How many times have you looked at the bottom right-hand side of an evaporator coil and seen all sorts of rust, even on a fairly new coil? You may have noticed that many evaporator coils and even some condenser coils will start to corrode where the galvanized steel endplates touch the copper u-bends of the […]

We've been getting many questions on micron gauges that are ”going haywire” or reading in the micron range, even at atmospheric pressure. First, micron gauges measure absolute pressure, so you can’t ”zero” them out. They use tiny, very sensitive sensors that are calibrated to air, not refrigerant, so anytime refrigerant gets into the gauge, it's […]

This article includes significant contributions from Neil Comparetto and Brian Chadwick, both of whom are HVAC technicians in Virginia. Brian is also the owner of Chadwick Air, and Neil is a co-owner of Comparetto Comfort Solutions and a longtime contributor to HVAC School. Thanks, guys! DISCLAIMER: A lot of the information in this article is […]