+ All Categories

B-12

Date post: 27-Dec-2015
Category:
Upload: rochdi-sahli
View: 8 times
Download: 0 times
Share this document with a friend
Popular Tags:
22
NATIONAL OIL CORPORATION GENERAL ENGINEERING SPECIFICATION GES B.12 HEATING, VENTILATION AND AIR CONDITIONING Rev Date Description Checked Approved 0 1999 Issued for Implementation DL Compiled by Teknica (UK) Ltd
Transcript
Page 1: B-12

NATIONAL OIL CORPORATION

GENERAL ENGINEERING SPECIFICATION

GES B.12

HEATING, VENTILATION AND AIR CONDITIONING

Rev Date Description Checked Approved

0 1999 Issued for Implementation DL

Compiled by Teknica (UK) Ltd

Page 2: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 2 of 22 Rev 0 1999

INDEX SEC TITLE PAGE 1.0 SCOPE OF SPECIFICATION 4 1.1 Introduction 4 1.2 Other NOC Specifications 4 2.0 DEFINITIONS 5 2.1 Technical 5 2.2 Contractual 6 3.0 DESIGN 7 3.1 Codes and Standards 7 3.2 Design Conditions 7 3.3 Air Quality 8 3.4 HVAC Design Requirements 9 3.5 Special HVAC Design Requirements 10 4.0 VENTILATION 13 4.1 General 13 4.2 Further Requirements 13 4.3 Cooling and Heating Loads 13 5.0 ABNORMAL SITUATIONS 14 5.1 Devices to Cope with Abnormal Situations 14 5.2 Equipment in Operation during Abnormal Situations 14 6.0 NOISE AND VIBRATION 14 7.0 CONTROL AND ALARM SYSTEMS 15 7.1 Control 15 7.2 Alarming 15 7.3 Electrical Power supply-Electrical Safety 15 8.0 INSPECTION AND TESTING 16 9.0 DOCUMENTATION 16 9.1 Introduction 16 9.2 Schedule/Reports 17 9.3 Data and Calculations 17 SEC TITLE PAGE

Page 3: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 3 of 22 Rev 0 1999

9.4 Drawings 17 9.5 Final Records, Documents and Manuals 18 10.0 PRIOR TO SHIPMENT 18 10.1 Painting and Coatings 18 10.2 Spares 19 10.3 Packing and Storage 19 10.4 Shipping 19 10.5 Warranty 19 Notes on Figure 1 20 Figure 1 Detailed Space requirements Data 22 (Normal Conditions)

Page 4: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 4 of 22 Rev 0 1999

1.0 SCOPE OF SPECIFICATION 1.1 Introduction 1.1.1 This specification sets out the minimum design requirements and recommended engineering practices for

the environmental conditioning (HVAC) of buildings in oilfields, petrochemical plants and refineries. 1.1.2 The aim of the specification is to provide clear design guidelines and criteria for the provision of climatic

conditioning equipment for worker's comfort and safety. In addition, it attempts to streamline the briefing process, set benchmark standards for climatic conditioning installations, and to enable a degree of standardisation and cost control to be implemented.

1.1.3 The intent of this document is to standardise design and ensure that submitted designs for HVAC

installations are appropriate and conform to good practice with regard to function, convenience and ease of maintenance, by providing comprehensive recommendations and requirements within a single document.

1.1.4 This document is intended to serve as a minimum design requirement for Owner and Vendor/Contractor for

the administration of the design process for HVAC installations during contract stages. It is not a definitive, project specification. Vendor/Contractors are in no way relieved of their responsibilities for the production of safe, functional design and completed installation.

1.1.5 The Vendor/Contractor shall fully comply with the provisions laid down in the specification, any exception

shall be authorised in writing by the Owner. 1.1.6 In the event of conflict between this specification and any applicable codes and standards, the

Vendor/Contractor shall inform the Owner in writing and receive written clarification before proceeding with the work.

1.1.7 This General Engineering Specification shall form part of the Purchase Order/Contract. 1.2 Other NOC Specifications Where indicated in this specification, the following additional GES Specifications shall apply: GES A.04 Noise Level Criteria and Noise Control of Mechanical Equipment GES A.06 Site Data GES L.19 Building Electrical Systems GES L.34 Electrical Equipment in Contaminated Environments GES L.35 Electrical Equipment in Hazardous Areas GES X.01 Surface Preparation and Painting Application GES X.02 Colour Coding of Equipment and Piping GES X.03 External Protective Coatings

Page 5: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 5 of 22 Rev 0 1999

2.0 DEFINITIONS 2.1 Technical Air Cooler In this instance a finned coil over which air is blown, the coil is cooled by chilled water or by being used as

an evaporator in a Direct Expansion (DX) system. (See Liquid Chiller, 1, following.) Air Handling Unit (AHU): HVAC equipment through which air is transported and processed to the required conditions by means of

filtration, heating, cooling and humidification or dehumidification. AHUs form the central part of an HVAC ducted air system.

