I've heard the phrase, “It's too cold to set the charge!” for as long as I've been in the trade. I've also heard some variations of, “We need to come back and set the charge,” or, “We need to come back to do XYZ [some other thing].” Granted, there are cases where you do actually […]

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 […]

Disclaimer: “Ghost voltage” is a term used by techs to explain a phenomenon where they measure voltage they don't expect or when the voltage they see doesn't do the work they expect. More advanced techs know how to use the Lo-Z (low impedance) mode on their voltmeter if it has one to help eliminate this. […]