Have you noticed a dark area along your baseboards or under closet doors? This is called “Air Infiltration” and is caused by your HVAC system moving air from place to place in your house. Your carpet is actually one big filter and traps this dirt as it settles out from your air vents. If you experience this condition you may consider getting your air ducts cleaned and have the ducts themselves checked for air leakage. Alternatively, you can also cheaply purchase electrostatic filters to install at each exit point to capture material before it is expelled in to the room. Once cleaned, you can maintain these problem areas simply by using your vacuum’s edge tool around your baseboards once a month.