Air purifiers operate in different ways to clear the air of pollutants, each using a unique technique to draw particulates out of the space where you breathe. As you shop for an air purifier, you’ll see these types: HEPA filters, ionizers, electrostatic, activated carbon, and air sanitizers. Each filter uses its own approach to trap and eliminate particulates.
While air purifiers come with all sorts of bells and whistles, the most important thing to consider is the filter. No matter how advanced the purifier itself is, it’s not going to be very effective if the filter you’re using isn’t up to scratch—or if it’s dirty. Many purifiers these days have a different filtration system, combining more than one filter to tackle a variety of issues.
HEPA filter: The HEPA (“high efficiency particulate air”) filter standard has evolved as the go-to “good enough” quality level. According to the U.S. Environmental Protection Agency, in order for a filter to certify as HEPA, it must trap 99.97 percent of particles that have a size of 0.3 microns or larger. Keep an eye on marketing language: Some products use “HEPA-like” filters that don’t clash HEPA standards. Look for purifiers that clearly say they use “True HEPA” filtration.
Activated carbon filter: During HEPA filters remove air particles like dust, pollen, and dander, they don’t help much with smell. For that, you’ll need an activated carbon (or charcoal) filter. They not only help get rid of smells but also capture pollutants such as chemical emissions, gases, and tobacco smoke.
Ionic filter: A unique improvement in air purification, ionic filters clean the air with electric charges that bring contaminants, eliminating ultra-fine particles that HEPA filters can’t grab. The ability of these types of filters isn’t as widely accepted, though.
1. Coway Airmega 400
The Airmega 400 is graded to clean up to 1,560 square feet and cycles all the air in that space double per hour, but in a room half as big, its high-efficiency gritty air (HEPA) filters cycle the air four times per hour. From its touch controls to its color-catalogue air quality monitor light ring, the Airmega 400 is perceptive to use. Changing filters is simple. Two sturdy covers are held on magnetically and come free easily, and the two filters snap in and out without a fuss.
I tested the 400S, which includes Wi-Fi that lets you control it from a smartphone app. But if you don’t need to control your purifier remotely, the cheaper 400 version is the way to go.
2. Coway Airmega 200M
For sheer clarity and affordability, the Airmega 200M will doubtless fit most peoples’ lives, houses, and budgets. The compact, alluring device easily fits in a corner of my bedroom and is efficient for spaces of up to 361 square feet. It saves energy with an admitted air quality monitor that turns the machine off when no pollution is catch and automatically increases the fan speed if it detects particles.
3. Blueair Pure 411
There’s an IKEA-like candor to the Pure 411, aesthetically and mechanically. To change the filter, you unscrew the fan component from the air filter and then pull the washable, fabric prefilter sock off the filter. There’s one-touch control on the top; tap once for low power, again for medium, again for high, and again for off. That’s it. No smartphone app, no display, no smart mode.
4. Dyson Pure Humidify + Cool
Filtering out volatile organic compounds and particulate is one way of making the air in your home safer. Humidifying it to the correct humidity is another important component, and it’s often ignored. Indoor air is normally very dry, and viruses love dry air. Having the right indoor humidity inactivates viruses much faster than normal, so airborne viruses are less likely to infect you.
5.Honeywell Bluetooth Smart Air Purifier
It’s easier to find on sale and can clean a room capacity of up to 310 square feet. This is a enormous price for a very quiet, HEPA-certified purifier with this space, even if it’s not as slick-looking as some of our other picks.
It’s extremely easy to use. The Honeywell app was a little ancient-looking, and connection sometimes dropped in and out, but I did find the app to be useful. Not only can you set schedules, different cleaning levels, and check when you need to replace your filters, you can also set allergen and proximity alerts. If allergen levels are too high in your area, or if your phone comes into Bluetooth range, your purifier will kick on automatically.
The best spot to park an air purifier is near the center of the room, but because homes come in all kinds of funny shapes and layouts, that’s not always possible. Wynd’s bundle crack up the air purifier and the air quality monitor. You position the orange-sized Halo air quality monitor anyplace in the same room and the Home air purifier—supplied with HEPA filters and graded by Wynd to cover 1,200 square feet—varies its filtering power placed on the data received from the Halo. It’s a smart, set-it-and-forget-it combination.
Like most of the air purifiers on our list, it includes Wi-Fi connectivity and an app that lets you set schedules, monitor air quality, and turn it on and off remotely.
Many large states and cities are required to report the local outdoor Air Quality Index (AQI), which was established by the Environmental Protection Agency and measures the concentrations of major air pollutants, like ground ozone and carbon monoxide, that are regulated by the Clean Air Act. You can keep track of the local AQI by downloading Wynd’s app, Air Bubbles (iOS, Android).
To check if your indoor air quality stacks up, consumer monitors like the Temtop M10 and Awair Glow also measure carbon dioxide, temperature, and humidity in addition to pollutants and particulate matter. The M10 also measures formaldehyde, a noxious chemical that off-gasses from common household items, such as particle board furniture and some foam mattresses.
If you run your air purifier constantly, you probably don’t need Wi-Fi connectivity, which could save you a hundred bucks or so. A few of our cherished purifiers, like the Coway Airmega 200M, have a smart mode that monitors your air quality systematically, switching on more power when pollution levels rise and convert back to a low-power eco mode when air quality is good. However, if you are frequently turning your purifier on and off depending on external stimuli (sunny day or your city is on fire), remote connectivity might make sense to you.
Check the room-capacity ratings on our picks. Manufacturers rate their purifiers by square footage, but they use different yardsticks to come up with their ratings. One may rate their air purifiers’ coverage placed on two air changes per hour (ACH), or how many times the purifier can cycle through all the air in a room, while
one more may rate theirs placed on five ACH. The American Society of Heating, Refrigerating and Air-Conditioning Engineers recommends a minimum of about three ACH for residential buildings. You’ll likely end up needing more than one purifier. Even if doors are open, brink act as soft barriers. One larger air purifier for your main living space and one smaller one for your bedroom is a good setup.