During this period, companies, businesses, and individual citizens are taking various measures to counteract the spread of viruses, in particular SARS-CoV2-19, responsible for the Covid-19 disease. In addition to the disinfection and sanitization of the environments, the availability of medical aids, such as disposable masks and gloves, and the controls aimed at protecting the health of employees, the Italian Association of Air Conditioning, Heating and Refrigeration (AICARR) has published some useful tips on its website to limit the spread of pathogens through HVAC systems, that is, air conditioning and ventilation systems.
The first necessary clarification is that this article and the AICARR itself does not consider private homes, because in the absence of infected people in the home, there can be no virus, therefore switching on the systems does not affect the risk of infection in any way
Diffusion by aerosol
There has been much discussion about the possibility that the virus, like many others, can also spread in the air, through aerosol, that is, the tiny droplets of water emitted while speaking or breathing.
The problem, writes AICARR, is to quantify the effect of aerial diffusion on the danger of overall contagion. The only certainty is that the contagion by direct contact, due to the infected droplets emitted with coughs or sneezes that reach close people, is much more dangerous than that due to the light droplets that spread through the air conditioning systems or ventilation, but nevertheless, it is appropriate to pay due attention.
AICARR’s suggestions for ventilation systems
AICARR has activated a group of experts to draw up a series of documents on how to operate and use ventilation systems to prevent and limit the risk of spreading the virus, suggesting some basic interventions to users and technicians:
- reduce the level of occupation of the rooms
- ventilate rooms without mechanical ventilation frequently
- always keep the ventilation systems that supply fresh air on
- always evaluate the opportunity or the need to close the recirculation ways and avoid that the air introduced is contaminated by that extracted or expelled from the rooms
- the assessment of extraordinary sanitation of the plants and air ducts
The spread of viruses and … confusion!
Unfortunately, given the general confusion on the subject, not only as regards the ventilation systems, AICARR publishes a further document to clarify its position on the diffusion of SARS-CoV2-19 and its relationship with the air conditioning and ventilation, presented with this declaration:
After analyzing the possible mechanisms of contagion, the document provides indications, based exclusively on scientific evidence, about the management of air conditioning systems for next summer and next winter, starting from the assumption that the virus, albeit with different intensity, will still be around. The reference is to existing systems, in particular: systems serving residences, all-air systems serving a single environment, all-air systems serving large buildings, all-air systems with zone recirculation serving a few environments in one property, and primary air systems. As for the previous documents, special systems, such as hospital systems, which are subject to detailed analysis are excluded.
A document accessible to all
With further effort, AICARR has developed a further document, dedicated to non-professionals, a handbook entitled
“Role of winter and summer air conditioning systems in reducing the spread of Covid-19” (only available in Italian, at the moment) in which it’s explained that the risk of transmission can occur only if there are air recirculations between one room and another, and not from the outside air, and numerous measures to verify the system installed in your business.
We thank AICARR for the precious work done. If you are on our blog to find out more about our enclosures ventilation products, visit our website fandis.it or send an email to firstname.lastname@example.org. Our staff will answer as soon as possible.