If you've stepped outside this week, you already know. Smoke from the fires burning in central and eastern Oregon has settled over the Treasure Valley, and the Department of Environmental Quality has an air quality advisory out for Ada, Canyon, Gem, Payette, and Washington counties, with air quality forecast to reach unhealthy levels. It's paired with a heat advisory and temperatures over 100, which is the worst combination we get around here.
So what can you actually do about the air inside your house? More than you'd think, and most of it involves the system you already own. Here's the rundown.
Does My Air Conditioner Filter Out Wildfire Smoke?
Partially, and it helps more than you might expect. Your central AC pulls the air in your house through a filter before sending it back out, so every hour it runs, it's cleaning that air a little. But a standard cheap filter is designed to protect the equipment from dust and hair, not to catch the microscopic particles in wildfire smoke.
The other thing worth knowing: your central AC isn't pulling smoky air in from outside. It recirculates the air already in your home, which is exactly what you want on a week like this.
What's the Single Best Thing I Can Do This Week?
Set your thermostat fan to "ON" instead of "AUTO."
On "AUTO," the fan only runs when the system is actively cooling, so your air only gets filtered part of the time. On "ON," the blower runs continuously and pulls your indoor air through that filter around the clock. It costs a little more in electricity, but during a smoke event it's the cheapest air cleaning you'll ever do. Switch it back to AUTO once the air clears.
What Kind of Filter Should I Be Using?
For smoke, you want a pleated filter with a higher MERV rating. MERV 11 to 13 is the range that starts catching the fine particulate that makes wildfire smoke harmful. The flat fiberglass filters catch almost none of it.
One caution, and it matters: don't just jam the highest-rated filter you can find into an older system. A very dense filter restricts airflow, and a system that can't breathe runs longer, cools worse, and can even freeze up. If you're not sure what your system can handle, ask. MERV 13 in a system built for it is great; MERV 13 in a system that can't move air through it causes new problems.
And change it more often than usual right now. A filter that would normally last three months can load up fast in a smoke event.
If You Have a Swamp Cooler, This Week Is Different
This one's specific to our area, and it's important. Evaporative coolers and swamp coolers work by pulling outside air through wet pads and blowing it into your home. That's efficient in our dry climate, but during heavy smoke it means you're actively pulling smoky outdoor air inside.
If you're running one this week, that's worth reconsidering while the advisory is in effect. Shutting it down and closing up the house keeps the smoke out, though you'll need another plan for the heat given the temperatures we're seeing.
What Else Helps?
A few practical moves for a smoke week:
- Keep windows and doors closed, even at night. Cooling the house off with night air is a great valley habit most of the summer, but not this week.
- Set up one clean room. Pick a bedroom, keep it closed up, and run a portable HEPA air cleaner in it. Health officials suggest this for anyone sensitive to smoke, and it's a lot easier to keep one room's air clean than the whole house.
- Skip anything that adds indoor particles: candles, incense, frying, vacuuming without a HEPA vacuum, and definitely no indoor burning.
The DEQ advises limiting time outdoors during the advisory, especially for kids, older adults, and anyone with heart or lung conditions. If breathing gets difficult, that's a call to your doctor, not to us, but keeping your indoor air as clean as possible is something we can help with.
What If I Want a Real Fix Instead of a Smoke-Week Workaround?
Everything above is what you do with the equipment you already have. It genuinely helps, but it depends on you remembering to flip the fan on and swap filters every time the valley fills up with smoke. Smoke season comes every summer now, and plenty of folks would rather solve it once.
There are two upgrades that install right into your existing system, and they solve two different problems.
A whole-home air cleaner is the one that addresses smoke. This is a serious filtration system built into your ductwork, well beyond what a one-inch filter off the shelf can do. It captures the fine particulate that makes wildfire smoke a health concern, and it cleans every bit of air moving through your house instead of one room at a time. It also handles the valley's dust and pollen the rest of the year, which most people notice within a week or two of running it.
Air purification and UV systems (REME and iWave-style) do something different. They target germs, viruses, odors, and mold growth on your indoor coil. Those are real benefits, especially through cold-and-flu season or if anyone in the house deals with allergies. What they don't do is filter smoke particulates. Paired with a good air cleaner, though, they cover the part filtration doesn't.
If you're curious what would actually make a difference in your home, we're happy to come look at your system and tell you straight, including telling you a better filter is all you need, if that's the truth.
The Short Version
Run your fan on "ON" so your system filters around the clock, put in a good pleated filter your system can actually handle, keep the house closed up, and set up one clean room with a portable air cleaner. If you're on a swamp cooler, know that it's bringing the smoke indoors with the cool air. And if you're tired of doing this dance every August, a whole-home air cleaner is worth a conversation.
Take care of each other out there this week, and check on the older neighbors especially, with the heat and smoke both hitting at once.
We're a family-run shop covering Nampa, Caldwell, Meridian, Boise, and beyond. Call us at 208-455-5158 and we'll walk you through your options.