Professor Butler

04/18/2026

This month has been wild, we’ve had over 2,500 new followers join the page. If you’re new here, welcome. I appreciate every single one of you, and I wanted to take a minute to introduce myself properly.

My name is Patrick, and I’ve been in the trades my entire adult life.

I started out in 2002 as an electrical apprentice, and in 2005 I made the switch to HVAC. I’ve been in this trade ever since, commercial service, troubleshooting, controls, and everything in between.

I’m a 20‑year master service technician working commercially, and I’m also a building automation specialist. HVAC has taken me into hospitals, labs, schools, high‑rises, and some of the toughest mechanical rooms you can imagine.

In 2011, I started teaching at my union apprenticeship school, nights, in the classroom, helping apprentices get their footing. It’s where I got the name Professor, my student started calling me that. When the pandemic shut the school down, I shifted to teaching online, making videos so techs could keep learning no matter what was happening in the world.

Along the way, I’ve been honored with a couple of recognitions in this industry:

• In 2019, I was named one of the Top 40 Under 40 in the HVAC industry by ACHR News Magazine.
• And in 2026, I was selected as one of the Top 25 Most Influential HVAC Educators & Instructors of the Year by ESCO and True Tech Tools.

I’m also a husband and a father, and this trade has supported my family and shaped who I am. Everything I do here, the videos, the breakdowns, the explanations, is meant to give back to the community that gave me a career and a purpose.

To all the new followers: welcome.
I’m glad you’re here.

Drop a comment and introduce yourself, tell me where you’re from, what part of HVAC you’re in, and how long you’ve been in the trade. I love hearing everyone’s story.

And if you ever need anything, a question answered, a breakdown, a second set of eyes, my DMs are open. I answer every single one.

Let’s keep building this community.

Patrick (Professor Butler)

04/17/2026

Why do we call it relative humidity?
Most people hear the term every day, but very few understand what it’s actually relative to. In this video I break it down using simple visuals, cups of water standing in for air at different temperatures, to show how warmer air can hold more moisture and colder air can’t.

Once that clicks, relative humidity stops being a mystery and starts becoming a tool.
I also touch on grains of moisture, dew point, and why HVAC techs should think in terms of actual moisture content, not just the percentage on a weather app.

If you want a clearer picture of how moisture behaves inside a building, and why your equipment reacts the way it does, this one’s worth the watch.

04/16/2026

PID loops run your HVAC systems the same way cruise control runs your car.
In this video I break down what a PID loop actually does, why it matters for heating and cooling, and how techs can use it to diagnose unstable systems, overshooting, hunting, and bad tuning.

If you’ve ever wondered why a system can’t “hold speed” or why the temperature keeps drifting, this will make it click.

Like, share, and tag a tech who needs this.

HVAC

04/15/2026

Walked up to a chiller that wasn’t running, looked like a controls/sensor issue at first.

Tracked down the problem, rebound the sensors, got everything talking again…

Still no flow.

Started digging deeper and found the another cause… and yeah, wasn’t expecting this one 🦝

Had to do a quick field repair just to get the unit back online.

Anyone else ever run into animal damage like this on a job?

04/11/2026

(Long video). Come along on a service call on a constant volume rooftop unit that has dehumidification. The problem is the unit thinks it’s a heat pump in its configuration and is over cooling the space and not firing the gas furnace. Full call from start to finish.

04/10/2026

A quick variable frequency drive tip when replacing a VFD with a direct replacement. Make sure to back up the parameters to the keypad. It will save you future hassle and prevent having to add parameters manually one by one

04/09/2026

Attention all junior HVAC technicians and apprentices. You need tools to do the job. Make sure you buy one tool a week to grow your collection so you can have the right tool for the job to advance as a technician.

04/07/2026

Update from Professor Butler. Click my link to sign up for HVAC Know It All newsletter and sign up to the Grindstone discord.

02/25/2026

How to safely reset a tripped breaker

01/07/2026

Starting up a new rooftop unit and best practices

01/03/2026

2025 treated me really well. We pushed hard, stayed consistent, and because of all of you, we grew by over 50,000 followers across all platforms. That still blows my mind. I’m just a guy who loves HVAC, loves teaching it, and loves breaking things down so techs can succeed in the field, and somehow this little community turned into something huge.

I’m also proud to share that I was selected as one of the 2026 Top 25 Most Influential HVAC Educators & Instructors of the Year, recognized by ESCO Institute-HVAC Excellence and TruTech Tools, LTD. That one meant a lot. It’s an honor, and it motivates me to keep raising the bar for the next generation of techs.

Now for the big news going into 2026:
I’m officially collaborating with HVAC Know It All , and I’ll be producing exclusive videos twice a month for their newsletter. If you want deeper dives, field-ready breakdowns, and content I don’t post anywhere else, make sure you join and sign up for the newsletter. They put a lot of work into the newsletter. It’s a great resource for techs.Huge thank you to Gary and Ben for believing in what I do and bringing me into the HVAC Know It All family. https://hvacknowitall.com (Click the orange SUBSCRIBE button at the top of the page)

2026 is going to be a year of leveling up, more education, more field-focused content, more transparency, more real conversations about this trade, and more tools to help techs grow. More mentoring. I’m excited for what’s coming, and I’m grateful I get to build this with all of you.

Thank you for following, supporting, sharing, commenting, pushing this mission forward. None of this is possible without all of you. 
A few special thanks:
Trent Parker aka Mr Fat Cheeto aka Papa Cheeto
Ty Branaman Love2HVAC
Stephen A Smith
Joe Joe The HVAC Man
HVAC School

Let’s make 2026 the strongest year yet.

— Professor Butler

As an HVAC technician, staying up-to-date on the latest techniques and technologies is crucial for success in your field. That’s why HVAC Know It All offers a wide range of resources to help you hone your skills and advance your career. We have everything you need to become a true HVAC expert.

08/06/2024

I drew this logo 3 years ago today