HVAC contractor requirements in North Carolina.

HVAC is licensed by the State Board of Examiners of Plumbing, Heating and Fire Sprinkler Contractors under Article 2, with no project-value threshold. G.S. 87-21 defines heating group number one as steam, vapor or hot water comfort heating with its piping, ducts and mechanical equipment; group number two as an integral heating or cooling system with a mechanical refrigeration capacity in excess of fifteen tons that circulates air; and group number three as a direct heating or cooling system of fifteen tons or less using electric elements or products of combustion through ducts.

The single-family carve-out is the fact that trips people up. The statute says systems installed in single-family residences are included under heating group number three regardless of size. A twenty-ton system in a large house is still H-3 work; a twenty-ton system in a small office is H-2 work.

Ground-water and domestic-hot-water coil systems split across two licenses on purpose: extending piping from valved connections in the domestic hot water system to a heating coil requires a plumbing or group one license, while installing the coil, duct work, controls, drains and appurtenances requires a group one or group three license. Separately, commercial and industrial refrigeration — as opposed to comfort cooling — is a different board entirely, the State Board of Refrigeration Contractors under Article 5.