AIR HANDLING UNIT | Pre-Commissioning Inspection Checklists

This AHU system commissioning inspection checklist can be used and completed throughout the project and its different stages:

• delivery,
• storage,
• installation &
• pre-commissioning

Once completed, the entire functional testing of the Air Handling Units can be conducted.

🟩 Delivery Inspection

Once the Air Handling Unit arrives at the site, usually delivered by a transport company, and before being accepted into storage, the following should be checked with the driver.

🔗If you want to know more on Air Handling Units see our article: 'AIR HANDLING UNITS | All we need to know'.

Any damage noted should be reported to the manufacturer/supplier within 3 days in writing, supported with photographs.

Ref	Inspection/Task
1	Supplier's consolidated delivery ticket is available, showing all equipment and ancillaries for inspection and being used to check against.
2	A copy of the order that was sent to the supplier is available for reference and is being used to check against
3	Equipment is packaged and crated in separate boxes, for maximum protection
4	The unit nameplate and details match the purchase order
5	Delivery protection is dry
6	Unit/s are dry internally
7	The external casing of the unit/s are undamaged
8	All frames, if ordered are included
9	All pipework connections are the correct size
10	Pipework connections are undamaged
11	All pipework handing’s are correct
12	All ducting connections are the correct size
13	All ducting connections are the correct size
14	All ancillaries [valves, actuators, dampers, filters] are included in delivery as per the order and delivery note
15	Spin the fan to ensure not damaged and out of line
16	Check all coils for damage externally and internally
17	Replace all protection that has been removed

🟩 Storage Inspection

🟧 Storage Area

If the equipment is to be placed into storage on site before installation, an inspection will be completed checking the following.

Ref	Inspection/Task
1	The area is internal and will not be affected by the weather. [if the unit is not rated for external use]
2	The surface where the equipment is to be placed is flat.
3	The equipment will be raised off of the floor to allow airflow and stop the risk of water ingress.
4	The area is well covered and protected.
5	The area is well ventilated and has no risk of high humidity.
6	The area is clean & dust-free.

🟩 Storage of Air Handling Unit

Before the units are placed into storage, the following should be checked.

Ref	Inspection/Task
1	Units will not be stacked.
2	Units will not have materials stacked on them.
3	All ancillaries will be placed in a safe and secure location so items do not go missing or get damaged.
4	All original packaging is intact and not removed.
5	Pipework caps are not removed.
6	Unit and all components placed on a flat surface.

🟩 Pre-Installation Inspection

Before the units are installed, the following should be checked.

Ref	Inspection/Task
1	The plinth/base is ready, flat, and level & can bear the weight of the installation.
2	The room/area is dry and watertight.
3	The area being installed is not prone to flooding or ponding of water.
4	The room/area the unit will be installed into is clean and dust-free. If there is dust/construction work then the unit should be protected.
5	If the unit is installed externally then ensure it can be fixed to the floor, check for internal mounting requirements with the manufacturer.
6	If there is a buildup of snow it will not affect the unit’s operation or maintenance requirements.
7	The installation of the unit will not impede the installation of the condensate trap/pipework.
8	All connections, pipework/ductwork, etc., can be independently supported and not supported by the unit. The best practice is to install self-supporting brackets prior to the connection of the unit
9	Ensure that all access doors are clear and not blocked from brackets or other services.
10	Check to ensure that all connections kits containing – gaskets, bolts, cleats, screws are available to allow bolting up of the equipment.
11	Remove all transport feet and bolts.
12	Check that all required cabling can be run through the unit and on appropriate containment.

🟩 Maintenance/Access

Ref	Inspection/Task
1	There is enough space allowed around and above the unit once installed to perform maintenance, and remove components. [check the manufacturer’s maintenance instructions for requirements]
2	All doors can be fully opened to gain access to the unit.
3	Check that there is enough space for coils and fans to be removed and replaced. [Don’t forget that if the unit is mounted outside the surface will need to be hard and flat]
4	If the unit is mounted at a high level, confirm that there is a safe manner to remove the parts and components and that there is enough space at a high level and at the floor level to allow this.

🟩 Pre-Commissioning Inspection

Once the equipment has been installed and before the functional testing and commissioning phase, the following will be checked.

