HVAC is an industry, not a license.
There are many different licenses people in the HVAC industry can hold. This includes:
LicenseAuthority HHeatingGas Technician or Oil BurnerTechnical Standards and Safety Authority (TSSA) VVentilationSheet Metal MechanicSkilled Trades Ontario (STO) ACAir ConditioningResidential AC Systems Mechanic 313DSkilled Trades Ontario (STO) RRefrigerationRefrigeration and AC Systems Mechanic 313ASkilled Trades Ontario (STO)  OtherPlumber and ElectricianSkilled Trades Ontario (STO)
All licenses regulated by Skilled Trades Ontario (STO) require a 3 - 5 year apprenticeship. However, the Heating licenses regulated by TSSA are not apprenticeships. You can complete an approved course, pass your TSSA exams with a minimum of 75% and be fully licensed.