This tech tip was inspired by Alex Meaney and Ed Janowiak’s session at NCI’s High-Performance Summit 2025: “Good Design Isn’t a Buffet: The Importance and Interconnection of Manuals J, S, and D.” Alex is a building science expert who worked at Wrightsoft (now MiTek) for several years before launching his consulting firm, Mean HVAC Consulting […]

HVAC technicians typically focus on diagnosing issues related to mechanical wear, refrigerant leaks, or control problems within the equipment. However, damage can also originate from external sources. For instance, a failed control board might be attributed to internal shorts or rubouts. Yet, the root cause could be external, such as the voltage spike that can […]

If you have a multimeter for HVAC work, you most likely have a meter with a CAT III rating on it. Some might also be rated for CAT II at higher voltages or CAT IV at lower ones—or both, like this model of the UEi DL599 from our Multimeter 101 for HVAC 3D video. In […]