Air Purifiers & Coronavirus
35 Comments
A straightforward look at the complexities of capturing viruses
With the global outbreak of novel coronavirus (COVID-19), many are wondering whether air purifiers can help combat airborne viruses. Amid much confusion and misinformation, we want to clear the air and provide some useful facts, not to mention a few tips for staying safe.
“ Our greatest enemy right now is not the virus itself. It’s fear, rumors, and stigma. And our greatest assets are facts, reason, and solidarity,” said World Health Organization Director-General Dr. Tedros Adhanom Ghebreyesus.
First and foremost, if you believe you or someone in your household might have COVID-19, take immediate action by following the Centers for Disease Control and Prevention (CDC) guidelines .
The Facts
Can an air purifier capture coronavirus? To a degree...Yes. An air purifier equipped with a HEPA (high-efficiency particulate air)-rated filter can technically capture a portion of airborne virus-sized particles. Once trapped, viruses cannot multiply on their own or remain infectious for long. But NO air purifier can completely protect you from a virus.
"We believe air purification provides additional support to your body’s most important tool for fighting viruses—a healthy immune system," said Alen President, Andy Graham. "It's a passive, 'always-on' way to improve the overall health of a breathing space that doesn’t require major lifestyle changes."In this article, we’ll break down the following:
- HEPA filtration technology
- How current HEPA air purifiers can remove a portion of viruses sized particles from the air
- How long COVID-19 can survive in your home
- How purifiers benefit your immune system & support a virus protection plan
How HEPA Really Works
Originally developed in support of cleanrooms for atomic energy development, the U.S. Department of Energy (DOE) created HEPA as a specification for suppliers of filtration products based on particle removal effectiveness (e.g., 99.97% at 0.3 microns and above). Filters are commonly perceived as nets or a screen that will stop objects larger than the smallest holes while letting air through.
HEPA filters trap particles much differently than a simple screen or net.
Here’s the reality: HEPA filters are a complex weave of tiny fibers that carry an electrostatic charge which attracts bypassing particles—more like a magnet than a net. The smaller the fiber with the greater charge coefficient, the greater the likelihood of trapping ever smaller particles. All of this is effective to the extent that air can be channeled through enough filter material without air bypassing around it.
An extreme close-up of HEPA material, courtesy of Engineering360.
How Do HEPA Air Purifiers Capture Viruses? It’s All About Physics
The most current state of the art in filter material is referred to as True HEPA or H13 by the DOE. True HEPA removes 99.97% of particles at 0.3 microns or higher, but this is a helpful yet incomplete description of HEPA capability. Even though some of the particles (like the COVID -19 and H1N1 flu viruses) will bypass the filter—a portion of those will be trapped due to the charged magnetic effect of HEPA fibers.
Further enhancing capture of tiny virus particles—which can be over 100 times smaller than particles like dust, pollen, and dander—is a phenomenon known as Brownian Motion , in which microscopic particles bounce around in zigzag patterns and get trapped in HEPA’s maze-like fibers.
A diagram showing the size range of airborne particles.
But here’s the important take away: Although HEPA is a DOE specification, testing and manufacturing protocol in the consumer sector varies to the extent that no purifier brand should claim they can completely protect people from COVID-19. Air purifiers are an additive protective measure if properly sized to a room.
HEPA filters can remove a portion of airborne particles such as COVID-19 and other flu viruses. But the extent of removal that may be truthfully claimed can only be done by proxy tests in controlled environments, which are still underway.
With current HEPA technology, 99% or more of airborne virus particles in a room cannot be removed by an air purifier nor by other means that have yet to be proven. Of course, this would also not include virus particles that remain alive for periods of time on surfaces open to touch.
How Viruses Spread & Why Air Purifiers Can Help
COVID-19 spreads by close person-to-person contact, especially when an infected person coughs or sneezes, according to the CDC. Virus particles are attached to and carried by water vapor, which are tiny droplets that float in a fine mist. Coughing is one of COVID-19’s main symptoms, so airborne transmission is a big concern.
The only way to reliably remove virus sized particles from the air is by circulating the entire volume of air in a room or enclosed space multiple times per hour to increase the likelihood that nearly weightless virus particles will enter the airflow of a filter.
Since health experts are advising more and more people to stay home, a HEPA air purifier can play a significant role in minimizing airborne transmission and supporting overall wellness.
