It also produces ozone which is not great to be breathing. UV-C is more effective than plasma but still produces some nontrivial ozone if it's bright enough to be disinfecting air.
Thank you did not do much research just took the techs word as he told me about all the courses he took and how great they are.
I used to sell similar home products -- if it's similar to my experience, those "courses" are given by the manufacturer, and really, they're just tutorials for their dealers on how to sell/install/use the product. They're not academic in nature, but telling the customer you've taken "courses" on the subject makes them feel quite compelled to trust you.