Best Air Quality Monitors

The air you breathe may not seem like a major health concern, but it turns out that air pollution is one of the world’s leading killers, responsible for 6.4 million deaths per year.[1]

Air pollution is a major contributor to cardiovascular disease. Children, the elderly, and low-income communities are especially at risk. Evidence suggests that air pollution is linked to higher risk of diabetes, autism, and lower IQ scores.[1]

Particulate matter

Air is made up of small airborne particles like dust, soot, and drops of liquids called particulate matter (PM).[1]

Coarse particulate matter, or particles less than 10 microns in diameter (PM10), is known to cause nasal and upper respiratory tract health problems. Finer particles less than 2.5 microns in diameter (PM2.5) penetrate deeper into the lungs and cause heart attacks, strokes, asthma, and bronchitis. Studies show that higher PM2.5 exposure can impair brain development in children.[1]

In a study of the Medicare population, there was significant evidence of adverse effects related to exposure to PM2.5. This effect was most pronounced among racial minorities and people with low income.[2]

Testing the best sensors

I try to never buy anything without third-party testing. Fortunately, there is an organization that does exactly that for air quality monitors.

The website for the South Coast Air Quality Management District (AQMD) does high-quality standardized testing of particulate matter air sensors (those that measure particles as opposed to gases like ozone). This includes laboratory and field testing.

I searched their database of results. My search criteria was the following: under $300, over 80% correlation to the reference instruments, still in production, consumer devices, and available in the US.

The following are the 3 best air sensors, and the only ones I would consider purchasing.

  • Most precise sensorPurpleAir PA-II. Almost reference grade quality, comparable to sensors that cost thousands of dollars. However, it has no display screen and requires continuous wifi access. Detects down to 0.3 micron particles, including temperature, pressure, and humidity. Used by the Clean Air Carolina organization to monitor local air quality.
  • Most user friendly sensorIQAir AirVisual Pro. Has a user-friendly display screen. Also integrates with services like IFTTT. Measures PM2.5, CO2, temperature, and humidity. Also comes with a popular mobile application.
  • Best handheld sensorDylos DC1100 Pro. An accurate sensor for taking spot readings. However, unlike the other devices it does not seem possible to extract the data to your computer. Make sure to get the Pro version which detects down to 0.5 microns.

Which did I buy?

I bought the PurpleAir to put in my bedroom for tracking air quality while I sleep. Precision is what matters most to me, although I was tempted to buy the AirVisual Pro because of the convenience of a screen.

See my review of the PurpleAir PA-II-SD air monitor.