If it takes 10-20min of UVC to kill a virus...How does an air filtration system flowing air through UV light for only seconds hope to kill coronavirus? Does it cycle the air repeatedly through the light for 20 min before releasing it?
I was thinking about this too when I looked into UV-C. It seems to me it's only really useful in a room setting where you turn it on for a while and leave. It also generates a bit of O3 which also helps.
Which brings me to another thing, if you want to decontaminate a room and nobody can be inside anyway, you may as well use an O3 generator as I think it will be more effective as the O3 will get everywhere. With light it needs to be moved around to cover all surfaces due to shadows.
I wonder if there are actual scientific studies on which method is better, the UV-C light DOES work with enough exposure and it will catch anything airborne too, and from my understanding some hospitals have "robots" they use, which is basically a giant light on wheels that can move around a room. So since it's automated the shadows are less of an issue.
Actually funny thing about the term robot, I used to work in a hospital and some people refereed to COW (computer on wheels - basically a cart with a laptop on it) as robots, always thought that was funny.