I keep sweeping up fine white powder under my vents and it keeps coming back. What is it?

9. Simple At-Home Tests vs. When to Call an HVAC Pro or Lab
Homeowners can perform simple tests to identify the source of fine white dust. Start by collecting a sample of the dust and examining it under a magnifying glass. Look for characteristics such as color, texture, and composition that might indicate its origin.
If the source remains unclear or if there are concerns about health risks, it’s advisable to consult an HVAC professional or a laboratory for more comprehensive testing. Professionals can conduct indoor air quality assessments, inspect ductwork, and identify any hazardous materials that may be present.
10. Repairing or Replacing Deteriorated Duct Liner Safely
If deteriorating duct liner is identified as the source of the dust, repairing or replacing it is essential. This process should be carried out by a qualified HVAC technician to ensure safety and compliance with local regulations.
The technician will assess the extent of the damage and recommend appropriate solutions, which may involve replacing sections of ductwork or applying new liner materials. Addressing this issue not only resolves the dust problem but also improves the overall efficiency and longevity of the HVAC system.