Nov 17, 2016
In this episode of the HVAC School Podcast, Bryan talks with Jeremy Smith about refrigeration tips, terms and processes. They also cover the similarities and differences between A/C and refrigeration.
Being on-call as an A/C tech is not all that different from being on-call as a refrigeration tech. Similarly, the principles of heat transfer don't change between the A/C and refrigeration trades. Both trades follow the same basic rules, but all of those valves, adjustments, and tuning on rack refrigeration systems may make an A/C tech's head spin.
Refrigeration techs may come across glycol chillers, rack refrigerators with several refrigerant circuits on a single piece of equipment, or piping that has been warped by hot gas defrost. There is also a greater emphasis on regulating suction pressure rather than merely measuring it, and refrigeration techs use EPR valves to help control that pressure. Each refrigerated case also has its own expansion valve.
Jeremy also covers the complexity of defrost. In A/C, defrost could be as simple as shutting a unit off for a period of time. Defrost is more critical in low-temperature applications, though hot gas defrost may damage pipes and make them prone to leaks. Electric defrost typically has a lower potential to cause damage.
Also, subcooling is less of a big deal in refrigeration. Sight glasses and receivers make subcooling less vital than it is in HVAC.
Join Bryan and Jeremy as they discuss:
- Reznor startup
- Being on call in the refrigeration world
- Differences and similarities between rack refrigeration and A/C
- Hot gas and electric defrost
- Glycol refrigeration systems
- Subcool and superheat
- Refrigeration TXV settings
- EPR valves and their settings
- Rack manifold pressure
And many more refrigeration tips...
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