Method Statement for Split AC Installation of DX Split and Packaged Units

Below is the a detailed split ac installation method statement covering the installation of DX Split Units and packaged units including the installation of outdoor units.

All the split ac installation inspection and testing works shall be carried out in accordance with the project specifications and manufacturer’s installation instructions.

AC installation works including indoor and outdoor installations shall be done by qualified staff in supervision of mechanical engineers and shall be checked and approved by MEP subcontractor’s Construction Manager along with QA/QC Engineer.

Contractor has to clarify the procedure for material delivery to the site through consultant Engineer at site.

Necessary Tools / Equipment

Following tools shall be arranged before starting the AC installation job.

• Tool Box.
• Measuring Tape.
• Hack Saw Blade
• Spirit Level
• Electric Drill Machine
• Step Ladders
• Threading Machine
• Solvent Cement
• Torque Wrench
• Pipe Cutting Machine
• Grinding Machine
• Pressure Gauge
• Hammer
• Water Level Marker
• Mobile Scaffolds
• Staging Platforms

Material Transport/ Delivery 

DX Split Units are shipped & dispatched carefully in good condition, carefully loaded in containers with suitable crating / boxing, hence, in case of transit damage, supplier must be informed immediately.

Special care must be taken to ensure that units are offloaded from containers without damages, rough handling can result in damage to the unit.

Use appropriate type of vehicles in transporting the units and ensure that they are protected against mechanical & weather damage.

All the received units shall be checked & inspected to ensure that it is complying with the approved material submittals prior to site storage.

Material Receiving Storage and Handling

All the materials received at site shall be as per the approved technical material submittal of DX Split & Packaged Units to be inspected upon receipt & approved by the consulting engineer prior in proceeding with the installation of AC.

Any discrepancies, damages etc., should be reported to the supplier for rectification or replacement and non complying items to be removed from site immediately.

To ensure that deterioration of the DX Split Units does not occur during storage, it is recommended to store the equipment in sheltered conditions that are protected from weather elements and accidental damage.

DX Split Units shall be protected with plastic/ tarpaulin or shall not be removed from the shipping package unless otherwise instructed to do so.

Avoid any mechanical shocks and strokes during handling operations.

All packages for the equipment reaching the site shall be identified as per package list.

Health and Safety Requirements

• All site safety rules & regulations shall be complied with.
• Supervisors will deliver tool box talks, relevant to these activities to all operatives involved in the installation and shall be recorded.
• All operatives will be equipped with minimum personnel protective equipment; hard hat, coveralls, safety boots, safety glasses.
• The persons using cleaning fluid and solvent cement have to wear hand gloves.
• Ensure only qualified personnel shall install, test & commissioned the equipment.
• During Installation display warning sign boards and barricade the area whenever necessary.
• Only competent, experienced & trained personnel shall perform all the required activities stated in this method statement.
• Ensure that all operatives fully understand the method of installation as per manufacturer instructions.

Split AC Installation – Pre Requisites

Before commencement of installation of split AC units, the supervisor must ensure that:

• Delivered DX Split Units have been inspected & approved via MIR by the consultant.
• All Installations & Pressure Testing of Pipe/ Duct works have been completed & approved by the consultant.
• Relevant documents or certificates shall be presented at the time of inspection if required by the Consultant, therefore arrange all necessary certificates/test reports etc..
• Civil Clearances prior to installation has been given by the main contractor.
• Installation activities shall only commence when all associated works by the Civil has been completed.
• All relevant Shop drawings for the installation of the equipment are available & approved by the consultant. No installation shall be done without Approved Shop Drawings.
• Safe access to the work area is provided by the main contractor in coordination with the Safety in charge at site.
• Inspect the relevant area for any possible clashes with other services and resolve any clashing conditions/situations.
• Check other nearby services, making sure that there is no interference between each service, and adequate access to work and for future maintenance is maintained.

AC Installation Procedure for DX Split Units (Indoor)

Indoor Type DX Split Units can stand or lie on floor, or hang from ceiling or wall, while deciding the final installation location consider and allow space for wiring, refrigerant/chilled water piping and servicing etc.

For the installation of Horizontal Right Conversion of Units with Slope Coils following AC installation method to be followed:

To achieve optimum condensate drainage performance in horizontal installations, ac unit should be leveled along its length and width.

In a Horizontal Installation, units must not be installed with access panels facing up or down.

All other units are factory built for horizontal left installation.

When suspending unit from ceiling, dimples in casing indicate suitable location of screws for mounting metal supports.

In a Down flow Installation; field conversion of the evaporator coil is required using accessory down flow kit, along with an accessory base kit.

Side return is a field option on slope coil models.

Cut opening as per dimensions.

A field-supplied bottom closure is required.

In an up flow installation if return air is to be ducted through a floor, set unit on floor over opening and use 1/8 to ¼ inch thick fireproof resilient gasket between duct unit and floor.

• Remove blower and coil access panels and fitting panels.
• Remove coil mounting screw securing coil assembly to right-side casing flange.
• Remove coil assembly.
• Lay fan coil unit on its right and reinstall coil assembly with condensate pan down.
• Attach coil to casing flange using coil mounting screw which was removed.
• Align holes with tubing connections and condensate pan connections, and reinstall access panels and fitting panel.
• Make sure liquid and suction tubes are in place to prevent air leaks and cabinet sweating.

