Everything You Need To Know About Air Filters |

Everything You Need To Know About Air Filters

Rustina March 20, 2023

By Rustina, Contributing Writer

Everyone likes to have a breath of fresh air every now and then. It’s just common scents 😉. Between allergies and the feel of stagnant air, we need relief for our noses and airways. One great way to turn that around to nice, fresh air is with air filters and purifiers. 

So What’s In Our Air?

There are contaminants in the air from ordinary, everyday items like the drywall in your home to mold spores to even train wrecks as we are discovering recently. Some air pollutants are monitored or reported regularly to the EPA by state and county based agencies. These are measured using weather forecast models, satellite images, air monitoring data, and computer models that estimate how pollution travels. 

Ozone and particle pollution are the two most widespread pollutants tracked. Ozone forms where different types of pollutants react in sunlight. Those pollutants may be from vehicles, power plants, and even chemicals such as cleaners and paints. Particle pollution (or particulate matter) is things like dust or pollen, any tiny particle or liquid that takes up space in the air we breathe. These forecasts are given 8-24 hours ahead of time, and are not “a live indication of pollutants,” but a way to help gauge it. You can check your area on the US government’s Air Quality Index.  

Why It Matters

In today’s world, there are so many toxins out there. We have to wonder about additives in our food to pharmaceuticals and other chemicals! Check out this list of The Toxic Twenty and How to Ditch Them. Reducing the chemicals that we bring into our home, reduces the breakdown and pollutants in our home. Just like how our hair breaks down into dust, so do the objects we surround ourselves with every day. 

It isn’t just mundane things that we need to be cautious of either, as we are witnessing (and unfortunately for many, living and dealing with currently) in Ohio. Events outside of our control can cause air pollution as well. Knowing we have the tools and knowledge to help reduce these risks can go a long way.

What Types of Air Filtration Exist

So, what are we supposed to do?  What kind of air filtration should we be using?

Air filters can be used to remove particles like dirt, dust, mold, grit, odors, and even some gaseous pollutants from the air. There are two main types of air filtration and many techniques. The two main types are Whole House (usually referred to as Air Filters) or Room Filters (usually referred to as Air Purifiers). 

The two different approaches to air filtration:

  • Air Filters

    • Usually the whole house, mechanical (and sometimes added electrostatic) air filters in the HVAC (Heating Ventilation and Air Conditioning) system
    • Pros:
      • Most useful for those who have special medical needs, pets, or extreme allergies.
      • Reduces air pollution in every room.
      • Discreet (in ductwork) and very little maintenance required.
      • Usually very quiet.
    • Cons
      • More costs in the beginning.
      • Since it uses forced air, it cannot filter small particles as well since that may restrict airflow.
      • Requires an HVAC technician for installation.
      • Requires clean and efficient duct work for a consistent performance.
  • Air Purifiers

    • Usually portable units that service a specific area such as a room
    • Pros
      • Can filter smaller particles since airflow restriction is not as worrisome as it is for restricting an HVAC unit.
      • Less costs in the beginning.
      • Portable room to room.
      • Easy to use, no special installation required.
      • No ductwork modifying required so easy for apartment use also.
    • Cons
      • While they do great, since it does not filter the whole house, recontamination is always occurring every time a door opens.
      • Filters can be expensive and require more frequent cleaning or changing – especially the units that filter the smaller sized particles like HEPA (High-Efficiency Particulate Air) and ULPA (Ultra-Low Penetration Air).
      • Requires multiple units to cover large areas.
      • Since each unit can only process a specific volume of the air, you will need to calculate what size filtration you need/how many units/etc.
      • Ion units may create trace amounts of ozone that is a potential lung irritant as a byproduct of its process.

Are Air Filters/Purifiers Quality Tested?

Yes. Air filters are rated using the Minimum Efficiency Reporting Value (MERV). MERV ratings measure the air filter’s performance based on how effectively it removes airborne particles. The higher the rating, the better the smaller particles are removed. The MERV ratings go from 1-20, however most residential ones peak around 13. For systems higher than 13, special equipment would be needed for whole house air filters that work alongside the HVAC units – not within them due to airflow restriction.

How Do Whole House Air Filters work?

Most whole house air filters are part of the HVAC and ductwork. The filter is usually near the base of the HVAC unit. As air is pushed through the duct work, it goes through the filter (air throughout the house is returned to the unit for filtering again through cold air returns vents. 

Because this system is providing air throughout the house, airflow is as important as removing particles. Because of that, it usually does not restrict as small particles as room units that do not have the responsibility of providing heated or cooled air throughout the house. Most use a pleated-paper, HEPA, active carbon, or fiberglass filter. These mechanically trap particles removing them from the air. 

What can they filter?

  • Pet dander
  • Dust
  • Smoke (tobacco or otherwise)
  • Pollen
  • Dirt
  • Mold and Mildew
  • Fungus and Bacteria
  • Fibers
  • Other microorganisms including dust mites

Different types of Air Filters (all mechanical in nature):

Activated carbon 

Activated carbon filters are more porous so are typically used as secondary or pre-filters to another filter type (just like with water filters). The carbon creates a bond with the pollutants in the air and “traps” them in the filter. 


