Regular air duct cleaning is essential because they become dirty due to various factors like pets, allergies, smoking, and home renovations. Vulnerable individuals, such as those with asthma or allergies, children, and the elderly, are more susceptible to indoor air pollution. Air duct cleaning addresses these issues by removing contaminants like dander, dust, and chemicals that accumulate in the HVAC system. These pollutants are re-circulated multiple times a day, leading to a buildup in the ductwork. If left untreated, this buildup can pose severe health risks for those with respiratory conditions, autoimmune disorders, or environmental allergies.