🟧 General

Ref	Inspection/Task
1	Document the information of the unit from its nameplates and cross-reference with the specified information to ensure correct.
2	Ensure the unit is level.
3	Ensure all gaskets are installed and sealed.
4	Ensure that all cleats are installed as per manufacturers’ instructions.
5	All-access doors can be open and closed with no gaps or leakage.
6	Check that all transport bolts and feet are removed.
7	Roof canopy, if being used, is installed and fixed.
8	All vibration mounts installed
9	Seismic restraints, where required, installed.
10	Unit and all components including valves and controls are labeled in line with the project naming convention.
11	Operation and startup manual for the AHU available.

🟧 Electrical General

Ref	Inspection/Task
1	Unit and components are fully earthed in line with the manufacturer’s instructions.
2	Earthing has been tested
3	Emergency disconnect installed for each component in line with NFPA/local code requirements
4	Electrical voltage from the site matches the unit required voltages.
5	All cabling is installed and connected on the correct containment/raceways and not damaged.
6	All cabling has been tested/torque tested.
7	A local motor control panel [LMCP] has been installed
8	The local motor control panel has been electrically tested
9	All electrical cabling is labeled in line with the project naming convention.

🟧 Variable Speed Drive

Ref	Inspection/Task
1	A variable speed drive has been installed.
2	Variable Speed Drive [VSD] has been electrically tested
3	Variable speed drive has been functionally tested

🟧 Controls System/Motorized Dampers & Interlocks

Ref	Inspection/Task
1	Motorized dampers installed as per the drawings and open/close freely.
2	All controls and panels have been installed to operate the motorized dampers
3	Fire trip has been installed and operating/interlocked with the ventilation system.
4	Freezing safety interlocks installed as per the design.
5	Pressure differential measuring devices are installed across all filters

🔗To see our Ductwork Checklist, see our article: 'DUCTWORK | Pre-Commissioning Checklist'

🟧 Fresh Air Intake

Ref	Inspection/Task
1	The position of the intake louver is in line with the design requirements and positioned so as will not be affected by any exhaust air.
2	Weather louver/roof cowl installed and weather tight with relevant mesh and is unobstructed.
3	Weather louver installed with correct mesh.
4	Weather louver mesh-free area meets the design requirements
5	Plenum installed connecting the louver to the ducting.
6	Plenum has drain installed with trap to remove any unwanted ingress of water
7	Plenum has access hatch/s installed to allow future maintenance and inspections
8	All fresh air ductwork is installed, correct size, and connected to the unit with correct fixings
9	All attenuators are installed as shown on the drawings.
10	All non-return dampers are installed as per construction drawings.
11	All volume control dampers are installed as per construction drawings.
12	Ductwork insulated and vapor seal in line with the specification.
13	Test holes available in the duct to allow air readings

🟧 System Fire Dampers

Ref	Inspection/Task
1	If fire dampers were installed as per the drawings, confirm that they have been tested in line with the project requirements.

🟧 Filters

🟨 Panel Filters

Ref	Inspection/Task
1	Filter mounting frames are clean and dust-free.
2	Panel filters are installed, clean, and are of the correct grade.
3	Filters have the correct sealing gaskets installed.
4	The filters are not jammed in the rails
5	All components upstream of the filter are clean and dust-free
6	Panel filters are locked in place
7	Differential pressure sensors are installed and calibrated.

🟨 Bag Filters

Ref	Inspection/Task
1	Filter mounting frames are clean and dust-free.
2	Bag filters are installed, clean, and are of the correct grade.
3	Filters have the correct sealing gaskets installed.
4	The filters are not jammed in the rails
5	All components upstream of the filter are clean and dust-free
6	Bag filters are locked in place
7	Differential pressure sensors are installed and calibrated.

🟧 Supply Air Fan

Ref	Inspection/Task
1	Electrical connections and cables are complete, fully tested, and torqued in line with project/manufacturer requirements
2	Motor protection installed and operating [Overload]
3	Motor protections calibrated
4	Voltage from electrical systems is correct for the unit requirements [within +/-10%]
5	Fan housing is clean and dust-free
6	Fan, blades, and motors are clean and dust-free.
7	Fan belt tension is correct
8	Fan belt condition is good
9	Ensure the fan wheel is centered on the intake section
10	Check the tightness of fixings [torque]
11	Check flexible connections between the motor/impeller and unit to ensure are in good condition and leak-free.
12	Impeller is balanced
13	Fan/motor rotates in the correct direction with no obstructions [by hand]
14	Fan/motor rotates in the correct direction with no obstructions [electrically bump unit on]

