An air handling unit preventive maintenance schedule lists the checks and jobs done on the equipment at fixed intervals, how long each takes, and in what order of frequency, so problems are found before the air handling unit fails. This page gives the schedule used in the PlantOps360 task library for air handling unit (ahu), which follows common industry practice for general-purpose equipment. It is also searched for as AHU, air handler, ducted unit, fan coil AHU.
The maker’s manual and your site safety procedures always come first where they differ. Intervals set by law differ by state.
Air handling unit preventive maintenance schedule and checklist
| How often | Task | Estimated time |
|---|---|---|
| Daily | Check supply air temperature, differential pressure of filters and for abnormal noise | 3 min |
| Weekly | Check filter differential pressure; clean pre-filters | 15 min |
| Monthly | Check belts, pulleys and fan bearings; grease motor and fan bearings | 45 min |
| Monthly | Check dampers, actuators and condensate drain pan and trap | 30 min |
| Quarterly | Clean cooling coil and check coil leaks; replace pre-filters | 60 min |
| Half-yearly | Replace secondary (bag or panel) filters; check VFD and fan balance | 90 min |
| Annual | Deep clean the unit and coils; check insulation, door seals, motor insulation and controls calibration | 300 min |
Air handling unit maintenance frequency and yearly workload
At the estimated times, one air handling unit needs about 58 hours of preventive maintenance a year. The biggest single job is “Deep clean the unit and coils; check insulation, door seals, motor insulation and controls calibration” at 300 minutes, done annual. Multiply by the number of units you have to see the workload for your plant.
| Frequency | Tasks | Time per round | Hours per year |
|---|---|---|---|
| Daily | 1 | 3 min | 18.3 h |
| Weekly | 1 | 15 min | 13.0 h |
| Monthly | 2 | 75 min | 15.0 h |
| Quarterly | 1 | 60 min | 4.0 h |
| Half-yearly | 1 | 90 min | 3.0 h |
| Annual | 1 | 300 min | 5.0 h |
What goes wrong on an air handling unit without preventive maintenance
- Clogged filters raising fan energy use
- Dirty or leaking cooling coil
- Belt and bearing wear
- Blocked condensate drain
What to watch between services
- Filter differential pressure
- Supply air temperature
- Fan noise and vibration
Safety and statutory notes for air handling unit maintenance
Clean areas have HEPA filters and pressure monitoring, with their own schedules and requalification rules.
Where an air handling unit preventive maintenance schedule is used
An air handling unit is found in almost every industry. The industry guides below show how it fits into the wider schedule of each one:
- Preventive maintenance schedule for pharmaceutical plants
- Preventive maintenance schedule for food, dairy and beverage plants
- Preventive maintenance schedule for automotive plants
- Preventive maintenance schedule for chemical, fertiliser and petrochemical plants
- Preventive maintenance schedule for cement, glass, ceramics and building materials plants
- Preventive maintenance schedule for steel, foundry, forging and metal plants
- Preventive maintenance schedule for textile and garment mills
- Preventive maintenance schedule for thermal and hydro power plants
See all industry preventive maintenance schedules.
Related equipment maintenance schedules
- Chiller preventive maintenance schedule
- Air-cooled chiller preventive maintenance schedule
- Cooling tower preventive maintenance schedule
- Fan coil unit, split AC preventive maintenance schedule
- Variable refrigerant flow system preventive maintenance schedule
- Cold room preventive maintenance schedule
- Ammonia refrigeration plant preventive maintenance schedule
- Desiccant dehumidifier preventive maintenance schedule
Browse the full list of equipment preventive maintenance schedules (317 types).
Run this air handling unit schedule in maintenance software
In preventive maintenance software, each row above becomes a recurring task on the asset with its checklist, time estimate and parts. Tasks can be triggered by calendar date, running hours, meter readings or production cycles, each completed task is recorded with the person and date, and a failed check can open a work order. For the method behind it, read the guide to the preventive maintenance schedule, or use the free generator to get a 12-month plan for your whole equipment list.
Build my preventive maintenance schedule (free Excel)
Frequently asked questions
How often should an air handling unit be serviced?
In our schedule an air handling unit has 7 tasks: 1 daily, 1 weekly, 2 monthly, 1 quarterly, 1 half-yearly, 1 annual. The biggest job is “Deep clean the unit and coils; check insulation, door seals, motor insulation and controls calibration”, which is done annual. Always follow the maker’s manual where it gives a different interval.
What is included in air handling unit preventive maintenance?
It covers routine checks and jobs such as “Check supply air temperature, differential pressure of filters and for abnormal noise”, “Check filter differential pressure; clean pre-filters”, “Check belts, pulleys and fan bearings; grease motor and fan bearings”, up to the annual overhaul or inspection. The full list with times is in the table above.
How many hours of maintenance does an air handling unit need per year?
About 58 hours per unit per year at the estimated times in our library, including the daily checks done every day. Use it to plan workload, not as a benchmark.
Is there a free air handling unit maintenance checklist?
Yes. The table on this page is a ready checklist. The free preventive maintenance schedule generator turns it into a 12-month Excel schedule for your list of equipment, with monthly workload hours.