METHOD STATEMENT FOR HVAC WORKS

METHOD STATEMENT FOR HVAC WORKS

CONTENTS

  1. INTRODUCTION
  • PURPOSE
  • SCOPE
  • REFERENCES
  • DEFINITIONS
  • ORGANIZATION CHART
  • DUTIES AND RESPONSIBILITIES
  • METHOD STATEMENT FOR EQUIPMENT INSTALLATION
  • METHOD STATEMENT FOR DUCT INSTALLATION
  1. METHOD STATEMENT FOR REFRIGERANT PIPING INSTALLATION
  1. Refrigerant pipe Insulation
  1. METHOD STATEMENT FOR HVAC SYSTEM TEST
  1. METHOD STATEMENT FOR TESTING, AJUSTING AND BALANCING(T.A.B)
  1. QUALITY CONTROL
  1. SAFETY PLAN
  1. INTRODUCTION

This method statement details the method of performing the various activities involved in the course of works for field installation works of HVAC system for ERC REFINERY PROJECT. These method statements are applicable only for the HVAC system Installation of various building in this project.

  • PURPOSE

This method statement gives guidelines contained herein so as to ensure that the job execution complies with the requirement of the specification and the authorities concerned and serves the intended purpose to satisfactory level.

  • SCOPE

This method statement covers the nature and type of work for the installation of HVAC Equipment, Ducts and Refrigerant piping works in the building and frequency at which inspections are to be carried out.

  • AABC : Associated Air Balance Council
    • ADC : Air Diffusion Council
    • ARI  : Air–Conditioning and Refrigeration Institute
    • ASTM : American Society for Testing and Materials
    • ASME : American Society of Mechanical Engineers
    • ASHRAE:American Society of Heating Refrigerating and Air Conditioning Engineers Inc.
    • NEBB : National Environmental Balancing Bureau
    • NFPA : National Fire Protection Association
    • NEMA : National Electric Manufactures Association
    • SMACNA : Sheet Metal Air Conditioning Contractors National Association
    • UL: Underwriters Laboratories, Inc.
    • FM : Factory Mutual Engineering Corporation
    • ISO : International Organization for Standardization
    • Project Specifications
    • Project IFC Drawings
    • Inspection and Test Plan for HVAC System
  • DEFINITIONS
SITE MANAGER
QC INSPECTOR
CONSTRUCTION MANAGER
SAFETY SUPERVISOR
DUCT FORMAN
HVAC SITE SUPERVISOR
REFRIGERANT PIPING FORMAN
TECHNICIAN / HELPER
TECHNICIAN / HELPER
Daily Work Communication
  • DUTIES AND RESPONSIBILITIES

All workers who are involved in HVAC work shall be oriented to the nature of work, to ensure that the procedure is followed accordingly and to assure that the safety requirements is strictly adhered.

The contractor shall check all documents to ensure that the work is being carried out following the latest revision of issued IFC drawing.

Staff and foreman involved in the Works, whether he is working with GS E&C or Subcontractor, shalltake the responsibilities according to his entitled positions and the Works.

  • SITE MANAGER

The Site Manager shall be responsible for the over-all direction, coordination and control of all site activities and all construction works including HSE and quality control, etc.

  • CONSTRUCTION MANAGER

The Construction Manager shall report to and receive technical direction from the Site Manager and developing and arranging the site construction team to the site necessary to manage and supervise theconstruction works including HSE and quality control, etc. The Construction Manager shall be responsible for the overall implementation and monitoring of all the activities for the successful completion of construction works.

  • QUALITY CONTROL INSPECTOR

The QC Inspectorshall be responsible for performing the inspection and test in accordance with Inspection and Test Plan as approved by Company. And also QC Inspectorshall prepare hold point inspections and the corresponding work releases by reviewing records and test results as proof that work inspected conforms to specification.

