Re: House Dust
I suspect that one or more of the ducts are split and drawing in dust/dirt from the surrounding area. Another problem may be the locations of the return air inlets, anything down at the floor is going to pick up more dust/dirt than an elevated inlet. Filters in a furnace are not tightly sealed, a significant amount of dust can be drawn around the filter, especially when the filter becomes partially plugged, therefore it is important to always keep your filters clean.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!