The weather did not require us to turn the air conditioning system on so far this year. Please don't turn your system on before reading the attachment. Perhaps it will prevent you from experiencing severe symptoms of COVID-19.
I put a few thoughts based on my experience with HVAC systems. It is not a scientific study and is not approved or endorsed by any authority.
I would like to thank John Bachmann for proofreading.
See you all soon on bikes!