  • SAFETY SUPERVISOR

The Safety Supervisor shall be responsible for the organization of Health Safety and Environment (HSE) activities on site. To ensure that all safety plans, safety rules and regulations are being implemented accordingly. And also Safety Supervisor shall prepare prior to the start of the work a safety plan that must be implemented and observed during the HVACEquipment, Ducts and Refrigerant piping works and safety awareness of workers during the activity

  • HVAC SITE SUPERVISOR

The HVACSupervisor shall be report to and receive project direction from the construction manager.The HVACSupervisorshall be directly involved in the planning and execution of the activities in the HVAC Equipment, Ducts and Refrigerant piping works. And also HVAC Supervisor shall prepare prior to the start of work, a safety action, controlling of construction schedule, including submittal and inspection of materials that must be implemented and observed during the HVAC work.

  • HVAC FORMAN

The Forman shall be responsible for the direct execution of works involve in the HVAC work according to the plan and shall directly control and give instruction to the working personnel. The Forman shall also ensure that works are done with utmost regard to safety and quality.

  • METHOD STATEMENT FOR EQUIPMENT INSTALLATION

All units shall be inspected by contractor and company prior to start work and after inspecting the units, protect them properly in storage until their actual installation at site. The Contractor shall be installed HVAC equipmentas per approved layout.

  • Air Handling Unit Installation
    • Place the equipment on the foundation.
    • Connect the supply & Return ducts to AHU with flexible duct connector.
    • Connect the refrigerant piping, suction and liquid line to the AHU and Condensing unit with necessaryaccessories like filter drier, sight glass with proper support such that it should not be stressed.
    • Connect the power and control Cables to the unit Control Panel as per the wiring diagram supplied by themanufacturer along with the unit.
    • Connect the drain piping to the unit condensate drain outlet.
  • Air Cooled Condensing Unit Installation
    • Lift the outdoor unit with suitable lifting gear and position it on foundation as per the drawing.
    • Ensure that the unit position on foundation is such that the condenser fan intake and discharge is asshown in the working drawing.
    • Connect the refrigerant pipe work to the respective connections in the outdoor unit.
    • Connect electrical power and control cabling to the units control panel, as per the wiring diagram suppliedwith the unit.
    • Single Package Rooftop Air Conditioner Unit
    •  
      • Place the equipment on the foundation.
      • Connect the supply & Return ducts to RTU with flexible duct connector.
      • Connect the power and control Cables to the unit Control Panel as per the wiring diagram supplied by themanufacturer along with the unit.
      • Connect the drain piping to the unit condensate drain outlet.
  • Split Air Conditioner Installation
  •  
    •  
    •  
      • Place the Air Conditioning unit as per approved layout.
      • Marking for drilling work at hanger’s point.
      • Place the Vibration Pads between the AC unit and Foundation.
      • Connect the ducts to package unit with flexible duct connector (if any).
      • Connect the power and control cables to the unit control panel as per the wiring diagram supplied byManufacturer alongwith the unit.
      • Connect the drain piping to the unit condensate drain outlet.
  • FAN Installation
    •  
      • Place the fan as per approved layout.
      • Marking for drilling work at hanger’s point.
      • Drilling & installation of anchor fastener in the required position as per drawing
      • Threaded rod installation.
      • Connect flange joint of fan & duct by flexible of tighten bolts & nuts.
      • Ensure the alignment before and after connecting with the duct.
      • Apply duct sealant at the joint after connecting with duct to prevent air leakage.
      • Connect the power and control cables to the unit control panel as per the wiring diagram supplied byManufacturer along with the unit.
  • Air filter unit and filter boxInstallation
    •  
      • Place the unit as per approved layout.
      • Connect flange joint of fan & duct by flexible of tighten bolts & nuts.
      • Connect with the damper and bleed fan make sure the mechanically functional.
      • Ensure the alignment before and after connecting with the duct.
      • Apply duct sealant at the joint after connecting with duct to prevent air leakage.
      • Connect the power and control cables to the unit control panel as per the wiring diagram supplied by Manufacturer alongwith the unit.
  • Electric Duct Heater Installation
  •  
    •  
    •  
      • Place the electric duct heater as per approved layout.
      • Marking for drilling work at hanger’s point.
      • Threaded rod installation (If required).
      • Connect flange joint of fan & duct by tighten bolts & nuts or by using cleat.
      • Ensure the alignment before and after connecting with the duct.
      • Apply duct sealant at the joint after connecting with duct to prevent air leakage.
      • Connect the power and control cables to the unit control panel as per the wiring diagram supplied byManufacturer along with the unit.
    • Humidifier
  •  
    •  
    •  
      • Remove the front cover
      • Check the accessories are exit, and remove the protective film.
      • Fit the front cover again
      • Connect the water line, taking into consideration installing a manual valve upstream the installation.
      • Connect a section of non-conductive pipe or hose for draining (resistant to temperatures of 100 °C (212 °F) and with aminimum inside diameter of 40 mm/1.6”).
      • Threaded rod installation (If required).
      • Connect flange joint of fan & duct by tighten bolts & nuts or by using cleat.
      • Ensure the alignment before and after connecting with the duct.
      • Apply duct sealant at the joint after connecting with duct to prevent air leakage.
      • Connect the power and control cables to the unit control panel as per the wiring diagram supplied byManufacturer along with the unit.
      • Connect the drain line to spill off the drain with air gap on the trench grating.
        Important: when installation is completed, flush the supply hose for around 30 minutes by piping water directly into the drain, without sending it into the humidifier. This will eliminate any scale or processing residues that may block the drain pump and cause foamwhen boiling.
      • Install the jet distributer inside the AHU.
      • Connect the steam hose supplied with the unit as rigid pipes may break and cause steam leaks.
      • Avoid the formation of pockets or traps (causes of condensate);
      • Avoid choking the hose due to tight bends or twisting.
      • Fasten the end of the hose to the connectors on the humidifier and the steam distributor using metal clamps, so that these do not detach dueto the high temperature.
      • During the operation of the humidifier some of the steam may condense, causing a decline in efficiency and noise (gurgling), to drain the condensate, connects a drain hose with a drain trap and aminimum slope of 5° to the bottom of the humidifier.
  • Connect the power and control cables to the unit control panel as per the wiring diagram supplied by Manufacturer alongwith the unit.
  • METHOD STATEMENT FOR DUCT INSTALLATION

