Cutting-Edge Ultrasonic Clothes Dryer Studies

clothes dryer
Kerri-Ann Richard, ERS, for Zondits

Common household appliances like dishwashers, refrigerators, freezers, cooking equipment, and laundry equipment make up over 12% of the US residential energy consumption. Of that, clothes dryers alone account for about 4% of the total electricity use. Yet, it has not been until recently that there have been any significant changes in the technology that operates that equipment. In addition, only recently have US energy efficiency administrators established initiatives to support the advancement of and build a market for energy efficient dryers.

A recent paper presented at the AESP 26th National Conference on February 3, 2016, outlined how advances in heat-pump clothes dryer technology results in significant energy savings. The study established baseline energy usage through field studies in the Northeast and Pacific Northwest. Data was compared with energy usage of ENERGY STAR qualified dryers that use heat-pump technology. Results demonstrated that potential savings are higher than the 30%–40% savings as estimated by ENERGY STAR.

Cutting-edge “ultrasonic” clothes dryer studies are currently underway in Tennessee, where the DOE is partnering with Oak Ridge National Laboratory to develop a system that uses 70% less energy than standard clothes dryers. Essentially, this technology takes the heat out of the drying process and uses an amplified electric current to vibrate the water out of clothes. Besides the considerable efficiency gains, benefits include reduction in drying time (50%), less wear and tear on the clothing, and a reduced amount of lint disposal. In addition, the cool mist released during the drying process could be an opportunity for water reclamation.

As with any developing technology, success is dependent on the funding and support from the public and private sectors. Researchers are just scratching the surface of potential energy efficiency opportunities in drying clothes, and it seems that with the right backing the US could emerge as the industry leader.

Energy Dept., GE Cook Up New Green Biz Opportunities

Triple Pundit, May 23, 2016

Building a better clothes dryer

The basic idea behind the new clothes dryer efficiency research is to remove heat from the clothes-drying process, and replace it with high-frequency vibrations. In effect, the ultrasonic vibrations “atomize” water in the fabric. Instead of being released as hot steam, water exits the fabric in the form of a cool mist.

So far, Oak Ridge and GE have proven the new technology in principle. The plan is to scale it into a working device by the end of this summer, with the expectation that the new dryer will take less than half the normal time and use 70 percent less energy.

Those two factors also work strongly in favor of adoption in the commercial sector. Public laundries, for example, would see a higher customer turnover per machine while reducing bottom-line operating costs. The high turnover/lower cost equation would also apply to institutional laundries.

Dude, where’s my piezoelectric transducer?

The key to the new technology is a device called a piezoelectric transducer, which sounds like it could be second cousins with a continuum transfunctioner except that, unlike the continuum transfunctioner, piezoelectric transducers are real.

Piezoelectricity refers to the ability of certain materials to generate an electrical current when exposed to mechanical stress. You probably interact with piezoelectric technology every day without knowing it. Piezoelectric materials are deployed in many touchscreen devices, where your finger provides the stress. As deployed in the new dryer, the stress comes in the form of sound waves.

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