What is filtration soiling and what does an air filter have to do with it? Filtration soiling is soot-like discoloration that appears primarily along the edge of your carpet. Some carpet professionals also refer to this type of staining as aromatherapy candle soot, draught marking, fogging or dust marks. It is more noticeable on lighter colored carpeting than darker shades, but … [Read more...] about Can Air Filters Affect Filtration Soiling?