All the ducts will be fabricated by approved manufacturer and will be delivered to site. Duct work shall be fabricated by galvanized steel for all work except for battery room and laboratory rooms will be Stainless steel 304, and constructed in a thorough and substantial manner in accordance with practices as described in the ASHRAE guide and Data Book and the SMACNA duct construction standards.

  • DUCT Fabrication and Assembly
    • Check & review relative drawings prior to fabrication.
    • Check required materials such as galvanized steel sheet, corner plate, carriage bolts & nuts, neoprene gasket, cleat bar and silicon for caulking as well.
    • Clean surface of galvanized steel sheet. Normally GI coils are using the factory for Duct.
    • Fabrication; these coils are usually dust free and well packed from factory. So there is no need to cleanthe GI coil before fabrication. Unless otherwise any greasy or white corrosion found on the GI coils orsheet before duct fabrication, can use the following steps can be followed.
    • Manually wiping of the duct internal surface using a medium (rags or soft brush) appropriate for thepurpose.
    • If any heavy debris, it shall be removed by hand scraping hand brushing or manual.This shall carried-out/repeated until visual acceptance.
    • Cut necessary size of the galvanized steel sheet by using of cutting machine according to shop drawings.
    • Make TDF (Transverse Duct Flange) on the end of galvanized steel sheet by use of TDF machine.
    • Bend the galvanized steel sheet by using of bend machine according to marked line.
    • Complete duct connecting each longitudinal seams on edge of galvanized steel sheet. Attach cornerplate on 4 corner of flange.
    • Attach reinforcement bar on the surface of duct according to HVAC duct general detail drawings ifnecessary.
    • Apply duct sealant to all joints after duct fabrication/assembly is completed to prevent air leakage.
  • Round DUCT Connection (if any)
    • Identify where the round duct start and finish as per the approved drawing.
    • Cut the appropriate size hole in the square duct and slide your duct collar in. Most are a tab collar,which means they have tabs that slip into the hole you cut and tab over inside the duct. This locks thecollar in to the square duct so it doesn’t come back out. (See. Fig. A)
    • Install the round duct by sliding the first piece onto the crimped tab collar and secure it with four sheetmetal screws (One on each side , one on the top, and on the bottom)
    • Continue installing the round duct by sliding the non-crimped end over the crimped end and screwingtogether. If need to cut a piece, cut it with cutter and then use crimper to put a crimp on one end.
    • Support the round duct with galvanized hanger straps. Screw one end into a structural member, looparound the flexible duct, and then screw the other end into a structural member as per the approveddrawing.
    • Seal all joints and seams with duct sealant to prevent air leakage. (See Fig. B)
        Figure B. Collar in Duct min. 2” 
Figure A. Collar (Dovetail) 
  • DUCT Installation

