Due to the increase in the greenhouse effect of the earth caused by atmospheric pollution, the number of air conditioners is rapidly increasing every year, which is why air-conditioning disease is increasing, and it is especially serious in large buildings with central heating and cooling systems. The cause of this air-conditioning disease caused by cooling tower pollution is Legionella pneumophila bacteria (LDB), and it cannot be eliminated using standard chemicals, so it is the greatest risk to human body protection. Until now, there was no method other than sterilization and disinfection using chlorine, but the NASA/JPL (National Aeronautics and Space Administration)
proved that the sterilization effect of ozone is far superior to chlorine, and because chlorine-induced corrosion of cooling towers and heat exchangers is a problem, ozone is used the most in the Americas, including Europe.