IT WAS AN UNBELIEVABLE DISCOVERY WHICH CHANGED OUR UNDERSTANDING OF OZONE LAUNDRY SYSTEMS.
We received a call from a Commercial Laundry System in a Major Hotel Chain. He was unhappy with our Ozone test kit. He complained that the kit practically did not find any Ozone in the water inside his laundry machine. It seemed strange to me, so I decided to help the customer and locate the problem. To determine how much ozone is in the system, I asked what ozone system he used in his laundry.
The system was purchased from a large manufacturer of Ozone Laundry equipment in the USA. Furthermore, the representatives recommended and installed the system. The installed Ozone Generator produced 2 grams of ozone per hour (according to the operator’s manual) using dry air as a feed gas.
The ozone generator appeared significantly undersized, so I checked the numbers.
LET’S DO THE CALCULATIONS…
I took out my calculator and checked how much ozone was in the laundry machine. I did them in detail because I needed to show and explain my calculations to the customer.
1) one gram of ozone dissolved in 1 (m³) creates an ozone concentration of 1 part per million (ppm). One gram of ozone dissolved in a 0.4 (m³) (400 liters) will create a concentration of 2.5 ppm.
2) The recommended concentration, by most experts in the field, of ozone for commercial laundry systems is 4-5 ppm. As the customer had the 2 (g/h) ozone generator, everything looked good on the surface. However, when I looked deeper, I discovered an entirely different picture.
3) The laundry machine needs only 3-4 minutes to fill. Therefore, the amount of ozone produced during this time was only 0.13 g. (2 g/h * 4 min * 1/60)
4) this type of generator can handle a maximum concentration of 1% w/w. At a concentration of 1%, it is practically impossible to dissolve more than 10% of the ozone in water. Therefore, the actual amount of ozone dissolved was only 0.013 (g). Inside the laundry machine, the dissolved ozone concentration would be 0.3 ppm.
0.013 (g)/0.4 (m³) = ~0.3 ppm.
That assumes that the ozone generator produced 2 (g/h). Nevertheless, air-feed ozone generators produce only half of what they claim after a few months of use. It would be safe to say that the actual concentration of ozone inside the laundry machine was about 0.1-0.2 ppm.
6) An American and Canadian requirement to disinfect filtered and generally clean bottling water is 0.2-0.4 ppm. However, such a low ozone concentration would not be enough to disinfect a few hundred pounds of industrial linen. In fact, for commercial laundry systems, the industry suggests 4-5 ppm.
When ozonated water came into contact with a load of soiled linen, the ozone rapidly reacted with the impurities. Since there was so little of it, all the available Ozone immediately reacted, leaving nothing for the customer to measure. That simply explained the customer’s problem.
It was very clear that at such low concentrations, the ozone was not doing much for the disinfection of linen. What disturbed me was a question:
WHY ARE SO MANY LAUNDRIES BUYING OZONE GENERATORS, PAYING THOUSANDS OF DOLLARS, AND GETTING ALMOST NOTHING IN RETURN?
had contacted several dozens of customers who virtually had the same type of horribly undersized ozone system in their laundries, and I had discovered an interesting answer:
When the laundries installed the ozone generator, they stopped using hot water to disinfect linen. This turned the laundry room from terribly hot and humid hell-like working conditions into a cool and comfortable working environment. Obviously, laundry employees would not complain about ozone, as it improved their lives.
In addition, As only 10% of ozone was dissolving in water, 90% of it was escaping; therefore, even with a good air exhaust system, there is always a smell of ozone. Any inspector/supervisor would be happy to see and smell the ozone.
Most modern-day laundry detergents have enough bleaching agents to kill most germs and are designed for cold-water use, as we know from many years of experience doing our laundry at home.
On top of everything, it is a well-known fact that there is not so much linen deterioration when the washing is done in cold water, which, as many customers point out, increases the service life of linen and towel.
Ingenious, now commercial laundries could finely do what we have done for decades at home, use cold water and take advantage of achievements of the modern chemical industry, which produces such great laundry detergents.
That is absolutely amazing. However, there is just one question: why not buy a little, made in China $150 so-called “Mickey Mouse” ozone generator, which will generate plenty of ozone smell for everyone’s satisfaction, instead of wasting thousands of dollars on the ozone generator system which is basically equally ineffective and hardly does anything?
Strangely enough, after talking to people in the laundry industry, we are actually finding more and more customers who actually want to have real ozone disinfection, which will ensure that they could save as much as 20-40% on detergents, that no germs will survive in the linen, that the lined will be whiter and cleaner than usual.
WHY SHOULD YOU CHOOSE AN ABSOLUTE OZONE® SYSTEM?
As surprising as it may seem, a good quality system does not necessarily cost more money, as long as it is installed by people who manufacture and install quality ozone generators, which are not embarrassed to publish on their website not only how much ozone their generator produces, but at what concentration and how little feed gas is needed for production. People who would help you to achieve 4-5 ppm ozone concentrations inside the laundry machine will guarantee that you will achieve it.
When a customer buys a car, all specifications like horsepower, torque, mileage, top speed, and other features are available so that the customer can make an intelligent choice according to his requirements, needs, and desires. It is, therefore, surprising that when a customer buys an ozone generator system, he is treated like a person incapable of making an intelligent choice. As a result, he could be persuaded to purchase a system that does not meet his needs and requirements. (Check this article, Sizing of Ozone Equipment)