Ensure that all openings required through floors,walls,partitions etc. for the duct system are provide inthe exact location as required.

  • After receiving ducts from factory. Performing quality check & inspection.Cleaning inside & outsideduct by rags.
    • Duct Mastic sealing for duct connection joint. Corner & seam line inside duct.
    • Tapping gasket around flanges.
    • Marking for drilling work at hanger’s point.
    • Drilling & installation of anchor fastener in the required position as per drawing.
    • Threaded rod installation.
    • The combined duct pieces shall be lifted to proper elevation for connection to other ducts.
    • The supports (steel channel or steel angle) are installed underneath the duct.
    • Connect flange joint of ducts by tighten the bolts & nuts & clip lock (C-cleat).
    • The leakage of the jointed duct shall be tested by Light Test. (1,000 w Lamp).
    • After passing inspection,touch up with glue at remaining place for insulation (if any)
    • Outside lining fiber glass insulation with aluminum tape.
    • After insulation completed, both side of open duct shall be blocked by plastic vinyl sheet to prevent dust.
  • DUCT Insulation
    • The entire fabricated duct will be covered to avoid scratch & dents and to protect it from moisture, water,dust and debris.
    • Clean and remove dust on exterior surface of the duct by manually wiping the ducts external surface using a medium(rags & soft brush) suitable for the purpose.
    • If any heavy debris, it shall be removed by hand scraping, hand brushing or manually.
    • This should be carried-out/repeated until visual acceptance.
    • Adhere insulation pins which have adhesive backing on the surface of duct as per specification.
    • Attach aluminum foil faced fiberglass roll mat or board adhere vapor barrier to the duct.
    • Press the washer of insulation pin in order to lock the aluminum foil faced fiberglass roll mat or board of the duct.
    • Adhere vapor barrier tape or aluminum tape to insulation joint.
    • Attach corner clip and tie up aluminum foil faced fiberglass roll mat or board firmly by aluminum band.
    • Insulate around flange joints with insulation and cover with foil vapor barrier.
    • Remove dust inside duct and close opening of duct with vinyl preventing from dust ingression.
    • Unless otherwise specified, all finished insulated air duct (for outdoor work only) shall be externally cover with aluminum cladding as per detaildrawing.

Note. The insulated duct pieces shall be stored safely and securely until the time of erection to prevent damage and to avoidobstruction to the work site.

  • Grill, Register and Diffuser Installation

Final connections to diffusers shall be carried out using flexible ductwork or solid spigots as detailed in theProject documentation.

  • Check the correct material for duct fixtures like square diffusers, grilles, registers etc. according to ceiling drawing andHVAC drawing.
    • For the wall or ceiling openings for air outlets, refer to Architectural plans for details of construction.
    • Extension duct collar for mounting/installation of air outlets shall be sized in accordance with drawings and air deviceschedule.
    • Flexible duct should extend straight for several inches from a connection before bending.
    • Support system must not damage flexible duct or cause out of round shape.
    • Extract flexible duct hose in ceiling and connect to diffuser adapter by use of hose clamp.
    • All air outlet shall be fixed properly using sheet metal screw and with rubber gasket all around as per drawing details.
    • Observe proper alignment for all air outlet accessories.
  1. METHOD STATEMENT FOR REFRIGERANT PIPING INSTALLATION

Refrigerant pipes are site routed in order to avoid obstructions to A/C equipment, access or maintenance and to avoid any extra load on the system. The pipes and fittings are connected with the suction and liquid line to the respective connections on the indoor as well as outdoor unit by brazing.

