Basic ACDP
Natural Gas and Propane Fired Boilers (with or without #2 diesel oil back-up(a)) of 10 or more MMBTU but less than 30 MMBTU/hr heat input constructed after June 9, 1989. (a) “back-up” means less than 10,000 gallons of fuel per year.
General ACDP
Oil fired ≥ 10 million Btu/hr and natural gas fired ≥ 30 million Btu/hr heat input.