PNNL, under direction from DOE, conducted a screening analysis to determine the energy savings potential from the efficiency level for commercial HVAC and water-heating equipment listed in Standard 90.1-1999, as well as the potential from several higher efficiency levels. We estimated the annual energy consumption for each type of equipment, at various efficiency levels, through engineering building types in 11 U.S. locations. W also Conducted an economic analysis to identify the efficiency levels that would provide the highest value of economic benefits. From 2004 through 2030, the estimated national energy savings for the equipment meeting, the Standard 90.1-1999 efficiency levels is about 3.8 exajoules (EJ) (3.6 quads).(1) The total estimated carbon emissions reduction is 52 MMtons.