This bond creation makes them great at filtering out chemicals/gasses that cause odors and fumes as well as filter out smoke. 


Low MERV rating. 

Activated Carbon cannot filter out microorganisms such as viruses, bacteria, or mold spores. It also does not remove dust well from the air which causes many allergens in a home. This gives them a low MERV rating.


Pleated- paper uses cotton or polyester fiber material that is folded giving it the “pleats.” This creates more surface area to trap particles. This makes it very effective at capturing more particles, even the smaller particles, but it does come with a slightly raised price compared to less efficient ones like fiberglass. This gives them a high MERV rating.


High MERV rating. 

They are very efficient and last longer than many other types. Bonus –  some are recyclable.


May be more costly. 

May restrict airflow when overdue for a filter change.


Fiberglass filters are the most affordable and common disposable filters. Pollutants are trapped in the layers of fiberglass. Some of these are electrostatically charged which increases the number of particles it can capture. They do have lower MERV ratings and are not very effective for removing small particulate matter from the indoor air supply. Also, they need to be replaced more frequently than other types of air filters.



Great for larger debris such as lint or dust.


Low MERV rating. Cannot filter smaller particles well. 

May need to be replaced more often since they clog up easier.


High-Efficiency Particulate Air (HEPA)  filters are very efficient, trapping 99.97 percent of particles! They trap even down to a size of 0.3 microns (1). They utilize a variety of fibers arranged in a pleated form with a mesh surrounding. This brings in three different mechanisms to filter the air: diffusion, interception, and impaction. Because of this high efficiency and the concern of airflow restriction, HEPA air filters cannot be used in all equipment.


Very high MERV rating (usually around 16 out of 20).

HEPA filters are highly effective against both large and small pollutant particles including viruses, bacteria, and mold. 

May not need to be changed as often.


More costly.

Cannot eliminate odors from gasses and fumes. 

Prone to sedimentation – even mold growth!

How Do Room Air Purifiers Work?

Air purifiers work by cycling through the air in a specific area size (based on fan strength). They use mechanical filters similar to the whole house filters, however many use additional types as well including the UV lights and electrostatically charged filters. Air purifiers work by trapping or neutralizing pollution particles vs the air filters that primarily just trap.

Most air purifiers use fans to draw “dirty air” in and push it through the filters thus creating “clean air.” These usually use a fine mesh to catch larger particles, then most commonly a HEPA filter to trap the smaller particles, then a “deodorizing” filter, and followed up by a UV filter as it is pushed out of the unit.

What can they filter?

  • Pet dander
  • Dust
  • Smoke (tobacco or otherwise)
  • Pollen
  • Dirt
  • Mold and Mildew
  • Fungus and Bacteria
  • Fibers
  • Other microorganisms including dust mites

Different Types of Filters Used in Air Purifiers:


Usually a combination of HEPA and Activated Carbon.


Some air purifiers use an electrostatic charge to attract pollutants. We most often refer to this as Ionicfilters. An electrical field is around particles, known as ions. These are either positively or negatively charged. In the electrostatic charge created by these filters, it attracts the oppositely charged bacteria in the air to the filter, thus trapping it. 

They may not be as effective alone at catching larger pollutants, like mold spores and large dust particles. They may be disposable or washable.


Lower cost. 

They are available in reusable options, reducing waste and costs.

Efficient for some particles, particularly smaller particles.


Not efficient for trapping larger particles like mold spores or dust.

May produce a lung irritant called ozone (2), combined with low removal of larger particles it is not best (as a stand alone) for asthma or respiratory conditions.

More frequent changing or washing is required, usually monthly.

UV light purifiers

Ultraviolet light radiation enters the microorganisms damaging the cells of it leaving it no longer capable of functioning or reproducing. 


Removes viruses, bacteria, yeast, and mold.

Very helpful for those with respiratory conditions or troubles with their immune systems


Higher costs initially and in operation.

Not effective as a stand alone.

How Often Do Filters Need to be Changed?

In general, filters of all units should be changed every 3 months. However, some situations may change that. For example, if you have multiple indoor pets or severe allergies, it is recommended to change the filters monthly. However, if it is a vacation house or only a single occupant with no pets or allergies: every 6–12 months is sufficient. Each individual will give its most optimal suggestions so be sure to confirm those details.

Some of the filters are washable and reusable, making those the most cost-effective. These do have a lower MERV rating however and need to be washed more often than most disposable filters need to be changed.

Which Air Filtration Systems Are Out There Right Now?

Now that we know what we’re looking at and an idea of what your needs are…let’s look at the systems out there and see which ones meet those needs!

Here are some highly rated options that are currently available.

