Ozone system for air treatment in conditioning systems has the benefits from solving problems with the ozone produced by UV lamps. Ozone will pass to destroy the protein cells that encapsulate and sustain various kinds of germs, fungus, fungus spores, bacterias, viruses, and various diseases very quickly. Therefore, the diseases cannot be alive. This is the reason why ozone then can eliminate various kinds of undesirable odors effectively. Furthermore, it will make better indoor air quality with no harm to humans. Ozone will get inside to eliminate bad and humid odor directly when the amount of use to maximize effectiveness depends on the using time and ozone-producing capacity to reduce cigarette, food, and bad odors inside the room by oxidation reaction of all kinds of odors that occur. In case of the hotels, hospitals, or office buildings that have rooms-modification precess, or new building area consisting of thinner odor from painting, ozone can also eliminate the odor classed toxic gas as well.