also known as germicidal filters, antibacterial filters kill germs and bacteria. These use various methods, such as a HEPA filter coated with bacteria-destroying agents. Other filters make use of a UV lamp to serve as germicidal filters. These are typically used in places that must be kept germ-free, such as hospitals, childcare centres and laboratories.

Air Purifier Benefits

Do air purifiers really work? If so, what tangible benefits do you get from having one at home. Here are the most important ones:

  • Improved sleep quality
  • Deeper and fuller breaths
  • Improved respiratory function / health – especially if you suffered from some kind of respiratory illness before
  • Reduced allergic tendency

The costs or dangers of air purifiers are minimal:

  • Energy cost – air purifiers are actually extremely energy efficient. Leaving one on for an entire day consumes the same energy as leaving a 60W light bulb on for an entire day.
  • Noise – most air purifiers are extremely quiet. However, some do generate sounds that are audible. Even so, some people like this white noise for it helps shut out noise from the surroundings.
  • Ozone – Some ion and ozone generators generate traces of ozone, a respiratory irritant which can be harmful to your lungs

Where to Place Air Purifiers

As mentioned above, make sure the size of the space you plan to use the air purifier in corresponds with the coverage on the labeling! An air purifier meant for the bedroom will not work effectively if placed in a large living room that is three times as large. For starters, we would recommend buying air purifiers first for the bedroom, for this is the place you spend most of your time in.

How Many Air Purifiers Do I Need

This depends on the coverage area of the air purifier you are looking to buy. For example, if you buy an Alen Breathesmart with a coverage area of more than 500 square feet, you probably will just need to place one in your master bed room. That said, you probably need two if you live in a large house. There are no air purifiers that will truly cover the whole house. Your best bet is to get two if your house if larger than 1,000 square feet – one for the bedroom and one for the living room. This ensures adequate coverage.

Maintaining Air Filters

Change your pre-filters regularly – if you live close to the street or in a dustier environment, your pre-filters may need to be replaced more frequently.

Air Purifier CADR Ratings

CADR ratings come from AHAM, the authority that reviews air purifiers and assigns CADR ratings to each.