The U.S. Department of Energy (DOE) is initiating an effort to consider amending energy conservation standards for evaporatively-cooled commercial unitary air conditioners (ECUACs) and water-cooled commercial unitary air conditioners (WCUACs). Once completed, this rulemaking will fulfill DOE’s statutory obligation to either propose amended energy conservation standards for this equipment or to determine that the existing standards do not need to be amended. To this end, DOE must determine whether national standards more stringent than those currently in place would result in a significant additional amount of energy savings and whether such amended national standards would be technologically feasible and economically justified.