“ Essentially, we breathe in rooms or 'boxes' at home, work, restaurants, schools, and play spaces,” said Andy Graham, President of Alen. “Any shared-air breathing space would benefit from a right-sized, always-on air purifier with a well-sealed, high capacity True HEPA air filter .”
Why Filtering Airborne Viruses is Just One Part of Prevention
Given justified concerns over the spread of COVID-19, there are some who have suggested that air filtration is ineffective and instead make other recommendations. We believe this is a false dichotomy. Protective measures are both reasonable and cumulative; both/and rather than either/or. Why not take an all-of-the-above approach to virus protection?
Yes, we sell air purifiers and have for 15 years, but we will be the first to recommend additional means of wellness and immune system support in addition to breathing pure air. For example, transmission by physical contact can only be addressed by other non-airborne measures.
COVID-19 can remain infectious for three hours when aerosolized into floating particles, like a cough or sneeze, according to a new study. On surfaces, it remains viable for up to three days.
Likewise, “viruses can’t multiply on their own—they must infect the cells of a living creature,” Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Disease, told PBS.
What this means is that viruses trapped in an inorganic HEPA filter will stay there and die without further harmful effects. But since COVID-19 can live for up to three days on surfaces, it's critical that you follow ALL the CDC’s guidelines to prevent illness.
How Air Purifiers Support Immune System Health + Tips to Stay Well
Each airborne particle you inhale—whether it’s a pollutant, allergen, or pathogen—triggers a response by your immune system. By capturing those harmful particles and circulating clean air throughout your space, your body can focus on keeping your immune system strong day and night.
Breathing air that’s free from harmful particles is just one part of a wellness plan that should include ample sleep, plenty of purified water, good hygiene, and a balanced diet.
Many Alen filters feature an antimicrobial coating capable of killing 99.99% of E. Coli and Staph bacteria while inhibiting fungi and mold. Although not tested for viruses, air filters capable of killing other harmful airborne microbes can contribute to a healthier indoor environment.
According to the CDC, here are the top seven ways to protect yourself from COVID-19 every day:
- Wash your hands often with soap and water for at least 20 seconds, especially after going to the bathroom; before eating; and after blowing your nose, coughing, or sneezing.
- If soap and water are not readily available, use an alcohol-based hand sanitizer with at least 60% alcohol.
- Avoid close contact with people who are sick.
- Avoid touching your eyes, nose, and mouth.
- Stay home when you are sick.
- Cover your cough or sneeze with a tissue, then throw the tissue in the trash.
- Clean and disinfect frequently touched objects and surfaces using a regular household cleaning spray or wipe.
Bottom Line
Air purifiers alone will not protect you from viruses, but they can contribute to an overall healthier indoor environment and better sleep. A purifier’s effectiveness depends on its ability to draw in contaminated air and circulate pure air throughout your entire breathing space or 'box.' Alen is proud to make top-rated purifiers that do just that—quietly and efficiently.
To learn more about Alen’s powerful and customizable line of air purifiers, click here .
Your wellness is our highest priority. Our air quality experts are available to answer your questions 8 a.m. to 6 p.m. CST M-F and 10 a.m. to 4 p.m. Saturday. Call 800-630-2396, email service@alen.com , or chat at alen.com.
IMPORTANT: Alen does not provide medical advice. Consult your doctor or a medical professional with healthcare questions.
Dan Mottola
35 Responses
Dan Mottola, Alen Content Marketing Manager
@Wayne Schulz, We appreciate your questions. Unfortunately, no, we do not make HVAC products. If you are wanting charcoal or carbon to remove smells and gases, HVAC-scale airflow would saturate that type of filter in a short amount of time. If you are attempting to reduce particles or deal with virus concerns, then there are companies that offer 4’ wide filter cartridges that mount on or near the air handler plenum. However, none of these are as effective in each room as a standalone HEPA air purifier.
Dan Mottola, Alen Content Marketing Manager
@Jill R, Thank you for your question. The physics of HEPA fiber material properties to attract particles as referenced in the article apply similarly to vacuum bags. Otherwise, a vacuum cleaner would not be able to achieve enough airflow for suction to work properly. Vacuum bag manufacturer’s published specifications vary widely vs the air purifier industry since the focus is primarily on dust and dirt removal. In general, we would say that vacuum bag material in a mask offers superior filtration to a cotton mask while less effective than filter material used in air purifiers. All of this depends on how well the filter is sealed around the edges of facial contact which can be difficult to achieve with one size fits all masks.
