Tech Tips

Take a look at the screenshots above. The one on the left is for Death Valley at 282′ below sea level, and the one on the right is Denver, CO, at 5,280′ above sea level. Notice the barometric pressure values; they are almost the same. That means that barometric pressure is corrected or “normalized” to […]

  In this 60-second tech tip video by Brad Hicks with HVAC in SC, he shows us how and why to remove the weep port plugs on a condensing fan motor. I know from experience that motors can fail prematurely when this practice isn't followed. Remember that motor orientation dictates which weep port plugs are […]

The definition of a transformer is a device that changes the voltages in an alternating current circuit. You may have heard of an autotransformer or a buck-boost transformer, and these terms are usually used for the same type of device; they just highlight different aspects. A transformer does not need to be a buck-boost to […]

In order to wrap my head around diagnostic issues, it helps me engage in thought experiments where I think of more extreme examples of an issue or situation or consider the ideal to find the “edges” of a concept. Once I find the extreme edges, I can begin to sort down to a more exact […]

DISCLAIMER: HVAC School is NOT an official OSHA safety training resource! Although we provide safety tips in good faith, our website is not a substitute for safety training from an authorized OSHA training source.   Let’s be honest: most of us probably got into the HVAC trade because we enjoy working with our hands. Unfortunately, […]

I am consistently surprised by how much false information still circulates out in the field, and one of the ones I hear often is the idea that you cannot or should not “top-off” or recharge R410a systems on top of an existing charge of R410a when the system is low. So, to be clear, before […]

  We’ve already made a few tech tips and uploaded a few podcasts about HVAC business practices, including some on profitability. That content is all fine and dandy, but those podcasts, articles, and videos may seem out of touch with most of our audience. After all, that content hardly seems to apply to the bread […]

Probably the most popular measurement method for indirect airflow readings is total external static pressure (TESP). A dual-port manometer or two Bluetooth single-port manometers are essential to the HVAC technician toolbag. Here’s a quick review of TESP, why it’s important, and how to make the measurements. TESP is a pressure reading of the “balloon” pressure […]

Some of the scariest practices that occur in the field surround brazing practices and tank and regulator handling. A few obvious tips are: Store tanks completely secure and upright with nothing nearby that can easily open or damage the tank valve. NEVER store tanks in a torch kit with it off only at the torch […]