California and other states with hot dry climates need air conditioners that maximize indoor temperature reductions for the expended energy. This is particularly true at high outdoor temperatures. This study found that existing single speed air conditioners utilizing outdoor units, indoor coils, and furnaces selected to meet the performance standards set in the HDAC project can produce peak electrical power reductions and annual cooling energy savings of 20% and control modifications to the fan timing can reduce annual electric consumption and peak consumption an additional 9% to 17%, for total savings of 29% to 37%. For more information, please contact the sponsoring organization.