Humidity
Humidity, Mold and Your AC in Shreveport and Bossier City
The EPA’s target is indoor relative humidity below 60 percent, ideally 30 to 50 percent. An air conditioner that cools the house but leaves it above that usually has an airflow, drainage or run-time problem, and most of those are ordinary repairs. Humidity figures below are the EPA’s, read November 11, 2026.
Published November 11, 2026 · Figures and rules checked against the sources listed at the end of this page.
The numbers to know
| Topic | What the EPA says |
|---|---|
| Indoor relative humidity | Below 60 percent, ideally between 30 and 50 percent |
| Wet areas and materials | Dry within 24 to 48 hours to prevent mold growth |
| AC drip pans and drain lines | Keep pans clean and lines unobstructed and flowing |
| System suspected of mold | Do not run it; it could spread mold through the building |
Why a house can be cool and still damp
- Short run times. Moisture comes out of the air only while the coil is cold and the system is running. A unit that satisfies the thermostat in a few minutes removes little.
- Fan set to ON. With the fan running between cycles, water on the coil evaporates back into the house. AUTO lets it drain.
- Blocked drain. Water that cannot leave the pan sits in the air handler.
- Dirty coil or filter. Poor airflow across the coil cuts both cooling and moisture removal.
- Leaky ducts. Return ducts in an attic or crawl space can pull in damp outside air.
What you can check yourself
- Measure the humidity. Put a humidity meter in the main living area and read it over a few days.
- Fan on AUTO. Set the thermostat fan to AUTO.
- Filter. Change the filter.
- Drain pan and drain line. Look at the drain pan under the indoor unit for standing water, and at the drain line outlet outside for a steady drip while the system runs.
What a contractor may recommend, and the price range
| Work | Typical range |
|---|---|
| Drain line flush | $75 to $250 |
| Drain pan replacement | $200 to $600 |
| Condensate pump | $100 to $450 |
| Coil cleaning | $100 to $400 |
Source: HomeGuide 2026. National figures, not local quotes.
Ask the contractor to measure humidity and run time before proposing equipment. If the answer is a new system, compare the quote with the replacement cost ranges and check the license first.
If you can see or smell mold
The EPA’s guide covers when a homeowner can handle cleanup and when to bring in a professional. This page does not give health advice; for symptoms, speak to a doctor.
Sources and dates
Every figure and rule above names where it came from and the date it was read. If a source disagrees with a quote you receive, the quote wins: it reflects your house, your equipment and this week's demand. Prices are rechecked at least every six months.
- U.S. Environmental Protection Agency, “A Brief Guide to Mold, Moisture and Your Home” — read November 11, 2026
- HomeGuide, “How Much Does AC Repair Cost? (2026)” — read November 11, 2026. National ranges, not Shreveport or Bossier City quotes