To avoid infection with coronavirus in the room, you must properly ventilate the room, getting rid of stagnant air.
As he writes in The Conversation Professor of mechanical engineering University of Colorado at boulder (USA) Shelley Miller, if the virus got into the air inside the building, you can try to remove the pathogen from the premises or give access to fresh air outside.
If inside is a few people, then refresh the air in norm should be not less than 6 times every hour. This indicator is called the rate of air exchange. In commercial buildings air is normally supplied through the heating system, ventilation, and air conditioning and in residential homes through open Windows, doors and cracks.
In the event of a pandemic air renewal should happen more often. A study conducted in 2016, showed that the rate of air change equal to 9 times per hour, helping to reduce the spread of SARS, MERS and H1N1 in the hospital of Hong Kong.
However, many buildings in the United States and other countries, especially schools, do not meet the recommended standards of ventilation. In this case, Miller advises people to keep Windows and doors open.
To find out whether the level of the air in the room is optimal for preventing the spread of coronavirus, it is possible to determine the concentration of carbon dioxide. On the street level of carbon dioxide is just over 400 parts per million (ppm), in a well ventilated area – about 800 parts per million.
According to Miller, to avoid being infected with coronavirus, the concentration must be below 600 ppm. To determine the concentration it is possible to use sensors of carbon dioxide with an accuracy within 50 ppm.