Indoor Air Quality in St. Louis, MO

Indoor air quality starts with how air moves through your house, so fix the path before you add equipment. In a forced-air home, every cubic foot of air passes the filter, the blower and the ducts several times an hour. If any of those is wrong, a standalone gadget treats the symptom and leaves the cause.

What should you check before spending money on air quality?

Check three things in order, because each one is cheaper than the next.

1. The filter. Is it the right size, in the right direction, and changed on schedule? Our filter change guide covers timing.
2. The return air. Where does the system pull air from? A return in a dusty basement or leaky attic pulls that dust into every room.
3. The ducts. Leaks, disconnected runs and crushed flex duct move air to the wrong places.

Most of the improvement in older St. Louis homes comes from these basics. The median City home was built in 1938, according to ACS data via Neilsberg, and ductwork in houses that age was often added or altered long after construction.

Is duct cleaning worth paying for?

Usually not on a schedule. EPA says it does not recommend routine duct cleaning and suggests considering it only for visible mold, vermin, or excessive dust and debris. If you see one of those, air duct cleaning is a reasonable step, and the inspection should come first. If dust returns a week later, the cause is airflow or leaks, and cleaning alone will not hold.

Our duct cleaning guide goes deeper on when it pays.

When do ducts need repair instead of cleaning?

When air leaks or a room never gets enough of it. Leaky ducts lose conditioned air into attics and crawl spaces, pull in dust, and make one room run hot or cold. Duct repair and replacement covers sealing, reconnecting and rebuilding runs, and a load calculation tells you what each room needs. Permits apply here too: St. Louis County says a permit is required to install, alter, repair or replace heating, air-conditioning or duct systems, so ask who pulls it and have the quote say so.

Where do filters, purifiers and thermostats fit?

After the basics. A better filter or whole-home purifier helps when the system can handle its airflow resistance, so have the blower checked before you buy. Read air purifiers and filtration for what each option does and does not do, and thermostat installation for blower settings and wiring checks. No device removes the need to find the source of an odor, so call us if the smell comes from the furnace or has a gas-like quality. For a gas smell, leave the house first and call 911 or Spire at 800-887-4173 from outside.