Let’s examine this mysterious, colorless gas.
One of the key advantages of ozone is that it keeps your store smelling fresh. If you’ve got a properly operating ozone system, you can be assured that, when a customer opens a machine, there will be no funky smell. There also will be no mold or mildew in the door gasket or soap dish. When you open your bulkheads, they will be clean and fresh-smelling. There will be no leftover residue and no excess smell from detergent, softeners and other chemicals. An ozone system can make your customers’ store visits seem like aromatherapy treatment.
Another advantage of ozone is the ability to clean in cold water. In fact, ozone actually gets consumed by water at about 110 degrees – so, if you’re mixing ozone with hot water, it will have virtually no use at all. Of course, cold-water cleaning has energy-saving and environmental advantages, which can provide owners with opportunities for rebates from their energy providers.
In addition, cleaning with ozone in cold water significantly reduces the amount of detergent and chemicals required – and increases the effectiveness of those chemicals. However, this sometimes can be a double-edged sword, as self-service customers are notorious for over-dosing their laundry with detergent. Unfortunately, such over-dosing can lessen ozone’s effectiveness.
In the cleaning world, ozone is referred to as a “wetting agent,” which means it opens up the fibers of a fabric to aid in the release of soils, as well as creating a natural softening effect. Ozone also will assist in reducing the fabric’s ability to retain moisture and, thus, reduce drying time.
Clearly, there are real benefits to utilizing ozone. However, there also are some chemical considerations when introducing it to your cleaning process.
First of all, ozone has no effect on oil-based stains. Ozone won’t remove any of those types of stains with any success. In fact, some oil stains will react to ozone by oxidizing and leaving behind a yellow stain. In general, cold-water cleaning – without certain types of chemistry – has no impact on oil-based stains.
A chemical dose in a warm or hot bath with no ozone is the best way to solve these types of stains. Fortunately, the chemicals with which ozone reacts poorly all work better in warm or hot water.
Those chemicals that negatively impact ozone are citrus-based cleaners and enzymes – both of which are ideal for attacking oils and greases. In fact, ozone will kill the enzymes and actually have a negative chemical reaction with citrus-based solvents.
Additionally, ozone and oxygen bleach cancel each other out. But you’ll notice that your ozonized cold rinses will be much more effective than bleaching. At my business, we’ve nearly eliminated bleaches from our chemical arsenal.
For typical, residential laundry loads, cleaning in cold water with a warm-water wash will be the most beneficial method. You’ll get the benefits of the ozone during the rinse cycles.
A commercial accounts application benefit of ozone is that you can follow a hot wash (more than 160 degrees) with a cold rinse (70 degrees or less) with no fabric shock, if the cold water is ozone-saturated.
How Much Ozone is Enough?
What is the right amount of ozone? To find the answer, you need to understand your water. Every laundromat has different water, and it can change throughout the year, depending on its source.
The two major factors that affect the cleaning ability of water and ozone are hardness and pH levels. Ozone’s effectiveness is altered by both, so be sure your ozone system is designed around each. And, if you do commercial accounts work, have your chemical supplier check those levels a few times per year.
Traditionally, ozone is measured in laundry applications by an electrical charge (in millivolts) that increases in the water with the presence of an oxidizer. The measurement is called oxidation reduction potential (ORP).
As an example, a commercial swimming pool with chlorine (an oxidizer similar to ozone) will be between 650 and 750 ORP. By contrast, a typical laundry application will look to achieve an ORP reading in the 850 to 925 range.
Here is where water quality comes into play. ORP is not a measurement of ozone in the water. Rather, it’s a measurement of the effect ozone is having on the water to create the ideal level for cleaning. In other words, if your water is hard or features high PH levels, the ozone will be consumed, thus requiring a higher quality of ozone to reach the 850+ OPR reading required to enjoy the full benefits of ozone for a traditional laundry application.
As a result, it’s important to have ozone professionals size your system to ensure it will deliver the results your business needs.
Introducing Ozone to the Wash
There are two ways to get ozone into a washing machine. One way is to inject it into the cold water supply using a Venturi valve – making a single washer, a bank of washers or an entire laundromat’s cold water supply the delivery system for the ozone. The second method, which is common in fire/water restoration applications, involves “bubbling” the ozone directly into the sump at the bottom of the washer wheel.
Both methods have pros and cons. For example, ORP sensors last only a year or two and are sensitive any residue buildup. If ozone is being generated for each washer individually – as with the bubbling method – each washer would require a sensor. However, if the entire water supply or a dedicated group of washers are all on the same ozonized cold water supply – as with the injection method – the ozone can be measured at one single point.
With injection, ozone (at levels that are high enough to be effective in cleaning) will break down and deteriorate the rubber in most water valves more quickly than they normally might. Of course, if you already have high pH or hard water, you’re going to be experiencing that level of diaphragm deterioration in your washers anyway – and, therefore, you already should be replacing those diaphragms in your machines every couple of years.
If your water is soft or you have neutral or low pH levels, you will require less ozone to achieve the 850 to 925 ORP level. So, deterioration will be less of an issue.
Clearly, when bubbling ozone into the sump at the bottom of the washer, you’re avoiding the rubber components and water valves, so you won’t experience the deterioration to your valves. Again, with this method, you’ll traditionally have some type of sensor monitoring the ozone so that it doesn’t off-gas – and this means extra electronic equipment on each machine to regulate how much ozone is actually in the washer.
Excess ozone and the eventual excess off-gassing of that ozone into a confined space like a laundromat over a period of time is a potential risk to customers and staff. Ozone can have short-term respiratory effects, especially for those who already suffer from preexisting respiratory conditions. Just as a safety precaution, I would consider installing a room sensor that detects high ozone content in your laundromat.
When ozone tops a 975 ORP reading, the water typically can no longer “hold the ozone” within it any longer, and the gas begins to escape within the drum, which means a heavy ozone smell within that space.
No doubt, understanding the ways in which ozone can benefit a laundry operation and managing your expectations for ozone use is important.
If operating a correctly designed ozone system, you’ll see amazing results with many types of cleaning. Ozone clearly outperforms all other methods when tackling human or animal soils, such as urine, blood and other bodily fluids.
Gym clothing can be washed in just cold water. Any type of animal coverings or beds will be cleaned and sanitized – and the odors removed – in cold water alone. And terrycloth garments will look and feel like new after a few ozone washings, as the fibers will open up and any residual chemical buildup will be removed.
Perhaps best of all, at the end of the day you’re going to have a cleaner, more sanitized and better feeling laundromat with ozone. Your store will be much more appealing – and your customers will notice it.
