Best Air Purifier Buying Guide | What To Know

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Unleashing the Secrets to Purchasing the Perfect Air Purifier: The Ultimate Guide

Navigating the labyrinth of air purifiers in today’s market can be complex, with each touting its unique features and cutting-edge technology. But the real question is: how do you identify the ideal one for you?

There is important information to know to help you select the best one for your needs such as the filter type and noise level. This article will provide what you need to know about air purifiers.

Learn about the differences in filtration, noise levels, and effectiveness of air purifiers in this buying guide. These tips will help you purchase the right purifier for you.

And if you want to learn some other skills such as how to fix issues with an instant pot, or looking to buy a water filter, or wondering if a Dyson Fan is worth it, I’ve got you covered with my other articles.


What is an Air Purifier?

An air purifier is a specialized device with a significant role in enhancing indoor air quality. Its primary attributes include:

  • Purifying function: The core purpose of an air purifier is to cleanse the surrounding air, thus elevating the standard of the air you inhale.
  • Mechanism: The device operates primarily through the use of filters, coupled with supplementary techniques in certain models.
  • Particle Removal: Air purifiers are proficient in trapping and eradicating a wide range of detrimental particles, such as:
  • Dust
  • Pollen
  • Pet dander
  • Smoke
  • Advanced Models: Some superior models have the capability to remove even ultrafine particles or volatile organic compounds.
  • Health benefits: The use of air purifiers can result in a healthier living environment. They are particularly helpful for individuals prone to allergies, asthma, and related respiratory ailments.

Indoor air contains pollutants of all kinds, from dust particles, smoke, pollen, mold, etc. These pollutants can affect a person’s health and cause allergies since people spend the majority of their time indoors.

This is where an air purifier comes in, its job is to remove these pollutants and provide clean, fresh air for us to breathe. An air purifier can be a large whole-house unit or a smaller portable unit designed to clean the air in a room.

Types of Air Purifiers

In our quest for clean air, we find a variety of air purifiers available in the market, each employing a different technology to combat air pollutants. When deciding on the best type for your needs, it’s important to understand the functionalities and benefits of each.

  • HEPA Air Purifiers: High Efficiency Particulate Air (HEPA) purifiers use a dense filter to trap airborne particulates. Known for their high efficiency, they can capture particles as small as 0.3 microns including dust, pollen, and pet dander. However, they’re not as effective against odors, chemicals, and gases.
  • Activated Carbon Air Purifiers: These purifiers utilize a bed of activated carbon to absorb odors and gases. They’re excellent for removing smells, chemical emissions, and smoke, but not as effective for particulates.
  • Ionic Air Purifiers: Also known as ionizers, these purifiers work by releasing charged ions into the air. These ions attach to pollutants, making them heavy enough to fall to the ground or stick to surfaces. Despite their silent operation and energy efficiency, they produce trace amounts of ozone as a byproduct.
  • UV Air Purifiers: Utilizing ultraviolet light, these purifiers kill airborne microorganisms such as bacteria and viruses. While they are exceptional at germicidal tasks, they don’t remove particulates or odors.

Remember, the best air purifier is one that fits your specific needs. You may consider a combination of technologies for comprehensive air purification.

Types of Air Purifiers

Understanding Air Purifier Functionality

Air purifiers operate based on a fundamental principle: drawing in air and passing it through an intricate filtration system. There are various types of filters, each playing a unique role in the purification process. Some filters specialize in eliminating gaseous pollutants like odors, while others excel at capturing particles such as pollen.

It is important to note that filters designed for particle removal may not effectively combat odors and gases. On the other hand, filters proficient in odor removal might not be as effective in capturing particles. However, certain advanced air purifiers incorporate both types of filters, providing a comprehensive solution for air purification.

To effectively eliminate odors, it is advantageous to choose an air purifier that features both an activated carbon filter and a HEPA filter. An exceptional example of such a product is the Bissell Smart Purifier with HEPA and Carbon Filters for Large Rooms.

