Science Technology The 5 Best Air Quality Monitors of 2021 Keep an eye on the quality of the air you breathe By Lorraine Wilde Lorraine Wilde Twitter Lorraine Wilde is a freelance writer for Treehugger. She is the Owner and Strategist of the public relations and content company Wilde World Communications. Learn about our editorial process Updated August 17, 2021 Fact checked by Elizabeth MacLennan Fact checked by Elizabeth MacLennan on August 13, 2021 University of Tennessee Elizabeth MacLennan is a fact checker and expert on climate change. Learn about our fact checking process Share Twitter Pinterest Email Science Space Natural Science Technology Agriculture Energy Our editors independently research, test, and recommend the best products; you can learn more about our review process here. We may receive commissions on purchases made from our chosen links. With an air quality monitor, you can get a better idea of various pollutants in and around your home and office. You can also analyze the conditions when they’re at their peak. With more information, you can have peace of mind about the air you breathe and also decide if you need to take action to clean up your air. Although air quality metrics vary widely from city to city, air quality in the United States has generally improved since the 1970s, when advocates began pushing for better pollution controls (more on that in the FAQs below). In addition, recent changes to air quality standards and a shifting climate have increased consumer interest in real-time air quality monitoring. We’ve put together this list of the best air quality monitors available on the market today to help you keep an eye on the quality of the air you breathe. The Rundown Best Overall: Airthings Wave Plus at Amazon An award-winning Smart-Home capable and customizable monitor that also detects radon. Best Smart Monitor: Awair Element Indoor Air Quality Monitor at Amazon Full integration and in-app feedback and tips help you improve air quality based on your custom goals. Best Budget: Temtop M10 Real-time Air Quality Monitor at Amazon An excellent affordable indoor/outdoor monitor that doesn’t sacrifice on quality. Best Portable: Biaoling Air Quality Monitor at Walmart Clear, simple monitor design and display for no-fuss, hand-held use on the go. Best Indoor/Outdoor: IQAir AirVisual Pro at Amazon This air monitor pairs easily with home and phone smart technology, giving you access to outdoor air quality data. Best Wearable: Atmotube PRO at Amazon Real-time, phone-capable monitoring that lasts a week on a single charge. Best Overall: Airthings Wave Plus Radon & Air Quality Monitor View On Amazon View On Home Depot View On Lowe's To earn the best overall rating, an air quality monitor must be easy to use, compact and well-rated. The Airthings Wave Plus monitor offers all of this and much more. In addition to measuring Total VOCs, carbon dioxide, air pressure, temperature, and humidity, it is one of the few monitors that also monitors radon. The Airthings Wave Plus looks like a typical smoke detector and can hang on the wall. Connecting via Bluetooth technology, it works well with your smartphone, Alexa and Google Assistant, and has customizable “If This, Then That” (IFTTT) technology options. That means you can custom program how you’d like to be notified based on the indoor and local outdoor air quality. For example, via the Airthings app or online dashboard, you can program it to text or email you when to turn on an air purifier or close a window. The monitoring device itself does not have a numerical display, but you can simply wave a hand in front of it to trigger a green-yellow-red light system where green is good air quality and red is poor. The monitor is old school, using two AA batteries. The free mobile app will notify you when they need replacing. Not only do users love this monitor’s functionality, but it has also won Time Magazine’s 2019 Award for Best Invention and was a 2019 honoree for the CES Innovation Award, presented annually by the Consumer Technology Association for outstanding design and engineering. Why Radon Matters According to the EPA, radon is the number one cause of lung cancer among non-smokers. It causes about 21,000 lung cancer deaths a year. If you know you live in an area with naturally occurring soil radon, or you work in the basement or underground areas with floor drains that connect directly to the soil, the sensor you buy should detect radon. Best Smart Monitor: Awair Element Indoor Air Quality Monitor View On Amazon Many products made today are designed to interface with smart-home technology, allowing you access and manipulation no matter where you are via Bluetooth and Wi-Fi to your smartphone, tablet, or computer. We like the Awair