The answer to 'why is my ductwork smells bad' is that there are a few common causes, including mold growth, debris buildup, and pest infestations. Musty or foul odors coming from your ductwork can indicate an underlying issue that requires attention.
Mold and mildew can grow in damp areas of your ductwork, often due to high humidity or water leaks. Dust, dirt, and other debris can also accumulate over time, trapping odors. Additionally, pests like rodents or insects nesting in the ducts can lead to unpleasant smells. Addressing the root cause is important to eliminate the odor and prevent further problems.