Dry Bulb (DB) Temperature: The temperature of the air indicated by an accurate thermometer. Fan Coil Unit (FCU) A unit mounted within the conditioned space which has a fan to recirculate the air from the space through

an integral heat transfer coil to condition the space. Fresh Air Handling Unit: An air-handling unit in which fresh air is drawn into the building and processed to the required conditions

to be used as ventilation air. HVAC System: The Heating, Ventilation and Air-conditioning System which maintains the temperature, pressure, relative

humidity and air-quality in a room or building, within defined limits. Liquid Chiller A refrigerating system, usually packaged, that has water or a process fluid passed through it to have heat

removed from and rejected to atmosphere, either directly or via a cooling tower. This is usually accomplished with either of two systems Direct Expansion (DX) or Absorption. When producing chilled water, the water can be used to remove heat from air conditioning systems, such as AHUs.

1. Direct Expansion uses a compressor to compress and move a refrigerant, that starts as a gas, through a

heat exchanger (condenser) where its latent heat is removed and it is condensed into a liquid. The liquid is then forced through an orifice or expansion device to become a saturated vapour which is passed through a heat exchanger (evaporator) which has the fluid to be cooled on its other side, from which the refrigerant absorbs heat to evaporate and return as a super heated gas to the compressor.

2. Absorption uses the affinity of lithium chloride to water and added heat to transfer heat through two

interconnected pumped fluid cycles.

Page 6: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 6 of 22 Rev 0 1999

Recirculation Air Handling Unit: An air-handling unit in which the room air is recirculated (with no fresh air input), to be processed to the

required condition, to be utilised as the medium to maintain the specified environment of the space(s) it is serving.

Relative Humidity: The ratio of the weight fraction of water vapour present in the air, to the weight fraction of water vapour

present in saturated air at the same temperature and barometric pressure. Stand-Alone Air Handling Unit: An air-handling unit which is an individual system, usually located in the space which it is serving and

recirculating the air from that space. Split Units: Two unit systems, each with one unit in the conditioned space in the form of a fan coil unit that circulates

the air to be conditioned through filters, adds or removes heat, sometimes re or de-humidifies, and distributes the air by a directed discharge arrangement. The other unit is positioned or ducted outside the conditioned space, where heat that is to be removed or added can be rejected or absorbed. The two units are inter-connected by pipework that transports refrigerant between them and either unit may have the compressor, which motivates the system. Both units usually have an air to refrigerant heat exchanger in the form of a finned coil. Fresh air may be ducted to the room unit for a conditioned fresh air supply.

2.2 Contractual The commercial terms used in this specification are defined as follows: 2.2.1 Owner The oil or gas company, an associate or subsidiary, who is the end user of the equipment and facilities. 2.2.2 Vendor The company supplying the equipment and material. 2.2.3 Contractor The main contractor for a defined piece of work. 2.2.4 Sub-Contractor A company awarded a contract by a Contractor to do part of the work awarded to the Contractor. 2.2.5 Inspection Authority The organisation representing the Owner or Vendor/Contractor that verifies that the equipment and

facilities have been designed, constructed, inspected and tested in accordance with the requirements of this specification and the Purchase Order/Contract.

Page 7: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 7 of 22 Rev 0 1999

2.2.6 Inspector A qualified individual representing the Owner, Vendor/Contractor or the assigned Inspection Authority,

who verifies that the equipment and facilities have been designed, constructed, inspected and tested in accordance with the requirements of this specification and the Purchase Order/Contract.

3.0 DESIGN 3.1 Codes and Standards This specification has been based on the requirements of the international standards and codes of practice

set out below. They are to be adhered to in all submitted designs that concern the heating, ventilation and air-conditioning systems for all types of buildings. In the event of conflict between codes, standards and this specification, the requirements leading to the safer design shall be used as determined and approved by the Owner.

3.1.1 Electrical and Mechanical ASHRAE Handbooks for Current Years ASHRAE 52.1 Gravimetric Dust Spot Procedures for Testing Air Cleaning Devices ASHRAE 55 Thermal Environmental Conditions for Human Occupancy ASHRAE 62 Ventilation for Acceptable Indoor Air Quality NFPA 90A Standard for the Installation of Air Conditioning and Ventilation

Systems. DIN 5751/VDE C 0510 Specification for Electrical Storage Batteries and Battery Plants IEC 654 - 4 Part 4 Corrosive and Erosive Influences 3.1.2 Safety Institute of Petroleum Model Code of Safe Practice : Part 1: Electrical Safety Code Part 3: Refinery Safety Code Part 15 : Area Classification Code for Petroleum Installations. 3.1.3 Building Construction U.B.C. Uniform Building Code (USA) The Building Regulations (UK) 3.2 Design Conditions The design conditions set below shall apply to all GES 'B' series Specification building types.