Dan Mottola, Alen Content Marketing Manager
@ Alireza Afshari, Thanks for reaching out. We don’t normally comment this early on new product development but given the urgency and pressing need, we wanted customers to know that we were acting with all deliberate speed on an improved capability. We will share more when as soon as we have testing results.
Dan Mottola, Alen Content Marketing Manager
@ Kent Bernard, We appreciate your question. The material in our filters is True HEPA grade H13, which traps 99.97% of particles at .03 microns and greater while the N95 mask uses filter material that captures 95% of particles at.03 microns and greater; hence the term “N95.”
Dan Mottola, Alen Content Marketing Manager
@Barbara Bopp, Thanks for your thoughtful question. For maximum personal protection while replacing an entire Alen filter at the end of its service life, use gloves (and a mask if you wish) to pull the filter from the unit, put it into a trash bag, and tie the top. Particles caught in the filter are held securely by HEPA fibers unless the filter is vigorously shaken or dropped. For occasional cleaning of the prefilter, it is best to use gloves to pull it off and dispose it—again in a trash bag while replacing with a new one. In very dusty or high pet dander/fur conditions, you can also wear gloves and vacuum the prefilter in place carefully with a brush attachment.
Dan Mottola, Alen Content Marketing Manager
@Paul Morneau. We appreciate your question. Our understanding of this virus is evolving quickly as new research emerges. We now know that Coronavirus particles (which, like H1N1 and others range between 80-120 nanometers) become airborne or aerosolized by a cough, sneeze, or breathing and attach to much larger particles from 300-500 nanometers as “carriers” including mucus and water vapor. When these pass through current-state-of-the art HEPA filtration, they will be trapped.
The greater challenge is ensuring that those particles reach the HEPA filter. This is why an effective volume of air circulation within space is important. The HVAC systems in most homes move a far greater volume of air in order to heat/cool, so the nature of your concern is valid for those reasons. A HEPA air purifier is designed to purify a single room, so no purifier maker can speak to whole-house virus protection with certainty.
Janice Byrum-Jackson
If you have confirmed cases of COVID-19, and the people were in the building 2 to 5 days ago, should the High Efficiency MERV 13 Air filters be immediately changed?
Dan Mottola, Alen Content Marketing Manager
@Steve, Thanks very much for your insightful question. It’s top of mind for a lot of people.
Under most circumstances, we don’t think it is harmful to use HEPA material from an AIR PURIFIER filter in homemade masks given the COVID-19 situation. We believe that the value of using this material outweighs possible disadvantages. Here’s the critical detail: Air purifier filters typically do not contain the fiberglass found in certain HVAC filters, which can release harmful crystalline particles.
A HEPA filter is constructed of two or three layers consisting of the actual HEPA layer (which itself is fibrous), a melt or bonding layer, and a polypropylene backing layer required to hold the delicate HEPA layer in place. Polypropylene is essentially a woven sheet of plastic fibers of varying lengths to provide stiffness.
It is possible to ingest polypropylene fibers into your lungs, but the thread count of most common cotton and other synthetic materials makes it unlikely that the fibers can be separated from the backing and then make their way past that screen.
In the case of ingestion, the body cannot decompose these fibers in the same way as similar particles from other common plastic sources as cited in this and other research findings https://pubs.acs.org/doi/10.1021/acs.est.9b01517
So, while the full effects of possible ingestion are not yet known we are operating in unprecedented circumstances where the CDC, FDA, and medical facilities are welcoming PPE of this type and of even far less efficacy in light of the COVID-19 risks which are still not fully understand across patient populations.
To be clear, we cannot make a product claim for HEPA material in this use case – nor are we speaking for the industry. We as a company want to say as much as we can as soon as we can to help people to make their own informed decisions.
Steve
Dan – There is a small, family run company in the US selling masks with slot for an HEPA filter. They send along HEPA filters that are roughly 1/8th of an inch thick. Do you know whether or not it is advisable to have a HEPA fliter inside a mask up against your face? I’ve heard anecdotally that this may be a bad idea because it contains fiberglass. Any insight into this? Thanks.
Paul Morneau
Not mentioned in your article: If a virus is not captured by the HEPA filter in it’s first pass through the filter, it will be airborne longer (by the fan or blower in the air cleaner), thus potentially increasing the probability of someone inhaling it. Wouldn’t that suggest people who are sheltering at home and may have the virus should NOT use an air cleaner? Without careful studies, it is impossible to recommend either way.
