HVAC Excellence Master AC study plan

Define pressure, temperature, enthalpy, and entropy in your own words and write a one-page glossary that ties each term to a component in a vapor-compression circuit.

Trace a complete refrigeration cycle on a blank pressure-enthalpy diagram, labeling the compressor, condenser, metering device, and evaporator state points with approximate pressures and temperatures for R-410A and R-32.

Calculate superheat and subcooling from four sets of gauge and line temperatures, showing each step of the arithmetic.

Explain the difference between sensible and latent heat and give two field examples of each in an air-conditioning system.

Classify R-410A, R-32, R-454B, R-466A, R-290, and R-1234yf by ASHRAE 34 safety group and state the flammability and toxicity basis for each classification.

Compare the GWP of these refrigerants against R-410A and explain why the AIM Act and the Kigali Amendment drive the transition to A2L and A3 alternatives.

Identify the four components of a refrigerant cylinder label and explain what each tells a technician before charging.

Describe how glide affects charging and coil performance for a zeotropic blend and identify where the bubble and dew points appear on a gauge manifold.

Draw and label a ladder diagram for a call for cooling that includes a thermostat, contactor coil, compressor, condenser fan, and a low-pressure safety switch.

Apply Ohm's law and the power formula to solve eight circuit problems involving resistance, current, voltage, and wattage.

Explain the operating sequence of a potential relay and a current relay in single-phase compressor starting, and describe what a failed run capacitor does to amp draw.

Read a manufacturer wiring diagram and trace the path from the low-voltage transformer through the safety circuit to the contactor.

Describe the control strategies used in a variable-speed ECM blower and a variable-frequency compressor drive, including how each communicates with a thermostat or board.

Explain how to measure and interpret delta-T, delta-P, and static pressure across an air handler to diagnose airflow and refrigerant-side faults.

Use a psychrometric chart to plot entering and leaving air conditions and determine sensible heat ratio for two sample systems.

List the data points a technician should record during a commissioning or performance check and explain what each reveals about system efficiency.

Calculate required airflow using the sensible heat equation and verify the result against a measured temperature rise or drop.

Perform a manual duct sizing exercise for a trunk and three branches using equivalent length and friction rate, and explain how fitting losses change the result.

Describe the causes and field measurements for duct leakage, and explain how a duct blaster test is set up and interpreted.

Explain how building envelope air sealing, insulation, and window performance affect manual J load calculations and equipment sizing.

Outline the safe handling procedure for A2L refrigerants, including PPE, ventilation, leak detection, recovery, and charging, and state how it differs from A1 practice.

Explain the ignition risk characteristics of A3 refrigerants such as R-290 and the charge limits and mitigation requirements that apply to their use.

Describe the correct procedure for recovering refrigerant from a system and for handling a cylinder that has been overfilled or heated.

Identify the sections of ASHRAE 15 and 34 that govern refrigerant concentration limits, machinery room requirements, and cylinder storage.

Explain the difference between a manual J load calculation, a manual S equipment selection, and a manual D duct design, and describe what happens when one is skipped.

Calculate a simple payback and a life-cycle cost comparison for two equipment options with different SEER2 ratings and installed costs.

Describe the major categories of an energy audit (envelope, HVAC, lighting, plug loads) and the instrumentation used for each.

Explain how refrigerant choice, equipment efficiency, and building envelope interact to determine a home's overall energy performance.

Complete a timed 100-question practice set across all five domains and record your score by domain.

Review every missed question and write a one-sentence correction for each, citing the underlying principle rather than the answer.

Re-derive the psychrometric, airflow, superheat, and subcooling calculations from memory without notes.

Recite the safety group, GWP, and handling requirements for the six most common refrigerants without reference materials.