Commercial Reverse Osmosis Solves Problems in Car Wash Spot Free Rinses

Spot free rinses offer car washes an opportunity to charge customers for additional services while increasing the perceived quality of the car wash. Every person who has had a car wash can relate to the frustration of leaving the facility to find that their vehicle is covered in unsightly white spots. The customers are left with perception that the car wash they received was of poor quality.

But what actually causes these spots that leave customers so frustrated? These spots are caused by dissolved minerals in the water. The water droplets that remain on the car after the wash contain dissolved minerals.

“The content of these minerals in the water is known as Total Dissolved Solids or TDS. The amount of TDS in the water is dependent on geographic and the source of the municipal water supply. Depending on where your car wash is located will determine how much TDS exists in your water. The higher the TDS the worse the spotting will be.”

As these droplet s of water evaporates, the minerals are left behind. These remaining minerals create unsightly white spots that can be difficult to remove once the vehicle is dry.

Now you must be asking, “What can I do about it?” There are three ways to prevent spotting after a car wash, each represents its own set of costs and advantages. The traditional way to remove spots is by hand drying afterwards. However, the employees and time required to hand dry each vehicle represents a much higher cost than other solutions. The most effective way to prevent spots is with a De-Ionization or DI system. These systems contain two types of resin that remove positively and negatively charged ions, resulting in mineral free water for a true spot free rinse. These DI systems come with a huge downside. The resins they contain must be regenerated often with hazardous chemicals. Most

commercial car washes are not equipped to perform this regular maintenance, as it requires specialty equipment, and disposal techniques. Most commercial car washes rely on an expensive service to swap their system with a newly regenerated one, so they can take the system to their facility to maintain. The third option is a commercial reverse osmosis or RO system. These commercial reverse osmosis systems have seen an increase in popularity as an alternative to DI systems. These RO systems can mechanically remove 95-99% of the mineral content in water, making them more than suitable for a car wash spot free rinse application. A commercial reverse osmosis system also requires only minor maintenance, that can easily be performed by the car wash staff. This maintenance consists of filter replacements at set intervals.

How Does Commercial Reverse Osmosis Work?

Now that we have discussed the various options available to you, let’s dig a little deeper into how a commercial reverse osmosis or RO system works. An RO system uses a process called reverse osmosis to remove a massive amount of contaminants from water. RO utilizes a membrane made out of an extremely thin film that is tightly wound around a core tube. Water pressure is used to force water through this tightly wound film. As the water is pushed through the film, pure water is collected into the core tube, while the remaining concentrated contaminated water is discharged through a drain line. The water that is discharged can be collected and reused for other applications. Commercial reverse osmosis requires a series of stages in order to increase life of components and ensure quality water on demand.

  • Stage 1 Pre-Filtration: The pre-filter, or sediment filter on a reverse osmosis (RO) system is designed to remove large particles from incoming water to protect the further stages from being exhausted too quickly. Without a pre-filter the carbon filters and membrane would become plugged with fine particles, resulting in reduced water flow and efficiency, and inevitably no output.
  • Stage 2 & 3 Carbon Filtration: Carbon filtration plays an even more important role in a reverse osmosis system. The semi-permeable membrane used in a commercial RO system are vulnerable to chlorine and chloramines. These chemicals are introduced by your city water supply will quickly destroy your membrane. Therefore, carbon filtration is required to remove chlorine and chloramines prior to the water coming into contact with the membrane. Typically two carbon filters will be placed before the membrane. The first carbon filter removes up to 99% of chlorine and chloramines, and the second carbon filter removes the majority of trace chlorine, and acts as a backup in case the first filter becomes exhausted.
  • Stage 4 Semi-Permeable Membrane: We discussed the role that a semi-permeable membrane earlier in this section. These membranes use an ultra-purification technique called reverse osmosis. Incoming water builds up pressure behind the membrane, forcing water through the multiple layers of wrapped membrane. The tight layers of the membrane allow water molecules to pass through, but restrict passage to other molecules, such as those that make up dissolved minerals, chemicals and organic matter. Semi-permeable membranes are rated on production and efficiency. Production is typically measured by gallons per day. It will need to be determined how much water you are using each day to adequately size the system for your car wash.
  • Storage Tank: Due to the low production rates achieved by reverse osmosis a storage tank will be required to house purified water. This will allow for the volume and pressure required to provide instantaneous access to water in enough quantities for your spot free rinse application. Once it is determined how much water your car wash will consume daily in a spot free rinse application, an adequately sized storage tank will be selected to ensure the highest quality water is available at all times.
  • Booster Pumps: Typically, your incoming water supply is not going to provide enough pressure for your spot free rinse application. A booster pump is usually required to produce adequate pressure from the storage to the sprayer assembly.
    Please follow this link to get a better idea of what a commercial reverse osmosis system assembly would look like for a car wash spot free rinse application.
Required Maintenance for a Commercial RO System

One of the biggest advantages of a commercial reverse osmosis system is that they require very little maintenance when compared to alternatives. Your installer will provide you with a replacement schedule based on the quality of water and your estimated daily use. The scheduled maintenance will include pre-filter and carbon filter changes at a specified gallon or month interval. Many commercial RO systems also contain a built in TDS meter. These meters detect the total dissolved solids in the water after it has been treated by the RO. Over time the membrane will become exhausted and the level of TDS will begin to increase. This will be your indicator that it is time to replace the membrane.

How will a Commercial Reverse Osmosis System Save My Car Wash Money?

A commercial RO system can help your car wash save a ton of money. These systems typically pay for themselves within a year. Some of the ways that a commercial reverse osmosis system can you’re your car wash reduce costs are:

  • Compared with alternatives there is very little ongoing maintenance required for a commercial reverse osmosis system, and required maintenance is a relatively low cost.
  • No toxic chemicals required to regenerate the system like with DI. No expensive regenerating equipment and disposal costs, or the ongoing cost of a service to regenerate the system. Over time this represents an enormous cost savings.
  • A commercial reverse osmosis system produces adequate quality of water for a spot free rinse, therefore you will save money by not requiring additional personnel to hand dry cars to prevent spotting.
  • A spot free rinse is an additional service that customers are willing to pay for. You will be able to make more money per car wash by providing this service.
What Are My Next Steps in Selecting a Commercial Reverse Osmosis System for my Car Wash?

The best next step is to have your water tested, so that your incoming TDS can be determined. We provide free water testing (link to water testing instructions) for all commercial applications. Once your water quality is known, and your daily water use is calculated, a daily production and storage can be determined for your specific application. If you need additional assistance, please give us a call at 602- 414-0701, or drop us a line below.