Laundry equipment such as washers and dryers are always evolving, becoming smaller, quieter and more efficient. But throughout centuries of clothes laundering history, the use of one ingredient—water—is necessary to clean clothes and other fabrics.

That changed in 2008, when researchers at the School of Textiles, University of Leeds, U.K., developed a concept “waterless” washer. Machines like this one are usually called “almost-waterless” or “nearly waterless” because they need a small quantity of water to operate. The Leeds design uses about a cup per load, so compared to commercial machines that need at least a dozen gallons per load, it’s very close to waterless.

The Leeds researchers stumbled upon the new technology while investigating new ways to apply fabric dyes using polymers. They theorized that if polymer beads could anchor dye to fabric, they could also be effective in removing stains. The group’s research showed that nylon beads—which are resilient and highly absorbent in humid conditions—are ideal for this purpose and proposed the development of “polymer bead cleaning.” Leeds University spun off the Xeros company to commercialize the technology.

The Xeros Machine

The Xeros system replaces hot water with a significant quantity of polymer laundry beads. The beads come into contact with dirty fabrics via agitation, and stains are transferred from the fabric to the beads. The beads then absorb the stain.

The Xeros washing machine looks similar to a traditional machine, but it functions more like a bead circulation system. The machine stores beads in a wet sump housing low in the machine. A pump pushes a certain amount of beads into a drum using a small amount of water. After the beads enter the drum, the water returns to the sump for reuse. The beads mix with laundry in the drum, which agitates to allow the beads to massage stains out of the fabrics.

The basics of polymer bead cleaning. Image credit: Xeros

During the wash cycle, beads are continually transferred out of the drum and back into the sump area, where they are cleaned and reused in a later cycle. The machine then rinses the laundry with a small amount of water and finishes the wash cycle.

Xeros says that the waterless washing machine reduces or almost eliminates both detergent and water, two resources common to conventional machines. Also, because water is only lightly used in the rinse cycle, clothes come out nearly dry, reducing the need for heated drying.

The Future of Waterless Washing

Will waterless washing eventually translate to home use? So far, this remains to be seen. Some commercial laundry customers—such as the hotels, athletic clubs and third-party linen services highlighted on Xeros’ site—have employed waterless washing machines on a large scale and have reaped significant water savings. Cost is a major barrier to indvidual waterless washing, and while the Xeros machine may cost less to run through water, detergent and dryer energy savings, this savings must balance with its up-front and maintenance costs.

There are other questions and concerns about polymer bead cleaning aside from financial costs. Washing with water removes not only stains, but also dust, allergens, mold spores and other potentially unhealthy contaminants. It is doubtful that washing with little water and heat, as in polymer bead cleaning, could remove these contaminants as effectively as a conventional machine.

While the Xeros machine is the first true nearly waterless washer to see effective commercialization, there have been other developments that might also be considered by some as “waterless.” South Korean manufacturer LG rolled out its Styler in 2013. The Styler looks like a combination between a thin closet and a refrigerator. Clothes are hung inside and the machine uses steam to blast away odors, smooth wrinkles and “clean” the garment in about 20 minutes. Like the Xeros machine, however, there is doubt as to how effectively the Styler cleans. LG shows that 60-80 minutes in the Styler results in ~90% allergen reduction, about 25% greater than 3 hours of sunlight exposure.

Polymer bead cleaning and other waterless washing technologies are novel ways to reduce dependence on one of the planet’s most valuable resources. For now, though, they seem most useful for large-scale applications.