OH HVAC Contractor study plan

Build a one-page psychrometric and refrigeration-cycle reference sheet linking dry-bulb, wet-bulb, dew point, superheat, subcooling, and saturation states to the components that produce them.

Calculate superheat and subcooling from six self-made gauge and thermometer readings, showing every step, and verify each answer against a second method.

Sketch and label a split-system and a commercial refrigeration circuit from memory, naming compressor, metering device, evaporator, condenser, and each safety control in the order of refrigerant flow.

Explain in writing how airflow, charge, and metering-device selection each shift superheat and subcooling, and predict which direction each reading moves when one variable changes.

Size a heating and cooling load for a small single-family house using a manual method, documenting wall, window, infiltration, and internal-gain assumptions.

Select equipment and duct sizing for that load, then check static pressure and airflow against the selected blower performance table.

Diagnose five written fault scenarios covering low charge, restricted filter, failed capacitor, bad TXV, and shorted control board, listing the measured symptom and the confirming test for each.

List the combustion-safety and venting checks required on a gas furnace startup, including flue-gas analysis limits and heat-exchanger inspection steps.

Calculate fixture units and convert them into minimum supply and drain sizes for a two-bath house, citing the applicable code table logic.

Lay out a DWV system on paper, assigning trap arms, vents, and cleanouts, and verify each vent is sized and connected correctly.

Size a domestic water distribution system for pressure and friction loss, showing the longest-run calculation and the resulting pipe sizes.

Explain the difference between a backflow preventer, a vacuum breaker, and an air gap, and match each to a specific installation scenario.

Compute heat loss for a hydronic zone and select boiler output, circulator head, and pipe size, showing the pump-curve intersection.

Diagram a primary-secondary hydronic loop and identify where air elimination, expansion control, and isolation valves belong.

Compare series-loop, zone-valve, and manifold balancing approaches and justify one choice for a two-story house.

Describe the required safeguards for a boiler installation, including relief valve, low-water cutoff, and combustion air provisions.

Compute branch-circuit and feeder loads for a residential service using demand factors, and state the resulting service size and conductor ampacity.

Size overcurrent protection and conductors for a heat pump, air handler, and electric strip heat, applying the motor and appliance rules and the correct temperature-derating and conduit-fill adjustments.

Draw a ladder diagram for a call-for-heat and call-for-cool sequence with a transformer, thermostat, contactor, and fan relay, then trace the circuit path aloud.

Explain grounding, bonding, and equipment-grounding-conductor requirements for HVAC equipment, including disconnects and flexible connections.

Measure and interpret voltage, current, resistance, capacitance, and microamp draw on live and de-energized circuits, and describe the safe meter setup for each.

Diagnose six written electrical faults in HVAC equipment, naming the test point, expected reading, and corrective action for each.

Explain the function and failure modes of contactors, relays, capacitors, thermostats, and variable-frequency drives used in HVAC equipment.

Identify lockout/tagout, arc-flash, and personal protective equipment requirements that apply to servicing HVAC electrical components.

Outline the licensing structure under Ohio Revised Code Chapter 4740, distinguishing the contractor license from the tradesman and journeyman credentials and stating what each permits.

Summarize the application, examination, bonding, insurance, and renewal requirements a contractor must satisfy, and list the records a licensee must retain.

Describe the complaint, investigation, hearing, and disciplinary process, including the range of sanctions available to the board.

Explain continuing-education obligations and the consequences of unlicensed practice or contracting outside the licensed scope.

Take two full-length timed practice exams under test conditions and log every missed question by domain and error type.

Re-study the three weakest subareas from the error log and rewrite those concepts in your own words without notes.

Rehearse the calculation types most likely to appear, completing one load, one pipe-sizing, one hydronic, and one electrical calculation cold.

Confirm exam-day logistics, including identification, scheduling, and permitted reference materials, and build a final one-page formula and code-reference sheet.