If you've lived in Western Montana for a while, you know our air has seasons of its own. Summer can bring weeks of wildfire smoke. Winter brings inversions that trap smoke and haze down on the valley floor. And in between, we spend a lot of months with the windows shut and the furnace running.
I've spent more than ten years doing HVAC work in Western Montana, and air quality comes up constantly. There are a lot of products out there now, and some are far more proven than others. Here's a plain-spoken rundown of the indoor air quality options on the market in Missoula and where each one fits.
Start with the basics: source control and a good filter
The EPA's first advice is to control pollution at the source, like cleaner-burning stoves and kitchen and bath fans that vent outside. After that, filtration does most of the heavy lifting.
Higher-MERV filters. For wildfire smoke, the EPA recommends a furnace filter rated MERV 13 or higher if your system can handle it. Most systems can, but not all. A filter that's too restrictive can choke airflow. A technician can tell you the highest rating your equipment can handle.
Media filter cabinets. A deeper media filter, usually several inches thick, can give you high-efficiency filtration with less airflow resistance than a thin, dense filter. It's one of the simplest upgrades for a lot of homes.
Whole-home HEPA bypass systems. These pull part of the air from your ductwork through a true HEPA filter and send it back. They can suit households with allergies or breathing problems, or systems that can't take a high-MERV filter.
Run the fan: variable-speed blowers and continuous filtration
A filter only cleans air that moves through it. During smoke events, the EPA suggests switching your thermostat fan from "Auto" to "On" so the system filters all day. Older single-speed blowers can be loud doing that. Newer variable-speed blowers can run at a low, quiet speed for steady filtration and ramp up when you need heating or cooling.
Fresh air for tight homes: ERVs and HRVs
Newer and remodeled homes are built tighter, which is great for your heating bill. But a tight house can trap moisture, cooking smells, and indoor pollutants through a long heating season. Heat recovery ventilators (HRVs) and energy recovery ventilators (ERVs) bring in fresh outdoor air and exhaust stale air, while transferring heat between the two streams so you're not just heating the outdoors. An ERV also moves some moisture, while an HRV mostly moves heat. Which one makes more sense in our dry climate depends on the house and how it's lived in, so it's worth talking through. On smoky or inversion days, you'll want the incoming air filtered or the ventilation turned down.
Dry Montana winters: whole-home humidifiers
Our winter air gets very dry. The EPA recommends keeping indoor humidity between 30 and 50 percent. A whole-home humidifier mounted on your furnace can help hold that range without hauling water to a tabletop unit. The key is setting it right. Too much humidity can cause window condensation and mold, especially on our coldest nights.
UV-C germicidal lights
UV-C lights installed inside the air handler are best known for keeping the cooling coil and drain pan from growing mold and bacteria. According to the EPA, that's where they work best. They do much less for germs in moving air, because the air passes the lamp too quickly. Think of UV-C as an add-on to good filtration, not a replacement for it.
Ionizers and PCO: be choosy
Bipolar ionization and photocatalytic oxidation (PCO) devices get marketed heavily. The honest picture is mixed. The EPA calls bipolar ionization an emerging technology with limited real-world research. It also notes that these devices can produce ozone and other byproducts unless they're designed to prevent it. PCO devices can also create unwanted byproducts. If you're considering one, the EPA recommends choosing a device certified to UL 2998 for zero ozone emissions. For smoke, proven filtration is still my first recommendation for air purification in Missoula homes.
Know what's in your air: smart IAQ monitors
One of the more useful newer options is simply measuring. Standalone indoor air monitors, and some newer smart thermostats, can track things like fine particles (PM2.5), carbon dioxide, VOCs, and humidity. Seeing the numbers tells you when to run the fan, change a filter, or bring in fresh air, and whether an upgrade is actually helping.
Ductless heat pumps
If your home doesn't have ductwork, a ductless heat pump (mini-split) gives you efficient heating and cooling plus filters in each indoor unit. Those filters catch dust and need regular cleaning, but they generally aren't the same as a high-MERV central filter. During heavy smoke, a good portable HEPA air cleaner in the rooms you use most is a smart backup. The EPA says to choose one that doesn't produce ozone.
The bottom line
No single gadget fixes indoor air. The best results come from a few proven pieces working together: a good filter, enough airflow, balanced fresh air, and the right humidity. Add extras only where they make sense.
Let's take a look at your air
If you're wondering what would help your home or business, call ProCare Climate at 406-546-1289. We're your 24/7 HVAC team in Western Montana. You can also request a free install estimate, and we'll talk through options that fit your system and your budget.