Wildfire smoke reached a care home in the Rockies: what six days of indoor air quality data showed

On 29 June 2026, smoke from fires roughly 800 km to the northeast settled over the Bow Valley in Alberta. Canada’s Air Quality Health Index reached 11, above the top of its normal 1 to 10 scale, and the public guidance was the usual one: stay indoors.

Inside a long term care facility in Canmore, an inBiot MICA had been recording indoor air quality every 15 minutes throughout. So we could check something the guidance never tells you: how much protection staying indoors actually provided.

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What the sensor recorded

Outdoor PM2.5 peaked at 87 µg/m³ while indoor concentrations averaged 33.4% of outdoor across the six days, better than the 55 to 60% that ASHRAE’s wildfire smoke guideline treats as typical for a building with its openings closed.

We then read the same six days against three international references, each built for a different purpose:

• WHO 2021, the 24 hour health guideline that applies indoors and outdoors: exceeded for about a day and a half.

• WELL v2 feature A01, a certification threshold assessed across a full calendar month: 85.5% of readings met it within this six day window.

• GO IAQS Starter, a voluntary benchmark designed for continuous monitoring: every hour met both its PM2.5 and CO₂ limits.

Each answers a different question, over a different averaging period. Reading them together is what gives a building the full picture.

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‍What the report covers

The full analysis sets out what each standard measures and why the averaging period changes the answer, what the nearest official reference stations 100 km away missed about local conditions, and what CO₂ was doing throughout. A monitor measuring only CO₂ would have registered nothing during the entire event.

This analysis is retrospective. Anne, inBiot’s AI IAQ consultant, applies the same benchmarks, WELL v2, EU EPBD, GO IAQS, ASHRAE and WHO, continuously wherever a MICA is running.

Produced with Cirkuit, the Calgary based smart building platform whose client made this data available.

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Read the full report (PDF)