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Keedian operations · Standard procedure
AHU filter loading high — pressure drop past the change threshold.
The pressure drop across the air handler's filter bank has risen past its change threshold — the filters are loaded and the fan is working harder to push the same air through them. Left alone it raises fan energy, erodes the fan's ability to hold static for the floor, and eventually lets the filter bypass; caught in time it is a planned filter change, not an emergency.
01 Detail
Trigger, action plan, and escalation criteria.
optimization_metric
hvac
medium
essential tier
AI: hybrid
- Related metric
ahu_fan_vfd_performance- Trigger
filter_dp > filter_change_threshold, sustained ≥ loading_duration- Value drivers
-
Energy savings
Asset lifespan
- Preconditions
- The filter differential-pressure sensor (or switch) confirmed valid at onboarding; the clean and change-out ΔP thresholds recorded per AHU from the filter's design; the fan speed and airflow available so the loading can be read alongside the fan-energy penalty it drives.
- Human role
- Scales by tier — at Essential the customer sees the loaded filter and schedules the change; at Managed, Keedian Ops raises the filter-change work order and routes it; at Optimized, Keedian tracks the loading trend and times the change against the fan-energy penalty, with the work order routed to the responsible team. The physical filter change is always the building or vendor team's.
- Action plan
-
(1) Confirm the ΔP reading is valid before raising the change — a plugged sensing line or a mis-scaled sensor manufactures a false high reading; validate against the fan's speed-for-airflow, which should rise with a genuinely loaded filter.
(2) Confirm the differential pressure holds past the change threshold rather than spiking on a single interval.
(3) Time the change: a filter just past threshold with a mild fan-energy penalty is a scheduled work order; a heavily loaded filter dragging the fan toward its ceiling (pair with the static-below-demand condition) is a prompt one before the fan can no longer hold static.
(4) Route the work: at Essential the customer schedules it; at Managed Keedian raises and routes the work order; at Optimized Keedian times it against the energy penalty and routes it — the physical change is the building or vendor team's in every tier.
- Escalation
-
(1) A filter bank loaded to the point the fan can no longer hold the floor's static → prompt change before the floor loses air (pair with ahu_static_below_demand).
(2) AHUs whose filters load far faster than their change interval → an air-quality or pre-filter question for the MBR rather than a shorter change cycle alone.
(3) A ΔP that keeps reading high immediately after a confirmed change → a sensor or sensing-line fault; scope it rather than repeating the change.
- Prevention
-
(1) Record the clean and change-out ΔP thresholds per AHU and confirm the sensor is valid, so loading is scored against the right thresholds.
(2) Alert on ΔP sustained past the change threshold, and trend it next to the fan's speed-for-airflow so the energy penalty is visible and a sensor fault is separable from real loading.
(3) Keep a per-AHU filter-loading log so a bank that loads abnormally fast is visible as an upstream air-quality question over time.