Annual Fuel Utilization Efficiency Law and Legal Definition

According to 10 CFR 430.2 [Title 10 – Energy; Chapter II -- Department of Energy; Subchapter D -- Energy Conservation; Part 430 -- Energy Conservation Program for Consumer Products; Subpart A -- General Provisions], the term annual fuel utilization efficiency means “the efficiency descriptor for furnaces and boilers, determined using test procedures prescribed under section 323 and based on the assumption that all --

(a) Weatherized warm air furnaces or boilers are located out-of-doors;

(b) Warm air furnaces which are not weatherized are located indoors and all combustion and ventilation air is admitted through grill or ducts from the outdoors and does not communicate with air in the conditioned space;

(c) Boilers which are not weatherized are located within the heated space.”