From the Canadian 'Core Recommendations for Safer Indoor Air'
Recommended CO2 levels in compliance with current standards:
• Daycare – 850 ppm
• Elementary School Classrooms – 900 ppm
• Highschool Classrooms – 1150 ppm
• Offices – 1050 ppm
• Retail Stores – 1300 ppm
• Doctor’s Offices – 1000 ppm
• Dental Procedure Room – 800 ppm
EXECUTIVE SUMMARY
In spring 2022, the Ontario Society of Professional Engineers (OSPE) formed the Indoor Air Quality(IAQ) Advisory Group, responding to the need for evidence-based guidance around indoor air qualityand airborne transmission of COVID-19.
COVID-19 is primarily transmitted when airborne particles(aerosols) that contain the virus are emitted by an infected person and are inhaled by another person. Removing these airborne particles from the air can prevent exposure and infection. This underscores the vital importance of including engineers and other building science and air quality experts in the continued response to COVID-19.
As a first step, OSPE’S IAQ Advisory Group is releasing six recommendations that all businesses and organizations can implement to provide safer indoor air in their facilities. These recommendations set clear and achievable targets for clean air in all buildings, and if implemented, will create safer indoor environments and make a significant contribution to protecting all Canadians from the spread of COVID-19.
Additional details and guidance are shared following the six high level recommendations.
• Mitigation of Airborne Disease Transmission: Target a minimum of six air changes per hour in occupied indoor spaces using any combination of ventilation, filtration, and ultraviolet germicidal irradiation systems.
• Ventilation: Bring buildings into compliance with current ventilation standards established byASHRAE (American Society of Heating, Refrigeration and Air-Conditioning Engineers) [1] and the Canadian Standards Association (CSA) [2] confirmed through CO2 monitoring.
• Filtration: Upgrade filters in air handling units to MERV-13 or higher where possible, or use a portable HEPA filter or DIY CR box in each occupied space when air pollution is a concern.
• Ultraviolet Germicidal Irradiation (UVGI): Use upper room UVGI systems installed by qualified professionals in health care settings and congregate living settings. Consider its use in high-risk settings and places with high occupant density.
• Avoiding Additive Air Cleaning and Alternative Methods: Do not use additive air cleaning methods or similar products, such as ionization, until there is a standardized way to ensure their safety and effectiveness.
• Transparency and Public Education: Share information about your facility’s air quality with occupants including sharing the strategies you are using to ensure safe indoor air and install CO2 monitors with readable displays.
To read more click on this link: https://ospe.on.ca/wp-content/uploads/2023/01/Safer_Indoor_Air_Nov22_Final.pdf