Page 8: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 8 of 22 Rev 0 1999

3.2.1 Outdoor Site Conditions Prevailing climatic conditions in the region are as detailed by GES A.06. As a general rule, all exposed

surfaces shall be resistant both to windblown sand abrasion and exposure to intense sunlight. In addition, openings shall have seals to prevent ingress of windblown sand and dust. Generally, ambient temperatures and general external conditions may be assumed to be as set out below; however, because of the vast geographical extent of locations, designers should seek to ascertain locally prevailing conditions:

- maximum ambient temperature 50°C - minimum ambient temperature 0°C - relative humidity generally less than 30% - (up to 95% in coastal areas) - maximum basic wind speed for general design purposes 145 kilometres per hour. For general purposes, the following seasonal temperature ranges may be taken as a guide: - Summer season (April to October) : Temperature range 20°C - 50°C - Winter season (November - March) : Temperature range 0°C - 30°C 3.2.2 Human Thermal Comfort Requirements For human thermal comfort, the temperature inside constantly manned rooms should be between 20°C and

24°C and the relative humidity between 30% and 60%. 3.2.3 Electronic Equipment Requirements Rooms or buildings in which vital instrumentation or electrical equipment is installed, shall be maintained

at temperatures between 18 and 22°C and a humidity level of between 30% and 50% RH. Designers and those responsible for the maintenance of electronic components should also note that very low levels of air contaminants will effect equipment reliability.

3.2.4 Psychometric Conditions Refer to Figure 1 for the specific requirements for various rooms and enclosures in various buildings.

Under all climatic conditions, the indoor psychometric conditions shall be such that no condensation on window glazing, raised floor panels,roofs, walls and installed equipment can occur. All refrigerant or chilled water pipes and conditioned-air ducting, must be insulated and vapour sealed.

3.3 Air Quality As a general rule, it should be assumed that both fresh air and re-circulation air may contain small

quantities of contaminants such as toxic and flammable gases, vapours and dust. Acceptable levels for these are determined by safety, human comfort and equipment requirements.

3.3.1 Toxic and Flammable Gases Where the use of flammable and toxic materials, or production of toxic gases occurs the requirement for

gas detection shall be assessed at the design stage. 3.3.2 Airborne Dust Prevailing weather conditions in the desert result in seasonal high winds that carry airborne sand and dust,

where a high proportion of this is transported within the first 1500mm above ground level. This condition applies to all GES-B series specification building types and for this reason, any fresh air inlet, air handling unit or compressor/condenser shall be mounted at a minimum of 2000mm above grade, at roof level where practicable, or within the building, with fresh air being supplied via sand-trap louvres. In addition, all fresh

Page 9: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 9 of 22 Rev 0 1999

air handling units should be fitted with a pre-filter of 85% efficiency to ASHRAE dust spot test and an after-filter of 95% (Dust spot tests are to be in accordance with ASHRAE Standard 52.1).

For all buildings where recirculation air-handling units are used 65% efficiency ASHRAE dust spot test

filters shall be provided. Wherever dust-sensitive instrumentation requires to be protected, a dust collector shall be added wherever dust concentration is likely to be higher than 10mg/cu.metre.

In all instances Vendor/Contractors shall make due allowance for maintenance access to filters for cleaning

and replacement. Filters shall be fitted with differential pressure indicators (manometer) to indicate when filter pad replacement is due.

3.4 HVAC Design Requirements The following design requirements shall apply to all buildings such as administrative offices,

accommodation, clinics, and fire stations, where the HVAC requirements are primarily concerned with the provision of ventilation and heating/cooling for human comfort. In most instances also, the spaces to be served within individual buildings are small. The most practical and simple installations for the majority of buildings will therefore be those using stand alone, through the wall package units, or split unit air-conditioners, fitted with heating coils for limited use during the short winter period. The exceptions to this will be:

- Where economies of scale allow for several buildings to be served from a central chilling plant. - Larger spaces such as canteens and assembly rooms or a large number of adjacent small rooms, where

ducted air systems make practical and economic sense. - Kitchens, with high exhaust air requirements. Generally therefore, ducted-air systems with central AHU's shall be avoided for small spaces. Machinery

and components shall be kept as simple as possible from the point of view of installation running maintenance and replacement in part or as a whole.

Proposals shall give clear demonstration at design development stage of practical details both to avoid the

most common problems associated with HVAC installations within buildings and to ensure ease of maintenance. These will include:

3.4.1 Internal Equipment - When designing for ductwork, adequate space shall be provided within ceiling spaces and bulkheads,

to avoid clashes with structural members. - When sizing duct and pipe requirements, the thickness of required insulation shall be accommodated. - Plant rooms within the building envelope shall be sized, based on actual equipment sizes, with

allowance made for maintenance and removal or replacement. - Maintenance access shall be provided where it will cause the least interference to the building's

functional operations i.e. from corridors rather than within rooms. - Purpose designed riser access cupboards shall be provided. 3.4.2 Roof/Externally Mounted Equipment - Safe and practical access via purpose designed maintenance paths shall be provided, which will avoid

damage to roof waterproofing. - Shaded or fully enclosed equipment enclosures shall be provided where practicable to increase life-

expectancy of equipment.

Page 10: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 10 of 22 Rev 0 1999

- Clear details at design development stage, of weatherproofing of pipe and duct entries through the roof structure shall be provided.

- In exposed sites, in areas prone to dust and sand storms, equipment is to be housed within enclosures protected by sand-trap louvres.

