Your Home May Be 'Sucking' It All In.
If there are holes, the next question is, "What is the force that would cause the house to suck in the dust?" In your house, the most likely force would be negative pressures caused by leaks or imbalances in the forced air system.
If, for instance, the supply ducts in the basement are very leaky, then the system is blowing less air into the living area of your home than is coming back through the return ducts of your HVAC system. This will cause the house to have a negative pressure relative to the outside (and the attic). It's from your physics class if you took the course. In other words, it will cause the house to suck air out of the attic, if there are holes.
In some houses, this same effect is created by closing bedroom doors. Your HVAC system is either blowing warm or cool air into the bedrooms, but the air can't get back out to the return duct located in your hallway areas. The bedrooms are being blown up like a balloon,so to speak, except the walls don't expand and rest of the house is under a negative pressure, with the return trying to suck in air from wherever it can get it. In many cases, air gets sucked in from your attic, then that's where it will come from, complete with dust, insulation fibers, and whatever else might be up there between the roof and the attic.
Of course, it's also quite possible that these same forces are sucking air into the house from the basement or from outside, rather than from the attic. The only way to know for sure is to have the house tested with a blower door, a device designed to locate the holes in the house and measure their size.
Aside from the dust, the air is probably also hot and wet in the summer, cold and dry in the winter, and contaminated with a variety of pollutants all year round. Identifying the problems and fixing them will not only improve your dust situation, but will also reduce your energy bills, increase your comfort, and enhance the health of you and your family.
At Sims Heating And Cooling Services is to go beyond just repair and installing a new furnace or AC System.