
Clothes Washers Performance Requirement for Federal Purchases Washer Capacity Modified Energy Factora 1.6 to 3.5 cu. ft. 1.42 or more a) Modified Energy Factor (MEF) is the number of cubic feet of clothes washed and dried per kilowatt hour (kWh) of electricity used. MEF is calculated by dividing the tub capacity by the total energy (clothes washer, water heater and dryer) used per wash load (10 CFR 430, sub-part B, Appendix J). Buying Energy-Efficient Clothes Washers When buying residential and