“‘However, the risk is considered lower on aircraft because of the use of high efficiency particulate air filters, which are effective in capturing more than 99 per cent of airborne microbes in filtered air.’”
Viruses aren’t microbes.
https://en.wikipedia.org/wiki/Microorganism
All the airlines have to do is simply NOT OPERATE their Recirculation Fans - then they wouldn’t even need filters (since all air would be brought in fresh). The plane will fly fine without them...just a bit more fuel. We’re in the middle of a worldwide Pandemic (regardless of what China tells the WHO to call it), and they can’t even shut off the stupid fans.
What about bringing air in at high altitude ? Low oxygen and cold. Think that is why they recirculate ? Also pressure differentials.
Nah.
Outside air is much thinner than we need. Using it would be VERY expensive!
I think a ‘hot box’ heating system would be the thing.
But I still can’t find info on brief high-temp effects on covid.
Though it’s known to prefer cold.