Pollutants
Common Indoor Air Pollutants Found in Canadian Homes
From radon and carbon monoxide to VOCs and particulate matter — an overview of what accumulates indoors and how concentrations are measured.
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Indoor Air Quality Resource
What you breathe
What you breathe
inside matters
Practical reference on pollutants, ventilation standards, air purifier selection, and humidity management for homes across Canada.
Core Topics
Three focused areas that affect air quality in most Canadian homes.
Air Purifiers
How to Choose an Air Purifier Based on Room Size and Filter Type
CADR ratings, filter technologies (HEPA, activated carbon, UV), and how to match a unit's coverage area to the room you intend to treat.
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Ventilation
Ventilation Standards and Humidity Control for Residential Buildings
Canadian NBC and ASHRAE 62.2 requirements, HRV and ERV systems, acceptable indoor RH ranges, and practical humidity management strategies.
Read articleWhy Indoor Air Quality Matters
Canadians spend roughly 90% of their time indoors. The air inside a home is rarely stagnant.
90%
of time spent indoors on average
2–5×
higher pollutant levels indoors vs outdoors in some homes
21 kPa
is the pressure differential that drives stack effect air infiltration
0.35
air changes per hour minimum per ASHRAE 62.2
Ventilation Rates
The National Building Code of Canada sets minimum fresh air requirements for new residential construction, now aligned with ASHRAE 62.2.
Humidity Windows
Health Canada recommends maintaining indoor relative humidity between 30% and 55% to limit mould growth and dust mite populations.
Radon Testing
Health Canada's guideline is 200 Bq/m³. Long-term alpha-track detectors placed in the lowest occupied area give the most reliable readings.
Tight Envelopes
Modern energy-efficient homes built to R-2000 or Passive House standards require mechanical ventilation because natural infiltration is insufficient.
Humidity control is half the equation
Excess moisture feeds mould. Too little causes dry airways, static buildup, and wood shrinkage. A properly sized HRV or ERV maintains balance year-round in Canadian climates.
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