The Time is Ripe for Paying Attention to Clothes Drying Technology and Policy in Relation to Efficiency and Drying Time

摘要

The time it takes for a clothes dryer to dry a load of laundry is important to consumers.rnOn a heavy laundry day, many consumers expect the drying to be completed by the time thernwashing is done in order to quickly run one load after another. To assess the efficiency of dryerrntechnologies with respect to drying time, we tested a variety of North American and Europeanrndryers. Further, we modified a conventional dryer to include exhaust air-to-air heat exchangerrntechnology. We found various energy-efficient dryer technologies can have significant impactsrnon drying time. Unvented heat pump dryers, which can use 50 to 60 percent less energyrncompared to conventional electric dryers, take two to two-and-a-half times as long to dry.rnAnother efficient dryer technology is an exhaust heat exchanger that uses waste heat coming outrnof the drum to preheat incoming air. This technology can reduce energy use by about 20 percentrnand actually reduces drying time. Another method of saving significant amounts of energy isrnrunning the dryer in no-heat mode much of the time, saving about 25 percent of energy use butrntripling the drying time. Automatic termination saves approximately 15 percent of energy andrndecreases drying time. Natural gas dryers provide a cost-effective way of reducingrnenvironmental impact with fast drying, while vented heat pump and radiofrequency dryersrnrepresent promising emerging technologies. With increased network capability coming to thernmarket, some of these energy saving options could be turned on or off through softwarernupgrades.