🟧 Cooling Coil

Ref	Inspection/Task
1	The cooling coil is clean, in good condition, and the fins undamaged.
2	Ensure that the pipework is connected and the correct size
3	Ensure that the flow and return pipework handings are correct. [Water Inlet – downstream of the airflow direction Water Outlet – upstream of the airflow direction]
4	The installation of the pipework will not put stress on the equipment connections or create vibrations.
5	The materials used between the equipment and the chilled water system will not cause Electrolysis.
6	Pipework that is to connect to the unit has been weld tested.
7	Pipework that is to connect to the unit has been pressure tested.
8	Pipework that is to connect to the unit has been cleaned and flushed.
9	Equipment has been backflushed.
10	The system has been bled and air removed.
11	The chilled water system has been hydraulically balanced.
12	Pipework is insulated and vapor sealed
13	Insulation is labeled
14	All pressure gauges installed, and display scale as per design requirements.
15	All valves/control valves are installed and incorrect direction
16	All commissioning devices are installed

🟧 Heating Coil

Ref	Inspection/Task
1	The heating coil is clean, in good condition, and the fins are undamaged
2	Ensure that the pipework connection is the correct size
3	Ensure that the flow and return pipework handings are correct. [Water Inlet – downstream of the airflow direction Water Outlet – upstream of the airflow direction]
4	The installation of the pipework will not put stress on the equipment connections or create vibrations.
5	The materials used between the equipment and the heating water system will not cause Electrolysis.
6	Pipework that is to connect to the unit has been weld tested.
7	Pipework that is to connect to the unit has been pressure tested.
8	Pipework that is to connect to the unit has been cleaned and flushed.
9	Equipment has been backflushed.
10	The system has been bled and air removed.
11	The heating water system has been hydraulically balanced.
12	Pipework is insulated and vapor sealed
13	Insulation is labeled
14	All pressure gauges installed, and display scale as per design requirements.
15	All valves/control valves are installed and in the correct direction
16	All commissioning devices are installed

🟧 Refrigerant Dx Coil System

Ref	Inspection/Task
1	The refrigerant coil is clean, in good condition, and fins are undamaged
2	External condenser installed
3	Ensure that the gas and suction pipework is connected and the correct size
4	Ensure that the gas and suction pipework handings are correct.
5	The installation of the pipework will not put stress on the equipment connections or create vibrations.
6	The materials used between the equipment and the refrigeration pipework system will not cause Electrolysis.
7	Pipework that is to connect to the unit has been pressure/vacuum tested.
8	The system is charged with the correct amount of refrigerant.
9	Pipework is insulated and vapor sealed
10	Insulation is labeled
11	All solenoids installed and operating
12	All sight glasses installed
13	All valves/control valves are installed and in correct direction

🟧 Droplet Eliminator

Ref	Inspection/Task
1	Ensure is unobstructed and can be removed for maintenance/cleaning.
2	All pipework/condensate is connected to the drain [see condensate section]

🟧 Steam Humidifier

Ref	Inspection/Task
1	Unit is electrically connected with testing completed to electrical components.
2	Humidifier internals is clean and clear of debris.
3	Condensate pipework is installed [see condensate section].
4	Coldwater feed is connected to the humidifier standalone unit.
5	Connections between the standalone unit and the humidifier are using the specific manufacturer’s hoses
6	The hoses and pipework that is connected are installed in line with the manufacturer’s requirements. No tight bends, or kinks.
7	Metal clamps are used to connect the pipework between the humidifier and the standalone unit.
8	Controls valves fitted and operating to allow cold water into the system.
9	Check that the humidity sensor is calibrated.

