Best Air Purifier Buying Guide – 2017

There are few things as refreshing as the crisp clean air that follows a summer rain or the refreshing air of a spring morning. However, we spend the majority of our time indoors. We buy products to optimize our health and make our lives easier, but many of us never think to improve the quality of the air we breathe. Using the best air purifier is one way to improve your health and recreate that clean air sensation in your own home.

We review the best air purifiers to help you identify the best units for allergies, mold, dust, smoke, pets and more. Sorting through marketing claims and sifting through specifications is tedious. Especially for first time purifier shoppers. This buying guide will help you find the best air purifier for your individual needs.

DescriptionOur RatingPrice
GermGuardian AC4825
gemguardian AC4825 best rated air purifier review
#1 Top Recommended
  • Removes smoke, odors, and more
  • HEPA filter
  • Good for small to medium rooms
4.3 Stars
Read review
Honeywell 50250-S
Honeywell 50250 S air purifier for smoke review
  • Removes smoke, odors, and more
  • HEPA filter
  • Good for small to large rooms
4.2 Stars
Read review
Honeywell HFD-120-Q
Honeywell HFD-120-Q best rated air purifier review
  • Washable filters
  • Good for small to medium rooms
  • Sleek tower design
4 Stars
Read review

Finding the Best Air Purifier for you…

There are a lot of things to consider when you’re shopping for air purifiers and other air treatment systems. Here are a few of the most important factors to keep in mind during your search.

1. Room Size

First and foremost, you will need to consider the space where your purifier will live. Will it purify a small space, a large room, or a whole house? Avoid paying too much by matching the purifier’s capabilities size to size of the room.

2. Noise Level

Most machines are quiet and some are nearly silent. However, almost all create a bit of white noise. If you are using the purifier  in a space where even a little noise will be an issue, make sure you choose a very quiet model.

4. Odor Removal

If you need an air purifier to take care of household smells get one with activated carbon. Activated carbon kills odors through adsorption. From cigarette smoke to pet odor; carbon is a must for odor removal.

5. Asthma and Allergies

One of the best reasons to get an air purifier is if you, or a loved one, suffers from allergies or asthma. A quality hepa filter will remove almost anything that can trigger respiratory problems. Check out our comparison of the best purifier for asthma and allergies for more detailed information.

6. Clean Air Delivery Rate (CADR)

You’ll see CADR in a lot of air purifier product descriptions and reviews. Bottom line; higher is better. CADR is a standardized AHAM rating applied to purifiers from major manufacturers. CADR measures purifier efficiency by calculating the volume of clean air produced each minute. The rating effectively shows shoppers how much dust, pollen and smoke is removed from a 1,008 cubic foot room during a 20 minute test cycle. But, don’t rely on CADR alone… our CADR rating article explains why.

7. Air Changes Per Hour

This is a much simpler metric than CADR, but important nonetheless. In fact it’s a major contributor to the air purifier’s CADR. Simply put, it measures how much air a machine can move. Air changes per hour is calculated by taking a machine’s CFM (cubic feet of air moved each minute), multiplied by 60 (minutes), divided by a room’s volume (in cubic feet). We recommend that you focus primarily on an purifier’s features (e.g. HEPA, Activated Carbon). Not just how much air a machine moves or its CADR rating.

8. Efficiency

It’s easy to get dragged into electrical specifications an amp hours. However, we think an Energy Star certification is the easiest way to spot an efficient machine.

9. Filter Type and Maintenance

More often than not the best air purifier for most situations will feature a HEPA filter. But, it’s also important to consider how often the filter will need to be replaced. How much it will cost to replace it. And, what kind of maintenance is required  between changes. Filterless models are also available, for more information check out our filterless purifier review.

10. Customer Support and Warranty

Most products come with a warranty.There are a few manufacturers who offer limited lifetime warranties. But, we think you should look for minimum of a three to five year warranty.  Also, when we review a purifier we typically consider and include feedback from consumers regarding customer service experiences. Before you buy check the warranty and look into support experiences.

What is an Air Purifier?

details of what an air purifier doesAn air purifier is an appliance that filters various contaminates from the air indoors. Air purifiers are very popular in the homes of people who suffer from allergies and asthma, as well as in the homes of smokers and pet-owners, but there is no reason that the average person cannot benefit from breathing cleaner air.

There are many different contaminates that find their way into our homes, dust, pollen, pet dander, and mold just to name a few. Some of these particles are suspended in the air, while others accumulate over time on surfaces like couches, beds, and carpeting. To see evidence of this look no further than the dust on your nightstand.

There are also chemicals, gases, smoke, and other odors that are present in our homes. Air purifiers can work to eliminate these things as well. More details about air purifiers can be obtained by reading the article here.

How Does an Air Purifier Work?

