A high efficiency particulate air (HEPA) filter is a pleated device that can remove particles from surrounding air. A number of devices use these filters, such as air purifiers, which are designed to remove a host of particles and pollutants from the air in your home.
There is no federal certification or regulation for HEPA filters in the United States, but the Environmental Protection Agency offers some advice on how to choose efficient filters. Keep reading to learn some tips for choosing HEPA filters and how to find the best air purifier for your home.
HEPA filters remove tiny particles from dust, mold, pollen, bacteria, viruses, and more from the air. Thin glass fibers are randomly arranged into a dense, paperlike material that is folded into pleats to create the filter.
As air particles pass through these filters, pollutants are trapped in the fibers. Then, as larger particles stick to the filter, they keep other smaller particles from passing through. A HEPA filter can trap particles as small as 0.3 microns. For reference, the smallest thing the human eye can see is 25 microns, and a strand of hair is between 17 and 180 microns in diameter.
When placed into filtration systems like air cleaners and purifiers, HEPA filters can remove 99.97 percent of particles from the air. These filters were initially used in nuclear plants, but a host of new devices use this technology in products that can help clean the air in your home.
Types of filters
There are many kinds of air filters and air purification devices available for home use. HEPA filters can be used in cleaning devices, air filters, portable air cleaners, whole-home fan systems, heating and cooling units, and more. The goal is to filter tiny particles from the air as it passes through these devices.
HEPA filters aren’t the only way to do this, but they are recognized as highly effective, filtering some of the smallest particles from the air. Other examples of filters include:
- Ultra-HEPA filters or ULPA filters. These can trap up to 99.999 percent of particles 0.3 microns or smaller.
- Electrostatic filters. These trap particles using a small static charge, which help the particles stick to the filter.
- Electrostatic precipitators. These filters use metal plates or wires to attract particles with an opposite charge. They can often be washed and reused.
- Ionization. These filters rely on a small charge that emit a magnetic-like attraction to particles in the air. This type of filtration may release ozone gases and could cause irritation for people with respiratory diseases.
(Video) Top 5 - Best Air Purifiers (2022)
There are so many options when it comes to home air cleaning, and the choices can become overwhelming. While the EPA does not certify or recommend particular types of air filters, the agency does offer advice for selecting the right product for you. These recommendations were the basis of our selection process and include the following considerations.
- Size matters. Look for portable filters designed for the room size you are trying to use it in. Generally, the clean air delivery rate (CADR) score of your filter should be equal to about two-thirds of the area in the room.
- Avoid air cleaners that generate ozone. Ozone is a gas that is released during some air purification processes. While ozone gas is meant to clean and sanitize air, it’s also considered a pollutant that can cause irritation and damage to the lungs when inhaled. Air cleaners that use ozone are generally intended for rooms that are uninhabited at the time of use. They are not for use in confined spaces when you are present. No government agency in the United States has approved any ozone generators as air cleaners in homes.
- Look at industry ratings. While EPA doesn’t set rules for these filters, there are industry leaders that set standards for HEPA filtration. When purchasing a filter, it should meet one of the following criteria:
- designated HEPA filter
- CADR rated
- manufacturer states the product filters most particles smaller than 1 micron
How is filtration measured?
Clean Air Delivery Rate (CADR) is a way of measuring home air purifiers. It measures what sizes of particles can be removed in a volume of air, or how many cubic feet per minute can be filtered. The rating is assigned after testing small, medium, and large particle filtration — usually using smoke, pollen, and dust. How much of these elements are filtered per minute is measured, and a CADR score is assigned based on the results.
To decide what CADR rating you need, look at the size of the room you want to filter. The higher the CADR rating, the more particles the device will remove from the area, and the larger room it can service.
While CADR is the residential rating tool, industrial HEPA filters are usually measured with minimum efficiency reporting values (MERV) ratings that range from 1 to 16. The American Society of Heating, Refrigerating, and Air Conditioning Engineers developed this system. Higher values indicate better filtration power.
The price of an air purifier depends on the size, features, and how well it filters the air. Prices can range from $100 to thousands. On most commerce sites, you will be able to customize your search by filtration and price range to find the model that works best for your needs and budget.