Element Indoor Air Quality Monitor for its ease of use, customizable interface, and ability to integrate with its free app (iOS and Android) as well as Alexa or Google Assistant. An added bonus is the in-app feedback and tips based on your custom air quality goals that will help you immediately improve your living space to improve your indoor air quality. We also appreciate its compact, inconspicuous design that helps it blend seamlessly into your home or office décor. Check your home internet specs before you buy as this unit requires a minimum 2.4GHz Wi-Fi Connection to work properly. The monitor accurately and affordably measures temperature, humidity, carbon dioxide, VOCs, and PM2.5. Each is displayed on the front of the device as a series of stacked dots on a scale from one to five, with five dots being unhealthy. A numerical score from 0 to 100 and a green-orange-red light also indicates at a glance your overall air quality (100 is best, green is good). "I liked the Awair because it had an appropriate mix of measurements for a residential interior (although I would have liked to also have NO2); it connected to my phone and keeps a record so that I could track the air quality over time ... and it was a cute little thing that didn't look like some computer readout and doesn't look too out of place on the mantelpiece." ~ Treehugger Design Editor Lloyd Alter The 7 Best Energy-Efficient Air Conditioners of 2021 Best Budget: Temtop M10 Real-time Air Quality Monitor View On Amazon View On Temtopus.com Competition on the market and consumer demand has helped bring down the cost of air quality monitors without compromising technology quality. The Temtop M10 Professional Air Quality Monitor is a great option for quality and ease of use on a budget. For under $100, this monitor reports particulate matter as small as 2.5 microns (PM2.5), Air Quality Index (AQI), total VOCs, and formaldehyde. Formaldehyde is often found in indoor air settings due to smoking, off-gassing from household products, and from un-vented fuel-burning appliances like gas stoves and kerosene heaters. This unit is just over 3 inches tall and wide but has an easy-to-read full-width display. It can remain plugged in at all times via USB, or can be portable and run on battery power for about six hours on a full charge. Temtop offers a full range of monitors, including the P10, with slightly fewer features for about $20 less (view on Amazon). The 12-month warranty and 24/7 customer support will give you peace of mind too. Best Portable: Biaoling Air Quality Monitor View On Walmart View On Amazon A runner-up for Best Budget, the Biaoling Air Quality Monitor is a great combination of affordable easy-to-use portability without losing function. The unit will monitor air quality for up to 10 to 12 hours on a single four–hour charge and displays results on an easy-to-read LED screen. The battery charges via a USB port. It is the perfect size for hand-held use, measuring about 6 inches tall x 3 inches wide x 1 inch deep. Its built-in stand allows it to be conveniently placed upright for easy viewing. This model will identify PM2.5, PM10, and a range of VOCs, in addition to detecting formaldehyde and carbon dioxide. You can set the unit to sound an alarm when the air quality reaches an unsafe level. If you prefer to avoid apps, smart tech, and extraneous electronic devices for your no-fuss interface, you’ll appreciate the reliable, logical, and accurate performance of the Biaoling monitor. Its lack of a smart tech interface has not hindered this handy monitor from earning a top spot on many “Best of” lists. The 8 Best Mist Humidifiers of 2021 Best Indoor/Outdoor: IQAir AirVisual Pro View On Amazon View On Iqair.com Most air quality monitors designed exclusively for outdoor use tend to be professional-grade monitors that are watertight. They come with greater accuracy and often a much higher price tag. But there are also several monitors on the market rated for both indoor and outdoor use. Read the fine print before buying, as most are not watertight and will be destroyed by too much moisture. An excellent solution is IQAir Air Visual Pro which is well-rated for a number of reasons. This monitor reports outdoor air quality side by side with indoor air quality so you can add your city, and it will report real-time data. It has a large 5-inch LED screen, and it's easy to set up and pair via Wi-Fi with the native AirVisual app, available in both the Apple App Store and Google Play. An added special feature is that Air Visual Pro has artificial intelligence that you can connect to your smartphone and other Smart Home IFTTT integrations including compatibility with Google Assistant, similar to the Airthings Wave Plus. It monitors temperature, humidity, and