Field measurements of interactions between furnaces and forced-air distribution systems.

Measurements on three gas and two electric furnaces have been made to examine the field performance of these furnaces and their interactions with their forced-air distribution systems. The distribution systems were retrofitted as part of this study, and the impact of retrofitting on furnace performance is discussed. In addition to field measurements, this paper discusses how forced-air furnace systems are treated in proposed ASHRAE Standard l 52P and applies the resulting equations to the systems tested in the field. The distribution system calculations in Standard l 52P are compared to the current methods employed in the "Furnaces" chapter of the 1996 ASHRAE Handbook-HVAC Systems and Equipment, showing how distribution system efficiencies calculated using Standard l 52P can be incorporated into the Handbook.