- SCOPE OF WORK
- CODES AND STANDARDS
- RESPONSlBlTIES
- PRODUCT DELIVERY, STORAGE & HANDLING
- H/AC MAJOR EQUIPMENTS
- H\/AC MINOR EQUIPMENTS
- HVAC EQUIPMENTS LOADING/ LIFTING
- SAFETY HAZARDS
1.0 Scope:
This Article covers the requirements, method statement and procedures for installation of HVAC Equipments.
2.0 Codes and Standards:
- ASHRAE – American society of Heating, Refrigeration and Air-Conditioning Engineers.
- SAES – Saudi Aramco Engineering Standards.
- ASTM – American society of Testing and Materials.
- NFPA – National Fire Protection Association.
- UL – Underwriters Laboratories.
- UMC – Uniform Mechanical Code.
- SMACNA – Sheet Metal and Air Conditioning Contractors National Association.
3.0 Responsibilities
• Site Engineer:
Shall be responsible in the overall supervision of activities in connection with HVAC refrigerant piping work and pressure testing to ensure the correct follow of procedure. The project engineer shall define the parameter of the system that is being tested and make sure that all the components are ready and meet the safety regulations.
• Site QC Inspector:
Performs inspections for copper pipes installation work prior to start pressure test. Performs inspection, monitors in-place pressure testing and assures that pressure testing is done according to approved procedure. QC inspector shall complete all required documentation in connection with pressure testing including calibration certification of all testing instruments and test readings according to approved method.
• Site Supervisor:
Shall be responsible for preparation of pressure testing according to approved procedures and check all components against safety regulations.
• HSE Officer:
Check the possible hazards of the activities to be done and co-ordinate to The site supervisors to rectify if there is any to ensure the safety of the Workers at job site.
4.0 Product Delivery, Storage and Handling:
• Deliver HVAC Equipment’s with factory installed shipping skids and lifting lugs; pack components in factory fabricated protective containers.
• Handle HVAC Equipment’s carefully to avoid damage to components, enclosures and finish. Do not install damaged components; replace and return damaged components to equipment manufacturer. Avoid crushing or bending coils and fins and prevent dirt and debris from entering and settling on coils.
• Where possible, store equipment inside and protect from the atmosphere and construction worker traffic. When necessary to store outside, take the same precautions and store above grade and enclose with water proof wrapping.
• Identification tag or name plate of SS316 or better shall be attached to all equipment, securely with SS or Mone! Fasteners.
5.0 HVAC MAJOR EQUIPMENTS:
• HVAC Equipment’s shall be installed in accordance with this procedure and shall conform to Installation and Operation manuals as per recommendation of Saudi Aramco Engineering standards and Zamil.
• HVAC Equipment’s shall be installed with vibration pads or as required. If spring isolators are to be used, the installation of spring isolators shall be in accordance with the weights recommended Saudi Aramco Engineering standards and Zamil. The number of vibration pads or spring isolators shall be as per Manufacturer “Zamil’s” recommendation.
5.1 AIR-HANDLING UNITS/CHEMICAL FILTER UNITS:
• Air handling units shall be mounted on a concrete housekeeping pad at a minimum of 100mm above the floor or min of 150mm above unpaved ground.
• The tag or name plate shall be located such that information is visible and can be read after equipment installation.
• Condensate drain line shall be of Galvanized Steel Schedule 40 (corrosion resistant type) as ASTM A53/A53M per SAES.
• Condensate drain line shall maintain a min horizontal slope in the direction of discharge not less than 1 %.
• Ensure that the correct equipment is allocated to the specified zone. Confirm that the unit will fit within the space provided with adequate service access for the unit and all piping and electrical lines before installation.
• Equipment clearance shall be provided with a minimum of 1 m clearance on each side of equipment with open able panel or controls, unless equipment manufacturer requires greater clearances. Adequate space shall be provided for coil removal.
• Ensure the electrical supply conforms to the unit nameplate.
• Prepare the mounting position (concrete pad, I-beam base, steel stand or ceiling hangers) in relation to anti-vibration pads, power supply, control wiring and pipe work.
• Depending upon the model, the unit should be mounted either level or with a slight slope towards the drain.
• If the unit is suspended the ceiling prepare the mounting system and secure it with threaded steel rods and expansion bolts or any suitable fixtures with applicable anti-vibration mountings.
• Ensure that the unit is clean and free from any foreign material.
• Install the drain line; slope it away from the unit, preferably insulating it. Install a trap in the drain line near the unit.
• Install the refrigerant line. See Installation of typical refrigerant piping procedure.
• Install electrical and control wiring in accordance with unit wiring diagrams, and local standards.
• Install ductworks to recognize standards ensuring access panels for filters etc. are not obstructed.
• Check the unit installation, clean the unit removing all work materials and debris.
5.2 Air Cooled Condensing Units:
• Unpack the unit and move to final location taking care not to damage the unit. Remove shipping screws on wooden pallet and after removing the pallet refit the screws.
• Condenser units shall be mounted on a concrete housekeeping pad, at a minimum of 100 mm (4″) above the floor or a minimum of 150 mm (6″) above
unpaved ground. Air cooled condenser unit shall be mounted on leveled surface.
• Casings shall include doors to provide maintenance and removal access for all fans, motors, coils etc.
• For proper drainage, the condensing unit must be raised from the mounting pad.
• When installing the unit, allow sufficient space around the unit for air circulation, wiring, refrigerant piping, and servicing. The clearance must be as recommended by Saudi Aramco Engineering standards and Zamil. Above the unit the condensing fans must not be obstructed for airflow clearance and maintenance.