PM2.5 using laser technology. For monitoring carbon dioxide, it has an industrial-grade sensor. It also displays the weather report. This compact unit is just 7 inches long and has a built-in battery that recharges via a USB connector. Science lovers can also place the monitor outdoors and designate it as a public outdoor station so that you become a data source in an extensive network. Not only will you be providing neighbors and researchers with air quality information in your area, but you can also see how your data compares with others in the network anywhere in the world. Best Wearable: Atmotube PRO View On Amazon View On EBay When you’re on the go, you may want an air quality monitor that measures in real-time and can alert you when air quality is poor, so you can make immediate changes. The Atmotube Pro Portable Air Quality Monitor is just 3 inches long, weighing less than 4 ounces. It can be clipped to your belt or bag and lasts a full week on a single USB charge. It has particulate matter sensors that detect PM1, PM2.5, and PM10 pollutants as well as VOCs, barometric pressure, temperature, and humidity. Measurements are transmitted in real-time via Bluetooth to iOS and Android smartphone apps in a user-friendly interface so you can monitor your personal air score. Data is uploaded anonymously to their global air quality map. When your score gets below a healthy threshold, you’ll receive an immediate alert. If the price tag is too steep for you, check out our review of the popular and less expensive runner-up, Flow Personal Air Quality Sensor. Final Verdict A reliable, real-time air quality monitor can give you more information, peace of mind, and control over your personal environment. For an all-in-one, compact, Smart-Home capable, customizable air quality monitor that is capable of giving actionable feedback, it’s hard to beat our Best Overall monitor, the Airthings Wave Plus (view on Amazon). When you’re on the go or need outdoor air quality data, consider the portable Biaoling Air Quality Monitor (view on Walmart). What to Look for in an Air Quality Monitor Which pollutants it measures When choosing an air quality monitor, you first want to be sure it measures the particles and gasses that cause the greatest risk in your home or office. For example, those with wood-burning stoves should ensure their air quality monitor measures carbon monoxide. Many on the market today detect a combination of particles and gasses all in a single monitor. Particulate size When measuring particulate matter, make sure your monitor measures particles that are 2.5 microns or larger in size (PM2.5). Older monitors could not detect these smaller particles that can travel deep within our respiratory system. For comparison, a human hair is about 70 microns thick. Those monitors that claim to detect mold are usually including mold spores in their PM2.5 measurement rather than detecting it directly. Display and features When choosing a monitor, you’ll want one that is easy to use and well-rated for accuracy. Many are capable of pairing with your phone or computer to increase display options and screen size. You’ll also need to consider whether you want a stationary or portable model and whether your monitor will plug into a standard electrical outlet or use rechargeable batteries. Smaller portable units can be highly useful if you travel from place to place for work, but they also can have limited battery life and small display screens. So it’s important to consider each of these factors when making your selection. Understanding AQI Most air quality monitors meant for home use report an Air Quality Index (AQI). The index was developed by the U.S. Environmental Protection Agency (EPA) to streamline air quality information for the general public. It combines all of its air quality measurements of ground-level ozone, particle pollution (PM2.5 and PM10), carbon monoxide, sulfur dioxide, and nitrogen dioxide into a single number that ranges from 0 to 500, with 500 being the highest level of air pollution. Not all monitors that report AQI measure all of these pollutants, but most will display an AQI estimate and then offer users the ability to use monitor or app menus to dive deeper to see actual numerical values and graphed data over time. FAQs What are air quality monitors and how do they work? Although all air quality monitors are not created equal, most measure particulates, carbon dioxide, carbon monoxide, and volatile organic compounds (VOCs). The world is paying attention to particulates because they are tiny unseen floating particles suspended in the air—like dust, pollen, soot, and mold spores—that can be inhaled. When they reach the delicate cells in your lungs, they can cause allergic