In the past five years, I’ve tested dozens of indoor air-quality monitors but have relied on my iPhone’s Weather app to check outdoor air quality. On questionable days that might include haze or the smell of wildfire, I’ll check the government’s free AirNow website, where I’ll plug in my zip code and see its easy-to-read air quality meter. With the increasing wildfire activity from coast to coast, however, I realized it was time to test an outdoor air-quality monitor.
The Zen is larger than the PurpleAir Touch (see below) but uses the same EPA AQI color scale: green for good air, yellow for moderate, orange for unhealthy for sensitive groups, red for unhealthy, purple for very unhealthy, and deep violet/maroon for hazardous. And the glow’s intensity can be controlled by the number of taps of your finger. I’ve been using my Zen inside and outside since the summer. It can be mounted onto a pole or wall or can be placed on its circular stand. It has stood up to the elements, from hot and humid summer days to bitterly cold 0-degree Fahrenheit nights. And the more I review air quality monitors, the more I appreciate the Zen’s easy-to-see color scale. The other day when I looked out my window and saw the Zen’s yellow glow, I knew the outside air was moderate. I didn’t have to open my phone or go on a website. I knew in less than a second that I wasn’t going to open my windows to let in air. That’s the thing about moderate (above 50 AQI) or unhealthy air—you can’t always see dirty air. The air was clear. The Zen does something even more than tell me about the outdoor air quality in my little corner of Brooklyn: The Zen tells the world.
Each Zen can be linked to the crowdsourced PurpleAir’s Real-Time Air Quality Map. Linking the Zen is optional, but to see the actual Air Quality Index number that the Zen is reading, I had to link my specific monitor with its unique ID code to the PurpleAir website. Over the summer, PurpleAir told me an app was in the works, but for the moment it is the PurpleAir website that has the “community scientist”-sourced map. While linking the Zen is clunkier than the other Wi-Fi app-enabled air quality monitor pairings, it still only took a few minutes. There’s an option to have the monitor be public or private; by clicking public, you get to contribute as a citizen scientist to the Real-Time Air Quality Map. I was surprised to see just how many PurpleAir monitors there are in New York City, not to mention Brooklyn. I could also see that most outdoor monitors in close proximity to mine were within 5 points of each other. It gave an accurate close-up of my block and my neighborhood. In this current climate of extreme weather, the PurpleAir Real Time Map is especially useful.