Measuring and evaluating air quality is an important activity to reduce potential health risks to the people of Saskatchewan.
Airborne viruses, including COVID-19, spread between people easier indoors than outdoors. The use of ventilation mitigation strategies, combined with other public health measures, such as masking and physical distancing, can reduce viral particle concentrations and prevent the spread of airborne viruses indoors.
A properly installed and maintained heating, ventilation and air conditioning (HVAC) system can reduce the amount of infectious particles in the air and help reduce communicable disease transmission. To achieve optimal performance, an HVAC system must be configured to meet the specific dimensions and uses of the ventilated space. Maintenance of the HVAC system should be performed according to the manufacturer's operation manual, as well as consulting with an HVAC professional, if necessary.
Ways To Improve Your Indoor Ventilation
- Increase airflow by opening doors and windows. Ensure windows are properly screened and personal security is not compromised.
- Be mindful of occupant sensitivity to outdoor allergens, which can trigger other respiratory reactions, such as asthma attacks and allergy symptoms.
- Reduce or eliminate the HVAC system's closed-circuit air recirculation (recirculation mode), if outdoor air quality is good.
- Use fans to increase the effectiveness of open windows. Run fans at lower speeds. High speeds can unintentionally propel contaminated air. Direct the fans output towards the outdoors (like and opened window), or towards an unoccupied space.
- Improve ventilation system filtration. Ensure filters are properly sized and are changed regularly. It is recommended to use the highest efficiency particulate filter possible.
- Maintain an optimal indoor humidity level between 30 and 50 per cent.
Ventilation Additions and Enhancements
In spaces with insufficient ventilation and filtration, the use of a portable HEPA purifier (a.k.a. air scrubbers or air cleaners) may be considered. Unit filters should be sized and changed according to manufacturer's instructions to effectively reduce indoor respiratory particles.
As described by the National Collaborating Centre for Environmental Health (NCCEH), portable air cleaners can be used to reduce particulate matter exposure in several different contexts, such as:
- Reduce the presence of respiratory pathogens;
- During wildfire events, to remove smoke that gets indoors;
- During allergy season, to reduce exposure to pollen indoors; and
- To prevent exposure to everyday pollutants and allergens (e.g., emissions from cooking and wood-burning stoves, mould and animal dander) and infiltration from the outdoors (e.g., traffic exhaust, residential wood smoke and dust).
Portable air cleaners should run continuously and be positioned so they do not obstruct airflow (do not place too close to furniture or walls). Like fans, air cleaners should not be positioned in a manner that will increase the exchange of person-to-person airborne particles.
Carbon Dioxide Indoor Sensors
Carbon Dioxide (CO2) sensors may be useful detecting ventilation issues in indoor spaces. When occupants remain in enclosed spaces for extended periods, their expired CO2 accumulates if the air within the space is not exchanged with fresher outdoor air.
Immediate corrective actions may include increasing the mechanical ventilation rate, increasing the fresh air exchange rate, reducing occupancy or opening windows and doors.
CO2 levels in an occupied space do not directly correlate with the transmission risk of airborne viruses, including COVID-19.
Public health inspectors ensure safe air quality by responding to complaints about indoor air quality in public buildings and rental units.
Complaints may be related to health effects associated with:
- Carbon monoxide
- Nitrogen dioxide
- Carbon dioxide
Depending on the type of concern, public health inspectors also provide advice on indoor air quality issues related to private residences.
Public health inspectors also monitor air quality in ice arenas where air quality may be a health concern.
- Ice resurfacing equipment can produce exhaust gases and combustion products, e.g. carbon monoxide and nitrogen oxide.
- Improperly operated or poorly maintained ice resurfacing equipment and facility ventilation systems may allow exhaust gases to accumulate indoors which may make people sick.
The Air Quality Health Index is a tool developed by Environment Canada to help you understand what the air quality means to your health.
Complaints about air quality, except those related to a workplace environment, may be directed to the Saskatchewan Health Authority.
For more information related to the workplace environment, visit Safety in the Workplace.
For More Information on Indoor Ventilation
Health Canada Video - COVID-19: Ways to improve ventilation and air filtration in your home
Health Canada Poster - Ventilation helps protect against the spread of COVID-19
Government of Canada - COVID-19 and ventilation