NC HVAC study guide
NC HVAC · Work through your exam, one topic at a time.
The North Carolina HVAC contractor license is a state credential that lets a business legally bid, install, and service heating, ventilation, air conditioning, and refrigeration work in North Carolina. It is issued at the business level, so the qualifying individual demonstrates technical competence on behalf of the firm they represent. The NC HVAC study guide has 9 sections and about 2,607 words.
01Heating, Ventilation, and Air Conditioning Systems and Equipment
A candidate must be able to describe how each major system moves heat and air, and when each is appropriate. Know the difference between a gas-fired forced-air furnace, an electric resistance air handler, a hydronic boiler with terminal units, a heat pump (air-source and ground-source), and packaged rooftop equipment.
321 words, about 2 min02Refrigeration Principles and Components
Understand the vapor-compression cycle: compressor raises pressure and temperature of vapor; condenser rejects heat and subcools liquid; metering device drops pressure and temperature; evaporator absorbs heat and superheats vapor before returning to the compressor. Know the four major components and their accessories: filter-driers, accumulators, receivers, sight glasses, TXVs versus fixed orifices, and reversing valves.
289 words, about 1 min03Load Calculations and System Sizing
Manual J (residential) and Manual N (commercial) load calculations determine heating and cooling loads from envelope, orientation, internal gains, infiltration, and ventilation. Manual S selects equipment based on sensible and latent capacity, not just nominal tonnage.
309 words, about 2 min04Ductwork and Air Distribution
Understand static pressure, velocity, friction loss, and equivalent length. Know the difference between return, supply, and transfer air, and how duct design affects fan performance.
299 words, about 1 min05Electrical and Controls
Know basic electrical theory: Ohm's law, series and parallel circuits, AC power, and the difference between line and low voltage. Understand motor types (PSC, ECM), contactors, relays, transformers, capacitors, and defrost boards.
286 words, about 1 min06Fuel Gas and Combustion Safety
Understand combustion: fuel plus oxygen yields heat, water vapor, and carbon dioxide, with carbon monoxide as a product of incomplete combustion. Know gas piping basics: sizing, pressure (natural gas vs.
278 words, about 1 min07North Carolina Building and Mechanical Codes and Licensing Regulations
Know the structure of the NC codes: the NC Building Code, NC Mechanical Code, NC Fuel Gas Code, NC Energy Conservation Code, and NC Plumbing Code, all based on the International Codes with state amendments. Understand permit and inspection requirements, licensing through the NC State Board of Examiners of Plumbing, Heating, and Fire Sprinkler Contractors, and the classifications of HVAC licensure.
309 words, about 2 min08Business, Contract, and Project Management
Understand estimating (labor, material, equipment, overhead, profit), change orders, and contract types (fixed-price, time and materials, cost-plus). Know lien rights and the importance of written contracts, scope, and payment terms.
258 words, about 1 min09Safety and Environmental Practices
Know OSHA and NC safety requirements: PPE, lockout/tagout, fall protection, confined space, and electrical safety. Understand refrigerant handling under EPA Section 608: certification, recovery, recycling, evacuation levels, and prohibitions on venting.
258 words, about 1 min