We get many questions about the quality and price point of various ozone generators. These are fair questions as there are many price points for an ozone generator with the same basic g/hr or mg/hr ratings. Here we will try to lay out the biggest differences in ozone generators.
The purposes of this article we will be looking only at corona discharge ozone generators producing ozone from dry air or oxygen. We will not be evaluating UV ozone generators or ambient air ozone generators used for air treatment as these both have very limited application.
Corona Cell Materials
The heart of any ozone generator is the corona cell. This is where the corona discharge occurs and produces the ozone. Materials such as aluminum, tin (tin foil), low-grade stainless steel and plastics can be used to lower cost. This is typically the case for Chinese made ozone generators. These materials will be attached by the oxidation of ozone over time, and create leaks or a failed corona cell.
As these low-quality materials degrade they will contaminate the oxygen/ozone stream and allow impurities into the ozone stream. Keep this in mind for water treatment or medical ozone applications.
higher quality ozone generators will use high-grade stainless steel (316L), quartz glass, ceramic, and pure Teflon. These ozone resistant materials will withstand ozone and create a longer life to the ozone generator.
In 6-months of operation or very light use, there is no difference in corona cell materials. Long term, after 6-months, or heavy use reliability of the ozone generator will be greatly affected. Costs will be higher to manufacture corona cells from higher quality materials. However, the benefits are worth the cost.
To produce ozone a high voltage spark is required. This spark is occurring at all times and is an end-point ground. A high voltage transformer is used to create these high voltages and sparks. This transformer must be reliable and capable of handling the torment of shorting through a dielectric to ground at a high frequency for hours at a time. We have found the best success with open coil resonant transformers, or oil cooled transformers. Simple end-point transformers are less expensive and are commonly used in lower cost ozone generators, however, these will fail sooner.
Electronic Driver Boards
To produce ozone a high-frequency spark is used. Electronic components must be used to create this high frequency. Most commonly basic Mosfet transistors are used to switch DC voltage to create the high frequency. Lower cost ozone generators will use one transistor to create the high frequency. HIgher-end ozone generators will implement a series of transistors to split the workload.
In the event, the corona cell is contaminated, or adverse conditions exist the ozone generator driver board should turn OFF ozone production so that the transformer does not short directly to ground and fail. Many lower cost ozone generators do not implement this circuit protection. Those that do, may not react quick enough to protect the electronic equipment.
Ozone generators create heat. That is a non-negotiable fact. Many low-end ozone generators use small cooling fans that do not move sufficient air, and some use no cooling fan at all.
Ozone generators are normally rated with mg/hr or g/hr. How efficiently this ozone is produced is a measurement of the ozone concentration, normally measured in % by weight, g/m3 or gamma. It is important that the ozone generator you purchase produces the most g/hr at the highest possible ozone concentration. Higher concentration ozone will consume less oxygen, dissolve into water more efficiently, and simply work better for every possible application.
These are a few of the most important components to review on an ozone generator. Of course, low-quality ozone generators serve a purpose, they meet a low price point, and allow a user to determine if ozone is right for them. However, do not be confused, a $100 ozone generator is not a lifetime investment. And as with everything, higher quality is going to cost more.