When using low-cost particle monitors for the first time, participants in the Low Cost Monitoring Project (LCMP) are often surprised when incidents like burning toast or even just cooking an egg cause spikes in the readings. While it’s important to recognize and reduce the frequency of these spikes, they don’t tell the whole story of indoor air quality.

Once you know how to make sense of it, the data tells a much more nuanced story. Short, dramatic spikes, it turns out, do not appear to contribute significantly to the big picture of air quality in a house. The difference in indoor particle counts between any two LCMP participant sites can be remarkable—sometimes as much as a twenty-fold increase from one site to the next. That’s about a lot more than just a few mishaps on the stove, even though they send the numbers soaring.

It can be hard to know how to interpret the monitors’ output. How do outdoor particle counts influence indoor counts? How much does it help to use a kitchen exhaust fan or to use a portable air cleaner? In one week alone, the three Dylos particle monitors that we use in the LCMP generate 60,000 data points for each site! To help LCMP participants manage all this data, the ROCIS team has developed several useful tools outlined below.

For an overview of our initial data analysis and visualization efforts, see the ROCIS presentation for the US EPA’s 2017 Smart Cities Air Challenge webinar series, “Data Use in Community Air Quality Projects.”

What did we learn from having carbon dioxide monitors in over 400 Pittsburgh homes?