In March, employees of numerous organizations started to work from home instead of office. The World Health Organization strongly recommends staying in well-ventilated indoor spaces. But how does ventilation work and what does “well-ventilated” mean?
Open air is considered safe as regards risks of getting the acute respiratory viral infection. Viruses are actually non-existent in the fresh air due to bio-aerosols getting dissolved and viruses dying fast from solar radiation and thermal effects – while indoors, people constantly breathe, cough and sneeze, with viruses spreading in confined spaces.
The aim of airing and proper ventilation is to replace stale air with fresh. In regular conditions, properly ventilated rooms are those where air is replaced every hour: fresh air arrives through a supply ventilation system and forces out stale air. Carrying out the procedure every hour is enough to maintain proper carbon dioxide levels to prevent an enclosed space from becoming stuffy.
However, this is not enough to reduce risks of the spread of acute respiratory infections. To calculate a proper frequency of air renewal, one should consider regulations required for healthcare institutions. The main aim of ventilating medical facilities is to reduce bacteria in the air – that is, to decrease the concentration of hospital-acquired infections to minimize the possibility of transmitting diseases to other patients or doctors. To achieve this, air must be completely renewed three times per hour.
Airing is not necessary in case there are no sick people in the apartment and there is an inflow exhaust ventilation system. If no such system is in place, rooms must be aired out for ten minutes every hour. If any family member shows symptoms of acute respiratory disease and you want to reduce the risk of getting infected, a window should be opened for at least ten minutes every 20 minutes.
If the apartment has a breather or an inflow exhaust ventilation system available, you should calculate their efficiency depending on the apartment area and then make a decision as to whether windows should also be opened for airing.
Sadly, most apartments in Russia lack supply ventilation systems. Old regulations stated that fresh air flows into rooms through natural crevices in wooden windows. Today, when many choose airproof PVC windows, people have to install compact supply ventilation units or open windows every hour to let a healthy flow of air throughout rooms.
By Roman Smirnov, Research and Development Director, TION Smart Microclimate