Room Purifiers: 

Honeywell HPA300 HEPA Air Purifier for Extra Large Rooms

Type(s) of Filtration: HEPA and Activated Carbon

Intended Use: Room: Cleans Up To 2250 Sq Ft in 1 Hour

Price: Around $200

Coway Airmega AP-1512HH(W) True HEPA Purifier

Type(s) of Filtration: Mesh, Activated Carbon, and HEPA

Intended Use: Room up to 361 sq. ft

Price: Around $160

Winix 5500-2 Air Purifier with True HEPA

Type(s) of Filtration: Activated Carbon and HEPA

Intended Use: Room up to 360 square feet 

Price: Around $145

BLUEAIR Bedroom Air Purifier

Type(s) of Filtration: 

Intended Use: Room Quickly cleans 388 sq ft medium room in about 12.5 min or up to 1862 sq ft in 1 hour

Price: Around $240

LEVOIT Air Purifiers

Type(s) of Filtration: Mesh Pre-Filter, HEPA, and a Custom High-Efficiency Activated Carbon Filter

Intended Use: Room up to 403 sq ft 5x per hour and a 990 sq ft 2x per hour

Price: Around $215

Whole House Additions:

REKO Lighting R2000

Type(s) of Filtration: UV Light to install in an HVAC unit. This is to add on after a media filter.

Intended Use: Whole House

Price: Around $70

Notes: May require a professional for installation.

Aprilaire 1610 Whole House Cleaning Unit

Type(s) of Filtration: This is a unit that attaches to your ductwork and forces the air through a mechanical filter (comes with filters that have a MERV 11 or 13 rating)

Intended Use: Whole house 

Price: Around $210

Notes: May require a professional for installation.

Air Filters

Lennox Healthy Climate Carbon-Clean MERV 16 

Type(s) of Filtration: Activated Coconut Shell Carbon, Magnetic Mesh, Pleated-Paper

Intended Use: Whole house with a filter size of 16x25x5”

Price: Around $80 and should be replaced about twice a year

Notes: It is compatible with many brands of furnaces.

Aprilaire Healthy Home 213 MERV 13 Air Filter

Type(s) of Filtration: Activated Carbon (option), Mesh covered Pleated-Paper

Intended Use: Whole house with a filter size of 20x25x4”

Price: Around $50 and should be replaced twice a year

Notes: Compatible with Aprilaire units

Honeywell Home 20x25x4 MERV 12

Type(s) of Filtration: Fiberglass

Intended Use: Whole house with a filter size of 20x25x4”

Price: Around $70 for a 3 pack (replace every 2-3 months)

Notes: Fits multiple brands. This is a cost effective option, but not the most efficient option.

BNX 16x20x1 MERV 13 AC Furnace Air Filter, 4 Pack 

Type(s) of Filtration: Electrostatically Charged Non-woven Polypropylene (pleated, but not paper)

Intended Use: Whole house with a filter size of 16x20x1”

Price: Around $40 for a 4 pack (Change filter every 3 months)

Notes: Fits multiple brands. This is a cost effective option, but not the most efficient option.

K&N Air Filter, Washable, Merv 11

Type(s) of Filtration: Mesh, pleated synthetic polymers– washable and reusable 

Intended Use: Whole house available in multiple sizes

Price: Around $50 and wash monthly

Notes: Fits multiple brands. This is a cost effective option, but not the most efficient option.

What Types and Products We Recommend

If you or your loved ones suffer from severe allergies, asthma, chemical sensitivities, or other other medical conditions affected by air quality, then the best option is to invest in both a whole house air filter and a room purifier. 

Our favorite whole house filter: The REKO Lighting R2000 with a Lennox Healthy Climate Carbon-Clean MERV 16 Filter  – obviously, this is harder to recommend since it depends on the unit installed. Calling your local HVAC service providers and having them help you determine your options may be best. Once you know the size and abilities of your unit, then you can search for options online or stop by your local hardware store.

Our favorite air purifier: Honeywell HPA300 HEPA Air Purifier for Extra Large Rooms

Don’t forget to check your car’s air filter too!

Disclaimer: This post is not intended as medical advice. These statements have not been evaluated by the FDA, and nothing in this post is intended to diagnose, treat, or cure anything.  If you have questions, please do your own research or seek advice from a health professional.

Does air filtration concern you?  What system do you use?

This is the writings of:

Rustina started studying herbs and natural living after allopathic medicine was unable to provide answers or support when she needed it. She is continually working on learning more and improving her and her family’s health, diving in and researching any topic. A love of learning led her to homeschool and begin working from home. She now spends each day with her husband and four sons as they travel on their home education journey together. She is thankful for the opportunity to write about these interests and passions for Earthley Wellness and Modern Alternative Mama.

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Hi, I’m Kate.  I love medical freedom, sharing natural remedies, developing real food recipes, and gentle parenting. My goal is to teach you how to live your life free from Big Pharma, Big Food, and Big Government by learning about herbs, cooking, and sustainable practices.

I’m the author of Natural Remedies for Kids and the owner and lead herbalist at EarthleyI hope you’ll join me on the journey to a free and healthy life!

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