  1. Measuring and Cutting
    1. Ream pipes and tubes clean off all scales and dirt, inside and outside before assembly.
    1. Accurately measure the length of each tube segment (See. Fig. 1)
    1. Cut the pipe to the measured lengths. The pipe can be cut with a disc-type tube cutter (See Fig. 2).The cut must besquare to the run of the tube so that the tube will seat properly in the fitting cup.

Figure 1 Measuring

Figure 2 Cutting

  1. Reaming and Cleaning
    1. Ream all cut tube ends to the full inside diameter of the pipe to remove the small burr createdby cutting operation. Tools used to ream pipe ends include the reaming blade on the tubecutter, a pocket knife (See. Fig. 3).
    1. The removal of all oxides and surface soil from the pipe ends and fitting cups is crucial toproper flow of solder metal into the joint. Lightly clean the pipe ends using nylon abrasive pads(See. Fig. 4).
Figure 4 Cleaning 
Figure3 Reaming 
  1. Applying Flux
    1. Use a flux that will dissolve and remove traces of oxide from the cleaned surface from reoxidation during heating, and promote wetting of the surface by the solder metal (See. Fig. 5, 6).
Figure 6Applying Flux 
Figure 5Applying Flux 
  1. Assembly and Support
    1. Insert tube end into fitting cup, making sure that the tube is seated against the base of the fitting cup. A slight twisting motion ensures even coverage by the flux. Removing excess flux from the exterior of the joint with a cotton rag (See. Fig. 7, 8).
    1. Support the tube and the fitting assembly to ensure a uniform capillary space around the entire circumference of the joint. Uniformity of capillary space will ensure good capillary flow of the molten-solder metal. Excessive joint clearance can lead to solder metal cracking under conditions of stress or vibration.
    1. The joint now ready for soldering. Joints prepared and ready for soldering must be completed the same day and not left unfinished overnight.
Figure 7Assembly 
Figure 8Assembly 
  1. Heating
    1. Begin heating with the flame perpendicular to the tube. The copper tube conducts the initial heat into the fitting cup for even distribution of heat in the joint area. The extent of this preheating depends upon the size of the joint. Preheating of the assembly should include the entire circumference of the tube in order to bring up to a suitable preheat condition. However, for joints in the horizontal position, avoid directly preheating the top of the joint to avoid burning the soldering flux. Practice and experience will indicate the amount of heat and time needed.
    1. Next, move the flame onto the fitting cup. Sweep the flame alternately between the fitting cup and the tube a distance equal to the depth of the fitting cup. Again, preheating the circumference as described above, with the torch at the base of the fitting cup. Touch the solder to the joint if the solder does not melt, remove it and continue heating.

CAUTION: Do not overheat the joint or direct the flame into the face of the fitting cup. Overheating could burn the flux, which will destroy its effectiveness and the solder will not enter the joint properly.

  1. When the solder melts, apply heat to the base of the cup to aid capillary action in drawing the molten solder into the cup towards the heat source.
  1. The heat is generally applied using an air-fuel torch. Such torches use acetylene or an LP gas(See. Fig. 9).
Figure 9 Heating Pipe 
  1. Applying Solder
  1. For joints in the horizontal position, start applying the solder metal slightly off-center at the bottom of the joint. When the solder begins to melt from the heat of the tube and fitting, push the solder straight into the joint while keeping the torch at the base of the fitting and slightly ahead of the point of application of the solder. Continue this technique across the bottom of the fitting and up one side to the top of the fitting.
    1. The now-solidified solder at the bottom of the joint has created an effective dam that will prevent the solder from running out of the joint as the side and top of the joint are being filled.
    1. Return to the point of beginning, overlapping slightly, and proceed up the uncompleted side to the top, again, overlapping slightly. While soldering, small drops may appear behind the point of solder application, indicating the joint is full to that point and will take no more solder. Throughout this process you are using all three physical states of the solder: solid, pasty, and liquid. 
Figure 10Soldering

For joints in the vertical position, make a similar sequence of overlapping passes starting wherever is convenient.                                                                                                                    

  1. Cooling and Cleaning

After the soldering joint has cooled the flux residue should be removed with a clean cloth (See Fig. 9), brush orswab using warm water.Wrought fittings may be cooled more readily than castfitting, but all fittings should be allowed to cool naturally before wetting.

