Air Systems Cleaning Specialist (ASCS) Practice Exam

The selected answer highlights several key indicators that suggest duct cleaning is necessary. Visible dust buildup within the ductwork signifies that particles are accumulating, which can decrease indoor air quality and may lead to health issues. Strange odors can arise from mold, mildew, or organic matter trapped within the ducts, indicating that cleaning is essential to ensure a healthy environment. Decreased airflow is another critical sign; when ducts are dirty or clogged, they restrict airflow, resulting in an inefficient heating or cooling system and possibly increased energy costs.

In contrast, high energy bills and major system upgrades (as seen in another choice) might indicate underlying issues unrelated to duct cleanliness, such as inefficient equipment or the need for system replacements. Consistent airflow and absence of dust suggest effective maintenance; thus, these conditions would not warrant duct cleaning. Lastly, having no noticeable signs or indicators would generally imply that the ductwork is in satisfactory condition as opposed to needing immediate attention.