If you keep your HVAC unit’s fan set to “on” instead of “auto,” the fan will continuously run and pick up more dirt.
Also, if you have multiple cats and dogs, excess animal hair and dander can easily clog your filter. Finally, the problem may be because you have an accumulation of dirt in your air ducts.
Clean your air ducts and replace your filter regularly for the highest quality air—every 30 days for fiberglass filter, every 45-60 days for pleated and a monthly washing for electrostatic, and duct cleaning every 3-5 years.

Male wearing a jacket and black shirt

Bill Mashraky

Cool Air Mechanical
Years in Business: 8
Associations: NATE, BBB A+ Rated