Clothes dryers consume energy for both mechanical activities and the drying process. The majority of the energy used is for drying. Both machine energy and drying energy are directly dependent upon the number of loads dried. To estimate the energy consumption of these appliances, Equations 15 and 16 use the calculation method described by Wenzel et al. (1997).

 

EC_f = ME + DE           Equation 15

            where

            EC_f = Annual energy consumption for fuel f

            ME = Machine energy (kWh/year)

            DE = Drying energy in utility units (kWh/year or therms/year)

Energy consumption is portrayed in “utility units” for each fuel type; the electric utility is kWh, natural gas utility unit is therms,