Do Air Purifiers Work? 

Time for some real talk.

Are you aware that our indoor air quality is worse than outdoors? There are many airborne pollutants within a home, including mold spores, pet dander, allergens, and VOCs. If you have a runny nose, cough, or continuous headaches worse indoors, your home might just be severely polluted.

Many homeowners look to improve their home environment for themselves and their loved ones. So, what if we told you there’s a device that cleans the air that you and your family breathe?

Air purifiers have grown in popularity in recent times. These devices promise to improve your home environment, but do they work? Let’s find out.

Do Air Purifiers Really Work?

We can answer this with a simple yes; air purifiers really do work. However, it’s important to understand what they can and can’t do, which we’ll explain further down.

Air purifiers are designed to strip the air of pollutants. This includes allergens, dust, spores, pollen and more (1). Some purifiers will also capture or reduce bacteria, viruses and odors. However, not all units will be able to do this.

Additionally, it’s crucial to understand that not all units will be able to catch volatile organic compounds. These are commonly found in aerosol sprays and common household cleaners (2).

If you’re struggling with allergies or asthma, an air purifier will be beneficial as it removes common allergens. However, it will only remove airborne allergens; it won’t be able to remove allergens embedded in furniture or flooring.

For your air purifier to work efficiently, it’s crucial to replace the filters often. Most manufacturers will provide you with useful guidance. However, the exact time depends on a few factors, such as usage and air quality.

It’s also important to be realistic when using an air purifier. Many companies will claim their products to have an efficiency of 99 percent. However, air purifiers are tested in controlled rooms, so effectiveness can vary.

Where the unit is located also plays a significant role in how effective it will be. When installing your new air purifier, you must read the directions to ensure it’s placed in the correct spot. Some units require a certain space between them and the wall, while smaller units can usually be installed on a table or desk.

How Do Air Purifiers Work?

Air purifiers work by drawing air into via a fan powered by a motor. The air is then passed through a series of filters — the number of usually filters depends on the unit. Some air purifiers consist of a five-stage filtration system, while others use two or three.

However, as we mentioned above, there are various types of air purifiers and they all work differently. Let’s take a closer look:


One of the most effective and popular air purifiers is the filtered type. These are fitted with one or more filters that capture and remove pollutants as they pass through. How effective this type is depends on the filter and its quality.

Most filtered air purifiers are fitted with a HEPA filter. These are meant to capture up to 99.97 percent of airborne pollutants at the size of 0.3 microns (3).

However, not all filters marked as HEPA are genuine. There are HEPA-type, HEPA-grade or HEPA-like filters constructed similarly to true HEPAs. But these types will only capture 99 percent or less of pollutants.

Filtered air purifiers are usually also fitted with a pre-filter and an activated carbon filter. The pre-filter is designed to capture larger particles such as pet hair and large dust particles.

The activated carbon filter is also an essential part of an effective air purifier. You see, the HEPA filter won’t capture everything. Things like gases, odors and VOCs will generally slip past the grip of the HEPA fibers.

However, the activated carbon filter will effectively absorb unpleasant odors, gases, fumes and VOCs. If your air purifier has an activated carbon filter, you must replace it regularly — usually around every two to three months. These filters can only hold so much before they become less effective or not effective at all (4).


Air ionizers are the next most popular air purifiers on the market. Unlike the filtered version, these do not draw air in to pass it through a filter.

Ionizers work instead by emitting electrically charged ions into the room where they’re installed. The negative ions will bind to particles in the air (dust, pollen, allergens). These will then weigh them down and they eventually drop to the ground.

Some ionizers are fitted with a “collecting plate,” which is an oppositely-charged metal plate that attracts the electrically charged particles. The particles are then collected on the plate that you can wipe clean when needed.

On the other hand, some ionizers do not use a collecting plate. These are less effective since the particles will drop to the nearest surface, such as the wall, couch, carpet or bed. You’ll then have to spend additional time cleaning to get rid of the unwanted pollutants.

One of the more negative effects of ionizers is their byproduct: ozone. Ozone is a lung irritant and can trigger asthma attacks in sensitive individuals. Exposure to ozone can also trigger other effects such as nausea, headaches, coughing and fatigue (5).

Ionizers are commonly sold as standalone units. Alternatively, you can find filtered air purifiers with an ionizing feature.

Take Note

If you’re considering an ionizer, choose carefully. Opt for a unit that’s CARB-certified as these emit only safe levels of ozone (6). If you’re allergic or asthmatic, we highly recommend that you do not use an ionizer.

Are Air Purifiers Worth It?

As we saw above, air purifiers really do work and can definitely make a difference. However, whether or not you need an air purifier depends on a few factors. Air purifiers aren’t cheap; the initial price can range from anywhere around $50 to well over $1,000.