We combed reviews and ratings from a number of home HEPA air purifiers, compiling a list that combined those ratings and feedback with the recommendations from EPA and industry leaders. Air cleaners that used ozone or ionization technology were excluded. The results are:
- CADR rating: 300
- Price (MSRP): $249.99
This device can usually be found in many brick-and-mortar stores and on sale, making it an easy choice to buy in a hurry — when it’s in stock. This machine is made to be portable and easy to move between rooms. It’s quieter than some of its competitors but still delivers great filtration.
Models built for smaller rooms or for moving a smaller volume of air can also be found, bringing price tags down. Consumers love this product, according to ratings, listing it as an affordable and effective device.
- CADR rating: 260
- Price (MSRP): $219.99
Levoit is a favorite on consumer-driven sites like Amazon, and offers a variety of models to fit every price range. The Core 400s is priced just below the range of other high performers, so it’s affordable but also does the job.
Named for the room size it’s designed to filter (400 square feet), the Core 400s features a large HEPA filter. Options for bells and whistles like voice control are also available, and the device is easily portable.
- CADR rating: 246
- Price (MSRP): $249.99
The Winix line also offers several models, but the 5500-2 is a performer for the budget conscious. There are no smart sensors or fancy apps with this model, but you can use automatic settings.
AHAM Verifide, a manufacturers’ association and product testing program, certified this air purifier’s performance for rooms up to 360 square feet.
- CADR rating: 350
- Price (MSRP): $299.99
Blueair actually makes it onto our list twice. Once for this air purifier that tops several “best HEPA air purifier” lists on consumer sites. Consumer Reports praises the model for having top-rated filtration at both high and low speeds (CADR scores are usually based on filtration at the highest speed only). The second time, below, is for its line of air purifiers overall, which gives an option for most room sizes and budgets.
This portable machine is designed for home use and has washable filter components to extend the life of your filter. This isn’t the quietest model, but it has other features, like a light to remind you when it’s time to change the filter.
One thing to keep in mind is that Blueair doesn’t use True HEPA filtration. They use a combination of physical filters and electrostatic charge, that they call HEPASilent.
The 16-pound machine has no handle or wheels.
There are other sizes available in the Blue line as well.
- CADR rating: 380
- Price (MSRP): $349.99
Medify Air is another popular brand, especially among those who need air purifiers for medical reasons. While it promises to be “quiet,” the quietest setting is about half the volume of a vacuum cleaner, making its noise level a matter of opinion.
This large unit could be difficult to move due to its design and size, but it delivers high levels of filtration for the price. There are a variety of models from this manufacturer to choose from.
- CADR rating: 241
- Price (MSRP): $329.99
BISSELL is a well-known name in filtration and the air320 purifier evokes the feeling of nostalgia with a retro furniture look. While the device can be portable, this might be difficult due to its size. The 20-pound device does come with a carrying handle, though. BISSELL offers a number of other models as well.
- CADR rating: 200
- Price range (MSRP): $549.95–$639.95
For people looking for style and function, Rabbit Air offers a well-reviewed — albeit expensive — option. These devices come in black and white, or a few famous art prints like Monet’s “Water Lilies” and Van Gogh’s “Starry Night.”
Extremely quiet on the lowest settings, you may sacrifice some function for volume and appearance with this model. CADR ratings are lower than some cheaper models, but if you’re looking for function and appearance with high-tech options, this model could suit your needs.
This is the only device on our list that gives you the option to either set it on a tabletop or mount it on a wall.
- CADR rating range: 200–640
- Price range: $350–$900
There are several models in the Blueair Classic line of air purifiers. These workhorses earn top ratings from a number of reviews, especially from people who need air filtration for allergies or asthma.
Some from this line are heavier models than Blueair’s Pure line, and a few have caster wheels to help make them portable. Reviews claim these are quieter than Pure at lower speeds, but can be loud at higher speeds. Still, these purifiers are quick and efficient at higher settings.
- CADR rating range: 150–350
- Price range (MSRP): $189.99–$749.99
This line features a variety of styles and colors, but the real draw is its filtering power. While the filtration power is high, though, so is the price. One of the pricier options on our list, the Coway devices feature extras like Wi-Fi connectivity, a mobile app, and voice control.
When choosing an air purifier, keep in mind that you should purchase your device based on room size and filtering ability. Also, the device can only filter as well as you maintain it. A dirty or expired HEPA filter will not do its job well. Check the manufacturer’s recommendation on filter replacement. Generally, these should be switched every 60 to 90 days.
