Most indoor air quality equipment requires attention at least once a year, though the specific schedule depends on the type of system and how hard it is working. Air filters need the most frequent service — often every 1–3 months — while UV germicidal lights, whole-house humidifiers, and electronic air cleaners typically follow an annual service schedule tied to your HVAC tune-up. Letting IAQ equipment go unmaintained doesn’t just reduce its effectiveness; it can actually make air quality worse.

Filter Maintenance: The Most Frequent Task

Air filters are the workhorse of any IAQ system, and they need the most regular attention. Standard 1-inch fiberglass filters need monthly checks and replacement every 30–60 days. Higher-efficiency media filters (MERV 11–16, including brands like Aprilaire and Carrier Infinity) last 3–6 months but should still be checked regularly. During Colorado’s wildfire smoke season, filter life can drop dramatically — fine particulates from smoke load a filter much faster than ordinary household dust. A filter that’s past its service life restricts airflow, which strains your HVAC equipment and circulates unfiltered air through the bypass gaps that form around a clogged filter.

UV Germicidal Lights: Annual Bulb Replacement

UV-C bulbs used in germicidal HVAC systems degrade over time, and their effectiveness drops well before the bulb visibly burns out. Most manufacturers recommend replacing the bulb every 12–24 months regardless of whether it still appears to glow. An annual IAQ service visit is a natural time to swap the bulb and confirm the unit is positioned correctly and functioning properly.

Whole-House Humidifiers: Seasonal Startup and Shutdown

In Colorado’s very dry climate, a whole-house humidifier is one of the most impactful IAQ investments a homeowner can make. These systems need attention at two key points each year:

  • Start of heating season (fall): Clean or replace the evaporator pad (also called a water panel or vapor pad). Colorado’s hard water leaves mineral scale on the pad that reduces efficiency and can harbor bacteria. Replace the solenoid valve if it’s showing signs of mineral buildup.
  • End of heating season (spring): Shut off the water supply to the humidifier, drain and clean the reservoir, and close the bypass damper (on bypass-style units) so conditioned air isn’t unnecessarily routed through an idle humidifier all summer.

Electronic Air Cleaners and Polarized Media Filters

Electronic air purifiers (including electronic air cleaners and polarized media filters) have collection cells or media pads that accumulate captured particles. Most need cleaning or media replacement every 1–3 months. If the collection cell isn’t cleaned regularly, it loses its electrostatic charge and begins allowing particles to pass through. Some units also produce trace amounts of ozone — another reason to keep them maintained and operating within spec. Check the manufacturer’s interval and don’t skip it.

Duct Cleaning: A Different Schedule

Duct cleaning isn’t an annual task — most homes benefit from professional duct cleaning every 3–5 years, or after events like renovations, a rodent infestation, mold discovery, or purchasing a home with an unknown HVAC history. Cleaning more frequently than needed doesn’t meaningfully improve air quality and can disturb settled dust into the air if not done properly. Done uses NADCA-standard equipment and procedures when cleaning ducts.

Tying IAQ Maintenance to Your Annual HVAC Tune-Up

The simplest way to stay on top of IAQ equipment is to bundle its service with your annual HVAC maintenance visits — one in spring before cooling season and one in fall before heating season. A technician who is already inside your air handler can inspect the UV light, humidifier, media filter, and any other installed IAQ equipment while they’re there. Done’s Care Club membership includes annual tune-ups and priority service, which makes it easy to stay current on all of it without having to track multiple separate service calls.

Learn more about Done’s indoor air quality services, explore maintenance membership through Care Club, and if your ductwork needs attention, see duct cleaning.