Good practices and frequently asked questions about coronavirus and ventilation
- Do you have controlled mechanical ventilation, single or dual flow?
- What role could it play in this period of confinement?
- How to manage air renewal?
This article was produced with the help of one of our partners, BRINK Climate systems and the guide of the Association of Engineers in Air Conditioning, Ventilation and Refrigeration.
Does the ventilation system promote the spread of Coronavirus?
According to a study by the RIVM (Dutch Institute for Public Health and the Environment), infections (apart from physical transmission) pass from one person to another through the inhalation of droplets emitted when one coughs or sneezes. These droplets "travel" up to 1.5 metres.
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The SARS-CoV-2 virus is active for about 3H indoors (in the air). On surfaces, it may be present for 2-3 days unless specific cleaning is done.
Smaller particles can probably circulate in the air extraction/ventilation ducts. This is not yet scientifically documented or proven (as of 04-05-2020). Nevertheless, a number of precautions and actions can be taken to remove as many particles as possible.
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Does a heat recovery ventilation system increase the risk?
These systems, provided they are correctly installed and maintained, have near zero transfer of pollutants (including airborne bacteria, viruses and moulds).
Do I have to change my CMV filters in advance?
If your filters have been changed according to your manufacturer's recommendations, there is no need to change them. Indeed, it does not seem that viruses stagnate in the filters.
If the outside air is contaminated, the current standard filters provide a sufficient barrier.
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What should I do with my ventilation system?
We recommend that you increase the ventilation: run it longer and more often.
This allows you to bring in "fresh" air while expelling "stale" indoor air. Numerous studies prove that controlled, maintained ventilation reduces the spread of infectious diseases.
For professional buildings with scheduled ventilation, we recommend:
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Start ventilation 2 hours before people arrive
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Maintain minimum air circulation 2 hours after all employees/customers have left.
This should be complementary to a physical distance of about 2-3 metres minimum between people.
In addition, it is important to remember to deactivate air recirculation for systems that are equipped with it.
Are there any systems that filter viruses better?
Some CMV manufacturers have launched filtration systems that better retain microparticles. Basically, they are intended to reduce the impact of air pollution in homes.
Other solutions to clean the air?
Air purifiers intercept airborne particles. This creates a comparable and complementary effect to ventilation. UV treatment purifiers treat the air with "UVc". This acts on viruses, bacteria and moulds. These purifiers have the advantage of being environmentally friendly and do not give off secondary pollution.
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These products are now found in the treatment of air in public places, in the food industry and of course in health and hygiene. According to AFP, the solution was recently used in China to disinfect buses and elevators.