Air purifiers work to remove these contaminates from the air before they accumulate. There are several different types, but they all operate on the same basic premise. The air purifier uses a fan to circulate the contaminated air through a filter or other device designed to collect the foreign particles before returning clean air into the environment.

Choosing a Size

There are several different sizes and shapes of air purifiers, and these things need to be taken into account when choosing the model that is right for you. There are larger models for those people with bigger homes who require more air to be purified, and there are also smaller compact models that are perfect for college students living in dorm rooms.

The Different Types of Air Purifiers

There are a variety of different air purifiers to suit whatever needs you may have. The most apparent differences are in size and appearance, but the technological differences can be quite confusing. Some use simple filters, while others use complex technology originally used in space shuttles by NASA. The best air purifier often uses several of these different technologies within the same machine.

Air Ionizers

air purifer technologies available in the market in 2015Air Ionizers do not utilize a conventional filter to purify the air. Instead, they rely upon the generation of ions to magnetize contaminants in the air so they bind together and drop to the ground. This technology prevents contaminants from staying airborne, keeping them out of your lungs.

Higher quality models will incorporate electronic rods or ceramic plates that are capable of catching the newly charged contaminants inside the machine. These plates can be convenient because they are able to be cleaned simply by wiping them with a cloth.

The standalone problem with air ionizers is the controversy surrounding the health effects of ozone, which is produced during the ionization process. Experts say that those with breathing disorders should avoid ionizers altogether. Others regard ozone as a lung irritant.

The catch-22 here is the ozone produced by air ionizers is what is primarily responsible for the crisp, clean smell that is loved by many consumers.

Ultraviolet Light

Ultraviolet lights are never used as a standalone component to purify air. However, several manufacturers use this technology on the inside of their machines to eliminate germs, bacterial, and other dangerous airborne pathogens that can get trapped in the filters.


standard filterA pre-filter is commonly used as part of a three-step process in most HEPA machines. The function of the pre-filter is to trap as much large debris as possible, like dust and hair. This elongates the lifespan of both the carbon filter, and the HEPA filter.

Carbon Activated Filters

Carbon Activated filters are not typically used to purify the air on their own. However, these filters are an essential compliment to other air purifiers, especially HEPA models but also in some ionizers as well.

In HEPA machines the carbon activated filter rests between the pre-filter and the HEPA filter. Carbon filters are effective because they have a unique chemistry that allows them to filter chemicals, gases, and odors in a way that HEPA or ionizers cannot accomplish on their own.

HEPA Air Purifiers

hepa filter can remove smokeHigh efficiency particulate air machines are almost universally agreed upon as the kings of air purification.

HEPA filters were originally designed for use in the Second World War, and in modern times they are commonly used to purify air in commercial airliners.

The United States government has set strict regulations for a filter itself to qualify as HEPA, in the sense that it must remove 99.97% of contaminants larger than 0.3 microns, which means that virtually all dust, pollen, mold, pet dander, and similar contaminants are effectively eliminated through the use of HEPA filters.

Typically, HEPA machines use a three-step filtration process, where air is first filtered through the pre-filter and then the carbon filter, before finally being circulated through the HEPA filter. This process ensures the longevity of the HEPA filter by catching particles in the other filters.

Reviews of high-power Air Purifiers

The air purifiers reviewed below consist of high-power tower air purifiers. These can purify the air of an entire house even! They are well worth the investment.

GermGuardian AC4825 3-in-1 Air Cleaning System

gemguardian AC4825 best rated air purifier review

The GermGuardian AC4825 3-in-1 Air Cleaning System is Amazon’s best-selling HEPA air purifier. It incorporates multiple purification technologies to warrant being the best of the best. It has a compact streamlined design, and it weighs only seven pounds. Over multiple reviews it is favored by people with asthma more so than many other air purifiers, and is extremely effective at eliminating odors.

The AC4825 is a medium sized machine that works well in small to medium sized rooms. However, GermGuardian also makes the AC5000E which is a larger version of the medium sized model, which works well in medium to large sized rooms. Those with pets may want to consider the AC5250PT, which is identical to the other two models, but has a special antimicrobial filter to prevent the odor caused by household pets. Read the GermGuardian AC4825 air purifier review here.


  • Pre-filter and a charcoal filter work simultaneously to screen out larger pieces of matter
  • HEPA filter guards against dust, mold, and pet dander
  • Ultraviolet light works to eliminate germs and other viruses

Honeywell Pure HEPA Round Air Purifier

Honeywell 50250 S air purifier for smoke reviewThe Honeywell Pure HEPA Round Air Purifier can be considered a charcoal or a HEPA air purifier because it utilizes both technologies. However, it is Amazon’s #1 Best-Seller in the charcoal air purifier category, and seems to be a favorite amongst animal lovers.