3.5 Special HVAC Design Requirements Because of their special HVAC requirements the following building types are considered in more detail: 3.5.1 Blast Resistant Control Buildings: The assumption is made here that any blast-resistant building would be located within a hazardous area,

therefore all equipment will be housed within the protection of the control building structure, which shall be provided with a dedicated HVAC room or other protective shelter. During the period of October-February, a limited amount of heating will be necessary for human comfort, therefore heating provision shall be allowed only to spaces that are manned on a full time basis. Designers and Vendor/Contractors shall conform to the design requirements listed below:

3.5.1.1 Fresh Air Intake Designers must note that a minimum requirement, where internal ignition sources exist, is that the location

of any air intake must be in a non-hazardous area as defined in the IP Area Classification Code for Petroleum Installations - Part 15 Model code of Safe Practice. If intake is within 30 meters of a release source, then it must be a minimum of 4.5 metres above the classified area.

Vermin resistant grilles shall be provided for all intakes. 3.5.1.2 Overpressure/Positive Air Pressure Systems Because any blast-resistant building will be located in a hazardous area and will contain general purpose

electrical equipment and other potential ignition sources, its HVAC system shall be designed to prevent the entry of flammable atmospheric vapours or gases in order to achieve a general purpose classification. This shall be achieved by the provision of overpressure, using a clean air source in conjunction with effective safeguards against ventilation failure. In case of an abnormal situation, such as external fire, spillage or explosion, the HVAC system shall be placed on total re-circulation, with no intake of air. Other minimum precautions will include:

- Failure of the positive-pressure system shall be sensed by a differential pressure switch, which activates

both a visual and audible alarm. - A flammable vapour detector shall be used to determine when it is safe to energise the controls. - A disconnect switch and a fan motor shall be provided, which shall comply with the area classification,

in the absence of the positive air pressure system. - Power to the air pressure system fan motor shall be ahead of any disconnect, which energises power to

the control centre. If the control building is located within a Division 1 (Normally hazardous) area, enforced purging is

required wherein all power to the control centre shall be closed down in the event of a failure to the air pressure system. In such instances, and where the operation of critical facilities cannot be interrupted, then it will be necessary to provide redundant pressurising equipment.

In addition to the above, continuous gas monitors and smoke detectors shall be provided to detect

flammable or toxic vapours and activate an alarm system. Therefore allowance may need to be made for these devices to shut down the ventilation systems and not restart until manual all clear.

3.5.1.3 Ventilation The ventilation system shall cater for the requirements of human comfort in addition to overpressure of the

Page 11: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 11 of 22 Rev 0 1999

building. Particular points to note regarding HVAC installations in blast-resistant buildings include: - The fresh air heating and cooling load shall be covered by the fresh air system itself. - The fresh air handling unit shall be provided with a redundant ventilator, including dampers upstream

and downstream, to enable maintenance during normal operation. - To prevent the loss of overpressure, all entrance doors shall be provided with an air lock. - The source of fresh air must be determined from the nature of the processing operations, the physical

layout of the plant and the position of the building within it. In normal circumstances, the fan suction can be taken from one side of, or above the process area, where there is a minimal chance of flammable vapours being present. Where the building is positioned in the middle of general plant operations, consideration shall be given to the provision of a fresh air stack with a rain-proof and wire-screened air intake at 12 metres above grade.

- The fresh air intake shall be directed into the building via a reinforced concrete enclosure housing exhaust fans and the intake safety devices, i.e. explosion valves and gas tight dampers.

- Exhaust systems from laboratories, toilets and battery rooms containing lead-acid batteries, shall be separately routed to dedicated exhaust fans and be provided with non-return valves.

3.5.1.4 Re-circulating Air Handling Systems For rooms housing vital equipment, (control room, instrumentation auxiliary room, electrical equipment

room) heat generated by the equipment shall be removed by re-circulating air handling system(s). In order to ensure the availability of the re-circulation system, sufficient redundancy shall be provided to maintain the required space conditions during abnormal operations, or when routine maintenance is being carried out. For reasons of economy, stand alone air handling units are preferred. Such units can be located in the room they are serving and designers should note the following:

- Down-flow type units, blowing the conditioned air into the plenum beneath the computer floor are

recommended. Care must be taken to ensure that no condensation will occur within the plenum. However, control rooms should have their air handling units located in the machine room.

- An alarm indicating failure of one of the units must be provided within the control room. - Provision must be made to isolate systems for maintenance purposes. - The usage of redundant capacity can be on a continuous basis or by means of an automatic cut-in in

case of system failure. In any event, as a matter of good housekeeping, there should be a regular rotation of machine use.

- Designers shall take measures to prevent damage to equipment in the event of leakage either of chilled water or condensate. This should include proposals to ensure that the spaces below computer floors are able to drain readily in the event of the ingress of water.

3.5.1.5 Chilled Water Systems For blast-resistant buildings, chilled water systems are preferred. In the event of explosion therefore, it

must be assumed that any condensers will be lost. The capacity of each chilled water unit shall be selected so that in the event of failure of one unit, the cooling requirements shall be met. The chilled water system shall be located within the building envelope

and pumps shall have 100% spare capacity. The condensers shall be of the air-cooled type and be located externally, within a blast-protected enclosure.

