Verification starts with inspection, not assumptions, and it should follow a clear and repeatable process. Trained technicians look for visible debris, documented microbial growth, damaged components, or airflow restrictions that are confirmed through cameras, pressure readings, or other measurable tools. These findings provide objective justification for any recommendation. We caution homeowners against relying on dust at vents alone, since this is often caused by filter gaps, leaky returns, or normal household activity rather than dirty ducts. A proper evaluation includes checking filter fit and condition, measuring static pressure, inspecting coils and drain pans, and reviewing insulation integrity. When a provider can clearly show where contamination exists, explain why it matters, and describe how it affects system performance or indoor air quality, the recommendation is based on evidence and education instead of sales pressure or fear based tactics.