If you work in large commercial offices or mixed-use buildings, you almost certainly work with VAV systems regularly. If you aren't familiar with VAV, this is a quick intro to the basics so that they won't seem so overwhelming. VAV stands for variable air volume; this means that the AHU (air handling unit) can vary […]

Thought Experiment #3 – The Start Winding Has No “Inrush” with a run capacitor only  The name “start winding” is an antiquated term for the single-phase residential industry. It came from the days when CSIR (capacitor start, induction run) motors were still used commonly. In a CSIR motor, the start relay removes the start winding […]

I was listening to someone talk about air relative humidity the other day while looking at a psychrometric chart, and he commented that the chart ends down at freezing (32°F) because “all the water freezes out of the air at that point.” I think I made this Jed Clampett face: The psychrometric chart is designed […]