Page 12: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 12 of 22 Rev 0 1999

3.5.1.6 Air Distribution Systems All ducting for ventilation, exhaust and air recirculation, shall be distributed at ceiling level. No ducting

shall be installed beneath the computer flooring but this space may be used as a plenum. Refer to the air circulation requirements set out in Figure 1 at the end of this specification. Generally, control room air should preferably be supplied and exhausted at ceiling level. Other equipment rooms should preferably be supplied at low level and exhausted at high level.

3.5.1.7 HVAC Machine Room The main HVAC equipment, including chillers, fresh air handling unit, recirculation air handling unit for

the control room, chilled water (or ice) buffer, control panels etc., shall be housed within a dedicated HVAC room. This shall be located as close as possible to the control room which is served by the recirculating air handling units. Designs shall ensure that adequate space is allocated to the HVAC room to enable convenient maintenance access, that doors are sized to allow for machinery to be removed or installed, and that operations can continue during routine maintenance.

3.5.2 Non-Blast-Resistant Control Buildings Allowance must always be made for the extremes of climate, including high seasonal winds with

consequent persistently high levels of airborne sand and dust. In all cases therefore, and regardless of area classification, control buildings, or at least the critical core accommodation (control room, auxiliary/termination room), should always be maintained at positive air pressure.

Essentially, the HVAC installation should be as for blast-resistant buildings, without the need for explosion

valves in the fresh air intake or requirements for sheltering within the building structure. HVAC equipment may therefore be externally mounted, usually at roof level.

3.5.3 Field Auxiliary Rooms (FARs) FARs are assumed to consist of equipment rooms such as instrument auxiliary, electrical and battery

rooms. HVAC requirements shall generally follow that for control buildings. Requirements for blast-resistant FARs should follow those for blast-resistant buildings set out in 3.5.1 above, with the exception that normally, no fresh air intake and exhausts are required.

3.5.4 Analyser Houses Comprehensive design requirements for analyser houses are contained in GES B.04. 3.5.5 Electrical Substations Substation requirements will vary according to functional requirements and the extent of equipment to be

housed. Generally, all substations will require air-conditioning to deal with the removal of dissipated heat. This should normally be achieved by means of recirculating air via split-units consisting of at least two fan-coil units served by direct expansion chillers. One compressor/condenser unit shall be provided per FCU. Generally, constant average temperature should not exceed 35°C. The number and rating of FCUs shall be such that the internal temperature of the substation shall not exceed 40°C when one FCU is out of operation. Additional points to note include:

- Blowing of cool air onto switchgear should be avoided. - No condensate must leak onto switchgear. - Condensate must be drained to the outside of the building. - All HVAC equipment must be fully accessible for maintenance, without causing interference with

switchgear. - FCUs should be positioned at high level to ensure that all heat generating equipment is adequately

cooled.

Page 13: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 13 of 22 Rev 0 1999

In addition to the above, there will also be an occasional HVAC requirement for larger or more complex installations incorporating HV switchgear and/or Variable Speed Drive Systems (VSDS) etc.. These will require to be served by ducted recirculation air handling units. Designers must ensure that full information is given at the earliest design stages, regarding heat generation of equipment and dust-free environment requirements.

4.0 VENTILATION 4.1 General For all buildings, working areas shall be separately ventilated from associated office and support

accommodation, and fresh air intake/ventilation is necessary for the following functions: - Compensation for specific exhausts, such as acid-battery rooms, laboratories and toilets. - Compensation for the leakage rate of the building. - The maintenance of overpressure where required, inside a building or duty room, in order to prevent

the ingress of airborne contaminants from the outside. - The provision of a minimum quantity of air per unit of time, required for the comfort of occupants. 4.2 Further Requirements Refer to Figure 1 for the ventilation and filtration requirements of various room types. Additional requirements for ventilation, where a central air-handling unit is used, will include : - The ventilation rate shall provide a positive flow to the outside. - On combined systems, air flow shall be directional and to ensure flow from the clean rooms/areas to

the foul rooms/areas and thence to external discharge. - Air from fouling rooms shall be exhausted. - For batteries, which generate hydrogen during charging, and where the battery room is not permanently

ventilated, the ventilation flow rate shall be determined in accordance with DIN 5751D/VDE 0510 4.3 Cooling and Heating Loads Designers and Vendor/Contractors shall make provisions for all cooling and heating calculations for all

buildings. 4.3.1 Normal Cooling Load Cooling load calculations must form part of any air-conditioning proposals submitted by designers at

design development stage. This will require a survey and assessment to be carried out of the internal heat generated by :

- Heat transmission through the building envelope. This is especially important, where the temperature

of surfaces exposed to direct sunlight during summer months, may reach 85°C. - Personnel - Instrumentation and electrical equipment including lighting, computers etc. - Fresh air intake.

