Sustainable Energy

This Dryer Blasts Water Out of Fabric with Sound Waves

An ultrasonic dryer can extract moisture from your clothes faster and more efficiently than heat.

Apr 19, 2017

Forget heat—drying laundry is about cranking up the volume. At least, that’s how it goes in a lab at Oak Ridge National Laboratory, where researchers have built an ultrasonic clothes dryer that uses far less energy than conventional devices.

If you can be bothered to find out, you’ll find that clothes dryers are hugely energy hungry. A 2014 report by the Natural Resources Defense Council suggested that a typical household’s dryer used as much energy over the course of a year as its refrigerator, dishwasher, and clothes washer combined. Dryers account for as much as 4 percent of all domestic energy consumption, according to the Energy Information Administration.

That didn’t escape the attention of Oak Ridge’s Ayyoub Momen, who has been developing a new way to wrench moisture out of fabric over the last few years. His vision: a clothes dryer whose drum is lined with piezoelectric ultrasound transducers to blast laundry with high-frequency sound rather than heat.

The theory is that the ultrasound vibrates small water droplets out of a piece of fabric, forming a fine mist—as you can see happening in the GIF above. The mist is then driven to the edge of the drum, where it can be siphoned off, much the way it would happen in a regular dryer.

A prototype built by Momen and his colleagues shows that it seems to work in practice. The full-size dryer his team assembled is able to dry a medium-size load in 20 minutes, compared with 50 minutes for a regular machine. It’s also claimed that the device uses 70 percent less energy than a regular dryer.

And the good news is that this isn’t idle research. The project was carried out in collaboration with General Electric Appliances, which is now planning to use the ultrasonic approach in a press dryer and, at some point in the future, a regular drum dryer. So you might soon be able to turn up the volume on your laundry, too.

(Read more: Office of Energy Efficiency & Renewable Energy, BBC)