Gregory's Server
There are UV sterilizing lights available for ducted air conditioning systems.
~AUD$1000 fitted was the quote.
AIUI they do a good job of sterilizing viruses and bacteria.
But I have seen a caution from someone who seemed knowledgeable - UV light can increase amounts of cancer causing chemicals in the air and so using a UV light in a confined poorly ventilated space could result in in lung disease.
It seems complex.