[Llamamoe]

Is there any reason why they can't just be installed inside air purifiers/ventilation?

Especially since you could probably get more mileage out of the same amount of light energy by forcing the air through a narrower passage, since only airborne particles are actually going to absorb any energy anyway, and air is mostly just empty air.

[BobaFloutist]

The risk is that they generate ozone, and it's not clear how serious the risks of constant exposure to ozone are.

[rob74]

That solution is actually suggested in the article. However, that still leaves the cost issue mentioned by GP, and until that is solved, this will remain something for specialized applications (operating rooms) and maybe hypochondriac millionaires...

[DennisP]

From a quick search, they are not millionaire-level expensive. Here for example is a 20W 222nm lamp that costs $436, with a lifetime of several thousand hours.

https://uv-can.com/products/gerani-far-uv-light?srsltid=AfmB...

[wkat4242]

Several thousand hours is not a lot. A year is already 8760 hours.

[DennisP]

Sure, I'm not saying it's cheap. I'm just saying there are lots of software developers and whatnot who could keep themselves in UV air filters if they really wanted to.

[harddrivereque]

...and maybe diy germaphobes.. just like positive air pressure ventilation systems. In fact, you could combine