There are also maintenance costs to be accounted for as well. Filters need to be changed regularly, and these can be expensive, depending on the brand.

You can find filtered air purifiers with washable filters. These are easily cleaned, dried and put back into the unit. Ionizers, too, are easy to maintain as they don’t have any filters.

To know whether or not air purifiers are worth it, let’s see some of their advantages and disadvantages.


Good for Families

As parents, we want to protect our children from harm, even the unseen dangers. Creating a safe home environment for your children to thrive in is a priority for many parents.

Children are more sensitive towards allergens and contaminants in the air, compared to healthy adults. So if you have a newborn in the house, keeping the air clean becomes even more important.

Placing a small air purifier next to the crib will help to clean the air your baby breathes. This, in turn, lowers the risk of your child developing asthma or allergy symptoms.

Good for Pet Families

We love our pets like we love our children — they have a special spot in our hearts and home. But unfortunately, their presence is very much noticed. Shed fur, odors and dander are common allergy and asthma triggers.

If you’re struggling with these aspects of being a pet owner, you could benefit from an air purifier. A true HEPA filter will capture dander and an activated carbon filter will absorb unpleasant odors.

Removes Odors

If you’re struggling with unpleasant odors lingering in your house, an air purifier can help. Most filtered units are fitted with an activated carbon filter that absorbs odors and creates a more neutral space.

Traps Allergens

Did you know that 30 percent of adults and 40 percent of children in the US are affected by allergies? If anyone in your household is dealing with allergies or asthma, an air purifier will be very beneficial (7).

A true HEPA filter is highly effective at trapping allergens such as dust mites, pet dander and pollen. It will capture particles at the tiny size of 0.3 microns. To give you an idea of just how small this is, we’re unable to see anything smaller than 10 microns (8).

Neutralizes Smoke

Smoke is not something you want in your house. And if you have children in the house, keeping smoke at bay becomes even more important. Air purifiers will effectively remove smoke caused by cooking and tobacco. That way, you and your family can enjoy a healthy atmosphere.



For your purifier to work at an optimal level, you need to care for it. Regular maintenance is a must. If your unit uses replaceable filters, these need to be changed regularly.

Not only can this be inconvenient if your days are busy, but it can also be expensive (as we explained above). On the other hand, if you have an ionizer, you’ll need to deep clean more often to remove all of the fallen particles.


The manufacturer might claim an efficiency rate of 99 percent, but you shouldn’t expect this. Typically, these companies test their products in controlled conditions.

Tests are also usually done on the highest setting. In reality, though, you’re more likely to use lower settings due to noise.

Also, allergens such as dust mites often reside within mattresses, couches and carpets. Sadly, air purifiers can’t reach these embedded particles.

Noise Levels

As we briefly mentioned, noise levels are an issue for many homeowners. Some air purifiers can be annoyingly loud when on any setting other than low. Many compare the sound to a large fan blowing continuously, while others compare it to a loud buzzing.

Will an Air Purifier Benefit Me?

Whether or not you will benefit from an air purifier is a personal decision. It’s important to consider your home environment and the health conditions of the people living in your house. Ask yourself the following before buying an air purifier:

  • Do you or anyone in your house have allergies or asthma? If so, you can greatly benefit from an air purifier as it will remove allergens.
  • Do you live in a big city or close to a busy road? If so, an air purifier will help to reduce dust and car emissions.
  • Are you or someone in your house prone to infections? Some air purifiers are designed to capture and reduce bacteria and viruses.

If the above points don’t apply to you, an air purifier might not be beneficial. It could be an expensive, unnecessary purchase if there’s no need for it.

There are many ways to improve your indoor air quality without raising your energy bills (9). Try the following:

Air Purifier Myths

Air purifiers can be highly beneficial if truly needed. However, there are many myths about these devices. These cause a lot of misconceptions and false expectations for people new to air purifiers.

You Won’t Need to Clean as Often

This is one of the biggest myths about air purifiers. Many new buyers think that air purifiers will reduce the need to clean as often. However, this is not entirely true.

Air purifiers will remove dust and other particles from the air, but they will not remove dust or dirt from surfaces. It’s important to keep up your regular cleaning regime to assist the purifier and create a healthy home environment.

An Air Purifier Will Fix Your Allergy Blues

Air purifiers are well-known for improving your home environment by eliminating allergens. However, you shouldn’t expect your air purifier to be the perfect solution. This is a common mistake made by manufacturers who specifically market their purifiers as the answer to allergies.

You must continue to clean regularly, wash your bedding and vacuum carpets to get rid of allergens. Additionally, consider running a dehumidifier to reduce the chance of mold or mildew growing (10).