🟧 Cold Water Feed

Ref	Inspection/Task
1	Pipework pressure tested
2	Pipework insulated and vapor sealed
3	All valves fitted and operating [isolation, non-return]

🟧 Condensate drain/siphon

Ref	Inspection/Task
1	The condensate is installed to the correct fall.
2	Ensure is protected from any frost with insulation and/or heating cable.
3	There is a trap installed and is installed in line with manufacturers’ requirements. [Check manufacturer’s instructions for calculation/requirements]
4	If there are multiple coils installed on a unit, ensure the condensate pipework configuration is installed in line with the manufacturer’s requirements.
5	Check that the size of the condensate is correct.
6	Ensure the trap is filled to the correct level.
7	Ensure the drain pan is clean and free of debris

🟧 Electric Heater

Ref	Inspection/Task
1	Operation of the heating coil is fan controlled/interlocked
2	Fan delay incorporated into the controls logic, allowing the fan to run [15 mins] after the heater has deactivated/switched off.
3	Heater elements are clean and not obstructed by debris
4	All electrical testing was completed including torque tests of connections.
5	All safety components are connected and operational including all thermostats to cut power to the heater if needed.
6	All controls cabling is connected and installed in line with the manufacturers/design drawings.
7	Power is available to the electric heater/control panel for operation.

🟧 Supply Air Ductwork

Ref	Inspection/Task
1	All supply air ductwork is installed, correct size, and connected to the unit with correct fixings
2	All attenuators are installed as shown on the drawings.
3	All volume control dampers are installed as per construction drawings.
4	Ductwork insulated and vapor seal in line with the specification.
5	Test holes available in the duct to allow air readings

🔗To see our Fire Damper Checklist, see our article: 'FIRE DAMPER | Pre-Commissioning Checklist'

🟧 Return Air Ductwork

Ref	Inspection/Task
1	The position of the extract louver is in line with the design requirements and positioned so as will not affect the fresh air intake.
2	Weather louver/roof cowl installed and weather tight with relevant mesh and is unobstructed.
3	Weather louver installed with correct mesh.
4	Weather louver mesh-free area meets the design requirements
5	Plenum installed connecting the louver to the ducting.
6	Plenum has access hatch/s installed to allow future maintenance and inspections
7	All extract air ductwork is installed, correct size, and connected to the unit with correct fixings
8	All attenuators are installed as shown on the drawings.
9	All non-return dampers are installed as per construction drawings.
10	All volume control dampers are installed as per construction drawings.
11	Ductwork insulated and vapor seal in line with the specification.
12	Test holes available in the duct to allow air readings

🟧 Return Air Fan

Ref	Inspection/Task
1	Electrical connections and cables are complete, fully tested, and torqued in line with project/manufacturer requirements
2	Motor protection installed and operating [Overload]
3	Motor protections calibrated
4	Voltage from electrical systems is correct for the unit requirements [within +/-10%]
5	The fan housing is clean and dust-free
6	Fan, blades, and motors are clean and dust-free.
7	Fan belt tension is correct
8	Fan belt condition is good
9	Ensure the fan wheel is centered on the intake section
10	Check the tightness of fixings [torque]
11	Check flexible connections between the motor/impeller and unit to ensure are in good condition and leak-free.
12	Impeller is balanced
13	Fan/motor rotates in the correct direction with no obstructions [by hand]
14	Fan/motor rotates in the correct direction with no obstructions [electrically bump unit on]

🟧 Heat Recovery Unit

🟨 Plate Heat Exchanger

Ref	Inspection/Task
1	Electrical connections and cables are complete, fully tested, and torqued in line with project/manufacturer requirements
2	Condensate is connected where required.
3	Components are clean and undamaged
4	Ensure any bypass dampers can operate correctly and are not obstructed.
5	Ensure any pressure and temperature sensors are calibrated.

🟨 Thermal Wheel

Ref	Inspection/Task
1	Electrical connections and cables are complete, fully tested, and torqued in line with project/manufacturer requirements
2	Condensate is connected where required.
3	Components are clean and undamaged
4	The wheel is able to turn without being obstructed
5	Belts are tight
6	Motor alignment is correct
7	Ensure any pressure and temperature sensors are calibrated.

🟧 Extract Air Ductwork

Ref	Inspection/Task
1	All return air ductwork is installed, correct size, and connected to the unit with correct fixings
2	All attenuators are installed as shown on the drawings.
3	All non-return dampers are installed as per construction drawings.
4	All volume control dampers are installed as per construction drawings.
5	Ductwork insulated and vapor seal in line with the specification.
6	Test holes available in the duct to allow air readings

🟧 Controls

Ref	Inspection/Task
1	Ensure all sensors and instruments are installed as per the control logic/manufacturers wiring drawings
2	All sensors are calibrated

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⬜ Air Handling Unit Commissioning Checklist [PDF] & [.doc]

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⬜ AHU [Air Handling Unit] Pre-Functional Checklist [Microsoft Word]

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