Field Notes
Hands-on refrigeration & HVAC notes from a working technician — real jobs, real photos. Compressors, refrigerants, cold rooms and the small signals that save a callback.
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How a Refrigeration Compressor Gets Destroyed — An Overhaul in Photos
Real overhaul photos of a semi-hermetic R-22 compressor — burnt oil, broken valves and bearings — and the early signs that stop it from getting this far.
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Refrigeration Oil Isn't Just "Any Oil" — Matching Oil to Refrigerant
Why refrigeration oil must match the refrigerant — mineral oil for R-22, POE for R-410A/R-404A — and what happens in the compressor when it does not.
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Cold Storage Rooms — What a Tech Actually Checks First
When a cold room "won't hold temperature," the problem is often the room itself, not the compressor. Reading panels, door seals, and the ceiling unit cooler.
R-Pro — the field app behind these notes
Fault diagnosis, nameplate & receipt scanning, per-unit service history, refrigerant PT calculator and checklists — built by a tech, works offline.
See R-Pro