We’re excited to share that Local Haze now supports AirGradient sensors—a major step forward in our mission to empower open, citizen-driven air quality monitoring. In this first post of a two-part series, we spotlight the innovative AirGradient team, exploring the inspiration behind their technology, their mission to democratize air quality monitoring, and their vision for the future of grassroots environmental data.
Welcome to the Local Haze blog! The Local Haze team’s interest in air quality began with understanding our indoor environment, where we spend most of our time, and then extended to outdoor air, as what is outside comes inside. However, when we launched the Local Haze iPhone application, privacy concerns drove the focus to outdoor air. What is the AirGradient origin story from indoor air to outdoor air monitoring?
Our story began in 2019 when our founders Achim Haug and Dominik Schraner experienced the harsh reality of wildfire smoke during the Thailand fires. We started as a volunteer project in Northern Thailand, helping a school monitor classroom air quality during the “burning season” – a period when air pollution from agricultural burning reaches dangerous levels. While we were initially creating indoor air quality monitoring kits, after a few years we began getting increased demand for outdoor air quality monitors and it seemed like the logical next step.
When researching, we found that, while there are a few outdoor air quality monitors on the market, very few of these focus on transparency and open data sharing. We recognized that outdoor monitoring was crucial for understanding the complete picture – to see where pollution is coming from, how well ventilation systems work, and to provide communities with hyperlocal air quality data. Our Open Air became one of the first low-cost outdoor air quality monitors to include a CO2 sensor, enabling the detection of local emission sources that may not produce visible particulate matter. The expansion to outdoor monitoring also allows us to support larger community initiatives, like UNICEF’s ambitious project to install air quality sensors in 150 schools across Lao PDR.
Different groups offering low-cost air-quality monitors have focused on either a self-assembled kit (e.g. sensor.community) or a plug-in and go devices (e.g. PurpleAir). As both of these devices use identical sensors, Local Haze does not differentiate between them. How does AirGradient see the benefits to offering kits for monitors beyond the reduced cost?
We see a few different benefits to providing kits as opposed to just the lower price. Here are a few:
- Education and Understanding: Building a kit gives users hands-on experience with the different sensors and how the device works. We’ve given many kits to schools to assemble, and we’ve found the kits can have a much greater educational impact.
- Repairability and Sustainability: Our kit design (and, by extension, our assembled monitors which follow the same design) allows users to quickly and easily replace individual components rather than discarding entire units.
- Transparency and Trust: When you build something yourself, you inherently understand it better. There’s no “black box” mystery about how your air quality monitor works as you’ve seen every component and connection.
- Community Building: We’ve also found that the kit experience creates a more engaged community. People who build their own monitors tend to be more invested in the data, more likely to share it openly, and more willing to help others troubleshoot and improve their setups.
AirGradient has built a reputation for combining open-source values with solid engineering. What were your biggest design challenges in building a reliable outdoor air quality monitor for real-world environments and users who may not be technically-minded? How did you overcome these challenges?
Environmental durability proved particularly tricky. We needed weatherproof enclosures that protected the electronics from rain, UV, and temperature extremes, while ensuring proper airflow to sensors and preventing condensation as much as possible. Our first outdoor enclosures were 3D printed, which seemed like a cost-effective solution until they quickly yellowed from UV exposure and proved much less durable than we’d hoped. We actually still have one of those original yellow Open Air monitors sitting in our headquarters as a reminder of that first attempt. (More info here on the OpenAir monitor shown below).
Learning from that experience, we had to investigate more advanced manufacturing techniques to achieve proper UV-resistant casing. This led us to high-quality ASA plastic with UV protection that we use today. Luckily, we’ve found these to be far more durable and many of our initial batches of Open Airs are still running today.
Our biggest ongoing challenge is making the device accessible to all users. While we’ve taken great strides in this area, we still have something of a “techy” reputation that we’re working to overcome. It’s a delicate balance because we want to preserve the features that are so important to our original, core technical audience (like open-source firmware and many customization options) while making the device approachable for users who just want to plug it in and monitor their air quality.
Our solution so far has been to offer layered complexity: devices come pre-flashed and ready to connect via a simple web interface, but all the technical depth remains available for those who want it.
However, there are definitely still steps we can take to improve in this area.
Unlike reference monitors, which undergo regular scheduled maintenance and calibration, low-cost monitors are typically considered install-and-forget devices. This has driven Local Haze to contain a number of “bad sensor” detections to filter out the “noise” from failing sensors. How does AirGradient approach the lifecycle and maintenance of its monitors?
We’ve designed our monitors to be easily maintainable with straightforward component replacements. Our goal is for monitors to last indefinitely, requiring only individual sensor replacements when components reach the end of their lifecycle. We’re also upfront about expected lifespans – PM sensors typically last 3-5 years and are the most likely components to fail due to their moving parts (internal fans). Other components have lifespans of over 10 years.
In regard to calibration, we have a few other features to try and ensure monitors remain accurate:
- Automated Fault Detection: Faulty sensors can be difficult to identify without specialized equipment (or, at least, another monitor to compare to). We’re currently developing algorithms to automatically detect failing sensors and notify users when replacement is needed.
- Background Calibration: We’re introducing a “background calibration” feature that allows users to calibrate their monitors based on known background pollution levels. For those without access to expensive reference equipment, this provides a middle ground for maintaining accuracy over time.
We’re grateful to the AirGradient team for sharing their insights and continuing to champion open, accessible environmental sensing.
From climate-aware classrooms to sensor networks in underserved regions, the impact of community-led air monitoring is growing—and monitors like AirGradient’s Open Air are helping make that movement possible. As hardware continues to evolve, so does the potential for citizens everywhere to hold polluters accountable, influence policy, and protect public health with data that’s transparent, timely, and trusted.
Stay tuned for Part 2 of this interview with the AirGradient team and air quality insights and updates here on the Local Haze blog.