Tech Tips

This article was written by Senior Refrigeration Tech Jeremy Smith. Before we get to it, I want to remind you that ALL of the tech tips are available in chronological order HERE, and you can sort through them alphabetically by selecting the letters and numbers above the tips. It's a great link to share with […]

Here is another great explanation from Michael Housh of Housh Home Energy in Ohio. Thanks, Michael! I’m going to lay out and compare the sensible heat rate equations for both the air-side and water-side of HVAC to help draw similarities and dive deeper into the science behind these equations. This is the beginning of a […]

This tip was written by a 19-year service tech, Frank Mashione. Thanks, Frank. Here is a tech tip from the field that had stumped me. Luckily for me, I knew the right person to call to get back on track. This business has complained about heat calls for quite a while. I have heard other […]

Michael Housh from Housh Home Energy in Ohio wrote this tip to help techs determine the air-side charge on a pressure tank. Thanks, Michael! Determining the air-side charge of an expansion tank in a hydronic heating system is a relatively easy task.  A properly sized and charged tank is designed to keep the system pressure […]

This tip was a COMMENT on the sensible heat ratio tip left by Jim Bergmann. As usual, Jim makes a great point; once you get the “sensible” capacity for a piece of equipment at a set of conditions, you can easily calculate a true target delta T. Another interesting thing you can do is use […]

This tech tip was written by a friend of HVAC School, Brian Mahoney. He is an HVAC instructor at Western Suffolk BOCES/Wilson Tech. Thanks, Brian! The podcast on delta T for A/C the other day got me thinking about the formula I learned in school about calculating the GPM of a hydronic system. We will […]

This article was written by Christopher Stephens. He is a commercial HVAC/R service manager in the greater Los Angeles area. Thanks, Chris. Let’s start by covering the three elements needed for a fire: fuel, air, and heat (spark). With those three elements in the right condition, you can start a fire. So, if we reduce […]

Measuring airflow is easy. Measuring airflow accurately is quite a bit more difficult. In many cases, when we as technicians measure airflow, we are trying to get to the almighty CFM (cubic feet per minute) volume measurement. You can take CFM readings fairly easily with a hood, like the Testo 420, but even a hood […]

  This article is written by Christopher Stephens of JVS Refrigeration in California, with just a few additions by me (Bryan) in italics. Thanks, Chris! Reach-in refrigerators are an interesting side of our industry, often looked at as frustrating and troublesome. Since we usually see reach-ins in kitchens or convenience stores, the refrigerators are never […]