Air Handling Unit Maintenance Works

Full Scope :

1. General Inspection

   • Visual inspection of all components: casing, access panels, filters, dampers, coils, and fans

   • Check for unusual noise, vibration, or air leakage

2. Air Filter Cleaning or Replacement

   • Clean washable filters or replace disposable ones

   • Check for correct filter fit and MERV rating compliance

3. Cooling and Heating Coil Maintenance

   • Inspect and clean chilled water or DX coils using chemical coil cleaner

   • Check coil fins for damage or blockage and straighten if needed

   • Verify coil temperature differential (ΔT)

4. Blower and Motor Servicing

   • Inspect fan blades, housings, and shafts

   • Clean and lubricate motor bearings (where applicable)

   • Check fan alignment and tension (for belt-driven units)

   • Measure motor current and operating voltage

5. Belt and Pulley Check

   • Inspect belts for wear, cracks, or slack

   • Adjust belt tension and alignment

   • Replace worn-out belts

6. Drain Pan and Condensate Line Cleaning

   • Clean and disinfect condensate tray to prevent algae or mold buildup

   • Flush drain line to prevent clogging and water overflow

7. Dampers and Actuators Inspection

   • Test operation of fresh air, return air, and mixing dampers

   • Check actuator function and calibration

8. Filter Differential Pressure Check

   • Measure pressure drop across filters to determine if replacement is needed

   • Install differential pressure gauges if not present

9. Electrical and Control Panel Inspection

   • Tighten electrical terminals and check for overheating

   • Inspect sensors, relays, timers, and BMS interfaces

   • Test thermostat and controller accuracy

10. Airflow and Static Pressure Measurement

• Measure airflow at supply and return sections

• Check total static pressure to assess duct resistance and fan performance

11. Insulation and Casing Check

• Inspect internal and external insulation for moisture, peeling, or damage

• Repair leaks or broken seals in AHU casing

12. Disinfection and Indoor Air Quality (IAQ) Treatment

• Apply approved disinfectant and anti-microbial spray inside AHU chamber

• Optional UV lamp check or installation

13. Performance Reporting

• Record operational data, performance issues, and corrective actions taken

• Provide maintenance report with photos, readings, and recommendations

Frequency:

• Monthly / Quarterly: General inspections, filter maintenance, drain cleaning

• Bi-Annually: Full coil, fan, and motor servicing

• Annually: Comprehensive cleaning, performance testing, and parts replacement