S33 -- Furnaces (SI)

Furnaces are self-enclosed, permanently installed major appliances that provide heated air through ductwork to the space being heated. In addition, a furnace may provide the indoor fan necessary for circulating heated or cooled air from a split or single-package air conditioner or heat pump (see Chapter 10 of the ASHRAE Handbook -- HVAC Systems and Equipment). Components Heat Source Types Commercial Equipment Controls and Operating Characteristics Equipment Selection Calculations Technical Data Installation Agency Listings