Ozone Production in Air Purification

Ozone was proposed as a new substance in air in 1840 and its formula O₃ was determined in 1865.  It was named after the Greek verb ozein ("to smell"), from the peculiar odor after lightning storms. Ozone's odor is sharp, reminiscent of chlorine, and detectable by many people at concentrations of as little as 10 parts per billion in air. 

Ozone is a powerful oxidant. This same high oxidizing potential, however, causes ozone to damage mucus and respiratory tissues in animals, and also tissues in plants, above concentrations of about 100 parts per billion. This makes ozone a potent respiratory hazard and pollutant near ground level. 

In air purification, ozone can be manufactured by different processes: Corona Discharge, Cold Plasma and Ultraviolet light.  Here is a small explanation of each process and facts regarding each.

Corona Discharge: These units usually work by means of a corona discharge tube. They are cost-effective and do not require an oxygen source other than the ambient air to produce ozone concentrations of 3–6%. They also produce nitrogen oxides as a by-product. A product using this method creates audible and radio frequency noise.

Cold Plasma: In the cold plasma method, pure oxygen gas is exposed to a plasma created by dielectric barrier discharge. The diatomic oxygen is split into single atoms, which then recombine in triplets to form ozone.Cold plasma machines utilize pure oxygen as the input source and produce a maximum concentration of about 5% ozone. They produce far greater quantities of ozone and are very expensive.

Ultraviolet: UV systems generate ozone by producing a narrow-band ultraviolet light in a wavelength of 185 nanometers (Vacuum UV part of light spectrum).  These systems are less expensive than others and produce ozone with a concentration of about 0.5% or lower.  Unlike corona discharge systems, this production method does not produce harmful nitrogen by-products. 

Second Wind Air Purifier model 1000KCS

The use of ozone was the first method employed by Second Wind Air Purifier for air purification.  This process would treat the rapidly passing air with UV-C light at the same time as producing  ozone, which after creation would move into the living spaces of homes to prolong the reactive oxidation process.  If the unit was only producing ozone, it would be less efficient in its purification of the air.  We still use ozone producing spliced lamps in many of our products where it is desired to treat very irritating odors like those from cigarette smoke, but for most normal applications, our Photo-Catalytic Oxidation process is sufficient, and no ozone is created or noticeable by its own odor.

Ozone purification is still used by many of Second Wind's competitors, but the fears of ozone its effects on people led us to move to the Photo-Catalytic Oxidation process that we discussed in our last post as our preferred method of air purification.  After all, we need our customers healthy!