Most hospitals, offices and residential towers built today employ common heating and ventilation systems as a matter of course. They’re efficient, easy to manage and switchable winter and summer from heating to cooling. It’s now turning out, thanks to Covid-19, the whole idea is a colossal mistake.
This shouldn’t come as a surprise. Air recirculated through a building passes into and out of each room. Indeed, it passes into and out of each lung of the humans living in the rooms. Keep this in mind when you realize bacteria and viruses are small enough to become aerosolized so they can float into and out of the system like tiny biological bombs.
The National Institute of Health published a report in July 2014 called EHP – Rethinking Sterile: The Hospital Microbiome. It stated HVAC systems are one of the main vectors for transmission of infectious agents between humans and suggested tweaks to building design, such as altering humidity and ventilation systems, could help reduce the number of pathogens in the indoor environment
To that end, Researchers in Alberta are now working, with ther aid of a federal grant, to discover how to modify HVAC systems to avoid the risk of infection. They were prompted to do this because of contact tracing at a restaurant in the Southern Chinese city of Guangzhou. It showed patrons must have been infected by aerosolized coronavirus, not droplets.
We’ve been told by the WHO Covid-19 can’t be aerosolized, but this is nonsense since viruses are 10 to 100 times smaller than bacteria and bacteria can be transmitted this way. The Alberta engineers have know this for years.
they say, it’s well known that building ventilation systems are efficient disseminators of viruses and other pathogens, and they believe the COVID-19 bug is no exception.
Meanwhile, massive air movement systems are hard at work in office towers, condominiums and, yes, hospitals, circulating air containing aerosolized viruses to everyone in the building. If you’ve been reading the papers, and checking on-line, you’ll have noticed that many more people are getting sick in big cities than in suburban and rural areas. Clearly, one reason is human density that forces people to breath each other’s air in subways, streets and elevators. But another way, according to the researchers, is the air condition systems in their homes and condominiums .
Our warning of the dangers of air conditioning go back to the 1976 outbreak of Legionnaires disease in Philadelphia. One hundred and forty nine Legion members and 33 other people became sick and 29 died. Investigators found the bacteria causing the disease breeding in the cooling tower of the convention hotel’s air conditioning system.
Changes were made to air conditioning regulations, but not to the principle of central air.
Consider past practice where hospital wards, rooms in homes and offices in downtown buildings had doors and used windows for ventilation. An aerosolized virus couldn’t travel far because air in one room couldn’t easily get to a person in another.
Indeed, centralized air conditioning is very similar to globalization itself in that a problem somewhere in the system is efficiently distributed to everywhere in the system. The old way of doing things, which was de-centralized, protected nations and patients, by separating the air they breathed.
I believe the new world of virus control is going to rediscover the old world of air movement control. Let us hope we can also rediscover the nation state, borders and immigration control which, in a larger sense, is exactly the same as virus control in a building.