Barometric pressure and pressure trends help place indoor readings in a building-physics story. Weather systems change pressure outside. Wind and stack effect change how air moves through cracks, shafts, doors, windows, and mechanical systems. HVAC operation can create local pressure differences that pull air from spaces you did not intend to sample.
The BMP390L does not measure pollutant concentration and should not be described as an IAQ compliance sensor. Its value is contextual: when PM or VOC patterns coincide with weather shifts, wind-driven infiltration, exhaust fans, or door cycles, pressure data helps keep the explanation grounded.
In practice, pressure is useful for diagnosing placement and root cause. A repeated PM rise during windy periods may suggest envelope leakage. A VOC or NOx pattern near a garage door may suggest pressure-driven transfer. A pressure step during HVAC cycling can explain why a room recovers faster at some times than others.
That makes pressure commercially valuable even when it is not the headline metric. Facilities teams often need evidence that a pattern is caused by building operation, not just a pollutant label.
References
- Bosch BMP390L datasheet (PDF)
- NIST - Building pressure research www.nist.gov
- ASHRAE - Handbook of Fundamentals www.ashrae.org