Figure 11 Cooling and Cleaning

  1. Refrigerant pipe Insulation
  1. Insulation shall be applied in accordance with Manufacturer’s instructions over clean; dry pipe after all testing iscompleted and approved.
    1. The general intent is to provide a sealed insulation which will not permit condensation of the pipes and which will notretain moisture to the detriment of its insulating capability.
    1. Ensure all insulation materials are in dry condition during application.
    1. Pipe surface shall be cleaned properly before applying adhesive and insulation.
    1. Apply insulation with longitudinal seams at top and horizontal pipe runs.
    1. Pipe insulation shall be applied with least number of joints.
    1. Approved adhesive shall be applied in longitudinal seam and end faces of the insulation and entire pipe surfaces.
    1. All respective pipe and fittings above the ground shall be wrapped with Elastomeric Rubber Foamed insulation, painted with waterproof cement and covered with aluminum cladding.
    1. Removable type insulation sections shall be prepared and provided to valves including check valves and strainer basket and other valves.
    1. Pipe penetrations through roof, exterior wall, fire rated wall, floor etc… through sleeves shall be closed by ram packed with loose fiber glass insulation and sealed with approved mastic / sealing compound and for rated walls approved fire proof sealant shall be used.
    1. Identification of Refrigerant supply and return lines and specialties shall be done / provided as per specification requirements.
  1. METHOD STATEMENT FOR HVAC SYSTEM TEST

Testing shall be carried out under the supervision of Contractor & Company with allcalibrated tools and equipment’s.

Field test / Inspection report format will be used for this purpose.

  1. Air Handling Unit, Air Cooled Condensing Unit and Split Air Conditioner Test
    1. Note down the Maker, Model and serial no.of the each Unit.
    1. Note down gas line pressure, liquid line pressure, supply & return air temperature, ambienttemperature.
    1. Note down evaporator, compressor and condenser fan motor voltage and current.
    1. Check the power and control cable are connected.
    1. Switch on the power supply.
    1. Use the field test / inspection report (HVAC Equipment) for this purpose
    1. Manifold gauges are used for check the pressure in the refrigerant system.
    1. Anemometer is used for check the air flow of the equipment.
    1. Hygrometer is used for check the dry bulb and wet bulb temperature.
    1. Megger, Multi &Clamp meter is used for check electrical resistance, voltage and ampere of the operating equipment.
  1. FAN Test
    1. Note down the Maker, Model and serial no.of the FAN.
    1. Check the power and control cable are connected.
    1. Switch on the power supply.
    1. Note down fan motor voltage and current.
    1. Use the field test / inspection report (No load Test) for this purpose
    1. Megger, Multi &Clamp meter is used for check electrical resistance, voltage and ampere of the operating equipment.
  1. Electric Duct Heater Test
    1. Note down the Maker, Model and serial no.of the FAN.
    1. Check the power and control cable are connected.
    1. Switch on the power supply.
    1. Megger, Multi &Clamp meter is used for check electrical resistance, voltage and ampere of the operating equipment.
  1. Duct Leak Test

Identify and mark the unsealed holes and seal it with approved sealant. All the leakage testing of jointed duct will bedone by Light Test. Following are the common procedures for Light test.

