As air passes through the air conditioning and heating units and ductwork of the home, it is only a matter of time before those particles begin collecting on the unit and duct interiors. These accumulated particles will include anything and everything that floats in the house or comes in from the outside. Animal and human skin flakes, ground up stone and dirt particles, hair, mold spores, bacteria, vehicle exhaust fumes – all of these and more begin to collect on the duct interiors, fan, cooling and heating elements, filters, and registers.
In some instances odors develop in the air handler or ducts due to the particulate buildup. In other cases, dirt may begin blowing out of the registers.
Another concern is the buildup of mold or bacteria inside an air conditioning unit. Such microbial growth is rare in home systems, but can occur where moisture is present. Homes in humid climates or near bodies of water are particularly susceptible. Cleaning removes such growth and approved disinfectants can be used by a reputable duct cleaning company to retard or eliminate microbial contamination.
NOTE: “Streaking” around the registers is not necessarily a sign of dirty ductwork. This is the normal effect of air blowing or swirling across a surface continuously. Residential heating and cooling systems collect dirt. Streaking may give you an idea of what particulate is settling in your ductwork, however. Black “sooty” streaks usually come from vehicle exhaust, whereas whitish or light gray powdery, dust-like streaking is commonly from dander (skin flakes).
Having a home heating system cleaned every 3-5 years will prevent the continuous buildup of dirt and other particulate in the unit and ductwork.
