At the risk of sounding like a broken record, we’ve all been spending a lot more time at home these days.
We think of furnace/air ducts as the respiratory system of your house.
And lots of stuff can get into the ducts in day-to-day living. Just take a vent cover off and you’ll know what I mean.
Get that stuff out of the air and out of the ducts with an air duct cleaning to improve the quality of the air around you!