Estimating Commercial Clothes Washer Use in California Coin Laundry Stores

The LightWash program, in collaboration with California water utilities, provided rebates for over 8,000 high efficiency “family-sized” commercial clothes washers throughout the state of California from 2002 through 2005. Aside from a small number of studies on a limited number of washers (Tomlinson 1998; Sullivan 2000; Durfree 2001; FEMP 2002; Sullivan 2004), there is a dearth of publicly available information on the actual frequency of use (i.e., “turns per day”) for commercial washers. However, energy impact estimates are directly proportional to how often the washers are used. Since this vital piece of information had the highest degree of uncertainty in the LightWash savings estimate, evaluation resources were focused on metering commercial washers to estimate the average number of turns per day per washer. In this study, a total of 77 washers across thirteen coin laundry stores in the Pacific Gas and Electric Company service territory were randomly chosen from the 2004/2005 LightWash program participant database. The washers were metered for a two-week period in 2005 using the watts up? Pro data logger. The average number of turns per day was found to be 2.97 ± 0.70 at the 90% confidence level, roughly half of the number presumed by the program for washers in commercial laundromats.