For years, HVAC contractors and National Air Duct Cleaners Association (NADCA)-certified techs have worked under the shadow of federal guidance that downplayed the value of duct cleaning, sometimes even warning it could do more harm than good. Most in the industry have faced customers holding up that old EPA fact sheet – “little evidence cleaning ducts helps,” it claimed – making it tough to build trust or close business.
That original EPA guidance dates all the way back to 1997, when the agency released its first fact sheet on air duct cleaning. It became the default government position, echoed in updates and online resources for nearly three decades. The reason for its persistence? The EPA, like many agencies, is slow to update recommendations without overwhelming scientific consensus. For years, research on the direct benefits of duct cleaning was limited, and the agency chose caution over endorsement. Even as the HVAC industry evolved and new studies emerged, the EPA kept the same language, erring on the side of not recommending routine duct cleaning – a stance that cast a long shadow over the industry.
That’s starting to change. In its latest indoor air quality (IAQ) fact sheet, the EPA names “source control” – the core of NADCA’s approach – as one of three best practices for healthier buildings, alongside improved ventilation and filtration.
For those in the field, this isn’t new advice. Regularly at NADCA conferences, the old EPA guidance was lambasted, as the group backed research showing the benefits of duct cleaning, including a recent study that found the improvements to airflow after cleaning resulted in significantly less energy usage at schools across the world. The new fact sheet aligns with what the industry has practiced and promoted for years: removing contaminants at the source is key.
The impact of earlier DOE and EPA statements was felt everywhere. Guidance like, “little evidence exists that cleaning only ducts will improve efficiency,” or, “clean ducts only as needed,” fueled skepticism and made it harder for reputable contractors to justify their work.
Contractors often encountered visible dust, microbial growth, and airflow issues, yet found customers referencing the government’s longstanding guidance as a reason to hesitate on duct cleaning. This persistent skepticism made selling proper source control an uphill battle for much of the industry.
Now, the EPA’s shift puts source control front and center, echoing NADCA’s ACR Standard: identify and remove contaminants first. Clean systems mean better airflow, more efficient filtration, and improved occupant health.
NADCA continues to update standards and invest in research on energy use, system longevity, and the health impacts of clean HVAC systems. For business owners and techs, the new EPA guidance is a long-overdue validation of what’s already proven in the field.
With the new fact sheet, conversations with customers may get a little easier. Contractors can point to updated federal guidance that recognizes the importance of source removal, giving them clearer ground to stand on.