For an even superior purifying experience, consider a medical-grade air purifier like the IQAir HealthPro Plus – Medical-Grade Air Purifier with H13 HyperHEPA Filter for Particles, Gases, & Odors.

These options provide a powerful combination of filters, effectively targeting both particles and gaseous pollutants to ensure the air in your indoor environment is as clean as possible.

What Should I Look For In An Air Purifier?

You want to look for the efficiency of an air purifier as well as its noise level. Part of the efficiency is the airflow rate, shown as clean air delivery rate(CADR). CADR is measured in cfm and shows how much fresh, clean air is provided. A higher CADR number is better.

Noise is also a factor in selecting an air purifier. If a unit is too loud, you may turn it off, thus removing its effectiveness at removing pollutants from the air.

When buying an air purifier have these considerations in mind:

  1. Size of the room to clean. Multiply the length by the width of the room to get your square footage.
  2. What do you want to filter out? Choose a filter for particles, odors, or both.
  3. The air purifier’s rating. Check its CADR rating and noise level.

According to the EPA, a 400-square-foot room should have an air purifier with a CADR rating of at least 260 cfm.

Room Size

When purchasing an air purifier, the first factor to consider is the size of the room where you plan to use it. Air purifiers are designed to handle specific room sizes. Make sure to check the purifier’s Clean Air Delivery Rate (CADR) which indicates the volume of filtered air delivered by an air cleaner.

Types of Contaminants

Different air purifiers are designed to handle different types of contaminants. Some are more effective against particulates like dust, pollen, and pet dander, while others are better at removing gases and odors.

Choose a purifier that’s designed to handle the specific contaminants you’re concerned about.

Noise Level

Air purifiers can vary widely in terms of noise level. Some models are whisper-quiet, while others can be quite loud, especially on higher settings.

Look for an air purifier with a noise level that you find comfortable, particularly if you plan to use it in a bedroom or study.

Energy Consumption

Air purifiers can consume a significant amount of energy, especially when run continuously. Before buying, check the purifier’s energy consumption.

Energy Star certified models are typically the most energy-efficient.

Filter Replacement & Maintenance

Finally, consider the cost and frequency of filter replacement. Some air purifiers require regular filter changes, which can add to the ongoing cost of the unit.

Also, check if the unit is easy to open for filter replacement and cleaning.

How Do I Select An Indoor Air Purifier?

Now that we know a little more about air purifiers, let’s put all that information together and talk about how to select one for your house.

As mentioned above, when looking into purifiers check their 1) CADR rating, 2) What it filters, 3) Its noise level, and 4) note the cost of replacement filters.

What It Filters:

To remove allergens and other airborne particles, select a unit with a HEPA filter.
To remove odors and other gaseous pollutants, select a unit with an active carbon filter.
To remove both particles and odors from the air, select a unit with both types of filters.

Its Noise Level:

An air purifier has internal fans that draw air into the unit and through its filters. This fan produces some amount of noise which can be disturbing to people nearby. If the noise causes you to turn off the air purifier, then it is not useful to own.

Look for the noise level on the specs of a filter, it should be listed as dBA(decibels). A lower dBA indicates a quieter air purifier and is what you want. Obviously, when you increase the fan speed to maximum, the noise will be louder than when the fan is at its lowest setting.

A good dBA level for a fan on a low setting is about 21 dBA, while on max. the level may be about 50 dBA.

As an example, I’ve listed the specifications of the Blueair Classic 605 Air Purifier from Amazon to show you what to look for. Note that Consumer Reports gave this a recommended rating of 88.

Blueair Classic 605 Purifier
CADR Pollen640 cfm
CADR Dust and Smoke500 cfm
Filter Type: electrostatic and mechanical filtration99.97%
Energy consumption15 – 100 W
Sound level33 – 62 dB(A)
Room Size775 ft.

Find The Right Purifier By Room Size

<200sq ft.

Medium 200-400sq ft.

400-600sq ft.

Extra Large >600sq ft.

Why Do You Need To Care About Indoor Air Quality?

Indoor air contains particles of various sizes that can affect your overall health. The concentrations of some pollutants can sometimes be 2 to 5 times higher in indoor environments than outdoors.

