Mold in air ducts...

Mold in air ducts is a serious concern if it arises in a property-both commercial and residential. Sometimes, signs may be present that there is an issue, such as: 

-Leaks around the air handler
-Visible moisture in the ceiling drywall coming from the air ducts
-Odors in the property
-Visible mold spores on air vent
-Moisture streaking from air vent

The diagnosis of mold in an air duct is usually a team effort from HVAC technicians and mold inspectors. The mold inspector can test the air quality to see if there are any abnormal airborne mold spores in the property, as well as seeing if there is any visible moisture in the property via moisture readings. The HVAC technician can actually inspect the air ducts, as well as the air handler for any issues with the system. 

If you suspect that there might be an issue, it is recommended calling these professionals out to the property for a further diagnosis.