Static Pressure is like Blood Pressure - Short #258

HVAC School - For Techs, By Techs

Bryan Orr

Education, Business, Self-improvement, Careers

4.9 • 1K Ratings

🗓️ 23 September 2025

⏱️ 10 minutes

🔗️ Recording | iTunes | RSS

🧾️ Download transcript

Summary

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 mean your heart is pumping more blood than it should, a high static pressure doesn't mean your blower is moving a lot of air; both can indicate restrictions.

You also don't want an extremely low static pressure, either. It could indicate that airflow is weak, just like a very low blood pressure indicates that the heart isn't pumping as it should. If you want to know your system airflow, you should use TEC's TrueFlow grid. However, static pressure is particularly good at measuring trends so that you can see where the numbers deviate from the norm for each individual system.

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Transcript

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0:00.0	Yep, yep, this is the HVAC School podcast. I'm Brian. This is the podcast that helps you remember some things you might have forgotten along the way, as well as helps you remember some things you forgot to know in the first place. And today we're talking about static pressure. Is it like blood pressure? In some ways, yes. In other ways, no, on account of we're not measuring blood.
0:23.2	Anyway, hey, before we talk about that, we want to thank our great sponsors.
0:26.7	The WR. Mobile App by White Rogers and Copeland.
0:30.4	TrueTech Tools at TrueTechTools.com.
0:34.0	They're good friends of the podcast, I've known Bill and Bill for a long time, and they've been
0:38.7	providing a wide range of great tools and top-notch customer service for 18 years.
0:44.2	They supply over 90 brands and are adding more tools to their offerings each week.
0:49.2	You're going to find familiar hand-and-power tool brands like Milwaukee, DeWalt, and Klein,
0:54.1	building performance tools, including thermalWalt, and Klein, building performance
0:54.8	tools, including thermal imaging cameras, TEC's blower doors, precision monometers, and the
1:00.9	true flow grid. And as always, the True Tech team keeps a large inventory in stock to ship the same
1:06.7	day you order your tools. Don't see the tool you need in stock? Let them know and they'll look at
1:12.0	adding it to their offerings. True Tech Tools ships to all 50 states and territories, including Alaska
1:17.7	and Hawaii. Find out more at TrueTechTools.com and use the offer code get schooled for a great
1:25.1	discount at checkout. The HR Expo is coming back in 2026 as always from February 2nd through February 4th in
1:34.1	Las Vegas.
1:35.8	They have a massive show floor, over 1,000 exhibitors with unique equipment, tools, cleaners,
1:41.1	software, educational programs, and more.
1:45.0	Don't know where to start.
1:46.1	Get 20-minute previews of the products on the show floor at the new product theaters.
1:51.4	There's thousands of attendees, including industry experts and leaders.
1:55.6	Connect with them and hear them speak at educational sessions at the podcast pavilions or in panels,
	...

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