Purpose of this ahu ac maintenance procedures is to establish standard guidelines for the proper operation and maintenance of Air Handling Units.
This method will also serve as guideline for newly hired employee who will be dealing with Air Handling Unit operation and maintenance activity on a project or in a facility management organization.
Scope of this standard maintenance instruction also covers all Air Handling Units which are under hvac maintenance contracts and installation projects.
It is the responsibility of the maintenance engineer or technician to properly operate and maintain AHU’s. He shall be be competent enough to operate and maintain these equipments to avoid any maloperation or downtime of the equipment due to breakdown.
The Supervisor and the site engineer shall assure that this maintenance procedure will be followed during all works.
Brief Description of Air Handling Unit
Air Handling Unit is used to bring fresh air from outside the building to inside the building.
This helps to pressurize the air inside the building thus preventing dust or dirty air to come inside.
An air handling unit commonly uses chilled water on its evaporator coil to cool the air.
AHU comes in one assembly and consists of intake filter, blower, motor, and evaporator. It uses pump to drive chilled water into the system and uses ducting to provide the cold air inside the building.
AHU Air Handling Unit Operation Method
Prior to start-up, make sure that the suction and discharge valve of the water pump is normally open.
Check the condition of the bag filter, the filter must be in good working condition and that there must be no holes and no leak from the gasket of the filters.
Check the volume damper. It should be open.
Make sure that the circuit breaker is energized.
Switch ON the water pump. Open the air vent cock to release excess air.
Switch ON the AHU.
Check for any abnormality after starting-up.
Shutdown Procedure
Switch OFF the unit. If the unit shall be switch OFF for a long time, de-energize the circuit breaker.
Quarterly Maintenance of AHU
Wear safety goggles, hand gloves and safety shoes when conducting this maintenance procedure.
Switch OFF the AHU to be maintained.
De-energize the circuit breaker of the unit to be maintained.
Open the cover of the AHU to access the blower and motor assembly.
Verify and check the alignment of Blower and Motor Pulley.
Check the Bag Filters. Replace if found dirty.
Inspect the condition of drain pan. Clean any foreign material and dust that would contribute to clogging.
Check the condition of the drain pipe. Apply air pressure to remove any slime or foreign materials inside the pipe.
Inspect the V-belt condition. If damage is found replace it with the same type.
Apply specified amount and quality of grease on the motor and pump.
Switch ON the unit.
Check for any undue noise on the blower and motor. Rectify if found any.
Fill-up the necessary checklists for records purposes.
Semi Annual Maintenance of Air Handling Units
Wear safety goggles, hand gloves and safety shoes when conducting this preventive maintenance procedure.
Switch OFF the AHU to be maintained.
De-energize the circuit breaker of the unit to be maintained.
Do as per scope of works mentioned in quarterly AC maintenance procedure.
Access the cooling coil portion of the AHU unit by removing the access panel.
Check the coil for possible dirt. Clean if found dirty.
Check the 3-way valve and thermostat for proper functioning. Replace if found defective.
Switch ON the unit.
Fill-up the necessary checklists for records purposes.
Annual AHU Maintenance Steps
Wear safety goggles, hand gloves and safety shoes when conducting this maintenance procedure.
Switch OFF the AHU to be maintained.
De-energize the circuit breaker of the unit to be maintained.
Do as per scope of works mentioned in Quarterly and Semi-annually maintenance procedure.
Check electrical connections of motors and control wires on the electrical panel. Conduct bolt or screw tightening on all terminal connections.
Inspect the piping and ducting insulation for possible damage. Replace if any major damage is observed.
Clean the interior and exterior part of the AHU. Conduct painting on all rusted portion of the air handling unit AHU body.
Switch ON the unit.
Fill-up the necessary ahu inspection checklists for records purposes.
AHU Air Handling Unit Preventive Maintenance Checklist