If the Purifier Uses a HEPA Filter, It Must Be Good

HEPA filters are high-efficiency filters, but not all HEPAs are alike. As we discussed above, there are many different types. What you should look for is the one marked as true HEPA.

It’s also important to note that bacteria and mold can accumulate on the fibers within the filter. Spores and bacteria can then be released back into the air, re-contaminating your room. To avoid this, it’s crucial that you replace filters when needed.

Some units are also poorly constructed. For the filter to work effectively, it must be in an airtight case. If the case isn’t airtight, the contaminated air can escape around the filter, reentering the room.

The Air Purifier Will Remove All Odors

Some people think that their air purifier will eliminate all odors. Therefore, they might leave the litter box or not take the trash out as often. Sorry to burst your bubble.

An air purifier will eliminate odors to some extent, but it all depends on the carbon within the filter. If there are many unpleasant odors within your house, the filter has to be replaced more often as well.

Air Purifiers Remove Viruses and Bacteria

This is a common misconception about air purifiers. You’ll often find manufacturers marketing products with the promise that they’ll kill or remove bacteria and viruses. Unfortunately, this is simply not true.

You see, even if your unit is fitted with a true HEPA filter, some bacteria and viruses are simply too small to be captured. For this purpose, some companies add UV-C lights. For these, though, the lightbulbs need to be replaced often.

Finding the Right Air Purifier for You

If you think that you’ll benefit from an air purifier, it’s important you know what to look for. There’s a vast array of choices available on the market, so it can become overwhelming.

What to Look For

HEPA Filter

When buying an air purifier, we always recommend that you choose one with a true HEPA filter. These are the most effective and the standard for the industry.

A true HEPA filter will benefit you the most, whether you have allergies, asthma or simply want to improve your home environment. True HEPA filters can last you up to 12 months, some even 18 months. Refer to the directions provided by the manufacturer for more specific details.

Activated Carbon Filter

An activated carbon filter might be simple, but it’s highly effective. The carbon will absorb odors, VOCs and fumes. Choosing an air purifier that uses a true HEPA filter along with activated carbon, is sure to be effective.


Air purifiers can come with highly beneficial features to help make operation easier. Here are some of the features we really appreciate:

  • Auto mode: In this mode, most units will monitor the air quality using sensors. The purifier will then adjust the fan speed to suit the room.
  • Sleep mode: If you enjoy cleaner air while sleeping, you’ll like this feature. When in sleep mode, the air purifier will operate at the lowest speed and lowest noise level. Some units will have an optional nightlight — excellent for a child’s room or nursery.
  • Programmable timer: Having a timer on your air purifier is excellent if you often forget to turn it off. It’s also beneficial if you want to use the unit for a certain number of hours during the night.
  • Filter replacement indicator: Remembering when to change the filters can be tricky, and even if you mark the calendar, you might be off. However, some units come with an indicator that lets you know when it’s time. High-end purifiers also have sensors that monitor usage and air quality to calculate the exact time when replacement is needed.
  • App: Being able to control and monitor your home air, even when you’re not home, is a feature often sought after. Many air purifiers can be connected to an app that allows you to monitor and control the air quality from anywhere.

Energy Consumption

Air purifiers aren’t cheap, and they can be just as expensive to run. Most homeowners will run their purifier nearly around the clock, which means it will reflect on the energy bill.

Luckily, you can find air purifiers that use less energy. A good thing to look for is the Energy Star rating.

Fan Speed Options

We always appreciate the option of different fan speeds. Some units will have two-speed options, while others have four.

Whenever you feel like the room could benefit from a little extra power, set it to the highest fan speed. But when you’re in the room and want some quiet time, we’d advise setting it to the lowest speed.

What to Avoid


Despite the lower price and easier maintenance, we don’t recommend that you buy ionizers. These will emit significant amounts of ozone, which will be harmful to you and your family.

Ionizers are also not recommended for people with allergies or asthma. Because an ionizer won’t remove allergens from the air completely, it’s not effective. You will need to do extra cleaning to keep dust and allergens away.

The Verdict

Many homeowners choose to get an air purifier to improve their home environment. The indoor air quality is significantly more polluted compared to outdoors. However, does this mean you need an air purifier?

We concluded that air purifiers can be worth it if you really need one. If you or anyone else in your household is having trouble with allergies or asthma, an air purifier will help. Before purchasing a unit, though, consider why you might need one, and why you don’t.

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About the Author

Matthew Sullivan

Matthew is a freelance writer with several years of experience in DIY and HVAC. For as long as he can remember, Matthew has always found great pleasure in taking things apart and learning how to put them back together.