Last updated on January 1st, 2023
HEPA air purifiers utilize High Efficiency Particulate Air (HEPA) filters as means to remove particulate matter (PM) from the air. These particles include various allergens (pollen and others), bacteria, mold, dust, asbestos and many others. HEPA is an official name for such filters as defined by the U.S. Department of Energy.
To get HEPA certification, a filter must remove particles as small as 0.3 micron and its efficiency must be at least 99.97% for 0.3μm particles. Why 0.3 micron in particular? They are considered the worst case of the most penetrating particle size (MPPS); particles that are larger or smaller are trapped with even higher efficiency. Basically, the 0.3 micron standard was chosen as the worst case scenario for the removal of harmful particles from the air.
One micron (defined as micrometer by the International System of Units, uses the symbol μm) is one thousand of a millimeter (0.001mm) or 0.00003937 inches. For comparison, bacteria are often found in the range of 1 to 10 micron, while a human hair is 50 micron in diameter. Anything below 40 micron isn’t visible to a human eye.
But what does 99.97% efficiency mean? Here’s an example. If in a room there are 10000 particles of various sizes, that means a HEPA air purifier can remove at least 9997 of them, leaving only 3 in the air. Sounds good, right? But this is how it works in theory most of the time.
In practice, there are lot of reasons why it’s not true most of the time. The most obvious answer is bad air filters that aren’t even HEPA but are marketed as one. Do you know that majority of so-called “HEPA” filters are made at the same Chinese factories without even proper certification and cost $1 per piece whilst sold here in the US for $20-30?
Another problems include filter design, material quality and sealing. Any HEPA filter must be tightly sealed in the unit, preventing the air from evading the filter media. Some filters use low-quality materials or have issues with their design and can’t even capture particles as small as 1 micron, let alone anything smaller. All of them will have a “HEPA” sign attached for obvious reasons.
Another issue is low CADR. This acronym stands for Clean Air Delivery Rate and this is a metric used to determine the volume of air cleaned in one minute from particles of specified sizes. In the US it is measured in cubic feet per minute, CFM. If an air purifier isn’t capable to generate enough airflow, no matter how high-quality your air filter is, the result is going to be bad. Here’s a list of air purifiers with high CADR. There are also AHAM-Verified air purifiers, that have passed an independent test and their Clean Air Delivery Rate is proven by experts.
CADR is also used to determine how fast the air is cleaned in a specified area. If in a 500 sq. ft. room an air cleaner filters the air from pollution in 12 minutes, it’s going to be better than an air purifier that does the same in 30 minutes. It’s extremely important for people who suffer from breathing conditions or are allergic to anything as they need the air to be free from allergens or bacteria constantly, no matter what’s going on inside or outside. A metric called Air Changes Per Hour is the one that they need to understand if they want to improve their health conditions.
Some of the manufacturers do not even specify a CADR in their spec sheet. Sure, you can use this CADR calculator to find out it by yourself, but I do not recommend getting an air purifier that tries to hide this crucial information.
You have probably also seen the so-called “true HEPA” filters used in air purifiers. In most cases it means that they follow the US standard, as compared to the European one, a filter can remove just 85% 0.3μm particle to be considered high efficiency. In other cases it’s just a marketing trick that has no meaning behind this.
As you can see, a good HEPA air filter can’t do the job of keeping the air clean alone. It has to be backed up by other metrics and overall performance. Down below I have selected the best HEPA air purifiers that I consider “a must have” if you want to keep the air clean indoors in 2023.
Air Health Skye: Best HEPA Air Purifier in 2023
Air Health Skye is a portable, AHAM-Verified HEPA air purifier for large rooms. It is known to remove allergens, viruses, bacteria, dust, pollen, smoke and other smells from the air by utilizing 5-stages of air cleaning that include:
- Pre-filter for pet hair, dirt, pollen, dust
- Activated Carbon filter that removes various smells, cooking odors and gases
- HEPA filter to capture fine particles of dust mites, allergens, volatile organic compounds (VOCs)
- PRO-cell to trap chemical odors
- UV-C Light to remove bacteria, mold, fungi, kill viruses and sanitize the air
A recommended room size by AHAM is 453 square feet – that’s when this air purifier can achieve the necessary 4.8 air changes per hour so much needed for allergic people. A 550 sq. ft. room will have 4 air changes which is still a great result. For comparison, in a 1000 sq. ft. area this air purifier can achieve 2.2 air changes.
Air Health is a company founded in 1977, they have been developing air purifiers (including in-duct ones) for decades. It means there are no problems finding a replacement HEPA filter or UV-C bulb for the Skye air purifier.
When it comes to smart features, the Skye has plenty of them: auto-mode (turn on and forget), WiFi connectivity to control the air purifier with a phone or voice (Alexa), Timer and others.
I recommend getting this HEPA air purifier if you want to have an ultimate solution for the air pollution in your house.
Coway Airmega AP-1512HH: Popular Choice
Coway Airmega AP-1512HH also known as Coway Mighty Air Purifier is a very popular HEPA air cleaner. It is a reliable, powerful, yet affordable and low-maintenance air purifying machine manufactured by a Korean company Coway that has been proven to be one of the best on the US market in recent years.
Similar to the previously reviewed Air Health Skye, the Coway Airmega also features 3 filters (pre-filter, HEPA and Carbon) that greatly reduce the number of allergens and unpleasant odors (in a bathroom, for example) in any household. However, instead of a PRO-Cell and UV-C bulb, this air purifier features a built-in ionizer that produces ions to help the HEPA filter capture various VOCs, bacteria and other tiny particles. The ionizer makes the air smell freshener as well, deodorizing it in a way.
