The vapour-compression cycle and the hands-on work around it: piping, brazing, evacuation, charging, leak detection, recovery and the move to A2L refrigerants.

22 skills in 8 sections · listed in learning order

Refrigerant fundamentals

1. Refrigeration cycle basics

   Follow refrigerant around the circuit and describe its state and what happens to heat in each of the four main components.

   Foundation No courses yet

2. Saturation tables and P/T charts

   Convert between pressure and saturation temperature for any refrigerant, by table, slide chart or app, and convert gauge to absolute.

   Foundation No courses yet

3. Refrigerant types and blends

   Distinguish CFCs, HCFCs, HFCs, HFOs and hydrocarbons, understand blends, glide and fractionation, and what GWP means for the trade.

   Core No courses yet

Circuit components

1. Compressors and oils

   Identify reciprocating, scroll, rotary and screw compressors, calculate compression ratio and choose the right oil.

   Core No courses yet

2. Condensers and evaporators

   Explain, evaluate and clean air-cooled and water-cooled condensers and evaporator coils.

   Core No courses yet

3. Metering devices

   Understand capillary tubes, fixed orifices, TXVs and EEVs, how each controls superheat and how to replace or adjust them.

   Core No courses yet

4. Line components and pressure controls

   Know the job of filter driers, sight glasses, accumulators, receivers, head pressure controls and pressure switches.

   Core No courses yet

Piping & brazing

1. Refrigerant piping basics

   Cut, deburr, bend, flare and route copper line sets to size, keeping oil moving and the system clean.

   Foundation No courses yet

2. Nitrogen purge and pressure testing

   Flow nitrogen while brazing, then pressure test to the correct test pressure with a regulator set properly.

   Core No courses yet

3. Brazing and soldering

   Make leak-free brazed and soldered joints on copper and dissimilar metals with the right alloy, flux and heat control.

   Core No courses yet

4. Line set insulation and support

   Insulate and support line sets so they stay dry, quiet and protected for the life of the system.

   Foundation No courses yet

Evacuation

1. Gauges and service valves

   Connect a gauge manifold or wireless probes to the system through the right service valve and read what they tell you.

   Foundation No courses yet

2. System evacuation

   Pull and prove a deep vacuum with a micron gauge, choose the pump and hoses, and know when a triple evacuation is warranted.

   Core No courses yet

Charging

1. Charging by weight

   Calculate the total charge from the nameplate and line set length and weigh it in accurately with a scale.

   Core No courses yet

2. Superheat and subcooling

   Measure superheat and subcooling on a running system and use them to set or verify the charge for fixed-orifice and TXV systems.

   Core No courses yet

3. Charging blends and manufacturer methods

   Charge zeotropic blends correctly and follow manufacturer charging charts and literature when the generic methods do not apply.

   Advanced No courses yet

Leaks & recovery

1. Leak detection

   Find and pinpoint leaks with electronic, ultrasonic, dye, bubble and nitrogen methods, and decide what to fix.

   Core No courses yet

2. Recovery, recycling and reclaim

   Recover refrigerant to the required levels, understand recycling and reclaim, and handle cylinders and records lawfully.

   CoreSafety-critical No courses yet

Refrigeration diagnostics

1. Refrigerant charge diagnostics

   Diagnose undercharge, overcharge, restrictions and non-condensables from pressures, temperatures and the temperature split.

   Advanced No courses yet

2. Compressor efficiency and failure analysis

   Test a compressor's pumping efficiency and work out why one failed before installing the next.

   Advanced No courses yet

Low-GWP refrigerants

1. A2L refrigerant fundamentals

   Understand mildly flammable A2L refrigerants, their GWP, and the codes and standards that govern their safe use.

   CoreSafety-critical No courses yet

2. A2L installation and service

   Install, evacuate, charge, leak-check and transport A2L systems with the tools and procedures the class demands.

   AdvancedSafety-critical No courses yet