Short answer: 1 for a typical room, or about every 250 square feet
Long answer: It’s complicated
Unlike technologies like air filters, the efficacy of germicidal UV varies by pathogen. Some pathogens, like human coronaviruses, are very sensitive to far-UVC. Others are more resistant. However, there is significant uncertainty in just how sensitive various pathogens are to UV light.
The key metric to look for in all air disinfection technologies is the Clean Air Delivery Rate (CADR), usually given in cubic feet per minute (cfm). A typical high-quality portable air-cleaner has a CADR of around 400 cfm—a more typical one will deliver 200 cfm.
For a typical 250 square foot room with 9 foot ceilings, Aerolamp has an expected CADR of200-1500 cfm, depending on the pathogen and the study referenced.
And ChatGPT estimates 0.02 to 0.3€/1000m³ for the Areolamp—quite competitive esp. given that it is quieter.
In general, the longer your sightlines the better UVC does and vice versa. While air purifiers are a cost per amount of filtered air, UVC depends on how much air the beam can go through before it’s (mostly) absorbed by the wall / ceiling / floor / people.
What is the relative cost between Aerolamp and regular air purifiers?
For regular air purifiers, ChatGPT 5.2 estimates 0.2€/1000m3 of filtered air.
From the Aerolamp website:
And ChatGPT estimates 0.02 to 0.3€/1000m³ for the Areolamp—quite competitive esp. given that it is quieter.
In general, the longer your sightlines the better UVC does and vice versa. While air purifiers are a cost per amount of filtered air, UVC depends on how much air the beam can go through before it’s (mostly) absorbed by the wall / ceiling / floor / people.