Hvac School - For Techs, By Techs

In this short podcast episode, Bryan explains the science behind a common HVAC simile: static pressure is like blood pressure. He covers the similarities and differences between measuring static pressure during a service call or maintenance and a doctor measuring your blood pressure at a checkup. Total external static pressure (TESP) should be measured every time you perform service or maintenance on a unit. The exact test port location will vary between air handlers and furnaces; the coil adds extra pressure drop in furnace applications. You need to pick a coil that has the lowest static pressure drop (same consideration as filters). Typically, the lower the pressure drop, the better. Make sure you use proper ports for static pressure testing when you do make those holes. Static pressure isn't airflow itself. It can help diagnose airflow issues or give indications, but it doesn't measure the CFM. Static pressure is a balloon-type pressure exerted on the walls of the duct. Just as high blood pressure doesn't