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 (rated maximum input) must be not less than 81 percent.