Quotes from the episode:

"Ducts matter. Nobody cares much about them until something goes wrong." "HVAC systems are designed assuming clean, bare sheet metal."

"Even a small layer of dust can become a mountain range to an air molecule."

"Think like an air molecule."

In this episode, Bill speaks with Dan Stradford of Action Duct Cleaning about what really happens inside HVAC duct systems over time and why cleaning can matter more than many people realize. Dan shares how the duct cleaning industry evolved from its "wild west" early days into a more standardized field through NADCA, with better equipment, training, and certification practices.

Dan explains that even a thin layer of dust can disrupt airflow, increase turbulence, raise static pressure, and reduce system efficiency. Drawing from NADCA energy studies, he describes how cleaning returns, supplies, fans, coils, and air handlers each contributed measurable performance improvements, including major reductions in fan and compressor energy use.

The conversation also covers how HVAC professionals can evaluate duct-cleaning contractors, when homeowners or building owners should consider cleaning, and why ductwork deserves more attention as a hidden yet critical part of indoor air quality, comfort, and system performance.

Dan'sLinkedIn: https://www.linkedin.com/in/dan-stradford-b7509123/

The research paper we reference: https://www.sciencedirect.com/science/article/pii/S0378778824012635

Dan's company: https://actionduct.com/

The video Dan referenced: https://www.youtube.com/watch?v=HkGl7zljqN8

The National Air Duct Cleaners Association: https://nadca.com/

This episode was recorded in May 2026.