This Regulatory Review will provide an overview of what architects should consider, when designing buildings of all types, to achieve better indoor air quality (IAQ). This matter has become increasingly important over the past several years, with the prevalence of airborne viruses, wildfire smoke and urban smog, and overheating.
Background and Overview
The current dynamic nature of the world has introduced challenges that have not typically been the focus of what to consider when designing habitable buildings. COVID-19 was declared a pandemic in March 2020, which initiated important studies on the behaviour of viruses and pathogens in the air. There has also been a higher frequency of wildfires and extreme weather events. The culmination of these elements has led to a more complex discussion around indoor air quality within buildings.
The introduction of the BC Energy Step Code in the BC Building Code, better building practices, and the popularity of Passive House approaches have vastly improved the air tightness of our buildings. This directly effects indoor air quality and informs the design of the systems used to condition the air inside buildings.
It is incumbent on the architect and the team of consultants to provide a more detailed review of HVAC systems toward improving the IAQ of all buildings and prevent the transmission of airborne particulates. Weighing the implications of the HVAC system with the performance standards targeted and the expectations of the clients should be a key topic of discussion from preliminary design onward.
What to Consider
When designing buildings of all types, architects should consider building envelope performance in conjunction with HVAC systems that respond to these significant social and climatic issues:
- Wildfire Smoke and Urban Smog
The infiltration of smoke particulates into the envelope and throughout the occupied space through the mechanical system.
- Airborne Viruses
The transmission and movement of airborne viral particles or pathogens within the building.
- Overheating
Tight envelopes and climate change contribute to increased indoor temperatures.
Current code minimums may not be sufficient for dealing with poor ambient air quality and high temperatures. Despite this, architects and engineers have an obligation to protect human health and advise on the appropriate strategies for supporting optimal health and comfort for occupants in each building project.
Considerations for the design team and client include:
- Standards for both energy performance and IAQ
What standard is being targeted?
What minimum performance levels should we advise to clients in our designs? - Design strategies for IAQ
What systems and approaches are better for reducing CO2 levels, reducing TVOCs including NO2, and filtering pathogens? - Design strategies for comfort
Designing to address poor ambient air can also affect energy efficiency and comfort within the building.
What systems and approaches stabilize indoor temperatures and humidity to targeted levels with minimal impact on energy consumption? - Components
What are some of the key components and technologies we can specify to improve Indoor air quality and comfort?
Part II of this Regulatory Review will expand all of the considerations outlined above, as they relate to IAQ within buildings. It will highlight areas of importance and suggested strategies.
Supporting Documentation and Resources
Helpful Resources
Acronyms
- IAQ – Indoor air quality
- HVAC – heating ventilation and air conditioning
- TVOC – total volatile organic compounds
- CO2 – carbon dioxide
- NO2 – nitrogen dioxide
AIBC Contact
For more information about this Regulatory Review or if you have any questions about indoor air quality, please email practiceadvice@aibc.ca.
Issues of AIBC Regulatory Review will be published on a regular basis, announced via Connected and archived on the AIBC website.