When I first started in the trade, we used to run into shielded control wires on the Carrier Comfort Zone 1 zoning systems and also on a Carrier VVT system I used to maintain at a bank. I knew it has something to do with electrical “noise” and that communicating systems often called for it, […]

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 […]

Graphic Courtesy of Danfoss On 8/8/17,  the United States court of appeals struck down an EPA phaseout of HFC refrigerants under the Clean Air Act on the basis that the Clean Air Act only gave the EPA the right to regulate ozone-depleting substances. However, many of us figured that the decision was likely to be […]