You should also be sure to follow the manufacturer’s recommendations on placement, operation, and maintenance for best results.
Overall, consider why you want an air purifier, how well the device you are considering filters air, and your budget. Some units may have an attractive price, but it all comes down to how well a unit will filter the air in the size of the room you will be using it in.
- Best Overall Air Purifier. Blue Pure 211+ Air Purifier Blueair. ...
- Best Value Air Purifier. Macro Pro Dreo. ...
- Most Innovative Air Purifier. Core 400S Smart True HEPA Air Purifier Levoit. ...
- Best Air Purifier for Allergies. ...
- Best Air Purifier for Large Spaces. ...
- Best Multifunctional Air Purifier.
Won't remove every particle: Unfortunately, HEPA filters will not remove pollutants from the air that are smaller than 0.3 microns, including viruses, some bacteria, and volatile organic compounds (VOCs). VOCs are household items like hairspray and ammonia that are too small for a HEPA filter to eliminate.What should I look for when buying an air purifier? ›
- Outline Your Needs. ...
- Choose the Right Filtration System. ...
- Consider the ACH and CADR Ratings. ...
- Check Cleaning Requirement and Maintenance Cost. ...
- Consider Noise Level and Energy Consumption. ...
- Smart Features.
Airocide is the NASA air purifier. Our technology removed harmful VOCs from the International Space Station and the Columbia shuttle. It made the air safe for our astronauts, and the food they need. It does not matter how challenging the environment is.What is better than a HEPA filter? ›
ULPA filters trap more and smaller particulate matter than HEPA filters. ULPA filters are 99.999% effective at removing submicron particulate matter of 0.12-micron diameter or larger, while HEPA filters are 99.97% effective for eliminating particulate matter of 0.3-micron diameter or larger.Are there any air purifiers that actually work? ›
No purifier can capture all of the pollutants and particles that travel through a room, but depending on the type of filter used, they may capture many allergens and other unwanted substances. Many air purifiers feature HEPA filters that capture particles, including dust, pollen, and some mold spores.What air purifier do allergists recommend? ›
For people with allergies, scientific studies have shown that air filtration reduces these airborne allergens and may provide some relief. Experts recommend two types of filtration: For a single room, look for an air cleaner with a HEPA (high-efficiency particulate air) filter.Should you leave air purifier on all day? ›
Yes, you should run your air purifier 24/7 and you shouldn't turn it off anytime. In fact it's recommended to not switch off your air purifier at any time of the day or night, even when you're sleeping or not at home.Is it better to open windows or use an air purifier? ›
No one doubts that purifiers are most effective with the windows closed. That's obvious. Real-world tests show that – even without an air purifier – simply keeping doors windows closed keeps particulate pollution levels at 50% the level of outdoor air.How much does a good air purifier cost? ›
A whole-house air purifier costs $400 to $4,000, depending on the type of filtration system, efficiency rating, and labor to install or retrofit. HEPA filter systems cost $1,000 to $4,000 with installation and are the most effective at removing dust and allergens from the air.
Yes, in general, the more expensive air filters are more effective, but a single person with no pets and allergies might not need as much filtration as a family of five with three pets and a child with asthma. Also, consider how long your air filter will last.Can mold grow on HEPA filters? ›
It is possible that some especially tiny spores might get through a HEPA filter. However, the real problem with HEPA filters is mold can potentially grow on the filter surface. If it is not changed regularly, the filter can actually become the host surface for all the mold spores it has trapped.What do HEPA filters not remove? ›
HEPA filters will not remove most viruses, because they are simply too small. HEPA filters will also not remove VOCs, or volatile organic compounds, as they are also too small. Still, HEPA filter technology can be combined with other technologies that will remove these things from your air too.How many times can you clean a HEPA filter? ›
Air Purifier Filter Replacement
HEPA Filters: Replace every 12 to 18 months. Permanent Filters: Clean every three months; replace when appears worn or damaged.
