As a building's HVAC system provides conditioned air to occupied spaces within the facility, air from within an occupied space is drawn in through ductwork to an HVAC unit, where it is conditioned.
Before the air gets to the unit, it usually passes through a filter designed to protect the mechanical equipment from becoming contaminated by large particles of dust and debris. Many filters commonly used today will not prevent the introduction of small particles of dust and debris from the air stream into the system. Over time, these deposits may form sizable accumulations.
Cleaning HVAC systems provides many benefits. Cleaning lessens the likelihood of indoor air pollution in the building and may help to alleviate health and comfort complaints by occupants. Clean HVAC systems perform more efficiently, which may decrease energy costs. Well-maintained mechanical components are likely to last longer, reducing the need for costly HVAC system replacement or repairs.