Very small particles( <10 micrometers) can be inhaled into your lungs and can lead to nose and throat irritation, and even heart issues. An air purifier mold killer can remove mold with a UV lamp to improve air quality.

Some common sources of air pollution particles derive from the outside, cooking, cleaning products, fireplaces, smoking, and more.

You can take steps to reduce your exposure to indoor pollutants by providing adequate ventilation around stoves, fireplaces, etc. Also, regularly change and replace the air filter in your home’s A/C unit. Finally, use an air purifier in rooms that you frequently are in for an extended amount of time.

Air purifiers can significantly reduce a room’s pollutants but are generally not effective to clean a whole house as most are designed for single room sizes.

Top Air Purifier Brands

Quality Air Purifiers




Bissell Smart Purifier
w/ HEPA and Carbon Filters
for Large Rooms.

  • Active Carbon Filter
  • HEPA Filter
  • Large Room Coverage, filters 1252 sq. ft. with 1 air change/hour.
  • Quiet Fan Speeds

IQAir HealthPro Plus – Medical-Grade Air Purifier

  • Medical-Grade
  • Filters Particles, Gases, Odors
  • Filters particles 100x smaller than 0.3 microns, much smaller than a virus

Blueair Classic 605
Air Purifier

  • Extra-Large Rooms
  • Wi-Fi Enabled
  • HEPASilent technology

How To Improve Indoor Air Quality

Although air purifiers are effective at improving the indoor air of your home, there are some additional steps you can take to help as well.

5 Tips To Improve Indoor Air:

  • Clean and vacuum your home regularly. Vacuuming and dusting are exceptional ways to remove pet dander and other particulate matter that have settled on and in surfaces.
  • Wash bedding and other linens regularly. Bed sheets especially get a build-up of skin cells, dander, and dust mites. Wash these and other linens and towels weekly to improve air quality and reduce allergens.
  • Open windows for fresh air. Opening your windows can provide fresh air into the home as long as the outside air is clean too.
  • Ventilate around cooking appliances. Use proper ventilation around cooktops and ovens to rid the kitchen of odors and other pollutants.
  • Replace the A/C unit’s air filter as scheduled. Your home’s A/C unit has its own filter that must be changed on a schedule. Some filters require changing every 90 days, whereas others every 6 months or so.

Frequently Asked Questions

How long does it take for an air purifier to be effective?

It depends on its size and CADR rating. It may be from 45 minutes to 1 hour to be effective in a room.

Should I sleep with an air purifier on?

Yes, it is most effective to run an air purifier continuously. If it is off it is not cleaning the air.

Do air purifiers dry out sinuses?

No, air purifiers remove pollutants from the air, they do not dehumidify or adjust the moisture in the air.

How do I know if my HEPA filter is dirty?

Two ways to know if the HEPA filter is dirty. First, visually check the filter. Second, look for an indicator light on the unit to tell you to replace the filter.

Can an air purifier help with coughing?

Possibly, it depends on the type of filter and allergens in the air. HEPA filters can reduce allergens in the air and be effective against coughing if used properly.


  1. “Indoor Air Quality (IAQ)”. U.S. Environmental Protection Agency. Retrieved 2022-03-23 from [EPA].
  2. “What is a HEPA filter?”. U.S. Department of Energy. Retrieved 2022-03-23 from DOE.
  3. “CADR (Clean Air Delivery Rate)”. Association of Home Appliance Manufacturers (AHAM). Retrieved 2022-03-23 from [AHAM](
  4. “Blueair Classic 605 Air Purifier”. Amazon. Retrieved 2022-03-23 from Amazon.
  5. “Blueair Classic 605 Air Purifier Rating”. Consumer Reports. Retrieved 2022-03-23 from Consumer Reports.
J.S. Diyhouseskills

I’m J.S., I created and am the content manager at I do the research and write the articles that appear on this website. I’ve learned many household skills during my life and think it’s important to at least know the basics so that you can save yourself time and money… READ FULL BIO >