This tech tip was written by a friend of HVAC School, Brian Mahoney. He is an HVAC instructor at Western Suffolk BOCES/Wilson Tech. Thanks, Brian! The podcast on delta T for A/C the other day got me thinking about the formula I learned in school about calculating the GPM of a hydronic system. We will […]

If you do any larger commercial work, you've probably seen a DIN rail without knowing what it is called. It is simply a mounting standard that originated in Germany in the 80s and slowly worked its way over here. DIN rails can be used to mount terminal blocks, relays, starters, breakers, and just about anything […]

Sometimes, we can focus on the more complicated aspects of a system and parts installation—like evacuation and flowing nitrogen—and forget the simple and critical common-sense steps to keep contaminants out of the system. One of these is pre-cleaning the tubing and connection before cutting or unsweating. For example: If you are replacing a coil, use […]