The Ecoquest is a good air purifier. The amount of NoX it creates in your room air is very small compared the amount of ozone and it disperses quickly within 6 feet of the machine.. I have met a few people who have an extreme dislike for ozone air purifiers and I think it is because of the NoX rather than the ozone produced. Most people are not affected by the NoX.
The NoX becomes more of a problem when the output of an air-fed generator is put into a confined space like a sauna tent and the NoX gets concentrated. By the same token one should never try to maker fully ozonated olive oil with an air fed ozonator. It takes 500 hours to create fully ozonated olive oil with a small ozonator, so the cumulative NoX build up in the oil can be large. Oil made this way burns the skin because of the nitric acid content. However small amounts of lightly ozonated olive oil can be made by an air-fed ozonator when ozonated only a few hours. There is not enough time to build up large amounts of NoX in the oil.