Do HEPA filters actually remove viruses, including COVID-19, from the air? Is it possible for HEPA air
filters to play a role in curbing infections from communicable diseases like COVID-19?
HEPA stands for “high efficiency particulate air”. A HEPA filter is able to trap and remove microscopic
particles, like COVID-19 viruses from the air. In that sense, a HEPA air filter can protect against COVID-19
from spreading to someone from an infected person. However, as the EPA has noted, it takes a multi-pronged
approach to combat COVID and other viruses.
The following is a quick guide on how HEPA filters can play a role in preventing infections by helping keep
viruses out of the air.
How Do HEPA Air Filters Work?
HEPA air filters work like other air filters, they just purify the air more efficiently. HEPA is technically
a category of air filter based on the size of particulate media and percentage of particles that can be
removed from the air when passing through the filter.
A true HEPA filter can remove at least 99.7% of particles that are 0.3 microns in size or larger. Some HEPA
air filters can also remove smaller particles as well.
A HEPA air filter physically traps particles as circulating air passes through a pleated screen of
filtration material. The particles remain trapped in the screen’s fibers until the filter is cleaned or
Types of HEPA Filters
There are four types of HEPA filters:
Medical Grade HEPA Filters
Medical grade HEPA filters have the highest rating for filtration. This type of HEPA filter has a grade of
H13-H14, which indicates the filter can remove 99.95% to 99.995% of particles that are just 0.1 micron in
True HEPA Filters
A true HEPA filter isn’t as powerful as a medical grade HEPA filter, but it meets the HEPA classification in
removing at least 99.7% of particles that are 0.3 microns. True HEPA filters have a grade of H10-H12.
HEPA Type Filters
Any filter labeled “HEPA Type” is not a true HEPA filter. They may remove the vast majority of particles
from the air but they have not been proven to remove at least 99.7% of 0.3 micron particles.
These also don’t meet the qualifications of an actual HEPA air filter. Like HEPA Type, this labeling is
nothing but advertising that’s meant to entice the buyer.
How Effective Are HEPA Filters in Combating Viruses?
We know from past research that air filters with a high enough degree of filtration can reduce the number of
viral contaminants in the air. That’s proven to be the case with viruses such as SARS and is believed to be
the same with many other viruses, including COVID-19.
The COVID-19 virus is most commonly spread through droplet transmission, but the virus can be
airborne when moisture particles from the mouth or nose are released into the air. When a virus is
spread through the air it’s known as aerosol transmission.
Aerosol particles are much smaller than droplets. This is a challenge for several reasons:
- Aerosol particles can remain in the air longer than droplets
- Aerosol particles can travel greater distances than droplets
- Aerosol particles are harder to filter out of the air than droplets
Viral bio-aerosol particles are typically 0.3 to 100 microns in diameter. The 1-10 microns range is of
greatest concern to COVID-19 researchers.
HEPA air filters are able to effectively remove nearly all particles as small as 0.1 microns out of the air
by capturing 99.7% of particles that are 0.3 microns and an even higher percentage of larger particles.
Because of its particulate trapping qualities, HEPA air filters are an effective line of defense in
combating the spread of COVID-19 within indoor environments.
Best HEPA Filter for Viruses, Bacteria, and Germs
Like all products, some HEPA filters are better at combating viruses, bacteria and germs than others. Here’s
a look at some of the best HEPA filters and purifiers for viruses and other potentially harmful
Honeywell HEPA Filters
Honeywell is a top manufacturer of HEPA air filters for their top-rated air purifiers. The Honeywell True
HEPA Allergen Remover Air Purifier is a popular choice that comes in five sizes for spaces between 75 and
465 square feet.
Kenmore HEPA Filters
Kenmore is well known for home appliances and HVAC systems, so it’s no surprise they’re a frontrunner in
HEPA air filters.
Benefits of Choosing High Quality HEPA Air Filters
Buyers have to be careful when they’re purchasing air filters online. If health concerns are the primary
reason you want to get HEPA air filters then you want to purchase them from a highly reputable source.
An original manufacturer like Filterbuy that produces the product themselves or works with a manufacturing
partner to offer customers a wider range of products is a good option. You can also get high quality HEPA
air filters at big box home improvement stores, but the selection is likely to be limited.
When you choose a high quality HEPA air filter it’s an investment that should pay off. A true HEPA filter
can be used in purifiers throughout the home to make the air cleaner and less contaminated. Allergy
sufferers should also experience fewer symptoms, and people with asthma should find relief from respiratory
HEPA Filters vs COVID-19: Frequently Asked Questions
How long does COVID-19 remain in the air?
In certain conditions, COVID-19 viral particles can remain in the air indoors for hours.
Can COVID-19 be transmitted through the air?
There have been reported cases, but it is rare. COVID-19 is much more likely to be transmitted by droplet
transmission or direct contact.
Will an air purifier help protect me from COVID-19 in my home?
You shouldn’t rely solely on an air purifier, but an air purifier with a true HEPA filter can help.
Are HEPA filters the best air purifier for viruses?
HEPA filters are the best air purifiers for viruses as a standalone device. However, HEPA filters are
usually not the best option for the HVAC system. They can restrict airflow too much, putting the equipment
at risk and reducing energy efficiency. Instead, use a MERV 13 air filter.
An air filter with a MERV 13 rating
can remove 98% of airborne particles as small as .3 microns.