NATE Core study plan

Define and write from memory the core HVACR thermodynamic terms: sensible heat, latent heat, superheat, subcooling, saturation, and enthalpy, with a one-line plain-language definition for each.

Convert between Fahrenheit, Celsius, Rankine, and Kelvin for 20 practice values without a reference sheet.

Explain the standard vapor-compression cycle in order (compressor, condenser, metering device, evaporator) and state the pressure and state of refrigerant at each of the four points.

Calculate a basic heat load in BTUs using the sensible heat formula Q = 1.08 x CFM x delta-T, working 10 practice problems.

Identify and describe the function of the major system components: compressor types, condensers, evaporators, metering devices, and accessories such as accumulators and filter driers.

Distinguish among thermostatic expansion valves, fixed orifices, capillary tubes, and electronic expansion valves by operation and application.

Trace refrigerant flow through a full system diagram and label high-side versus low-side boundaries.

Explain the purpose of superheat and subcooling measurements and where each is taken.

Describe the properties and safe handling of common refrigerants, including R-410A, R-32, R-134a, and R-454B, noting pressure and glide differences.

Explain refrigerant classification (A1, A2L, A3, B1) and what each classification means for handling and leak response.

Outline the phaseout timeline and regulatory drivers behind refrigerant transitions at a high level.

Practice identifying refrigerant cylinders and their markings by description.

Explain the relationship among voltage, current, resistance, and power using Ohm's law and the power formula, and solve 15 practice calculations.

Describe the function of common electrical components in HVACR equipment: contactors, relays, capacitors, transformers, and motors.

Distinguish between series and parallel circuits and predict how a failed component affects circuit behavior.

Read a simple ladder schematic and identify the sequence of operation for a basic call for cooling.

Explain the function of the major controls and safety devices: thermostats, pressure switches, thermal limits, and defrost controls.

Describe airflow fundamentals, including static pressure, duct sizing basics, and the effect of restricted airflow on system performance.

Interpret a set of typical operating readings (suction and discharge pressure, superheat, subcooling, delta-T) and state whether the system is behaving normally.

Identify the symptoms of common faults such as undercharge, overcharge, restricted metering device, and dirty evaporator coil.

Describe combustion fundamentals for gas heating, including the combustion triangle, stoichiometry basics, and flue gas products.

Explain the purpose and process of combustion analysis, including what carbon monoxide readings indicate.

Outline the sequence of operation for a gas furnace from call for heat through ignition and blower operation.

Summarize safety practices for gas appliance service, including leak testing and ventilation requirements.

Consolidate tools and instruments knowledge: manifold gauges, micron gauges, vacuum pumps, recovery machines, and leak detectors, with their proper use.

Explain evacuation and dehydration procedures, including target micron levels and the reason for triple evacuation.

Describe recovery, recycling, and reclamation requirements and the recordkeeping obligations that go with them.

Outline personal protective equipment and safe work practices for refrigerant and electrical work.

Review all prior deliverables and rewrite any reference sheet or procedure card from memory without notes.

Complete at least 100 mixed practice questions across all Core topics and log every missed item with the underlying concept.

Re-study the three weakest concepts identified in the practice log until each can be explained aloud in under two minutes.

Simulate exam conditions with one timed full-length practice session and review the results.