Barbara Bopp
Can you recommend a safe method of removing for cleaning or replacing an Alen filter? A mask and gloves would help, but beyond vacuuming, but what’s the best way to minimize releasing particles into the air that might contain live virus/germs? I know that purifiers are not regulated, but can any scientists (CDC or on your staff?) make informed suggestions? Thanks—I’ve used and loved your purifiers for years and really appreciate your fair and balanced article.
Kent Bernard
Is the material used to make a HEPA filter equal to the material used to make N95 mask or at minimum a surgical mask?
Nancy Faber
I want to try purchasing a HEPA filter and take it apart to get a filter to add to surgical masks I am sewing for first responders. I know it doesn’t make the mask an N95, but it should help with the filtering out more.
Leo J Schefer
Helpful particularly the 3 hr and 3 day info. Leo
Alireza Afshari
Thank you for the interesting information. You say that: Independent test data shows that True HEPA filtration will trap viruses at the Coronavirus size but not at a predictable level across varying airflows. This is why we are working on a higher grade filter that will be more predictably effective in the coming months. ". I am very interested in the new filter and the results. May I have this information. Best regards, Alireza Afshari
Nadia
This is a decent article and I appreciate the restraint in over-claiming.
Here are some minor corrections, from a physicist working on infectious proteins.
COVID-19 is the disease, not the virus. The virus is called SARS-CoV-2 (the 2003 outbreak strain was called SARS-CoV) viruses are not killed but inactivated (e.g. by UV or chemical means), since they are not, strictly speaking, alive. electrostatics is not magnetism, so it is incorrect to say the “magnetic effect” of the HEPA fibers. I understand you’re usually “magnetic” in a colloquial way there, but wouldn’t do that under the subtitle “it’s all about the physics” and then use physics terms inaccurately. HEPA standards is actually even stricter. It’s quoting the capture rate at 0.3 microns because that’s where the efficiency is worst, which is great: means your HEPA filters are supposed to trap particles smaller than 0.3 microns AND larger than 0.3 microns even more efficiently. Stating “0.3 microns or higher” is channeling the common misconception you mentioned – that a HEPA filter is a sieve. See https://en.wikipedia.org/wiki/HEPAotherwise, thanks!
wayne schulz
I’m an hvac man at our school. Do u have type of a charcoal filter that can replace a standard filter in a 5t0n or greater air handle. Or isit possible to put just one filter over the exhaust vent to the room?
Robert Atwell
So, HEPA filters are not a perfect solution to protecting us against viruses, but it is still worth purchasing a HEPA system because it does offer some level of protection. That’s good, however, some systems include UV lamps in front of a HEPA filter, and these lamps do kill bacteria, viruses and fungi. However, to be fully effective, the UV light needs to shine directly on the pathogen for a minimum amount of time, and if the light is blocked in some way, it won’t kill the pathogens, so, like a HEPA filters, it is not a perfect solution. Still, using an air purifier that uses UV lights and a HEPA filter would appear to be a much better alternative than just using a HEPA sfilter alone. I wished you would have included a discussion of UV lights and HEPA filters and how they might work together to provide us with better protection.
Dan Mottola, Alen Content Marketing Manager
@Donna Woodman, Thank you for your comment. Someone from our Customer Support team will reach out to you directly with assistance. We are experiencing an extremely high volume of inquiries, so please bear with us. We sincerely value you as a customer.
Donna woodman
I have and love it but can not find my papers to order more.filters my husband always ordered them and he passed.so IAM not sure how to order.
Dan Mottola, Alen Content Marketing Manager
@Timothy Aiken, Thank you for your comments. We really do appreciate the gravity of your concerns. Our President, Andy Graham, has emailed you directly with a detailed response. In short, we elected to say what we believe is truthful and helpful in light of a declared National Emergency and pressing anxiety over the subject. Independent test data shows that True HEPA filtration will trap viruses at the Coronavirus size but not at a predictable level across varying airflows. This is why we are working on a higher grade filter that will be more predictably effective in the coming months. The FDA does not currently regulate portable air purifiers because they are not classified as medical devices and industrywide standards have not been adopted. In light of that, we chose to publish the most detailed data possible in response to a wave of advertising by our competitors and an outpouring of questions from customers—to offer a voice of reason and caution in an uncertain time. Thank you for being an Alen customer and for holding us to the highest standard of ethics for a brand committed to wellness.
