Uploaded July 2026 | Updated September 2026, 3 weeks ago
Most techs know when airflow feels off — but do you actually know how to measure it? In this video, Ty Branaman walks through how to properly test static pressure on a gas furnace and air handler, using real-world scenarios to show you exactly what the numbers mean and why they matter.
You'll learn what total external static pressure actually tells you (and what it doesn't), where to place your manometer probes on a furnace or air handler, and why exceeding the manufacturer's rated pressure limit means you've got a problem to solve. TY also breaks down the relationship between filter size, surface area, and pressure drop — including why that oversized filter box you thought looked weird might actually be the right call. He covers coil placement, transitions, probe placement considerations around diverter plates and drain pans, and how to think about external restrictions on both the supply and return sides.
The key takeaway: TESP is like reading your blood pressure — critical data, but it doesn't tell you actual airflow. Understanding how to test and interpret it properly is what separates a real diagnosis from a guess.
Whether you're working on gas furnaces in the field or trying to get better at air handler diagnostics, this one's worth your time.
Read all the tech tips, take the quizzes, and find our handy calculators at hvacrschool.com or the HVAC School Mobile App on the Google Play Store (hvacrschool.com/play-store) or App Store (hvacrschool.com/app-store).
Most techs know when airflow feels off — but do you actually know how to measure it? In this video, Ty Branaman walks through how to properly test static pressure on a gas furnace and air handler, using real-world scenarios to show you exactly what the numbers mean and why they matter.
You'll learn what total external static pressure actually tells you (and what it doesn't), where to place your manometer probes on a furnace or air handler, and why exceeding the manufacturer's rated pressure limit means you've got a problem to solve. TY also breaks down the relationship between filter size, surface area, and pressure drop — including why that oversized filter box you thought looked weird might actually be the right call. He covers coil placement, transitions, probe placement considerations around diverter plates and drain pans, and how to think about external restrictions on both the supply and return sides.
The key takeaway: TESP is like reading your blood pressure — critical data, but it doesn't tell you actual airflow. Understanding how to test and interpret it properly is what separates a real diagnosis from a guess.
Whether you're working on gas furnaces in the field or trying to get better at air handler diagnostics, this one's worth your time.
Read all the tech tips, take the quizzes, and find our handy calculators at hvacrschool.com or the HVAC School Mobile App on the Google Play Store (hvacrschool.com/play-store) or App Store (hvacrschool.com/app-store).
