I got a lot of comments that many of you discharge run capacitors with a voltmeter. I test this method vs. the capacitor discharge tool I created. Obviously, many of you use needle nose pliers or a screwdriver. While this is widely practiced, it could result in an arc, shock, or damage to the capacitor. […]

Ever since Nikola Tesla invented the modern induction motor, we have been struggling with varying the speed of motors efficiently and reliably. The trouble in the HVAC industry is that there are several different types of technologies in play, and they can easily get confused. ECM (electronically commutated motor) In residential and light commercial HVAC, […]

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 […]