Professional Carwashing & Detailing

The science of spot-free

July 1, 2011

Without the proper rinse, a carwash is a wasted venture. A faulty rinse will leave spots galore on exiting cars, and customers that end up seeing spots are soon seeing red. As a carwash owner, if your customers end up leaving angry with spotty, speckled cars, you will soon be seeing red too — red numbers on your profit sheets caused by deserted carwash bays.

The easiest way to guarantee customers a spot-free final rinse is by using an up-to-date reverse osmosis (RO) system. For decades, RO filtration technology has been used in carwashes, and, with technological advances in the field, today’s RO systems are more efficient and more cost-effective than ever before.

Spot-free science

The RO filtering process works because it actually strips the water of minerals and other impurities, according to Gary Hirsh of New Wave Industries. RO filtration forces water to pass through a semi-porous membrane using pressure, and the result is pure, mineral-free water. This pure water will not leave hard-to-remove mineral deposits on a car when it dries.

Brian Dohm of Reclaim Equipment Co. agreed that, with pure water, glass, chrome and painted surfaces should all dry perfectly spot-free. “Water that’s gone through an RO system will come out usually about 98, 99 or better percent pure. And anything that won’t go through the pores of the membrane…will get filtered out,” Dohm said. “I guess you could call it ultra-fine (filtration), but it’s finer than that.”

Dohm said the main benefit of incorporating an RO system into a self-serve or IBA carwash is the elimination of time-consuming hand drying. “It’s all about delivering your customer the optimum carwash experience, a reverse osmosis system/final spot-free rinse may be one of the best tangible features an operator offers to their customer.”

Modern improvements

RO filtration was first introduced to the professional carwash industry more than 25 years ago, but the process was initially inefficient and expensive, according to Hirsh. Since that time, RO technology has advanced significantly. “The current systems are professionally engineered and incorporate highly efficient membrane technology, automatic membrane flush and water recirculation features that have significantly reduced energy, water usage and cost of ownership while increasing water quality,” Hirsh said.

Dohm gave one example of how early RO systems were not efficient. Previously, the water had to be tempered, or heated, to 77 degrees, the optimum temperature for processing. Today, cold-friendly membranes are more efficient. “They are basically a cold water membrane, so you can use cold water and get higher output and cleaner water,” he continued. “So they’ve come a long way in the past 20 years.”

Dohm listed three specific improvements that make modern RO systems more efficient than their predecessors:

  • Recirculation;
  • Monitoring; and
  • Back flush.

On new RO systems, the recirculation feature allows users to make more water usable by taking a portion of the water and running it through the filter again. Newer systems also offer better monitoring. Dohm explained that many now have TDS meters so operators can monitor the quality of the water exiting the filters. This lets the operator know when the membranes aren’t operating efficiently. Finally, back flush lets users clean the membranes simply by flushing them with a volume of water. When water is flushed over the sides of the membranes, unwanted particles go down the drain, and the rejected water from the system is stored and used for other applications.

Taking the plunge

When it’s time to purchase a new RO system, Dohm said the first step is accurately calculating how many gallons of water your wash is actually going to use. This includes figuring out how many cars a day a location is going to wash. Using this information, an owner can get an accurate idea of what size RO system the carwash needs. “Sizing…is probably the most important thing,” Dohm explained. “You know you always want to be a little over, you don’t want to be under.”

In the past, many carwash owners have ended up buying a system that is too big for their location. Dohm recommended using common sense when it came to system sizing, and he said finding the right size system eliminates the need for excessive water storage. “That’s typically what we’ve found when we go into a site is an RO system that is twice as big, and they’ve got storage for the next week and a half.”

From there, Dohm said owners should choose what options they want on their RO system. A basic system is available “that has nothing on it,” while others offer a few options like TDS meters.

Hirsh said a good first step when purchasing a new system is education. “Educate yourself by understanding the technology and select a recognized manufacturer that can provide you with local factory-trained representation for professional installation, on-site training as well as any future, required after-sale service.”

Keeping it clear

Even with a new and improved system, there will be some upkeep involved to keep the clear water flowing. Owners should regularly monitor water quality and always perform preventive maintenance. Hirsh said if owners follow the manufacturer’s recommended maintenance schedule, an RO system should provide many cost-effective years of service.

Dohm also said an RO system will last for many years as long as the water that goes into the system is cleaned and filtered. “Basically, you’d run (the water) through a softener, depending on how many grains of hardness your water has,” he explained. “And after the softener, then you would go through a carbon filter which should remove any chlorine that would be in the water, because chlorine will ruin a membrane. And after the carbon filter, you’d usually go through a five micron filter.” From there the water enters the RO system pump and is pressurized for the membranes.

“That’s typical,” Dohm continued. “There are some … water conditioners, which some work and some don’t. You know there’s some copper zinc blends of metal that attract the magnesium and the calcium that would be in the water. Some will stick to it and … supposedly it changes the properties of the water so that it will pass by the membrane and not foul it.”

Spreading the word

Communicating the benefits of RO water to customers can be a tricky proposition. Hirsh said owners should provide employees with an ongoing curriculum of equipment training so that they will better understand the purpose and process of all carwash components. This will educate them on the process of RO filtration, and it will assist the employee in effectively communicating the features and benefits of a spot-free rinse to customers.

But, Hirsh explained that owners can best educate their customers by placing effective signage throughout their wash site. The signs can promote how RO features improve the carwash experience and how its spot-free rinse will result in their entire vehicle drying perfectly clean and spot-free.