About US Poorly maintained HVAC systems harbor mold, fungi, bacteria, pollen, dust mites and other disease-carrying biological pollutants that are re-circulated through forced-air systems. Given the right conditions of moisture and temperature, these contaminants can flourish in air ducts and be carried out into the work space where humans are exposed. Related Searches Air duct cleaning, air duct cleaning service, dryer vent cleaning, HVAC installation, professional air duct cleaning, furnace cleaning, dryer vent installation, dryer vent... read full review »