Hvac School - For Techs, By Techs

Brett Wetzel and Kevin Compass from the Advanced Refrigeration Podcast join us to discuss commercial rack refrigeration and identify components. In supermarket racks, we typically have anywhere from 2-5 compressors on a single rack (with multiple evaporators, metering devices, and sometimes even condensers). These compressors may come in several varieties (including screw and scroll) and be digital or have VFDs. They also have common suction and discharge headers.  The compressors all share oil from a single system. Oil separators can come in three varieties: centrifugal, impingement, and coalescing (most efficient). The separator would feed into the reservoir, which stores oil.  Many rack systems use several different valves. Check valves to direct the refrigerant flow, especially on heat reclaim systems and split condensers. In some cases, there is a three-way valve or a solenoid valve that controls or stops the refrigerant flow. LDR (liquid differential regulating) valves maintain the required differential