Ozone Generators Demystified

You know they’re good, but don’t know why. Learning exactly how an ozonator works will give you the upper-hand when selling its benefits to your customers.

Research By Rebecca Foley and Rochelle Belsito

Illustration by Michael Berrelleza

 

For over 100 years ozone has acted as a sanitizer and germ killer; during that time it has grown in popularity to help sanitize hot tubs. It reduces the amount of chemicals used and allows customers to save time and money maintaining their hot tub water.

Beth Hamil, vice president of corporate compliance at DEL Ozone, notes, “If the ozone generator is sized properly, the halogen chemical reduction is 60 to 90 percent.” This means consumers can save a substantial amount of money on chemicals.

 

CHEM 101

Ozone is created when oxygen molecules are split by a high-energy electrical discharge resulting in two individual oxygen atoms. Those individual oxygen atoms unite with remaining oxygen molecules to produce a three-atom molecule of ozone gas. The weak bond holding ozone’s third oxygen atom causes the molecule to be extremely unstable and thus, a very effective oxidizer.

An oxidation reaction occurs upon any collision between an ozone molecule and an inorganic or organic molecule or substance such as bacteria, viruses, fungi and algae, where the oxygen atom held by the weak bond splits off and only oxygen is left behind. So, ozone is actually a gas manufactured by the method described above, created inside a chamber, housed in various styles of containers.

But of course, it’s not quite that simple. According to Angelo Mazzei, chairman of Mazzei Injector Company that manufactures injectors that help the ozone mix with the water, the most difficult part of the ozone sanitation process is getting the ozone into the water. “Everybody talks about the ozonator, but they don’t talk about how to get the ozone gas into the water. An ozone generator is absolutely worthless unless the gas gets into the solution,” he says.

“The real dilemma is [getting] that O3 [ozone] molecule into the water, because as long as it’s in the bubble it comes through the jets and it pops up and that’s when you smell the ozone. [ed note: This is called off-gassing.] It hasn’t done anything yet because it has to be in the water to do something. Once it’s in the water, you’re not going to smell the ozone gas because it is dissolved in the water,” he adds.

There are two ways for the gas to enter the water according to Hamil. “One, ozone gas is pulled in through the venturi air suction in the spas jet system (one or more of the spas jets may be utilized), or two, it is pulled in through a dedicated ozone injector that is installed in the spa’s main return line,” she says. “Any manufacturer who offers an ozone system on their spa lines (either factory installed or made ‘ozone-ready’ for after-market installation) must pass a strict ozone off-gas test (under UL Standard 1563 5th Edition, 35.8.2, maximum 0.1 PPM). Therefore, ozone off-gas should never be present

at the water surface level of any spa.”

Once the ozone is in the water, it is ready to work. “When it’s in the water, it is looking for something to grab on to. The O3 actually attaches on to another molecule, it strips one of the O’s off and it becomes O2 and it oxidizes organics,” Mazzei says.

According to Jennifer Engelmeier, manager of aftermaket spa sales, and Charles Sterling, director of marketing, both at DEL Ozone, “In order to be effective at sanitizing water, ozone must come into direct contact with organic and inorganic contaminants. The higher the ozone concentration, the more likely it is to be dissolved in the water. When ozone is properly injected  and dissolved into water, it is environmentally safe and is the most powerful antimicrobial agent available today. Ozone is 200 times more effective than chlorine, acting 900 times faster than its chemical counterparts at destroying unwanted organic and inorganic contaminants.”

 

HOT TUB USE

“Retrofitting an ozone generator on a spa is quite simple. If the spa has been manufactured ‘ozone-ready,’ there is already an ozone-supply tubing and an electrical receptacle installed,” says Hamil. “If it is not ‘ozone-ready,’ then the consumer or tech can tap into the spa’s air line or add an injector in the spa’s return line for the ozone gas supply. Ozone generators can

be purchased in any number of voltages and any number of specialty plug configurations.”

