Controlling Pollutant Pathways

Mouse over the picture above to see messages which are referenced in more detail below.

(Hot Spot over the hinge.)

Remember...“Where dust accumulates in air passageways are clues to the direction of flow.”
As air moves through openings it often collects on protruding surfaces. Check door hinges, door frames, around electrical receptacle covers, grilles, and other similar locations for accumulated dust.
The dust side of the surface is the direction from which the air is moving.