Ozone Generator

You may have heard of an ozone generator, but you may not know how an ozone generator works. An ozone generator, or ozone machine, is a device that converts oxygen from various sources such as ambient air, dry air, or concentrated oxygen into ozone. Ozone generators produce ozone (O3) by adding energy to oxygen molecules (O2), which causes the oxygen atoms to part ways and temporarily recombine with other oxygen molecules. The ozone is then used for water disinfection and air purification. Ozone generators can come in small hand-held sizes, all the way up to large-scale industrial models that can produce several hundred grams of ozone each hour. Industrial ozone generators work very similar to ambient air units except they require very clean and very dry air or oxygen and have a corona cell specially designed to generate very high ozone concentrations.

Once the ozone is produced it reacts with a pollutant, bacteria, virus, or mold, and breaks it down into less complex molecules through a process called oxidation. Ozone that has not reacted with other molecules will decompose into oxygen over time. Ozonation destroys odors, and disinfects air, water, and other materials. It has even been approved by the USDA and FDA for use on food.

Although many manufacturers claim that ozone will render almost every contaminant harmless, it is important to follow safety guidelines, understand the structure of the contaminants, and have an ozone expert properly size the ozone generation unit.

Ozone Generation
The ozone generation process occurs naturally in the environment in one of two ways: Lightning strikes or Sunlight. After a thunderstorm, we probably all recognize the smell of ozone. The fresh, clean, spring rain aroma that we notice after a storm is most often a result from nature's creation of ozone. The second method is ultraviolet light from the sun. Through this method, oxygen in the presence of the sun's UV light can be broken down and form into ozone.

Ozone generators recreate these processes in a controlled setting. This leads into two types of ozone generators: Corona discharge generators and UV light generators.

Corona Discharge
These machines create ozone by taking oxygen and forcing it forcing it through a high voltage metallic grid. The high voltage splits apart the oxygen molecules into single atoms. These atoms then attach to other O2 molecules in the air to form ozone (O3.)

A few advantages of using corona discharge are that it creates a consistent ozone output, it generates high ozone concentrations, it provides fast organic (odor) removal, and it is ideal for water applications.

Ultraviolet (UV) Light
This process of ozone generation is similar to how the sun's ultraviolet radiation splits O2 to form individual oxygen atoms. UV light changes oxygen into ozone when a wavelength at 254 nm (nanometers) hits an oxygen atom. The molecule (O2) splits into two atoms (O) which combine with another oxygen molecule (O2) to form ozone (O3). UV Light occurs naturally through the sun rays, but this process is considered to be less efficient than corona discharge, according to InterNACHI.

The advantages of using UV Light include a lower cost than corona discharge, it is simpler to assemble and use, and the ozone output using UV Light is less affected by humidity.

Ozone Generator Safety
Ozone generators are for use in unoccupied spaces and not running when people or pets are present. While O3 is a powerful oxidizer that will eliminate most odors, long-term exposure is not recommended by government agencies because it can contribute to eye and respiratory irritation.

These are valid safety concerns because the ozone breaks apart molecules as part of the oxidation process, especially odor causing molecules. However, humans and pets are also made up of molecules, so ozone at high levels has the potential to irritate the eyes and respiratory system, especially those with asthma or COPD. Therefore, ozone should be used with caution.

In the recent past, some direct marketing companies sold air purifiers that produce ozone to consumers for use in occupied spaces. This created concern at the EPA, the FDA and the American Lung Association, which resulted in adverse publicity for the ozone industry. For decades prior to that time, ozone had been used commercially in the hotel, apartment, janitorial, water and fire damage remediation industries and many others, while spaces were unoccupied.

High Output Claims
All ozone generators require periodic cleaning of the ozone producing elements to continue operating. Beware of units offered on the Internet that cannot be maintained by the buyer because they will stop functioning after a period of time.

Many ozone generators have a very short lifespan. Always check the details of the warranty that a manufacturer provides. Ozone can be corrosive and all ozone producing elements build up a film on the plates that dramatically reduces output. Even plates protected by a filter will build up a microscopic film on the plates over time that causes the ozone production to drop. Beware of ozone plates that cannot be removed and cleaned by the end user.

This is especially true of mica plates because the material cannot be cleaned and alignment is very important. So the mica plates have to be permanently built into a handmade assembly for protection. Thus, the mica assembly can become the most expensive component, by far, in the entire unit. Once the inevitable microscopic film builds up on the mica plates or corrosion occurs, ozone output drops dramatically, making it a throwaway product or requiring a costly return to the factory. The most expensive part in the unit will need regular maintenance but cannot be serviced, so the warranty can become somewhat meaningless.