There are two types of ozonators used in hot tubs. One style produces ozone using an ultraviolet light, which oxygen passes through, immediately separating the atoms. The second style produces ozone by a process called Corona Discharge, or CD. This is actually a chamber inside the container that creates little electrical charges to split the atoms. The CD method has an operating life of about five years while the ultraviolet style lasts about one year.

One common thing that service techs, retailers and consumers should be aware of is that all ozone systems need to be refreshed when output levels begin to decrease. Service techs can test these numbers with a gaseous ozone test kit. Hamil indicates that “All ozone systems need to be ‘refreshed’ every couple of years. For the UV ozone system this means changing the lamp; for a CD system this means changing the electrode.”

 

HELPING THE CONSUMER

When customers are looking for a hot tub or an ozonator, it is important to let them know what is available and how it can benefit them in the long run. Mike Cook, owner of Ace Spas located in the DC metro area, has run a successful hot tub repair business for over ten years and recommends ozonators to all of his customers.

“With the use of an ozone system, the spa takes care of itself when [customers are] away on vacation so [they] don’t need someone to check in on [their] spa,” Cook says.

“Many systems work 24 hours a day, so water always stays clear. [Recommend that consumers] look for spas that have an automatic default on them, so that when [users] turn the jets on the ozonator automatically goes off. This is programmed so that people who are sensitive to ozone gas will not have a problem if the spa is experiencing off-gassing.”

Paul Derence, sales and service manager at Hot Water Productions in Colorado, adds, “I feel that consumers are looking for the simplest, most environmentally friendly way to take care of their spa and I think that ozone does just that. For years, people interested in owning a spa are turned away because [they] somehow were brainwashed to believe that spas are difficult to maintain.”

With ozone systems, as mentioned previously, there is a reduction in chemical usage since ozone gas is an oxidizer. David Priano, owner of Priano’s Billiards & Backyards in Dalton Garden, Idaho, also adds, “Many [consumers] are under the impression that ozone will do everything that is needed chemically in the spa. I let them know that they still need to do the standard mineral balancing on the spa. Ozone does not take the place of that part of the chemistry.” Ozonators can be paired with all hot water chemical types too, such as mineral and bromine systems. However, since not every hot tub is alike, it may be best to look at the type of spa the customer has or is wanting and see if an ozone system is the best fit.

“With some spas that have advanced filtration systems, 24-hour circulation, ozone makes sense. On some spas, I think that ozone is effective, just not as much as it should be. I’ve seen some spas that have the ozone return located 10 inches from the water level, so the ozone has a high gas off at the surface, [but] ozone is most effective when covering a larger surface area, which happens when it comes from near the bottom,” says Derence. “So I think it really depends on the brand of the spa, the engineering aspects behind the spa plumbing along with the filtration, as well as the amount of time that the spa circulates to really maximize the total benefit of ozone.”

 

Installation Tips

By Robert Stuart

1)            Bring ozone in through an air induction line or a dedicated injector (I recommend Mazzei).

2)            To use an induction line simply attach a barb to a line preferably above the water level.

3)            Hook a tube to the injector.

4)            Do a Hartford Loop in the tube – typically a double             loop in the airline pulling into the injector that goes above the waterline up to the lip of the shell. This helps keep water from backing in the ozone.

5)            Put a check valve in the line along with the Hartford Loop for double protection.

6)            Hook it into the circuit with the circulation pump or the low speed pump so ozone is only being created during the filter mode.

 

For a Mazzei install refer to their website or use the following steps.

1) With a small circ pump you can install the Mazzei barb fitting directly in the low flow line.

2) With a jet pump you need to create a bypass loop and, again, I recommend looking at their website for best fit.

3) Follow the other steps above with a Hartford Loop and filter cycles.

 

The Mazzei system will breakdown the ozone with venturi-type injectors providing a more dynamic and efficient ozone transfer to solution than the simple air induction system.

 

Remember, it’s not good for you or your customer to breathe ozone so it’s important to run the ozone only on filter cycles or with a contact chamber. Another trick is to put the ozone return jet directly under the filter so that it is constantly pulled back into the system.