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, […]

This photo is of a blower door test we performed at my own house using a Retrotec blower door. You will notice the 15-passenger van outside the window, which is a dead giveaway. A blower door is used to measure the tightness of a building and is often discussed in terms of an ACH50 number. […]

If you went to school and learned the “gas laws” early on, you probably thought it seemed LAME. Then, later, things like mass flow rates, airflow conversions, and compression ratios seemed HARD. Well… It's because HVAC is hard if you don't understand the concepts behind the gas laws, even if you never learn to do […]