reactions, inflammation, or in some cases, remain lodged in lung tissue causing cell death, infection, or tumors. VOCs are common organic chemical gasses like acetone, methanol, benzene, ethanol, toluene, and formaldehyde that evaporate into the air from manufacturing processes, gasoline and diesel exhaust, and from a wide range of fossil-fuel-based products and surfaces. Many household items off-gas, like flooring, adhesives, paints, and furniture foams, either when they are new or gradually as they age. You may have heard of VOCs because they are the chemicals that undergo photochemical reactions (in sunlight) with nitrogen oxides to form ground-level ozone, or smog, that contributes to climate change. Air quality monitors measure these particles and gasses with electrochemical sensors, infrared and UV lasers, and light detectors. Electrochemical sensors measure carbon monoxide by reacting with small amounts of the gas. This oxidation reaction creates a small change in electrical current on the sensor’s surface that is then measured, quantified, recorded, and displayed. The change in electrical current is proportional to the amount of gas in the air. Carbon dioxide is often measured by shining infrared light through the air sample inside the monitor. Carbon dioxide absorbs the light, so higher concentrations absorb more light than lower concentrations. Detection of particulates and VOCs use similar methods. VOCs use UV light instead of infrared light. Particulates use a laser with varying wavelengths of light. Air quality monitors are calibrated by the manufacturer by measuring known concentrations and developing a pattern of detection. So, it’s important to recalibrate monitors according to the manufacturer’s instructions to ensure they continue to produce accurate results over time. How can I improve my air quality? If you discover your local air quality needs improving, there are a number of simple things you can do to improve your conditions. From adding houseplants, cleaning your air ducts to using an energy-efficient air conditioner, or trying an air purifier, you can make a big difference right at home. Is air quality getting worse? In the 1960s, scientists began investigating the link between air pollution and human health. States passed legislation to reduce air pollution emissions. Then in 1970, Congress passed the Clean Air Act Amendments that established air quality standards for the U.S. As a result, the U.S. ranks well compared with many other countries for its air quality. When the pandemic shut down factories, refineries, and vehicle traffic, we saw incredible, yet temporary, improvements in air quality. These standards are set for industrial and municipal emissions but don’t account for the microscopic dust, dirt, cleaning chemicals, mold, and bacteria that are weightlessly floating unseen around our homes both indoors and out. Climate change is also having a negative effect on air quality. New research looking at the last three decades of pollen counts has shown that our “pollen seasons” are now starting earlier, lasting longer, and even increasing in concentration by more than 20 percent. The changing climate has also increased the incidence and severity of wildfires in the Western U.S. For example, the number of large wildfires has doubled in the Western States since 1984. The smoke from these fires is a major source of air pollution. Air quality varies from region to region, but these changes are impacting allergy and asthma sufferers and could translate to long-term impacts like increases in overall asthma and allergy rates, lung-related illnesses, and possibly even reducing the lifespan for our most vulnerable. But thanks to improvements in technology and increased consumer demand, we can now affordably monitor the air quality of our own homes, yards, and businesses with electronic air quality monitors. Why Trust Treehugger? Author Lorraine Wilde holds a master’s degree in environmental science and has several years of experience working on the cleanup of contaminated hazardous waste sites that degraded our air quality and posed a toxicity risk to both humans and the natural environment. She is a firm believer that consumers can make informed choices that protect our delicate planet. The 7 Best Water Filters of 2021 View Article Sources "Particle Pollution." American Lung Association. Anderegg, William R.L., et al. "Anthropogenic Climate Change Is Worsening North American Pollen Seasons." Proceedings of the National Academy of Sciences, vol. 118, no. 7, 2021, pp. e2013284118., doi:10.1073/pnas.2013284118 "Wildfires and Climate Change." Center for Climate and Energy Solutions. "Health and Environmental Effects of Particulate Matter (PM)." United States Environmental Protection Agency.