This article is an extension of HVAC School’s “How to Measure Gas Pressure” video. Additional input was provided by Jim Bergmann. Bubble test procedures and standards were provided by Honeywell. Links to source materials are available at the end of this article. If there’s one complaint that HVAC techs should never take lightly, it’s a […]

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 […]

Low pressures are often measured in inches of water column or “WC. Like most units of measure, it has a very simple origin; in a water manometer, 1″ of water column is literally the amount of force it takes to raise the column of water by 1”. While some water manometers (water tubes) are still […]