A modular laundry system comprises a first laundry appliance and a second laundry appliance horizontally arranged relative to the first laundry appliance. In one embodiment, user interface information is communicated to a client via a communications network. Here the improvement comprises, using as the starting material, a mixture comprising HCC-250fb and Heavies generated from the reaction of CCl4 and ethylene to produce HCC-250fb, wherein the Heavies comprise one or more tetrachloropentane isomers.