It is a fairly large unit capable of purifying large rooms of almost 400 square feet. It is also designed for efficiency, as its round shape allows it to have 360 degrees of airflow. This allows for it to remain effective despite where you place it in your home.

The only knock on this machine is that it can be noisy depending on the speed of the fan. For more information, read the detailed review of the Honeywell round air purifier.


  • Carbon activated pre-filter helps extend the life of the HEPA filter
  • A smart filter monitor reminds you when the filter is in need of a change
  • Easy to change filters
  • 3 fan speed

Five Star Ionic Air Purifier Pro

fivestar FS8088 best air purifier review

One of the most reputable air ionizers is the Five Star Ionic Air Purifier Pro. This model is sleek and compact. Because of its small size it can fit in a variety of places like on top of a dresser or on the kitchen counter. This unit does well in small rooms, but because of its small size it is not suited for large spaces. The Five Star is also effective for reducing odor.


  • 2 fan speeds – One setting for sleeping another for fast circulation
  • Ultraviolet light to kill germs and bacteria
  • Electrostatic dust rod collector – no need to buy new filters!
  • Washable Activated carbon filter – reduces odor such as smoke
  • Blue nightlight with separate on/off switch

Best Choice Living Fresh Ionic Air Purifier

best choice living fresh iconic air purifier review

If you are in the market for a bigger ionizer you do not need to look any further than Best Choice Products Living Fresh Ionic Air Purifier. This ionizer is elegantly designed and manufactured from solid cherry wood. This unit is also great at reducing odors.


  • Purifies up to 3,500 square feet. – entire household!
  • Filter captures contaminants – no replacement filters
  • Adjustable controls with sturdy knobs

Honeywell HFD-120-Q Tower Quiet Air Purifier

honeywell hfd120 quiert air purifier tower review

The Honeywell HFD-120-Q Tower Quiet Air Purifier is another multiple technology HEPA machine. However, this Honeywell is a bit different than most of the other air purifiers on the market. It uses an ionizer in addition to the HEPA filter. The most notable quality of this particular machine is the lack of noise that it makes. Many different reviews rave about how quiet this particular model is, while at the same time moving massive amounts of air.


  • Oscillating tower design with a weighted base – only purifier that does so
  • Permanent washable filters with indicator light to alert user of a dirty filter
  • Built-in ionizer to further enhance air purity

Reviews of the Best Compact Air Purifiers

The air purifiers reviewed below are compact – fit on your desk, or that small corner in your room. These are efficient and save on space.

Honeywell Compact Air Purifier with Permanent HEPA Filter

honeywell permanent hepa air purifier

If you are looking for a more compact model you can stop at the Honeywell Compact Air Purifier with Permanent HEPA Filter. This little machine works great in rooms up to eighty-five square feet, which can be perfect for small offices, dorm rooms, or any other compact space. Its compact design allows it to be placed on top of a desk, table, or a dresser.


  • A permanent HEPA filter, which means there are no filters to change
  • An additional washable pre-filter
  • Built-in ionizer
  • Variable fan settings
  • Clean filter indicator light

Honeywell QuietClean Compact Tower Air Purifier

honeywell quiet clean compact tower purifier

Another compact option is the Honeywell QuietClean Compact Tower Air Purifier. This unit is only seventeen inches tall, which makes it highly compact, yet it is shaped very differently than our last Honeywell mention.

The unique tower design makes it easy to stow away discreetly in a corner. It is also very light and portable, making it an attractive choice for someone who needs to move it around a lot.

Users on Amazon reported overwhelming efficiency neutralizing pet odors with this machine. It is also a good choice for bathrooms. Keep in mind this is a very simple machine, that only includes two variable fan settings.

Holmes HEPA Type Desktop Air Purifier

holmes hepa compact desktop air purifier review

While Honeywell makes several good compact air purifiers, the Holmes HEPA Type Desktop Air Purifier, is the best-selling electrostatic purifier on Amazon. It is capable of purifying up to 109 square feet. We have a more in-depth review, here.

Some of its features include:

  • A HEPA type filter
  • Three variable speed settings
  • Optional ionizer
  • Filter enhanced with Arm and Hammer Baking Soda – reduces odors!


There is a different type of air purifier to suit everyone’s individual needs. We are fortunate that a variety of models exist that utilize a variety of different technologies, to provide us with cleaner air to breathe. Hopefully, these best air purifier reviews helped you make a decision.

No matter what type of technology the unit uses, there are two simple tips you can follow to ensure the longevity of your machine. The first is to keep your air purifier clean. If you have an ionizer be sure to clean the plates off every so often. Replace filters if you need to. The second is to keep your machine clean. No matter what type of machine it is, it is almost a guarantee that getting water inside of it will affect its performance.


More Guides and Reviews


Share this Story

Leave a Reply

Your email address will not be published. Required fields are marked *