Have you noticed dark lines around the baseboards or under doorways in your home? Those lines have a name: the technical term for those lines is known as filtration soiling.
Filtration soiling is a term used to describe dark, black lines that may appear on carpet. This is not a carpet defect, but a situation in which dust and other airborne pollutants can accumulate on the carpet fibers in areas with a concentrated flow of air over the carpet or through tiny cracks or other open areas under the carpet. Depending upon the conditions in your home, the condition may occur quickly or it may develop over a period of months or years. The degree of soiling is dependent upon the volume of airflow and the level of indoor air pollutants. Filtration soiling has nothing to do the quality of carpet selected. The condition will usually appear more noticeable on lighter carpets than darker color shades.
Filtration soiling maybe more obvious around baseboards, under doors, along the edges of stairs and possibly away from walls where plywood sub flooring materials meet. Generally, the condition will appear worse on upper levels of the home due to warm air rising.
Modern homes are more airtight than ever due to energy saving requirements. Whenever your forced air heating or cooling system runs it’s like blowing up a balloon. The fan in your unit pressurizes your home, and air pressure always seeks equalization. Since windows and doors are tighter now, air pressure finds the path of least resistance which is under your baseboards. So in effect your carpet is functioning as an air filter.
Filtration soiling can occur under closed interior doors where a central heating, ventilation, and air condition (HVAC) system is utilized. When possible, open Interior doors to reduce filtration soiling that may develop while your heating or cooling system is in operation.
Filtration soil may be fireplace or automobile emissions, residue from furniture polishes, fine sand or clay particles, cooking oils, or a host of other soils or a combination of soils. Oily airborne contaminants trapped by carpet fibers will serve to attract more dry soil.
It is difficult to identify effective methods to reduce or prevent filtration soiling. Preventing airflow through carpet and carpet edges by sealing cracks in the subfloor, as well as under baseboards and edges of stairs, may reduce filtration soiling problems. Keeping air inside the home as clean as possible can be accomplished by reducing indoor air pollutants, such as cooking emissions, fireplace smoke, burning candles, cigarette smoke, and emissions from cleaning chemicals; and by the installation and regular replacement of high efficiency HVAC air filters.
While no one cleaning technique may be successful in all filtration soiling situations, recent innovations in soil- and stain-resist treatments applied to carpet have reduced the effort previously needed to remove the filtration soil. However, the complete removal of contaminants from the soiled areas can be complicated, depending on the type of contaminant materials present. To achieve the best results, the services of a cleaning professional should be considered.
Filtration Soiling Removal
Filtration soiling can be especially difficult to remove, since the soil particles are primarily fine particles that are allowed to build-up on carpet pile fiber over time. These soils can be a combination of water soluble and solvent soluble solids. Additionally, oily soil such as auto emissions, greasy kitchen soils, and other oily airborne soils can be quite difficult to remove even under normal soiling conditions. The type of soil that causes filtration soiling will vary over time (and by location) and complete removal may require a variety of aggressive removal approaches. At times, it may be much less difficult to restretch the carpet and trim away the soiled areas rather than attempting to remove the soiling. In most filtration soiling situations, a carpet cleaning professional should be consulted for more effective removal.