Maintaining good indoor air quality is often a challenge during spring and fall. The increased likelihood of poor IAQ during shoulder seasons is a result of a combination of poor ventilation, moisture and airtight insulation in buildings. The HVAC’s primary purpose is to maintain good indoor air quality and adequate air supply. During the shoulder seasons, it is on average neither hot nor cold, so the HVAC is not activated by the thermostat to correct the temperatures. As a result, the building may not receive a sufficient daily circulation of fresh air and accumulate pollutants from repair projects, cleaning procedures and simple daily activities.
Poor Indoor Air Quality can have consequences ranging from loss of productivity in the workplace to serious health challenges for building occupants. Eye and upper airway irritation are a common result of poor IAQ and are among the top symptoms reported in office questionnaire studies. To maintain optimum health it is important to lower the concentrations of indoor air pollutants in your environment. There are two ways of achieving this: to eliminate the source of indoor air pollution and to increase the amount of incoming clean air.
Eliminating the sources of indoor air pollution:
Monitor humidity and water infiltration: Dry Air, Mould & Bacteria
Regulating humidity levels will help make tenants comfortable and minimise health issues. During shoulder season, testing your IAQ will help monitor the environment for the development of mould allergens associated with high humidity levels and help prevent problems of dry skin, airways, and lips associated with low humidity levels. If you suspect mould you can visually assess your building and have your IAQ tested for mould spores. The correct level of humidity also prevents cracks in wood, helping the building and furniture in it last longer. To keep humidity within comfort ranges, the building should have humidity sensors in the thermostat or a separate hygrometer system that can control humidification separately.
Consider your building materials: VOCs, asbestos, formaldehyde and lead
In addition to passive health and comfort concerns, spring is the season for renovations and property maintenance. Make sure you know the building materials and property issues so that you avoid exposing building tenants to further health risks. Some building materials may contain substances such as asbestos and lead that pose a health risk if they are disturbed or improperly handled. New materials that are installed in the building may also contribute to indoor air pollution by off-gassing formaldehyde and other Volatile Organic Compounds. To learn more about VOCs and Designated Substances, visit our Hazardous Materials page.
Increasing the amount of incoming clean air:
Studies have found significant direct effects of ventilation rates on health and on increases in some allergy and asthma symptoms in buildings with less ventilation. Another study estimated that increases in building airtightness without compensating measures could increase indoor radon concentrations by 57%.
Create a sufficient exchange of clean air
Improving ventilation with outdoor air can make IAQ better, but only if the incoming air is cleaner than the indoor air. Often this is not the case, and ventilation worsens IAQ. Poor outdoor air quality can be a result of elevated outdoor contaminant levels, motor vehicle exhaust from nearby roadways and contaminants from adjacent buildings. In these cases increased air ventilation may be counterproductive unless it is accompanied by the appropriate and effective increase in air filtration and cleaning.
Consider IAQ during building performance improvements
Building owners and managers often miss the opportunity to improve IAQ and energy efficiency during routine renovations. Renovations are a great opportunity to improve IAQ if it is integrated into the project. Yet, efforts to achieve high levels of building performance without consideration for IAQ can lead to problems. Some common measures that can potentially affect IAQ are envelope tightening and the addition of insulation to the building envelope, all of which reduces air ventilation. A consultant can help evaluate the IAQ needs for your project or at the very least tell you if it is necessary to consider a consultation.
Keep pesticides, pollen & other outdoor pollutants in mind
Spring is the season for increased allergen levels in the outdoor environment. Paying close attention to the substances and plants in your landscape can also help with indoor air issues. Building managers often overlook the fact that every time a door opens in the building, outdoor air pollutants such as pollen enter the building’s air supply. Therefore, plants and pollutants near your building can affect tenant health. Managers should evaluate landscaping and vent placements to determine what is potentially entering their building. Additionally, you can integrate low-allergen plants and fertilizers to make sure tenants are protected.
Maintain your HVAC system
Everything in the building air will eventually end up in the indoor air duct system, caught in the air filters of the HVAC system or built up inside the HVAC system itself. As a result, a poorly maintained HVAC system may introduce pollutants every time it starts. This is a particular concern in spring and fall since the system starts and stops more frequently. To safely remove the accumulated debris, maintain your HVAC system and change filters frequently.
Sources:
https://www.epa.gov/indoor-air-quality-iaq/
https://www.epa.gov/mold
https://www.canada.ca/en/health-canada/services/home-garden-safety/pollutants-furniture-building-materials.html
https://www.onhealth.com/content/1/indoor_air_pollution
https://www.onhealth.com/content/1/asthma_lung_inflammation
https://medlineplus.gov/indoorairpollution.html
https://www.nrel.gov/docs/fy13osti/56023.pdf
https://medlineplus.gov/asbestos.html
https://medlineplus.gov/leadpoisoning.html