The share of run-time the air handler held its supply-air (discharge) temperature at the value its sequence commanded — including any supply-air-temperature reset. Supply air is the product the AHU delivers to every box it feeds, so a handler that cannot hold its discharge setpoint starves an entire floor at once. The air-handler-level outcome metric behind every VAV box downstream.
How reliably an air handler delivers supply air at the temperature its control sequence commands — the fraction of run-time the measured discharge temperature stayed within a tolerance band of setpoint, including any supply-air-temperature reset the sequence applies. Because every VAV box on the handler receives that supply air, it is the air-side outcome that sits above the terminals — a handler out of band affects the whole floor, not one zone.
Compliance over the period is time(|supply temp − setpoint| ≤ tolerance) / run-time × 100, evaluated only while the AHU is running and calling for cooling, so an off or economizer-only period is not scored against a mechanical-cooling setpoint.
The setpoint is the commanded value including any reset — where the sequence resets supply-air temperature against load or outdoor conditions, compliance is scored against the reset target at each interval, not a fixed number, so a correct reset is not read as a deviation.
A sustained deviation is separated by direction: supply air riding above setpoint under a cooling call points downstream to coil or valve capacity (pair with Cooling ΔT and valve position), while erratic supply air points to sensor, control-loop, or mixing problems.
| Range | Classification | Interpretation |
|---|---|---|
| In band ≥ 95% of cooling run-time | Expected — holding discharge | The handler delivers supply air at its commanded temperature; the boxes downstream have the air they were designed to receive. |
| In band 85 – 94%, or riding above setpoint under load | Losing the discharge — monitor | The handler struggles to hold supply-air temperature under load; scope coil, valve, or airflow before the whole floor drifts warm. |
| In band below 85%, or sustained deviation from setpoint | Out of band — investigate | The handler cannot hold its discharge; a fouled coil, a failed valve, a control fault, or a capacity shortfall — scope the AHU before floor-wide comfort loss. |
Reference bands only. The tolerance and the reset schedule are per AHU; confirm the reset sequence and the sensor calibration before reporting, because a correct supply-air reset scored against a fixed setpoint reads as a false deviation.
The per-AHU target is to hold supply-air temperature within tolerance for ≥ 95% of cooling run-time, scored against the commanded (reset-aware) setpoint. Agree the tolerance and confirm the reset schedule per handler before reporting against it.
The table below shows how moving AHU Supply-Air Temperature Compliance impacts each customer value driver the product is designed to improve — the metric page explains the mechanism; the product pages express the magnitude.
| Value driver | Impact strength | How AHU Supply-Air Temperature Compliance moves this lever |
|---|---|---|
| Customer experience | Direct, primary | Supply air is what every box on the handler delivers to its zone, so an AHU that cannot hold its discharge temperature warms an entire floor at once — the most consequential single comfort signal on an all-air floor. Catching it at the handler protects every downstream zone before the complaints arrive. Magnitude is expected (pending validation) — offices have no named Keedian reference deployment yet. |
| Energy savings | Direct | A handler that cannot hold setpoint drives its boxes to open wide and its own valve to full, and a supply-air-temperature reset that is not followed leaves cooling energy on the table. Holding the discharge — and the reset — is a direct air-side energy lever. |
| Asset lifespan | Indirect, leading indicator | A slow loss of supply-air compliance under load is the leading signature of a coil fouling or a valve losing authority. Flagging it at the handler turns a developing capacity fault into a scoped coil or valve service before it fails. |
The table below summarizes the alarms that fire directly from AHU Supply-Air Temperature Compliance. Each row links to the full operational detail (trigger, preconditions, action plan, human role, escalation, prevention) in the SOPs catalog.
| Alarm | Description | Severity | Tier | AI executes? | Value drivers | SOP |
|---|---|---|---|---|---|---|
| AHU not holding discharge — supply air above setpoint under a cooling call | The air handler holds its supply-air (discharge) temperature above the value its sequence commands while it is calling for cooling — it cannot make the air the floor was designed to receive. Because every box on the handler draws that supply air, one out-of-band AHU warms a whole floor at once: a fouled coil, a chilled-water valve losing authority, low coil flow, or a capacity shortfall at peak. | High | Essential | Hybrid | Customer experience · Asset lifespan | Open SOP → |
| AHU overcooling — supply air below setpoint | The air handler holds its discharge below the temperature its sequence commands — overcooling the supply air it feeds the floor. A chilled-water valve stuck or hunting open, a supply-air reset not applied, or a sequence overriding to a colder setpoint than the load needs; it spends cooling energy the floor did not call for and drives reheat and comfort complaints downstream. | Low | Essential | Hybrid | Energy savings · Customer experience | Open SOP → |
More alarms in development (single-metric): a reset-following check that flags an AHU ignoring its supply-air reset, and a slow-capacity-loss trend under load. Composite AHU alarms that combine supply-air compliance with Cooling ΔT and valve/coil performance to attribute a lost discharge to its mechanical cause will appear in a future release.
The action plan for each alarm lives on its own SOP page in the SOPs catalog — with the diagnostic steps, human role, value drivers, escalation, and prevention specific to that alarm. The list below maps each alarm to its SOP.
Supply-air compliance is meaningless if scored against the wrong target — a supply-air-temperature reset scored as a fixed setpoint manufactures deviations, and a drifted discharge sensor manufactures both false compliance and false breaches. Confirm the reset sequence and calibrate the supply-air sensor before activating the metric for a handler.
At Essential the customer sees the handler out of band; at Managed, Keedian Ops runs the alarm, triages the direction of the deviation, and dispatches; at Optimized, Keedian commands the AHU sequence directly (supply-air setpoint and reset, valve and fan within authority, with an audit trail) and refers a mechanical fault — a fouled coil or a failed valve — for a scoped service.
Per-alarm escalation criteria live in the Escalation block of each SOP in the SOPs catalog. The patterns below are metric-level — read from the portfolio view, not from any single alarm firing.