It is already known that the SARS-COV-2 virus which causes COVID-19, mainly spreads via respiratory droplets which are released when a person speaks, coughs, or sneezes. While most of these droplets quickly drop to the ground or nearby surface, some smaller droplets, in the form of an aerosol, can travel further and remain in the air longer. In addition, dry air and higher levels of relative humidity cause the droplets to travel even further and remain suspended longer. As such, it has been suggested by the World Health Organization (WHO) that this may be an effective means of transmission for the virus.

Coronavirus has been shown to spread more rapidly from person to person while indoors versus outdoors primarily due to the lack of air circulation and proximity of people. As a result, the ability to reduce the concentration of viral particles in indoor air is lessened with the absence of wind thus allowing more opportunity for the virions to become inhaled. This also creates a higher probability for the virus to contact the eyes, nose, and mouth of all those in the immediate area as well as accumulating on various surfaces. This is especially true when weighing in on how small the virus particle is at less than 5 micrometers in size when traveling through the air in respiratory droplets. 

An interactive visualization by The New York Times shows how increased ventilation in classrooms can help reduce the spread of airborne Coronavirus. The stunning visualization, based on a real New York City classroom, show how the lack of proper ventilation or open windows, even with social distancing and mask wearing, leads to a potentially very dangerous and contagious situation for anyone in that classroom if even one person in the room is infected. As the various scenarios demonstrated in the visualization show, protective measures must be considered regarding indoor air and implemented accordingly and alongside social distancing and mask wearing in order to reduce the potential for COVID-19 transmission.

How to Improve Ventilation to Reduce Contamination

Improvements can be made with the layout and design of buildings; use of heating, ventilation, and air conditioning (HVAC) systems; increasing the amount of outdoor air brought into buildings; and minimizing recirculated air. Some recommendations include but are not limited to the following: 

• Perform an indoor air quality assessment.

• Refer to the Guidance for Building Operations During the COVID-19 Pandemic from the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE).

• Open windows and doors to increase natural ventilation.

• Create directional air flow by:

  • placing a fan in a window to exhaust inside air from other open windows to the outside,

  • attaching ductwork to portable HEPA filtration units,

  • using dedicated exhaust systems that exhaust air out of windows, doors, or temporary ducts.

• Do not allow contaminated air to flow from one person over another.

• Ensure that air flow is not blocked. Keep all air diffusers, exhausts, return grills and unit ventilators clear and clean.

• Perform the necessary preventative maintenance on ventilation systems to ensure effective operation.

• Keep demand-controlled ventilation that reduces air supply turned off.

• Open air dampers all the way to allow for maximum outdoor intake.

• Maximize central air filtration.

• Operate restroom and kitchen exhaust fans at full capacity even when areas are not occupied.

• Utilize portable high-efficiency particulate air (HEPA) fan or filtration systems.

As we continue to learn more about how the virus that causes COVID-19 spreads, it is a best management practice to improve indoor air conditions in conjunction with as many CDC approved preventative measures as possible to reduce the risk of exposure to the virus and spread of the disease. Other important strategies for mitigation include social distancing, use of facial coverings, routine hand washing/sanitizing, and regular disinfection of surfaces.

KERAMIDA has qualified health and safety professionals on staff that are ready to assist with performing indoor air quality assessments to determine best proactive practices against the COVID-19 virus. Training for your staff in best disinfection and sanitizing practices along with sampling for disinfection verification services are offered as well. Fill out our quick response form or call (800) 508-8034 to speak with one of our professionals today.

Blog Author

Andrew Tirmenstein
Senior Project Manager, Security, Health and Safety Services
ISO 45001 & ISO 14001 Auditor
KERAMIDA Inc.

Contact Andrew at atirmenstein@keramida.com.