[Code of Federal Regulations] [Title 10, Volume 3] [Revised as of January 1, 2005] From the U.S. Government Printing Office via GPO Access [CITE: 10CFR431.77] [Page 329-330] TITLE 10--ENERGY CHAPTER II--DEPARTMENT OF ENERGY PART 431_ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT--Table of Contents Subpart D_Commercial Warm Air Furnaces Sec. 431.77 Energy conservation standards and their effective dates. Each commercial warm air furnace manufactured on or after January 1, 1994, must meet the following energy efficiency standard levels: (a) For a gas-fired commercial warm air furnace with capacity of 225,000 Btu per hour or more, the thermal efficiency at the maximum rated capacity (rated maximum input) must be not less than 80 percent. (b) For an oil-fired commercial warm air furnace with capacity of 225,000 Btu per hour or more, the thermal efficiency at the maximum rated capacity [[Page 330]] (rated maximum input) must be not less than 81 percent.