1. Introduction Air duct cleaning has become one of the most discussed yet misunderstood services in the HVAC industry. While the market continues to grow due to rising awareness of indoor air quality, skepticism remains strong among homeowners and businesses alike. Many consumers question whether duct cleaning is truly necessary or just another upsold service with minimal benefit. This uncertainty stems from years of inconsistent service quality, misleading marketing, and a lack of standardization within the industry. As a result, both customers and honest service providers face the challenge of rebuilding trust and credibility in the air duct cleaning sector.