Musty Odors from HVAC
StandardUnpleasant musty or moldy smells when HVAC system runs.
Musty smells indicate biological growth somewhere in the HVAC system or ductwork. The dark, damp environment inside AC equipment can support mold and mildew. Proper maintenance including coil cleaning and drain care prevents most odor issues. Persistent problems may require duct cleaning or UV system installation.
Symptoms to Look For
Possible Causes
What You Can Check
Before calling for service, try these safe checks that may resolve simple issues:
When to Call a Professional
Persistent odors after filter replacement suggest mold or contamination requiring professional cleaning. Coil cleaning, duct assessment, and proper remediation address the source.
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Prevention Tips
Frequently Asked Questions
Is musty smell from HVAC dangerous?
It can affect people with allergies or respiratory sensitivities. While not immediately dangerous for most, addressing the source improves air quality and prevents worsening.
Will duct cleaning help with musty odors?
If the contamination is in the ductwork, yes. However, odors from the indoor coil or drain pan need to be addressed separately. A proper assessment identifies the source.
Can UV lights prevent musty odors?
UV systems installed near the evaporator coil can reduce biological growth that causes odors. They are particularly effective in humid climates where mold thrives.
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