How Do I Know If I Have Mold In My Air Ducts?

Mold doesn't usually grow in air ducts, but it can happen. Experts recommend getting a second opinion if a company is pressuring you to treat for mold. (Photo by Doug McSchooler)

Mold can certainly grow in air ducts, but air duct cleaning professionals I’ve spoken with say it’s very uncommon.

Do you have visual evidence of mold in your ducts? If you can see or smell evidence of mold, you can probably skip having it tested and go straight to remediating it. Look for signs of water or moisture, especially in dark, hidden areas of the home.

If there is no evidence and you want to be sure you don't have mold, you could hire a qualified mold tester to check for mold. However, it's important to note that the Centers for Disease Control and Prevention states that there are no standards for what is an acceptable amount of mold, as every home contains some level of mold. The CDC recommends asking consultants who do testing to establish criteria for interpreting the results beforehand and share what they will do or recommendations they will make based on the results.

The good news is, because you live in Texas, you’re more likely to get accurate advice from a qualified mold tester. In 2005, Texas became the first state in the U.S. to regulate the mold remediation industry and require licensing for mold professionals. The company that inspects for mold can't be the same company that does the remediation — a situation many states still allow — which poses a conflict of interest, as a company that can both test for and remediate mold has an incentive to “find” mold. Testing can be expensive, however, as much as a few hundred dollars.

Mold Testing and Remediation

If the mold tester does find mold, then he or she should be trained and prepared to write a protocol for remediating the mold. From there, you could hire a mold remediation firm to follow that protocol. The mold tester can then go back in and retest to ensure the remediation company properly removed the mold. The EPA also offers homeowners guidelines on how to remove small amounts of mold themselves.

While it’s entirely possible that you do have mold in your air ducts, such claims are also a common scare tactic used by some less-than-scrupulous air duct cleaning companies, especially claims of toxic black mold.

There are several varieties of mold, and if you think you have any type of mold, including black mold in air ducts, it's best to leave the examination to a mold tester. If they determine you have mold in your air ducts, I’ve been advised by industry professionals that it would be best to remove the components, like the A/C coils, from the HVAC system to perform the most thorough cleaning. This will help ensure that there are fewer places for mold spores to remain untouched. A professional should not need to replace your air ducts, unless they're damaged or cannot be accessed for a proper remediation. The average air duct cleaning job – properly done – takes several hours and costs between $350 and $500.

The key to ridding your home of mold is to first identify the source of the problem; typically a water leak. Ridding your home of mold without addressing the root cause will just lead to a recurrence of the problem.