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.

• 

  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.

• 

  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.

• 

  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.

• 

  Inside a Reciprocating Compressor — The Parts That Wear Out

  A look inside a reciprocating refrigeration compressor — valve plate, bearings, connecting rods — and what each part tells you when it wears.

• 

  What a Compressor Overhaul Actually Replaces — Worn vs New

  An overhaul is not magic — it is swapping the worn parts for new ones. Scored pistons and valve seats out, fresh connecting rods in.

• 

  The Reed Valve — The Small Part That Decides Whether a Compressor Cools

  Inside every reciprocating compressor are thin reed valves — suction and discharge. Worn or cracked, they kill capacity. Old vs new, and why they get replaced.

• 

  The Crankshaft — The Backbone of a Reciprocating Compressor

  The crankshaft turns motor rotation into piston stroke. If its journals are scored, the compressor is beyond overhaul. How to read it on site.

• 

  Inside a Semi-Hermetic Compressor — Motor and Pump in One Housing

  A semi-hermetic compressor hides its motor and pump in one case, cooled by the refrigerant itself. Why that matters for burnout and repair.