Good Ventilation can prevent the spread of COVID-19 in Buildings
Infectious diseases specialists have warned that Ireland is at the beginning of a second wave of Covid-19. As professionals within the HVAC industry, our expertise is becoming more important to guide our customers through these uncertain times. We are Chartered Engineers and are the best source of up to date knowledge to advise our customers on how to safely operate their air conditioning, heating, ventilation systems and reduce the spread of the deadly airborne virus within the working environment.
ASHRAE Statements regarding SARS-CoV-2 Transmission
ASHRAE leadership has approved the following two statements regarding transmission of SARS-CoV-2 and the operation of HVAC systems during the COVID-19 pandemic.
- Transmission of SARS-CoV-2 through the air is sufficiently likely that airborne exposure to the virus should be controlled. Changes to building operations, including the operation of heating, ventilating, and air-conditioning systems, can reduce airborne exposures.
- Ventilation and filtration provided by heating, ventilating, and air-conditioning systems can reduce the airborne concentration of SARS-CoV-2 and thus the risk of transmission through the air. Unconditioned spaces can cause thermal stress to people that may be directly life threatening and that may also lower resistance to infection. In general, disabling of heating, ventilating, and air-conditioning systems is not a recommended measure to reduce the transmission of the virus.
Do you need help to carry out a covid-19 risk assessmentTalk to us today to arrange a full consultation.
How is Covid-19 Transmitted?
Much like a strong immune system, a strong ventilation system will be able to help in the fight to defeat the virus.
The three most common transmission routes for coronavirus which are:
- The combined droplet and airborne transmission in a 1-2 metre close contact zone. These droplets can be emitted when sneezing, coughing, singing, shouting, talking, and breathing.
- Long-range airborne (aerosol-based) transmission some of which are heavy and drop to the floor under gravity and some are exceedingly small and buoyant and can stay in the air for up to several hours.
- Surface contact through hand to hand contact, hand to surface.
Socially distancing from each other plays a major part of stopping COVID-19 from spreading. The real challenge is the prevention of the aerosol sized particles cross-infection beyond 1.5m from an infected person. This can be decreased with a correctly designed ventilation system.
Ventilation is key to diluting some of the airborne pathogens that carry the virus. There is scientific evidence which shows that occupants of a room are more at risk of catching a coronavirus in a poorly ventilated room than in a well-ventilated room. I a poorly ventilated room occupants are exposed to a higher concentration of airborne pathogens, and the risk will increase with a greater amount of time spent in such an environment.
Risk = Exposure x Time
The risk of airborne infection to the individual can therefore be reduced by:
- Reducing time spent in the location
- Reducing airborne exposure concentration of infectious material
- Reducing risk of contact spread through regular handwashing, surface cleaning and reducing deposition of infectious particles.
Ventilation rate and effectiveness play a role in both airborne exposure and deposition rates.
Covid-19 Risk Assessment
The government guidance reminds employers of their legal responsibility for the safety of those entering workplaces:
“To help you decide which actions to take, you need to carry out an appropriate COVID-19 risk assessment, just as you would for other health and safety related hazards. This risk assessment must be done in consultation with unions or workers.”
Undertaking that risk assessment may require advice from competent persons, such as professionally registered engineers who are Chartered or Incorporated engineers registered with the Engineering Council.