Page 14: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 14 of 22 Rev 0 1999

5.0 ABNORMAL SITUATIONS Where applicable, all air-conditioning proposals for plant buildings must include measures to deal with the

following abnormal situations: - The detection of flammable or toxic gas in the fresh air intake. - Failure of the main power supply. - An external emergency such as fire or explosion. - Smoke, fire or gas is detected within the building. - Failure of one redundant piece of HVAC equipment. - Allowance for vital equipment undergoing maintenance. 5.1 Devices to Cope With Abnormal Situations In this section, devices are described which shall be considered in order to cope with abnormal situations. The following measures are required: - Fresh air intakes shall be provided with flammable gas and/or toxic gas detectors, where applicable. - Where gas detectors are installed, the fresh air intake and exhausts shall be provided with gas-tight,

quick closing dampers. - Fresh air intakes and exhausts of blast-resistant buildings shall be provided with explosion proof

valves. - Rooms housing vital equipment shall be equipped with air-recirculation systems to remove heat

generated by the equipment, and shall have the HVAC control system fed from AC uninterruptible maintained power supply.

- To ensure that the heat generated by the equipment can be removed during mains power failure, a chilled water buffer should be provided. During power failure, only the chilled water pumps and recirculation fans shall run.

5.2 Equipment in Operation During Abnormal Situations During abnormal situations, vital instrument and electrical equipment must be kept within the

environmental limits set out in 3.2 above and Figure 1. the minimum range of equipment to be kept in operation should include:

- All vital instrumentation equipment controlling process and safeguarding systems. - All telecoms equipment including CCTV. - All fire and gas detection equipment. - All vital electrical equipment. The above equipment therefore defines the cooling load which will be required during an emergency or

abnormal situation. All submitted design proposals shall include calculations for this.Unless otherwise specified, the time period during which the above must be maintained will be 30 minutes, assumed to occur during full summer heat. In all instances, designers shall seek confirmation regarding the range of equipment to be kept in operation during emergencies, together with the redundant and back-up systems to be provided.

6.0 NOISE AND VIBRATION All buildings shall be designed with attention to noise and vibration control where all airborne noise to the

areas to be conditioned shall be reduced by applying one or more of the following: - Air duct silencers (Sound Attenuators) - soundproofing of air ducts - silent self-containing equipment Maximum allowable noise level or sound pressure level inside rooms shall be 50 dB(A) for Offices,

Page 15: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 15 of 22 Rev 0 1999

Control Rooms, Instrument and Electrical Auxiliary Rooms, see GES A.04. To reduce vibration, all rotating/vibration equipment shall be properly isolated from coupled piping/ducting

and structure, by using flexible piping, air duct connectors, vibration isolators etc. For equipment vibration limits, refer to ASHRAE Handbook(s).

7.0 CONTROL AND ALARM SYSTEMS All buildings shall conform with the conditions set below in regard to control and alarm systems for all

types of HVAC systems. 7.1 Control HVAC control systems must include the following features: - Temperature control for manned rooms. - Temperature control for equipment rooms. - Temperature control for substations and FARs. - Humidity control for rooms housing vital instrument and electrical equipment (excluding sub-stations). - Control systems should normally operate in automatic mode with manual override. - Control signals from a HVAC control cabinet and going to a HVAC motor control centre cabinet,

should go via an interface box. - The control (and alarm) cabinet and the motor control centre cabinet for AHUs must be physically

separated. - The HVAC control (and alarm) cabinet and the motor control centre (power) cabinet for non

stand-alone AHUs shall be preferably located within the HVAC machine room. In addition to the above, designers should note that careful control of humidity is especially needed

wherever a high concentration of corrosive gases are present in the environment. 7.2 Alarming The following notes shall apply: - Individual HVAC alarms shall be displayed on a local HVAC panel. - Common HVAC alarm signals generated by the HVAC control system, and which are to be displayed

in the main control room, shall be routed either via potentially free contacts and interface boxes, or via software links.

- No first failure alarm detection shall be included. No mimic type alarm display panels (ADPs) are required.

7.3 Electrical Power Supply-Electrical Safety In order to ensure that during abnormal situations, all vital instrumentation and electrical equipment

continues to function, the electrical power supply for HVAC equipment serving it shall be AC interruptible maintained and/or AC uninterruptible maintained, except for analyser houses. The power supply set up for a HVAC system may be as follows:

Page 16: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 16 of 22 Rev 0 1999

- AC uninterruptible maintained electrical supply: - HVAC control system and local panel(s). - AC interruptible maintained electrical supply: - (ie emergency generator) - Recirculation air handling

units, including its utilities (chilled water system or remote condensing unit). For HVAC systems required for vital equipment, including its utilities, the required capacity of the standby (diesel) generator must be verified.

All electrical and HVAC equipment must conform to area classification requirements and the IP Electrical

Safety Code. 8.0 INSPECTION AND TESTING The HVAC equipment Vendor/Contractor shall include all test equipment required to commission the

equipment and maintain it post contract. Test equipment must include amongst others: - Gauge manometers - Anemometers - Pitot Tube - Hygrometers - Thermometers - contact and insertion - Tachometers - Sound analysers - Vibration meters - Recorders for tuning control loops - Manifold and Gauges to measure pressure and relative temperature of refrigerant - Refrigerant Recovery System - Refrigerant Battery - Electronic scales - Refrigerant Charging battery - Acid Test Kit The HVAC Vendor/Contractor shall demonstrate with the equipment under test that it will meet its design

performance in terms of power consumed, air flows and temperature, and noise level under the maximum summer operating condition.

