"You can't really separate good air quality from good HVAC performance."
"I wouldn't recommend to someone something I wouldn't recommend to my grandma."
"Once you've seen them both, they can't be separated."
What does professional duct cleaning look like when you approach it through the lens of HVAC performance and building science?
In this episode, Bill talks with Zach Ortwine of Southeast Clean Air, a duct-cleaning contractor who has deliberately expanded his understanding beyond cleanliness and indoor air quality into airflow, static pressure, duct leakage, system performance, and building pressure.
Zach describes how his involvement with both NADCA and the National Comfort Institute (NCI) changed the way he evaluates homes. His early work focused primarily on indoor air quality concerns such as particles, odors, filtration, and ventilation. But as he learned more about HVAC performance, he realized that air quality and system performance are difficult to separate.
That realization led him to add tools such as thermal imaging, airflow measurement, static pressure testing, the TrueFlow grid, duct leakage testing, and video inspection to his process. Instead of automatically recommending duct cleaning, Zach now looks for the underlying conditions that may have contributed to the problem in the first place.
The conversation also explores what separates professional duct cleaning from poor-quality work, including NADCA certification, the ACR standard, technician experience, and knowing who will actually perform the work.
After the recording, Zach sent along one more thought that fits the conversation especially well: good collaboration also requires clear boundaries. When duct cleaners and high-performance HVAC contractors work together, both sides should agree in advance on what the duct-cleaning company can handle and when work should be referred back to the HVAC contractor. Zach shares examples from past partnerships where those limits were clearly defined, including how much duct replacement he could perform and when equipment or filtration recommendations were handed back to the HVAC company.
The larger lesson is that collaboration works best when it is built on measurement, trust, communication, and clearly defined roles. Done well, duct cleaners and HVAC contractors can make one another more valuable while giving customers a more complete solution.
EP273 with Dan Stradford:
This episode was recorded in August 2026.
