IAQng public signal
How hard has the air been on your filters?
The smoke map shows what the air is doing to people. This shows what it's doing to buildings — how much airborne dust, smoke and pollution your HVAC filters have had to pull from recent outdoor air.
- Low
- Moderate
- High
- Severe
Filter Load
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This estimates filtration demand from recent outdoor PM10 near you — not the condition of your specific filter. We don't know your filter type, when it was changed, or how your system runs; heavy load just means the air has been giving filters more to catch.
The particles behind that number
What drove the recent load
See the numbers
How it works
Filters don't wear out on the calendar — they wear out cleaning the air. Filter Load reads the PM10 (coarse dust, smoke and pollen) measured by the nearest EPA monitor over the last 90 days and compares it to the national-average load. Twice the average reads Severe; well below reads Low. The days-between-changes figure counts backwards from today, day by day at each day's actual level, until a 90-average-day filter's worth of particles has accumulated, so a recent smoke week shortens it in a way no simple average would. It's a public-awareness illustration of environmental demand, not a measurement of your filter.
Why PM10
Filters load by the mass of particles they trap, and coarse particles — road and construction dust, wildfire smoke, pollen — dominate that mass. PM10 captures them (and includes the fine PM2.5 the smoke map tracks).
Where it comes from
The U.S. EPA monitor network — historical daily PM10 from EPA AQS (AirData) stitched to the recent AirNow archive. Nearest-monitor, so a spot far from one is an estimate. Where no PM10 monitor is in range, we estimate it from the denser PM2.5 network, scaled by a ratio measured from monitors near you that report both, and the result says so.
What it isn't
Not advice to change a specific filter. Indoor sources (cooking, pets, renovation) and your system's runtime and filter grade all matter too — this is only the outdoor demand side, to help you know when to inspect.
Air-quality data: U.S. EPA AQS (AirData) & AirNow (preliminary, not regulatory; public domain). Refreshed by SpaceBot for IAQng.