A heating duct is not a normal place for mold to grow. The mold spores travel through these ducts all the time, but without moisture they cannot thrive. Getting rid of the mold is an easy task; however, getting to it may be a different story. Before taking on the task of removing your heating air vents; verify the mold is in them. If you smell mold or mildew coming from the vents, there is a very good chance that the smell is coming from another part of the house. Do not go after the mold unless you see it in the heating vents.
Things You'll Need:
Possibly a wet/dry vacuum and hair dryer
1. Shut down the central air unit. This will help to eliminate the possibility of spreading the active mold spores through the rest of house.
2. Remove the part of the heating duct has the mold. Follow the instructions provided by the heating duct manufacturer or installer to perform this action. If possible, take the removed heating duct outside while removing the mold. This makes the cleanup process easier.
3. Use a hard brush to clean away the mold.
4. Douse the remaining molded area with lemon juice. The lemon juice opens the pores of the mold and makes it more susceptible to the vinegar.
5. Pour a generous amount of vinegar onto the area, and let it sit for 10 to 15 minutes.
6. Rinse the area well with warm water. If you were able to take the piece outside then let it air dry, preferably in the sun. When dry, reattach the heating duct as per the instructions. If taking the heating vent outside was not an option, then use wet/dry vacuum to suck up the debris. Use a hair dryer to dry the area completely. When dry, reattach the heating duct as per the instructions.
For mold to propagate it needs moisture. If mold has accumulated in your heating ventilation system then there is a source of moisture. Find the cause of the moisture and repair it or the mold will be back.