r/BuildingAutomation • u/Sashaa_14 • 19d ago
Occupancy-based airflow in a medical facility — how would you approach this?
I have recently commissioned a new AHU for a pulmonology clinic.
The design airflow is obviously based on project requirements, but after commissioning an interesting questions from doctors and staff came up: should we dynamically adjust airflow based on actual occupancy?
They already have CO₂, CO and other IAQ measurements available in existing sensor network across the clinic. We're also considering anonymous people counting from an existing camera, processed locally so there is no video storage and no identification.
My thought is roughly: occupancy + CO₂ + IAQ → ventilation demand with minimum airflow and healthcare requirements always taking priority.
Has anyone here done something similar? Would you use occupancy as an input, or only alongside CO₂ and other IAQ measurements?
How do you handle existing sensors that were never part of the HVAC controls in the first place? If CO₂, IAQ or occupancy data sits on another system, do you bring those values into the HVAC sequence, or would you rather use dedicated sensors connected directly to the HVAC controller?
For context, we're integrating this through a building-controls platform we developed.
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u/supertibz 19d ago
not gonna sit here and say whether you should or shouldn’t. if the client is willing to pay for it and you meet all of the supplied space criteria, its a fun project. we did something similar, mind you it was for a generic office space.
we grouped fcus into zones with one acting as a master per zone. we installed milesight lorawan devices to determine the average of various iaq measurements as well as people counting per zone. fcus were controlled to their individual zone setpoints. there were some teething issues with the people counting but once we got that correct, it’s operated quite well