To answer the question in the title, we use it as a measurement of pressure. REALLY, it is a measurement of distance. First, any scale CAN be used to measure vacuum (negative pressure) and positive pressure. The trick is knowing which is best suited for which and the size of the scale. Larger units of […]

We all see a lot of questions about dyes, leak stoppers, lubricants, inhibitors, and snake oil. All of those were designed to go into the refrigerant circuit and “improve” something. I just go back to what Ray Johnson always said. (Ray is one of my early heroes in the biz, and he taught me a […]

Every now and then, a tech will call me and give me the same story of woe. They're working on a system and have the following readings: Low superheat Low suction pressure Low head pressure They'll reassure me that the system airflow is correct. So, what could possibly be wrong? I'll ask how they could […]