Check the type of filter used. We recommend sticking with a HEPA filter that removes at least 99.97% of particles larger than or equal to 0.3 microns in diameter.Where is the best place to put an air purifier in a room? ›
The best place to put an air purifier is somewhere in your breathing zone. The closer the unit is to your head, the shorter distance clean air has to travel before it reaches you. In the bedroom, this usually translates to putting the air purifier on a nightstand or small table close to the bed.How long should you run an air purifier in a room? ›
Leave your air purifier on all day, if possible. It will remove dirt, allergens, smoke, and odors from your indoor air. The longer you can leave it on, the cleaner your air will be. There's no clear downside to leaving your air purifier on 24/7.Can HEPA air purifiers capture the coronavirus? ›
When used properly, air cleaners and HVAC filters can help reduce airborne contaminants including viruses in a building or small space. By itself, air cleaning or filtration is not enough to protect people from COVID-19.Does CDC recommend air purifiers for Covid? ›
Use portable high-efficiency particulate air (HEPA) fan/filtration systems to enhance air cleaning (especially in higher risk areas such as a nurse's office or areas frequently inhabited by people with a higher likelihood of having COVID-19 and/or an increased risk of getting COVID-19).What air purifier does TikTok recommend? ›
TikTok users are turning to one air purifier specifically for pets, and the results are both satisfying and cringe-worthy. The Okaysou Air Purifier gained attention on TikTok after several videos revealed how much debris it actually captures from the air. Spoiler: It's a shocking amount.
To clean the HEPA filter, you should use a strong stream of cold water and not use any detergents or other chemicals. You should not rub or brush the filter, as this could damage it and cause it not to work properly. Wash it in cold water, being very gentle and making sure you don't damage the filter.Are there different grades of HEPA filters? ›
There are, however, different grades of HEPA filters, which range from H10 through H14. The higher the grade, the higher the performance. H10 to H12 filters are sometimes known as "True HEPA" filters. They trap less particles than the higher grade filters.What is a true HEPA air purifier? ›
A True HEPA filtration device or filter is the only type of HEPA filter that truly conforms to the DOE standard for HEPA filtration, has the highest efficiency, and hits the 99.97% threshold. If the HEPA filter does not meet the DOE's standards for HEPA filtration, then it is not considered True HEPA.Do doctors recommend air purifiers? ›
In addition to regular sanitizing, many doctors are now recommended air purifiers for work and home. In addition, a growing number of healthcare practices have bought air purifiers from us, and the results they experience have led to glowing recommendations.Are cheap air purifiers effective? ›
Are they effective? The short answer is yes — however, an air purifier likely won't remove or neutralize all aggravating particles in your home. This is due to the fact that many particles can sit on soft surfaces, such as furniture, bedding, and carpeting, as well as hard surfaces, such as your walls.How many air purifiers should you have in your home? ›
If you have a 1,400 sq ft home, you need 2 of them for proper air purification. If you have a living space with a 12×12 bedroom, 15×10 kitchen, and 14×14 living room, a single air purifier might be enough. You can even move it around from room to room to increase indoor clean air circulation.How do you get rid of dust mites in your house? ›
- Use allergen-proof bed covers. Keep your mattress and pillows in dustproof or allergen-blocking covers. ...
- Wash bedding weekly. ...
- Keep humidity low. ...
- Choose bedding wisely. ...
- Buy washable stuffed toys. ...
- Remove dust. ...
- Vacuum regularly. ...
- Cut clutter.
To some extent, an air purifier may be able to prevent or mitigate your sinus problems. By limiting the amount of pollen you're exposed to at home, an air purifier with a HEPA filter can reduce the likelihood of experiencing allergic sinusitis and secondary bacterial infection associated with allergies.Do air purifiers help with inflammation? ›
HEPA filters help reduce a variety of inflammation markers in your body. The reduced inflammation from air purifiers can be seen within 48 hours.Do you need air purifier in winter? ›
If anyone if your home experiences allergies, frequent respiratory illness, or sensitivity to airborne contaminants, an air purifier is an essential component of your HVAC system, especially during the wintertime.
Don't Clean If Not Necessary
If you don't use the appliance as often, you won't need to clean it as often. Once every three months might even be too often. Check the filter when cleaning is due; if it isn't dirty, avoid the trouble. You can, however, give it a quick go with the vacuum if you feel it's necessary.