Cynthia Merman
We’ve been using the air purifier in our bedroom for almost 5 years. It’s a great help for bedrest. The sound bothers my husband, so we turn it down overnight. So far it’s working well. Thanks for the update re Coronavirus, although I never expected it to prevent any infections.
Catherine Martin
We have been very pleased with the two alen units we purchased. I do appreciate the email with pertinent information given regarding the COVID virus and the units capability in capturing and varying amounts of virus particles.
Dan Mottola, Alen Content Marketing Manager
@Judith Walker, Thanks very much for your comment. We sell Prefilter multipacks for customers with concerns just like yours. Click the link below and be sure to select the correct prefilters for your purifier, as sizes vary. When it comes to cleaning prefilters, we advise customers to vacuum their prefilter in place since removing it can release dust, as you noted. However, if you believe someone in your household is sick, we advise people to avoid touching filters or prefilters because viruses can remain infectious for up to three days on surfaces.
https://www.alencorp.com/pages/search-results-page?q=pre+filter
Dan Mottola, Alen Content Marketing Manager
@MICHAEL ZACHARIOU, Thanks very much for your comment and clarification…
Bobby
Great article. Thanks!!
Brent Bushay
Been using `Alen filtration since 2010 and have never been disappointed; mine run 24 hr. a day. Every company has their claims but just on the practical side these filters also collect dust particles making it easier to keep the whole house clean besides the ‘other’ added benefits.
Judith Walker
I wish you would have disposable pre filters since every time I take the pre filter out to wash the dust smacks me in the face as I am removing it. This actually makes the whole thing useless since I now inhale everything at once. Any help with that would be appreciated.
Michelle
Great article! I think it also bears mentioning that with a lot of self imposed isolation and social distancing, a lot of people are spending much more time in their home and Alen purifiers help to tremendously improve indoor air quality. So while being mindful of Coronavirus is important, also remembering we are breathing indoor air a lot more throughout the day when confined to the home and it’s very important to make sure that air quality is the best it can be.
Timothy Aiken
Even suggesting “To a degree…Yes” is disingenuous, especially without tests proving to what degree. Until you have such test results to publish that are substantiated by the FDA or a truly unbiased independent lab you should not make such claims. Doing so only adds to confusion and the abundance of misinformation that is circulating. I expect more from a company like Alen. This just seems like a scheme to subtly sell more filters and purifiers. This just does damage to your brand and makes me suspect about making purchases in the future from Alen.
Judy Templeton
Thank You for your information.
Cecilia Shelly
Although as you say it’s not 100% to remove viruses and air born germs, removing other harmful chemicals from all household sprays / solutions we use also help clean my home environment. My family has been using your product for years now and we’ve been blessed so far in the reduction of pollutants in the air we breathe while inside our homes. How often should we change the filters to maintain its efficacy?
Thanks for this email.
Michael Zachariou
I like and appreciate your blog and from someone who has built and works in clean room environments, it is mostly factual. Except for one statement and implication. HEPA filters (and any filter for that matter) DO NOT KILL VIRUSES. A more accurate and less misleading statement would be “HEPA Filters HELP REMOVE VIRUSES”. This is a very important distinction to make since your users may develop a false sense of security when replacing your filters. They have no way of knowing how long any virus captured in your filters has been there.
Francess McMahon
Thank you for your informative email and this blog post. It has been on my “to do” list to call Alen and inquire about the topics that you have addressed in this blog post. Now my phone call is not necessary because my questions have been answered here.
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Dan Mottola, Alen Content Marketing Manager
May 06, 2020
@ Robert Atwell, Thank you for your comment. To set the context for our response let’s consider that the gold standard for germ-free purification exists in well designed and maintained hospital operating rooms. In those spaces, multiple HEPA filters and directional airflow are used. UV light is used as an optional additive measure. https://www.bbc.com/news/business-51914722.
However, to be effective, UV light rays must have a direct line of sight to the virus particle and for enough time. Given their relatively small size, air purifiers must pull a lot of airflow through an efficient filter in order to clean an entire space. Thus, the amount of time between air entering and exiting the unit is very short. To further complicate matters, it is well documented that the Coronavirus is particularly robust by its length of survival time on various surfaces. Will UV kill viruses? Yes, but to a far lesser degree of effectiveness than efficient HEPA filtration and whole-room airflow. We could offer this but have yet to find the balance between effectiveness and cost.