  1. Be sure that all ductworks to be test are clean and free from obstruction.
    1. Check all the joints of duct installed, are tightly connected to each other, before conducting Light Test.
    1. Ensure to put sealant around all duct collars connecting the main duct.
    1. Place the Halogen lamp (1000 Watts) at one end of the Duct and close the both ends properly. If the length ofthe duct is more, place two halogen lamps from the both sides of the duct.
    1. Make sure that the area is dark (At Night) enough to identify the holes.
    1. Check all the transverse joints, longitudinal seam and all penetrations visually for any light coming throughleaked joints.
    1. Identify and mark if any unsealed holes and seal it with approved sealant.
    1. Ducts joining in the workshop prior to the field installation will be tested in the dark room provided adjacentto the workshop as per the above procedure.
    1. Refrigerant Pipe Test (Vacuum & Pressure Test)
      1. Pressure test is of the refrigerant pipe shall be carried out by using inert gas (Nitrogen).
      1. Test pressure should be 400 psig and Pipe should be observed for 2 hours (minimum) for any drop,Compound pressure gauge should be provided for this purpose.
      1. This method is only intended for liquid and suction line only.
      1. After the system is found to be without leak, release the pressure after inspection.
      1. Vacuum the refrigerant line until it reaches a vacuum of 28”of Hg and maintain this vacuum up to 6 hours.
      1. Then break the vacuum by charging the Refrigerant gas up to its standing pressure (operation Pressure).
  1. METHOD STATEMENT FOR TESTING, AJUSTING AND BALANCING(T.A.B)

Testing, adjusting and balancing shall commence after HVAC System installation is complete and in working order. Test shall be performed and adjustments will be made as necessary to accomplish the design objectives.

  1. Examination

Prior to commence testing adjusting and balancing, verify the following condition if deficiencies are evident. Submit Deficiency Report (Punch List) to the Project Management in Contractor/Company. Do not begin testing, adjusting and balancing until deficiencies have been corrected.

  1. Systems are started and operating in a safe and normal condition.
    1. Temperature control systems are installed, complete and operable.
    1. All automatic (motorized) and manual dampers are operable and fully open.
    1. Thermal overload protection is in place for fans, compressors and other equipment.
    1. Before Start up, air filters are removed and replaced it with final filters.
    1. Final filters are clean and properly installed.
    1. Duct and fan systems are clean.
    1. AHU’s Fans and Fans are rotating correctly.
    1. Fire and volume dampers are in place and open.
    1. Air coil fins are cleaned and combed.
    1. Access doors are closed and duct end caps are in place.
    1. Air outlets are installed and connected.
    1. Gauge and/or test ports are properly located for balancing.

Note. All instruments used for measurements shall be accurate, and calibration   histories for each instrument shall be available for examination. Each test Instrument shall be calibrated by an approved laboratory or by the manufacturer.

  1. Site Tolerances
    1. Air Handling Systems: Adjust to within plus 10 percent of outlet total plus allowable leakage rate.
    1. Air Outlets and Inlets: Adjust to within plus 10 percent or minus 10 percent of design for the space.
  1. Air Systems

Minimum tests and balancing should be performed as follows:

  1. Adjust all air handling systems to provide the required air quantity to, or through each component. Adjusting and balancing of all systems shall be conducted during periods of the year approximating maximum seasonal operations, to the extent possible.
    1. Equalizing device shall be adjusted to provide uniform velocity across the inlet duct side for supply of terminals prior to measuring flow rates.
    1. Test and adjust fan RPM to design requirements.
    1. Test and record motor full load nameplate rating and actual ampere draw.
    1. Test and record system static pressures, fan suction and discharge.
    1. Adjust all main supply and return air duct to within tolerance of proper design air flow rate.
    1. Test and adjust each diffuser, grille and register. Reading and tests of diffusers, grille and register shall include(designed velocity (m/s) and adjusted velocity, design air flow rate and adjusted air flow rate.)
    1. Test and records outside, mixed air and discharge temperatures (D.B for heating cycle, D.B and W.B for coolingcycle.)
    1. In coordination with the contractor, set adjustments of automatically operated dampers to operate as specified,indicated and/or noted.
    1. Test and adjust air handling unit and distribution systems to provide required or design supply, return, outside airand exhaust air quantities within design tolerance.
    1. Make air velocity measurements in ducts by Pitot tube traverse entire cross sectional area of duct in accordancewith SMACNA equal area method of Log Linear method.
    1. Use volume control devices to regulate air quantities only to the extent that adjustments do not crate objectionableair motion or sound levels.
    1. Vary total system air quantities by adjusting fan speeds. Provide drive changes as per recommendations.Vary branchair quantities by damper regulation.
    1. Measure air quantities at all air inlets and outlets.
    1. Measure static air pressure conditions on air supply units, including filter and coil pressure drops and total pressureacross the fan. Make allowances for loading of filters and coils.
    1. Adjust outside air automatic dampers, outside air, return air and exhaust dampers for design’s condition withinspecification tolerances.
  1. Air Handling Unit, Air Cooled Condensing Unit and Split Air Conditioner Unit