On the negative side, the ionizer releases a small amount of ozone, so it might be not suitable for some people. However, this feature can be turned off if needed.
Auto-mode and timer are also present in the Coway AP-1512HH air purifier, yet it lacks any WiFi support.
Overall, if you need a reliable, low-maintenance HEPA air purifier for any room in your house, the Coway Airmega is one of the best picks you can get for the price.
Winix PlasmaWave 5500-2: Korean-Made HEPA Air Purifier
There is a recurring joke in the air purifier community as to what air purifier was designed earlier – Winix PlasmaWave 5500-2 or Coway Airmega AP-1512HH. The reason for this joke is very easy to explain: both air cleaners utilize the same 4-stage air cleaning technology with pre-filter, HEPA, Carbon and ionizer. They are very similar in terms of CADR and other specs as well, including the price tag.
What makes the Winix different, is the long lifespan of its HEPA filter (12 months on average) and there is a consensus that it is slightly better at removing heavy odors and food smells from the air, compared to the Coway Airmega.
However, no matter which air purifier you are going to pick, either offer a great air filtration for the price.
Tracs TM250: Best US-made HEPA Air Purifier
Tracs TM250 is a totally different beast compared to the Winix or Coway air purifiers. It has a higher price tag compared to all air purifiers listed on this page, yet it offers something that others do not.
First of all, it’s a HEPA air purifier in a welded steel construction with a motor built to last for decades without any issues. The whole unit is covered by a 5-year warranty.
Secondly, the air purifier features a high-quality, medical-grade HEPA air filter. The same filters are used in laboratories and medical facilities to ensure the air people breathe inside is clean from all kinds of pollutants.
Finally, the Tracs offers a unique UV-C Light combination, I go into more details in this review. There is a study that claims 222 nm UV-C Light can inactivate airborne human coronaviruses (Covid-19). Whether it’s true or not, Ultraviolet Germicidal Irradiation produced by UV bulbs has been used for decades in hospitals to prevent spread of viruses, inactivate bacteria and sanitize the air.
To sum up, the Tracs TM250 is a HEPA and UV air purifier that can remove all kinds of airborne pollution, including viruses and microorganisms. If you want to have 100% clean air in your house, then this is the best portable air cleaning solution you can get.
Alen BreatheSmart 75i w/ custom HEPA Filters
Alen BreatheSmart 75i is also a great pick if you are considering getting yourself an air purifier for a large room or any other polluted area. It features a very quiet (inaudible at the lowest speed, not loud at the highest) operation, Auto and Sleep modes and generally good performance in different situations.
What makes the BreatheSmart 75i unique is the filter selection: at the official website you can select one of four available filters for your specific situation you want to deal with. If you want to remove germs or mold there is one filter, for pet smells there is another, for heavy odors there is a special large air filter, and so on. The filters vary in price, yet there is only $30 difference between the cheapest and the priciest one.
Now let’s answer some general questions regarding HEPA air purifiers.
What is an air purifier?
Please, read this page to get yourself more familiar with a concept of an air purifier.
Do HEPA air purifiers work? How do they affect someone’s health?
Yes, they do. They remove fine dust particles, fumes, gases, odors, bacteria, smoke and other airborne particulate matter from the air.
Compare an apartment that stinks or is polluted in any other way. Then compare it with the one where the air is clean. Where do you want to live or work? That’s what air purifiers do – make the place you live or work better by providing you and your family, colleagues, workers, etc. with a supply of clean air. And clean air results in better health, improved well-being and increased brain activity.
How do I know a HEPA air purifier works?
You can get yourself an air quality monitor based on your needs. It will measure the number of particles (PM2.5, VOCs, dust, formaldehyde, etc.) and you can compare how many particles were before you turn an air purifier and how many of them are still present in the air after some time.
When it comes to cooking odors, bathroom smells, fumes and other things you can feel, it’s obvious when an air purifier works and when it doesn’t. In my experience, most of the air purifiers do the job or at least reduce the smell.
Do they break?
Yes. This is even more true for some new brands that just entered the market. I recommend getting an air purifier from a trustworthy manufacturer, many of them listed on this page.
Are HEPA air purifiers safe?
Yes, they are safe. Air filters do not release any dangerous gas into the air. Sometimes an air purifier may smell
How often change do I have to change a HEPA filter?
Air purifiers have a filter indicator. It usually blinks red when any filter requires a replacement.
How long do HEPA filters last?
Usually from 3 to 6 months. There are also long-lasting air filters, like the ones used in the Tracs or Alen air purifiers.
Do I have to clean my air purifier?
Most of the time pre-filters can be cleaned. Follow the instructions you have received with your air purifier to know more about what filters are washable and how to clean them.
Are HEPA air purifiers good for asthma?
Yes, they can provide some relief. Just make sure an air purifier will provide at least 4 air changes per hour in the room where you are going to put it.
What about pet allergies, do they help?
HEPA air purifiers should help with cat, dog or any other’s pet allergies.
Is there are any smaller/budget HEPA air purifiers you can recommend?
Yes, here you have air purifiers for small rooms. Some of them are under $100. Just keep in mind, that cheap air cleaners are either designed for small spaces or just bad – you won’t have a powerful air purifier with a top-notch air filter that costs pennies. Miracles do not happen in this industry.