WW-F-2743A, FEDERAL SPECIFICATION: FURNACES, WARM AIR AND HEATERS, UNIT, FORCED AIR CIRCULATION, OIL- AND GAS-FIRED (27 MAY 1998)

WW-F-2743A, FEDERAL SPECIFICATION: FURNACES, WARM AIR AND HEATERS, UNIT, FORCED AIR CIRCULATION, OIL- AND GAS-FIRED (27 MAY 1998)., This specification covers self-contained, forced-circulation, air heating units designed to distribute warm air for heating purposes either through a duct system for central furnaces or by direct diffusion for unit heaters.