PODCAST with video: Most furnaces have insufficient airflow (w/ Steve Rogers)

In this episode, Reuben Saltzman and Tessa Murry talk with Steve Rogers, President of The Energy Conservatory (TEC), about the science behind home performance and why so many HVAC systems fall short of expectations. Steve shares TEC’s journey from early prototypes to industry‑standard testing tools and explains how comfort, moisture, and efficiency issues often stem from the building envelope. The conversation dives into blower doors, airflow testing, duct leakage, furnace short‑cycling, restrictive filters, oversized systems, and the key measurements inspectors and homeowners commonly miss, offering practical insights for homeowners, inspectors, HVAC technicians, and building‑science enthusiasts alike. You can check out The Energy Conservatory website here: www.energyconservatory.com Takeaways TEC manufactures tools that measure building airtightness, duct leakage, and airflow—core metrics for diagnosing home performance issues. Blower door testing became essential because leaky houses waste energy, cause comfort issues, and contribute to attic moisture problems. Early blower door prototypes were expensive and slow; TEC revolutionized the field with affordable, efficient models. Airflow is one of the hardest HVAC metrics to measure accurately; TEC’s TruFlow Grid helps techs commission systems properly. Most furnaces and ACs are never tested for correct airflow after installation, which leads to early equipment failure and poor efficiency. High temperature rise = low airflow. This often causes the furnace to hit its high‑limit switch and shut off prematurely. Oversizing is rampant—many homes have furnaces 1.5–2× larger than needed, increasing noise, inefficiency, and comfort issues. Filter restrictions depend on pressure drop, not just MERV rating. Pleat depth and surface area matter more than the number printed on the label. 3M Filtrete filters maintain reasonable pressure drops because they add pleats as MERV levels increase. The most important starting point in energy upgrades is a blower door test, not HVAC replacement. Older homes—especially balloon‑framed houses—are extremely leaky and need targeted air‑sealing. Complicated house shapes (L‑shaped, multi‑level splits, many dormers) are typically leakier than simple rectangular designs. Many contractors still do not measure airflow or static pressure, causing repeat callbacks and inefficiency. TEC’s tools and apps help HVAC techs commission systems properly—reducing callbacks and improving system performance. Homeowners can access subsidized energy audits through utilities, often including blower door and infrared inspections. Chapters 00:00 — Introduction and Guest Welcome 02:00 — Steve’s Background & The Origin of The Energy Conservatory 05:00 — How Blower Doors Were Invented & Early Challenges 08:00 — Engineers, Inventors & TEC’s Company Culture 11:00 — Advances in Airflow Testing: TruFlow Grid Explained 15:00 — Why Airflow Is Critical for Furnace & AC Efficiency 17:00 — Temperature Rise, High‑Limit Switches & Furnace Cycling 20:00 — Common Installation Issues & What Inspectors Should Look For 22:00 — The Truth About Furnace Filters & Pressure Drop 26:00 — Oversizing Problems & Proper Equipment Matching 31:00 — Why Most Homes Have Comfort Problems (and How to Fix Them) 35:00 — Blower Door Testing as the First Step in Home Performance 38:00 — Moisture, Attic Frost & Air Leakage Pathways 41:00 — Styles of Homes That Tend to Be Leakier 44:00 — Balloon Framing vs. Platform Framing 47:00 — Why the Industry Changes Slowly & The Role of Training 52:00 — How Homeowners Can Learn More & Access Energy Audits 53:00 — Closing Thoughts and Resources