A5 Daikin — Filter pressure drop high
At a glance
- Severity
- WARNING
- Domain
- air_handling_unit
- Reference standard
- EN ISO 16890, UNI 10339, ASHRAE 52.2
- Product / context
- Freeze-up protection (reduced airflow)
What it means
The pressure drop across the AHU filters exceeds the set limit value. The filters are clogged and reduce airflow, compromising indoor air quality and energy efficiency. If not addressed, the fan operates under overload and indoor comfort deteriorates.
Probable causes
- Filters not replaced according to the scheduled maintenance plan
- Particularly polluted outdoor environment (construction sites, industrial zones)
- Filter class not suited to the environment (too fine a filter that clogs rapidly)
- Differential pressure switch incorrectly calibrated or faulty
- Missing pre-filter causing the final filter to load too quickly
Reference values
| filter pressure drop pa | {"new":"50-120","replacement":"> 250 (indicative, depends on filter class)","nota":"Compare with the commissioning value at nominal airflow."} |
|---|
Where to start
Replace the filters immediately. Use filters of the same class and size. Check filter frame gaskets to prevent bypass. Reset the alarm after replacement. Record the date for the next service interval.
Full guided diagnosis in the app
The diagnostic tree for this fault has 5 guided steps with measurements, checks and resolutions. You'll find it in HVACIQ, one of the five IndexOS apps: free, works offline.
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