Installation of Horizontal Right Conversion AC Units

For Installation of Horizontal Right Conversion following Installation Procedure to be followed:

• Remove blower coil and access panels.
• Remove metal clip securing fitting panel to condensate pan.
• Remove fitting panel.
• Remove 2 snap-in clips securing A-coil in unit.
• Remove horizontal pan bracket and drain pan support by removing the screw.
• Slide coil and pan assembly out of unit.
• Remove horizontal drain pan support bracket from coil support rail on left side of unit and reinstall on coil support rail on right side of unit.
• Convert air- seal assembly from coil by removing the screws.
• Remove air splitter from coil seal assembly by removing 3 screws.
• Remove filler plate and install air splitter in place of filter plate.
• Install filler plate in horizontal right application.
• Remove condensate pan and install on opposite tube sheets.
• Install horizontal pan on right side of unit to secure horizontal pan.
• Slide coil assembly into casing. Be sure coil bracket on each comer of vertical pan engages coil support rails.
• Reinstall 2 snap-in clips to correctly position and secure coil assembly unit. Be sure clip with large offset is used on right side of unit to secure horizontal pan.
• Reinstall horizontal pan bracket, drain pan support and secure with screw which was previously removed.
• Remove knock out on right side of coil access panel.
• Reinstall access fitting panels, aligning holes with tubing connections and condensate pan connections. Be sure to reinstall metal clip between fitting panel and vertical condensate pan.
• Make sure liquid and suction tube grommets are in place to prevent air leaks and cabinet sweating.

Electrical, Piping and Duct Connections to Split Units

For Air Duct Connections, ensure to connect the supply air duct over the outside of the ¾ inches flange provided on the supply air opening.

Secure the duct to the flange, using the approved fasteners for the type of duct used and seal the duct- to- unit joint.

If return air flanges are required, install factory-authorized accessory kit.

Use flexible connectors between ductwork and unit to prevent transmission of vibration.

When electric heater is installed, use heat resistant material for flexible connector between ductwork & unit at discharge connection.

Ductwork passing through unconditioned space must be insulated & covered with vapour barrier.

Ensure all electrical connections have been properly installed & fixed.

Refer to unit nameplate for required supply voltage, fan and heater amperage and required circuit capacity.

Also refer to unit wiring diagram for unit & field wiring.

Ensure that the fan motor should never be controlled by any wiring or device other than the factory supplied control board and remote control.

Once the units are installed, they must still be protected from damage, in particular the pipe work & spigot connections and filters.

Select proper wall location to fix display pad.

If a disconnect switch is to be mounted on the unit, select a location where drill or fastener will not contact electrical or refrigerant components.

In installing the refrigerant tubing, use accessory tubing package or filed supplied tubing of refrigerant grade.

Suction tube must be insulated.

Do not use damage, dirty, or contaminated tubing which may plug refrigerant flow control device.

Check that the piston size shown on indoor unit rating plate if it matches to the required piston shown on outdoor unit rating plate. If it does not match, replace indoor piston with piston shipped with outdoor unit.

Ensure that condensate drains on the units are equipped with primary and secondary FPT drain connections.

To prevent property damage and to achieve the optimum drainage performance, both primary & secondary drain lines should be installed and also include properly sized condensate traps.

 Installation of AC Outdoor Units

Ensure proper location of the units as per the approved shop drawings.

Check and make sure that vapour-and liquid- tube diameters are appropriate to capacity of the unit.

Run refrigerant tubes as directly as possible by avoiding unnecessary turns and bends.

Check routing as per the approved shop drawings.

Leave some slack between structure and unit to absorb vibration.

When passing refrigerant tubes through the wall, seal opening with the approved material for sealing.

Avoid direct tubing contact with water pipes, duct work, floor joists, wall studs, floors and walls.

Do not suspend refrigerant tubing from joists and studs with a rigid wire or strap that comes in direct contact with tubing.

Ensure that tubing insulation completely surrounds the vapour tube.

If required, use hanger straps which are 1 inch wide and conform to shape of tubing insulation.

Insulate hanger strap from insulation by using metal sleeves bent to conform to shape of insulation.

Units shall be mounted to pad; tie down bolts should be used and fastened through knockouts provided in unit base pan.

Arrange supporting members to adequately support units and minimize transmission of vibration.

When installing the ac outdoor units, allow sufficient space for airflow clearance, wiring, refrigerant piping, and service.

When combined with same manufacturer indoor product, a hard shutoff, thermostatic expansion valve is required at the indoor section of the system for proper operation.

A filed installed liquid line filter drier is recommended for the ac outdoor installation.

Ensure field wiring complies with local regulations and electrical codes or as specified in the specification. Also make sure that available voltage is within limits shown on unit rating plate.

Operation of unit on improper line voltage constitutes abuse and could affect the units’ reliability.

Do not install the unit in electrical system where voltage or phase imbalance may fluctuate above or below permissible limits.

General AC Unit Installation Guidelines

Ensure condensing units are installed on a minimum 6 inch thick, ground mounted, reinforced concrete base; minimum 4 inches larger on each side than unit.

Install anchor with concrete base.

Ensure roof mounted components on equipment supports with approved rubber pad for outdoor unit as per structural requirements or specification.

Anchor units to supports with removable Cadmium plated fasteners or as per approved material submittal for supports.

Connect all piping and devices devices as per the approved shop drawings.

Raise inspection request for approval from client/consultant upon completion of split AC installation.