definition
strict definition
coal heating
A building heating system that burns coal on the site and distributes the resulting heat, normally through air ducts.
A coal heating system provides heat to a building by burning coal in an oven and distributing it, normally by forcing air through ducts reaching various points in the building.
Coal is burned to provide the building heat. Merely storing coal or obtaining electricity from a coal-fired power station does not establish this heating type.
Air ducts are the normal distribution method stated here, rather than a requirement for every coal-heated building. The combustion source distinguishes it from gas or oil heating.