This is because, as the temperature drops during the nighttime hours, the atmosphere traps car emissions, CO2, and other pollutants in the house and down near the ground – and the effect is much worse if spaces inside the home are poorly ventilated.Should the air purifier face the wall? ›
It is completely safe to place the air purifier against the wall. However, it is not recommended to place the unit against the wall if the air intake is located at the rear of the unit (i.e. AM 90/100/DX5). These models will perform better if NOT placed up against a wall.Should I sleep with air purifier on? ›
Should I Sleep With an Air Purifier On? The short answer: yes. The Asthma and Allergy Foundation of America (AAFA) recommends an air purifier during bedtime to promote better breathing while you sleep.Should I close the door when using air purifier? ›
You should keep the doors and windows closed when you're using an air purifier. A draft or an open door can draw unfiltered air into a room faster than the purifier can deal with it. (Normal in-and-out foot traffic isn't an issue; just close the door behind you.) Clean the prefilter monthly.What is the difference between a cheap and expensive air purifier? ›
The higher the MERV rating, the better the air filter is at removing particles. Cheap air filters typically have a low MERV rating of 6 or less, while expensive air filters can have a MERV rating of up to 13. This means that they can remove much smaller particles, like bacteria, viruses, and mold spores, from the air.What makes one air purifier better than another? ›
The higher the CADR, the faster and more efficient the air purifier is. Room air purifiers with HEPA filters often achieve the highest CADR. In our tests, a CADR above 240 receives an Excellent rating; 240 to 180, Very Good; 179 to 120, Good; 119 to 60, Fair; and under 60, Poor.How often should you run an air purifier in your home? ›
Air purifiers are generally designed to be run all the time if you prefer to. You can put the purifier on its lowest setting to diminish noise and let it run throughout the day. This 24/7 approach will use more a bit more power, and you may need to clean or replace air filters more frequently.How long does a HEPA filter last air purifier? ›
Although it depends on the specific filter you have, as a rule of thumb, replaceable HEPA filters should be replaced every 6-12 months, depending on air quality and environmental factors. Carbon pre-filters should be replaced every 3 months, depending on air quality and environmental factors.What is a HEPA 3000 for? ›
Designed for HF 3.0 and HF 3.1 models, this Venmar HEPA 3000 filter is considered one of the most efficient on the market. It captures 99.97% of airborne particles in your home, including those as small as 0.3 microns. This effective air filter helps keeps your home dust and allergen free.
H13 HEPA filters are considered the highest tier when it comes to this technology, which ensures that they are perfect for use in hospitals, clinics, and other medical settings. True or genuine HEPA filters can also be referred to as H11 or H12 filters.What is the difference between HEPA 11 and 13? ›
HEPA 11 filters are typically used in residential settings, while HEPA 13 filters are designed for more industrial or commercial applications. HEPA 13 filters are able to capture a higher percentage of smaller particles than HEPA 11 filters, making them more effective at removing pollutants from the air.Should I run my HEPA filter all day? ›
Is there any time you shouldn't run it? Yes, you should run your air purifier 24/7 and you shouldn't turn it off anytime. In fact it's recommended to not switch off your air purifier at any time of the day or night, even when you're sleeping or not at home.Is HEPA 13 Good for Covid? ›
In addition, portable air cleaners equipped with a high efficiency particulate air (HEPA) filter or a filter with a minimum efficiency rating value (MERV) of ≥13 can reduce SARS-CoV-2 aerosol exposure over time, helping to limit the risk of aerosol transmission.Is HEPA 13 or 14 better? ›
H13-H14 HEPA are within the highest tier of HEPA air filtration and are considered medical-grade. “A HEPA grade of H13 can remove 99.95% of all particles in the air measuring 0.2 microns in diameter, while a HEPA grade H14 removes 99.995%,” says Nagl.Can HEPA 13 filters be washed and reused? ›
You can try to clean them and reuse them, even if the brand says to discard them after use, but be aware that they won't be operating with the same thoroughness afterwards.Who is the largest manufacturer of HEPA filters? ›
The key is to look for specific numbers on labels such as: “99.97 percent of all particles at 0.3 microns in size.” If the marketing claims are fuzzy, such as “more than 99 percent of dust and pollen,” that is not the same as True HEPA.What is a good HEPA? ›
In the North American definition, “true HEPA” means that a filter removes at least 99.97% of airborne particles of a 0.3-micron diameter in a single pass; human hair, for reference, usually measures between 20 and 180 microns across.What are the three classes of HEPA filters? ›
All of them, by definition, remove more than 99.97% of 0.3-micron airborne particulates. Example of HEPA filter, used in high-performance Coway air purifiers. HEPA filters can be classified as H10, H11, or H12 filters.
These portable systems often contain essential filtration media such as a HEPA filter. However, not all "HEPA" filters are made the same and are often rated to capture particulate of varying micron sizes.