MD HVAC study plan

Trace the four-stage refrigeration cycle on a blank diagram and label pressure/temperature at each state point

Calculate superheat and subcooling from given gauge and line-temperature readings

Match each major component (compressor, condenser, metering device, evaporator, receiver, accumulator) to its function and failure symptoms

Interpret a saturated pressure-temperature chart for at least three common refrigerants without looking at a key

Read a ladder schematic and identify line, load, control and safety circuits

Wire a contactor, relay and thermostat circuit from a written description

Use a multimeter to describe continuity, voltage and resistance test procedures in sequence

Diagnose three given electrical faults (open winding, bad capacitor, open safety) from symptoms alone

Explain how compressor electrical failure modes map to refrigerant-side symptoms such as low capacity or high head pressure

Sequence the startup and shutdown order of a system's electrical and refrigerant controls

Convert between resistance, current and voltage using Ohm's law in circuit-fault examples

Identify motor types, their starting components and typical failure points

Describe the combustion process and calculate steady-state efficiency from flue-gas temperature and CO2 readings

Sequence the ignition and safety lockout steps of a gas furnace from call for heat to steady operation

Compare gas, oil, electric and hydronic heating systems by efficiency range, components and service checks

Adjust and verify airflow and temperature rise on a forced-air furnace given a specification

Calculate sensible, latent and total heat loads and convert between cfm, Btu/h and temperature difference

Diagnose duct static-pressure problems and specify corrective action

Explain how ventilation rates and outdoor-air introduction affect indoor air quality and equipment load

Identify common IAQ contaminants and match each to a control strategy

Measure and interpret external static pressure, filter pressure drop and coil pressure drop in a described system

Outline refrigerant handling, recovery and evacuation procedures required by regulation

Identify installation clearances, venting, brazing and electrical disconnect requirements from code language

Explain licensing, insurance and recordkeeping obligations that apply to service work

Apply lockout/tagout and personal protective equipment selection to four given job scenarios

Calculate a service job estimate covering labor, parts and overhead recovery

Explain refrigerant, combustion and electrical safety hazard classes and required responses

Verify torque, brazing, leak-testing and evacuation steps against accepted practice before sign-off

Complete timed mixed-domain practice sets under exam conditions

Re-teach weak objectives from prior weeks using notes only, without reference materials

Consolidate formulas, charts and code references onto a single authorized reference sheet if permitted

Simulate full-length exam pacing and review every missed item to root cause