How’s the air where you live — and what it means for your filter
Check your local air quality, then know whether it’s time to check or change your furnace filter. When the air is dirty, your filter works harder and loads up faster — so this tells you when to look, not to buy a different filter.
How hard your filter is working right now vs. a clean-air day.
Guidance for sensitive groups
Checking your local air…
We couldn’t load air quality for that location. Try another ZIP.
What’s in your air right now
Google measures six pollutants at your location. Here’s every one — how much is in the air, and whether it’s the kind of thing your filter can catch.
Today’s pollen — and your filter
Pollen is exactly the kind of particle a pleated filter is built to capture. On high-pollen days, a fresh filter does real work for you.
How air quality changes what your filter does
Your furnace filter and the air outside are connected. Every time your system runs it pulls household air across the filter — and when outdoor air is dirty, far more particles come with it. Your filter is the thing catching them.
Dirty air = a filter working overtime
On smoky or high-pollen days your filter captures far more than usual, so it clogs faster. A 1″ filter that lasts about 90 days in clean air can load up in a few weeks during heavy wildfire smoke.
Check sooner — don’t size up
The right response to bad air is to check and change your filter more often — not to jump to a denser, higher-MERV filter your system may not be built to push air through.
Run the fan to help
Set your thermostat fan to “on” and it circulates more air across the filter, capturing more particles on bad days. Just plan to change the filter a little sooner.
What a filter can — and can’t — catch
Air quality is driven by different pollutants. A filter is brilliant at some of them and does nothing for others — here’s the honest breakdown.
- Fine smoke particles (PM2.5)
- Dust & pollen
- Pet dander
- Mold spores
- Coarse particles (PM10)
This is most of what pushes AQI up — which is exactly why a fresh filter matters most on bad-air days.
- Ozone & other gases
- Smoke odor / VOCs
- Carbon monoxide
Gases pass straight through media filters. For odor and gases, look at ventilation or an activated-carbon purifier — we’ll tell you straight when a filter isn’t the answer.
Air quality & your filter — questions we get
Does poor air quality mean I need a stronger, higher-MERV filter?
No. The safest response to bad air is to check and change the filter you already run more often — not to switch to a denser one. A higher-MERV filter restricts airflow more, and going too high for your system can strain the blower and actually reduce how much air (and filtration) you get. Match MERV to your equipment; when in doubt, ask us.
Does a furnace filter help with wildfire smoke?
Yes — for the particles. Wildfire smoke is mostly PM2.5, the fine particles a pleated MERV 8–13 filter is built to capture. Change it more often during smoke events, because it loads up fast. It won’t remove smoke odor or gases, though — that needs activated carbon.
How often should I change my filter during smoke or high-pollen season?
More often than the calendar says. A 1″ filter that normally lasts ~90 days can clog in a few weeks during heavy smoke. Check it monthly during events and replace it when it looks loaded. Deeper 4″–5″ filters last longer but still shorten under heavy particle loads.
What does the AQI number actually mean for my filter?
When AQI is high because of particles (smoke, dust, pollen), your filter is pulling more out of the air and loading up faster — so it’s a signal to check it and change it sooner. When AQI is high because of a gas like ozone, a filter change won’t help that pollutant.
Can running my HVAC fan clean the air?
It helps. Setting the fan to “on” circulates household air through the filter continuously, so it captures more particles even when heating/cooling isn’t running. The trade-off is the filter collects more and needs changing a bit sooner.
Authorized AAF Flanders & Koch dealer since 2006 · 50+ years of HVAC filtration experience · NAFA member · Made in the USA · Ships nationwide
Shop filters for your home