Steam: Water in vapor form; used as the working fluid in steam turbines and heating systems. Also see District heat .
Steam coal: Coal burned, primarily in boilers, to generate steam for the production of electricity or for process heating purposes, or used as a direct source of process heat. Steam coal, also known as thermal coal, refers to all coal not classified as coking (or metallurgical) coal. See coal grade.
Steam or hot water radiators or baseboards: A distribution system where steam or hot water circulates through cast-iron radiators or base boards. Some other types of equipment in the building may be used to produce the steam or hot water or it may enter the building already heated as part of a district hot water system. Hot water does not include domestic hot water used for cooking and cleaning.
Steam or hot-water system: Either of two types of a central space-heating system that supplies steam or hot water to radiators, convectors, or pipes. The more common type supplies either steam or hot water to conventional radiators, baseboard radiators, convectors, heating pipes embedded in the walls or ceilings, or heating coils or equipment that are part of a combined heating/ventilating or heating/air-conditioning system. The other type supplies radiant heat through pipes that carry hot water and are held in a concrete slab floor.
Steam turbine: A device that converts high-pressure steam, produced in a boiler, into mechanical energy that can then be used to produce electricity by forcing blades in a cylinder to rotate and turn a generator shaft.