Keedian operations · Standard procedure

Minimum ventilation breach — occupied box below its ventilation floor.

A VAV box is running below its agreed occupied minimum airflow during scheduled-occupied hours — the ventilation floor the zone needs for indoor air quality even when it is not calling for cooling. Whether from an over-aggressive energy setback that starved ventilation, a damper stuck below minimum, or a minimum set too low at commissioning, the result is a quietly under-ventilated occupied zone — the stuffy, high-CO2 room no temperature reading explains. Read against the confirmed design minimum, never a computed ventilation rate.

01 Detail

Trigger, action plan, and escalation criteria.

optimization_metric hvac medium essential tier AI: hybrid

Related metric: vav_airflow_delivery
Trigger: time(measured_airflow < occupied_minimum during occupied_schedule) / occupied_runtime > breach_share (raises minimum-ventilation breach)
Value drivers: Customer experience Energy savings
Preconditions: Per-box measured airflow, the agreed occupied minimum setpoint (a design / ventilation figure — e.g. an ASHRAE 62.1 zone minimum — confirmed per box with its design basis recorded), and the occupancy schedule all mapped. The metric reports compliance against that confirmed floor, not a code-compliance claim or a computed per-person rate. breach_share and occupied_schedule are configurable server-side attributes.
Human role: Primary at Managed/Optimized — Keedian confirms the breach against the agreed occupied minimum and schedule, places the cause (energy strategy vs stuck damper vs mis-set minimum), and either corrects the setback or refers the device. At Essential the customer's team sees the under-ventilated box. Optimized runs the metric as a hard floor on its own occupancy-driven optimization.
Action plan: (1) Confirm the occupied minimum and the schedule before treating the breach as real — a minimum set wrong at commissioning, or a stale schedule, produces false breaches or hides real ones; the compliance figure is only as good as the agreed floor behind it. (2) Confirm the box is below its floor for a sustained share of genuinely occupied hours (breach_share), not a single interval or an after-hours parked box. (3) Place the cause: an over-aggressive occupancy setback starving ventilation (a strategy question), a damper stuck below minimum (a device question), or a minimum set too low at commissioning (a re-commissioning candidate) — pair with zone CO2 where it is monitored. (4) Tiered response — at Essential surface the under-ventilated box; at Managed triage the cause and dispatch a stuck damper; at Optimized hold the minimum as a hard floor on the occupancy-driven optimization and command the box back up (with an audit trail) the moment ventilation is at risk, referring a stuck damper for a scoped visit.
Escalation: (1) An occupied high-density zone (a full meeting floor, a call center) under-ventilated with rising CO2 → an IAQ exposure worth out-of-cycle action, not a cadence item. (2) A sequence or setback change that dropped many boxes below minimum at once → pause that strategy until the ventilation floor is restored across the affected boxes. (3) Boxes whose minimum was set low at commissioning → a re-commissioning candidate carried into the MBR rather than a repeat alarm, since the floor itself is wrong.
Prevention: (1) Record each box's occupied minimum airflow and its design basis, and confirm the occupancy schedule per floor, so compliance is scored against the right floor over genuinely occupied hours. (2) Set the occupancy-setback strategy to treat the minimum as a hard floor, not a target to undercut, and alert on a sustained occupied-hours breach rather than single intervals. (3) Trend minimum-ventilation compliance next to zone CO2 where monitored, and keep a per-box log so a re-commissioning candidate is visible over time.