The air ducts in your home are tubes connecting your HVAC system with air vents. Your HVAC system sucks in heating or cooling air through the intake vent. It then compels the heated or cooled air out via the ducts, which supply the conditioned air to your whole house through your air vents to heat or cool your home. Provided these ducts are clear and clean, air circulation throughout your home is mainly unhindered. However, if your ducts are clogged or dirty, it traps pollutants that contaminate the air in circulation. The clogs also put undue stress on your HVAC system, which works harder to compensate for the inhibited airflow. Mold can also grow in your air ducts if left unattended. It is one of the worst HVAC duct pollutants. Mold is a natural substance found in the air, both indoors and outdoors. When moisture accumulates in your air ducts as water droplets, instead of evaporating, the moist air duct provides a conducive environment for mold to grow and thrive, as mold spores will form colonies. Mold spores create colonies in damp areas with a food source. In such a situation, the mold spores will utilize particles such as dead skin cells, dust, and dirt as a food source. If you discover mold in your HVAC equipment, clean your ducts using home cleaners such as saturated bleach. Purchase the appropriate mold growth inhibitor products from your local home improvement store, and dispose of tools properly to avoid contaminating other areas.