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

7. Ruling Out Dangerous Sources: Asbestos, Mold, and Pest Activity
It’s crucial to rule out dangerous sources of fine white dust, such as asbestos, mold, and pest activity. Asbestos fibers, which can be hazardous to health, might be present in older homes with outdated insulation materials. If you suspect asbestos, it’s essential to have a professional assessment conducted immediately.
Mold can also produce fine particles and spores that appear as white dust. Check for signs of moisture or water damage near vents, and consider a mold inspection if you suspect this is the cause. Additionally, pest activity, such as the presence of insects or rodents, can lead to debris that resembles dust. Inspect for droppings or nests that might indicate pest issues.
8. The Viral HVAC Filter Hack—and Why It Might Be Making the Dust Worse
Recently, a viral hack involving the use of multiple HVAC filters has gained popularity, claiming to improve air quality. However, this method can inadvertently exacerbate dust problems. Doubling up on filters or using filters with overly high MERV ratings can restrict airflow, leading to increased pressure on the system.
This pressure can cause existing dust and particles to dislodge from duct surfaces, contributing to the accumulation of fine white powder around vents. It’s important to choose filters that are appropriate for your HVAC system’s specifications to avoid causing more harm than good.