I believe an upside of the 'in-room' UV approach is that it also cleans exposed surfaces. Putting the UV light only in the air-ducting does little to clean a su

I believe an upside of the 'in-room' UV approach is that it also cleans exposed surfaces. Putting the UV light only in the air-ducting does little to clean a surface someone coughed on. Whereas the UV approach would help to disinfect those surfaces.