Which of the following is a common method used in duct cleaning?

Mechanical agitation with brushes is a widely recognized method utilized in duct cleaning. This technique involves the use of specialized brushes that scrub the interior surfaces of ducts, effectively dislodging dust, debris, and contaminants that have accumulated over time. The physical action of the brushes enhances the cleaning process, allowing for a more thorough removal of particulate matter compared to methods that solely rely on air pressure or other less direct approaches.

This method is especially effective in conjunction with vacuum systems, which can capture the dislodged particles as they are released, ensuring that contaminants are not simply stirred up within the ductwork. Moreover, mechanical agitation is valuable for cleaning various types of duct materials and can reach into crevices and corners that other methods might miss.

In understanding duct cleaning as a whole, it's important to note alternative methods, such as washing ducts with water or solely using compressed air, which may not be as effective on their own, and sealing ducts without cleaning, which does not address the underlying contamination issue.