9.0 DOCUMENTATION 9.1 Introduction 9.1.1 This section covers the documentation required for the design, selection, fabrication, inspection and testing

of equipment, components and services to be provided against this specification. 9.1.2 The detailed list of documents that are required is included within the Purchase Order/Contract. 9.1.3 The documents as listed may be considered as a minimum requirement; all details to confirm compliance

with the relevant specifications, and to allow a full and continued appraisal to be made of the Vendor/Contractors proposals and interpretations of the ordered equipment, should be submitted in accordance with the schedule specified in the Purchase Order/Contract.

9.1.4 All documentation (drawings, calculations and data sheets, etc) shall be produced by the Vendor/Contractor

in an electronic format that is compatible with that used by the Owner and shall be agreed at the commencement of the Purchase Order/Contract.

9.1.5 Any production or procurement undertaken by the Vendor/Contractor which is prior to the relevant

documentation being submitted and reviewed by the Owner is at the Vendor/Contractors risk. 9.1.6 On all documentation the Purchase Order/Contract number, equipment title, tag number and project name

shall be quoted.

Page 17: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 17 of 22 Rev 0 1999

9.1.7 All documentation shall be checked and signed by the checker before submission. 9.2 Schedule/Reports 9.2.1 The Vendor/Contractor shall submit with his tender a preliminary quality control plan. 9.2.2 The Vendor/Contractor shall include with his tender documentation a statement of proposed sub-vendors, a

document submission schedule for all documents based on a review cycle of two weeks and outline programme for procurement and production activities.

9.2.3 The Vendor/Contractor shall incorporate any revisions agreed with the Owner during the enquiry review

stage and submit revised tender documentation for approval. 9.2.4 Monthly reports shall be submitted by the Vendor/Contractor detailing design, procurement, production

and documentation activities, the format of which shall be agreed with the Owner. 9.3 Data and Calculations 9.3.1 The Vendor/Contractor shall supply with his tender completed Data Sheets containing all the relevant

information necessary for appraisal of the design by the Owner. 9.3.2 Project specific instructions will be issued to the Vendor/Contractor with the Purchase Order, which

describes the data and calculations to be submitted, and the methods of submission. 9.3.3 The Vendor/Contractor shall be responsible for obtaining approvals from the Inspection Authority. 9.3.4 All calculations shall be carried out in clear and logical manner. Where conditions involve the use of

formulae or methods not specified in the Design Codes, the source of these formulae or methods shall be clearly referenced.

9.3.5 Computer calculations will only be acceptable if all input is shown, together with calculated values of

intermediate terms and factors and options chosen, as well as final calculated dimensions, stresses or other values and the computer program has been validated to the satisfaction of the Owner.

9.3.6 Calculations and drawings that are interdependent, i.e. foundation loading and equipment footprint, shall be

presented for appraisal together. 9.4 Drawings 9.4.1 The drawings listed with the Purchase Order/Contract shall be sent by the Vendor/Contractor to the Owner

and/or the Inspection Authority for review and approval. 9.4.2 The components and process to produce the ordered equipment shall be shown in sufficient detail to be

fully appraised. 9.4.3 General arrangement drawings shall be to scale and show the relative location and main dimensions of all

components including elevations and orientations of nozzles, lifting lugs, nameplates and supports. 9.4.4 Detail drawings which may be included on the general arrangement shall include thicknesses and

dimensions of all components, gaskets and nameplate details. 9.4.5 As-built drawings may be the general arrangement drawings marked-up with the actual as-built dimensions. 9.5 Final Records, Documents and Manuals 9.5.1 Two copies of the Data Dossier shall be supplied, and shall be a record of the manufacturing process.

Page 18: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 18 of 22 Rev 0 1999

Where stated in the Purchase Order/Contract, it shall contain the following: - general arrangement drawings and bill of material. - the quality control plan. - NDT procedures and records. - hazardous area certificates. - balance certificates. - hydrostatic pressure tests procedures, and test certificate. - performance test procedures, and test certificate. - non-conformity records. - approvals by the Independent Inspection Authority. - certificate of conformity. - Owner's release certificate. 9.5.2 Six sets of the Installation, Operations and Maintenance Manual (IOM) shall be specifically compiled for

the equipment supplied. A compendium of manufacturer's data for a range of like products is not acceptable. The IOM shall contain the following:

- a description of the equipment, process and controls philosophy. - the master document list and certified copies of key drawings. - packing, shipping and site preservation instructions. - step by step installation instructions. - step by step commissioning procedures. - normal start up, operating and shutdown procedures. - step by step procedures for dismantling and re-assembly. - normal operating and set point values for all instruments. - routine preventive maintenance schedule and major repair procedures. - lubrication, chemicals, consumables schedule. - list of special tools. - spare parts ordering information. - for PLCs, a copy of the programme and re-programming procedures. The IOMs shall be presented in A4 format, and be securely bound in heavy duty 4 ring binders. 9.5.3 The Vendor/Contractor shall produce as built documents revised to indicate field changes. 9.5.4 The Vendor/Contractor shall supply one set of mylar original drawings. 9.5.5 In addition to the 'hard copies' required under the Purchase Order/Contract, copies of the electronic records

shall be issued to the Owner for all approved documentation, this forming part of the Vendor/Contractor's contractual obligations.