Test air handling unit/air-conditioning unit, including the air-cooled condensing unit and the evaporator coils as one entity. Check and adjust the system for proper operation under available system cooling load.

  1. Amperage to the compressor motor (rated and actual) when operating.
    1. Condenser entering ambient air temperature, dry-bulb.
  1. Adjusting
    1. Recorded data shall represent actual measured or observed conditions.
    1. Permanently mark setting on dampers, and other adjustment devices allowing for settings to be restored. Set andlock memory stops.
    1. Leave systems in proper working condition, replacing belt guards, closing access doors, closing doors to electricalswitch boxes and restoring thermostats to specified settings.
  1. TOOLS & EQUIPMENTS
    1. Pitot Tube
    1. Manometer
    1. Flow Hood
    1. Tachometer
    1. Sound Level Meter
    1. Thermo-Hygrometer
    1. Anemometer
    1. Clamp Meter
    1. Vibrometer (Vibrograph)
    1. Sling Psychrometer
  1. QUALITY CONTROL
  1. Quality Control Plan
    1. Aquality assurance system shall be established to ensure conformance to related standards, codes, specification and procedures.
    1. Site Management, Supervisors and Safety Officer will closely supervise and monitor all phase of works to ensure full compliance with the procedures of Safety and work methodology.
    1. Significant stages of work shall be ensured by Site Supervisor /Quality Control Inspector to be conforming to the drawings and specification including:
  2. Use of approved materials.
  3. Set out of work before commencing installation.
  4. Check installed materials.
    1. Inspection TestRequest (ITR) shall be submitted 24 hours before the date and time of inspection for each stage of work as per approved inspection and Test Plan.
  1. Inspection and Test Plan
    1. All inspections and tests as identified in the Inspection and Test Plan.
    1. Inspection and Test Plan shall be completed by the SUB COTRACTOR and will be reviewed and approved by the CONTRACTOR.
  1. SAFETY PLAN

The responsible supervisor will periodically check the condition of the barriers, and where necessary refurbishment will be conducted.

  1. Safety Role and PTW
    1. Appropriate PTW is introduced and applied for approval from the central Safety Management.
    1. Training programs and competence standards are established and maintained.
    1. Monitoring/auditing/reviewing of PTW system is established and maintained.
    1. PTW is processed properly as follows:
  2. Defining, requesting and approving the work scope
  3. Hazard Identification, Risk Assessment and Proposed Controls
  4. Approval of Proposed Controls – Hold Point
  5. Implementing Risk Controls
  6. Permission to Proceed/Issuing the PTW – Hold Point
  7. Managing the Work after Issue of PTW
    1. Use of PPE
      1. All personnel will be issued with PPE and instructed to maintain safe working practices always. The HVAC Supervisor will be responsible to confirm that safety procedures are followed.
      1. PPE’s for ear protection (ear muffs, earplugs, etc.) must be used in areas where the noise level is high (above 85 dBA).
      1. Personnel executing the work will always confirm that:
  8. Eye Protectors (goggles /shields /spectacles) are suitable for the work being carried out.
  9. Adequate and appropriate respiratory protection is available while entering confined space.
  10. Appropriate type of hand gloves is used for the activity to be performed.
  1. Hand Tool and Equipment
    1. Construction equipment, machines, tools and measuring instrument to be used in the works will be thoroughly inspected to confirm its working condition prior to used.
    1. Operator will be trained and instructed in the safe use of the equipment.

All power hand tools and Equipment to be inspected and tagged.

Md Abu Zaed Khan
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