• Anti-vibration pads (rubber-in-shear) or other vibration mounts (spring type) are recommended, especially for roof top installation and adjacent to occupied areas. The number of pads or spring isolators shall be as per Saudi Aramco Engineering standards and Zamil recommendations.
• The tag or name plate shall be located such that the information is visible and can be read after equipment installation
• Ensure that the unit is clean and free from any foreign material.
• Install the refrigerant line. See Installation of typical refrigerant piping procedure.
• Install electrical and control wiring in accordance with unit wiring diagrams, NEC and local standards.
• Check the unit installation, clean the unit removing all work materials and debris.
• After installation, dehydrate system by placing a vacuum of -30 in.Hg absolute pressure. Hold vacuum for 4 Hours or cycle vacuum and dry nitrogen purge according to manufacturer’s recommendations. Charge system with quantity and type of refrigerant as per manufacturer’s requirements.
6.0 HVAC MINOR EQUIPMENTS
5.1 Exhaust fans:
• All Exhaust fans shall be installed in accordance with SMACNA standard or equivalent.
• The motor and its components shall be free of any debris or other materials which will obstruct the rotation of the pulleys.
• The location of the exhaust fans shall be as specified in the approved IFC drawings.
• All Exhaust fans shall have back draft dampers or motorized dampers which Shall close when fan is off.
• All fans shall be isolated from their ducts by flexible connections.
• Exhaust fan used for ventilating the battery room shall have their exhaust point(air outlet) located in the ceiling or its upper edge flush with ceiling if it is located in a wall.
• Fans and their motors shall be accessible for servicing and maintenance.
• Fan assembly will be provided a min 1 m clearance on each side with open able panel or controls.
5.2 Electrical Duct Heaters:
• All duct heaters shall be installed in accordance with SMACNA standard or equivalent.
• The duct heater elements shall be free of any debris or other materials which will create combustion.
• The duct heater elements shall be installed 100% along the air stream so that the air will flow to the elements.
• Heaters shall be slip in type for installation through sides of ducts, supplied complete with controls and protection devices and installed complete with necessary wiring etc.,
• Heaters operation shall be interlocked with AHU fan motors through an air flow switch.
• An access door of 300 x 300 mm (min.) opening shall be provided on each Duct heaters for maintenance.
• The location of the duct heaters shall be as specified in the approved IFC drawings.
• Access for servicing or for removal of duct heater shall be provided.
5.3 Blast protection dampers:
• All Blast protection dampers shall be installed in accordance with manufacturer recommendation. (as per IFC Drawing)
• Blast protection dampers shall be installed primarily into the blast side of the blast resistant wall
• The blast protection damper can be upright or horizontal position or on ceiling/floor.
• The damper is installed on ducting by means of anchor bolts (Type M12X100 or according to the sizes of holes in the dampers). (as per detailed drawings)
5.5 Bleed Fans:
• All Bleed fans shall be installed in accordance with SMACNA standard or equivalent.
• The motor and its components shall be free of any debris or other materials which will obstruct the rotation of the pulleys.
• The motor and its components shall be installed in an accessible manner to provide way for maintenance.
All Bleed fans shall be installed so to extract the sand from the sand trapping unit respecting the air flow as specified in the approved IFC drawings.
• The location of the bleed fans shall be as specified in the approved IFC drawings.
• Bleed fans shall be installed on concrete foundation or as specified in the approved IFC drawings.
5.6 Inertial Air Filter:
• Inertial filter unit shall be installed in accordance with approved IFC drawings.
• It shall be installed before the fresh air fan so that it collects the sand passing through it.
• It shall be installed higher than the bleed fan so that the collected sands will be extracted easily by the bleed fans.
• All inertial air filter units shall be installed in line with the fresh air ducting’s as specified in the approved IFC drawings respecting the air flow.
• All inertial air filter units shall be installed on substantial concrete foundation or as specified in the approved IFC drawings.
7.0 HVAC EQUIPMENT’S LOADING & LIFTING:
Before moving the units, ensure that the site is ready and suitable for installing the equipment and is capable of supporting the weight of units and all associated equipment. Units are designed for lifting and overhead rigging. Based on weight and dimensions of the units, either rigging holes are provided in the base rail or lifting eyes extending from the sides of the base rail. These rigging holes or lifting eyes are centered around the unit center of gravity.
• For units with rigging holes in the base rail, insert pipes thru these holes to support the whole unit and lift using rigging slings and hooks or shackles.
• For units with lifting eyes on the base rail, attach the hooks or shackles directly into them and lift using rigging slings.
• Center of gravity is not unit centerline; ensure center of gravity aligns with main lifting point before lifting.
• Use spreader bars when rigging, to prevent slings from damaging the unit
• Units must only be lifted from the base and at the points provided. All unit panels should be in place when rigging. Extra care must be taken to avoid damage to the condenser coil. Insert packing material between coils and slings as necessary. Refrigerant piping should never be used as a foothold or handhold. Never move the unit on roller or using a fork lift truck.
• Lifting equipment must be capable of handling the unit weight with adequate safety factor.
• An experienced, reliable rigger shall be selected to handle the unloading and final placement of the equipment.
• Handle unit with care during installation to avoid damage due to twisting, bouncing or tilting. Rigger should be advised that the unit contains delicate components & is to be handled in upright position only.
• Do not lift unit by coil connections or headers or other unit structural components.
• As test, lift the unit approximately 50 cm to verify proper center of gravity lift point, to avoid dropping of unit, reposition lifting point if unit is not levelled. Failure to properly lift unit could result in death or serious injury or possible equipment of property damage.