10.0 PRIOR TO SHIPMENT 10.1 Painting and Coatings 10.1.1 Surface preparation, painting and painting materials shall be in accordance with GES X.01,GES X.02 and GES X.03.

Page 19: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 19 of 22 Rev 0 1999

10.2 Spares The Vendor/Contractor shall submit with his proposal, a priced list of recommended spares for start-up and

two years operation, for review by the Owner. 10.3 Packing and Storage 10.3.1 This section describes the minimum requirement for the preservation and protection of HVAC equipment

during sea and land transportation and storage, prior to installation. 10.3.2 The probable storage period will be specified in the Purchase Order/Contract and will extend from the time

of despatch to the time of unpacking at site. If the storage period is not stated, a minimum period of 24 months shall be assumed.

10.3.3 The following preparation for shipment shall be a minimum requirement. (a) After mechanical completion at the works, the HVAC equipment shall be left in a clean dry condition. (b) The Vendor/Contractor shall be responsible for loading and anchoring the item(s) to prevent damage

during shipment. This shall be done at the Vendor/Contractor's works, and may be achieved by firmly fixing the equipment to wooden pallets or crates, as part of an approved packing procedure.

10.4 Shipping 10.4.1 Detailed shipping arrangements will be given in the Purchase Order/Contract. 10.4.2 HVAC equipment shall not leave the Vendor/Contractor's works for shipment until the release certificate

has been approved by the Owner's Inspector. 10.5 Warranty 10.5.1 The Vendor/Contractor shall warrant all materials and services supplied against any defect for a minimum

of 12 months after commissioning or 24 months from the date of delivery to site, whichever is the shorter period, or for the period stipulated in the Purchase Order/Contract.

10.5.2 Should any item be found defective, the Vendor/Contractor shall be responsible for all costs associated

with restoring the equipment to the standard specified by the Purchase Order/Contract.

Page 20: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 20 of 22 Rev 0 1999

Notes for Figure 1 1.1 During Normal operation, all systems run and maintain design conditions as stated. 1.2 During Abnormal situations, such equipment that is still available continues to operate and maintain

conditions. 1.3 Humidity may be allowed to rise or fall provided condensation and static are prevented. 1.4 Temperature may rise to 40oC or fall toward 5oC provided Note 1.3 is observed and occupants can still

work safely. 1.5 If toxic or explosive gas is detected externally, all fresh air intakes should close until reset manually and the

detected gas clears (HVAC ESD switch to achieve this). 1.6 If gas detected internally only, this should alarm and all systems run to dissipate the gas. 1.7 Conditions for Electrical equipment should meet those stated in IEC 60654 Part 1 (Class A1/Class B3). 1.8 In the event of mains failure equipment supported by emergency power should run. 1.9 On the failure of individual items of equipment redundant units should be brought into operation if

available. 2. Clean means: Clean conditions are required and the generation of flowing substances is not expected. Foul means: Normal conditions for personnel to be maintained; generation of fouling substances may take

place. 3. A minimum of 10 litres per second or 0.5 air changes per hour is required ensuring 5 1/s/person is

maintained. 4. Efficiency ASHRAE dust spot test, in accordance with ASHRAE Standard 52-76. 5. Prefilter for 85% and after - filter for 95%. 6. Separate air recirculation system is required to cope with spreading of smoke in case of fire in the control

room. 7. May be combined. 8. The balance of pressure between kitchens and adjoining rooms is to prevent cooking smells entering other

spaces and to stop the migration of smoke if smoking is allowed. 9. User client to specify. Air is exhausted via fume hoods. 10. See DIN 5751 D/VDE 0510 - Spec for storage batteries and battery plants. 11. At least 20 litres per second per shower head. 12. Normally clean, but measures are required to cope with emergency cases. Notes for Figure 1 (cont'd)... 13. The plant, equipment and use of these areas are to be designed for use in Ambient Conditions. Where

Page 21: B-12

GENERAL ENGINEERING SPECIFICATION HEATING, VENTILATION AND AIR-CONDITIONING

GES B.12 Page 21 of 22 Rev 0 1999

limitations for this are required, the Owner will specify and air circulation may be required. 14. The ventilation rate must be sufficient for the occupants and the processes undertaken in these areas. 15. Stored items should be packed to suit the ambient but specialised storage may be required for unpacked

items that meets the conditions of its eventual use. 16. Toxic/flammable gas detection may be required inside and out dependant on use and location of room or

building. S:\NOC9077\ADMIN\SPECIFICATIONS\B-SERIES\B-12\GESB12RF

Page 22: B-12

Recommended