Integrated Management System

PRD-ES-070

BUILDING SERVICES HVAC SYSTEM

Name Title Sig. Engineering Manager Prepared by Stuart Webster Projects

Reviewed by Musallam Al-Rashdi Construction Manager

Approved by Ahmed Al-Dhaheri Vice President Projects EMIRATES STEEL

HVAC System PRD-ES-070

1. GENERAL

1.1 Scope of Supply

2. DESIGN CONDITIONS

2.1 General Description 2.2 Ambient Conditions 2.3 Design Criteria 2.4 Design Space Conditions 2.5 Special Requirements 2.6 Plant and Control Rooms 2.7 Transformer Rooms 2.8 Analyzer Rooms in DRI Plant 2.9 Fire Dampers 2.10 Refrigeration 2.11 Monitoring and Control

3. MATERIAL SPECIFICATIONS

4. PIPING AND DUCTING SYSTEMS

5. INSULATION

6. LIFTING DEVICES

7. VIBRATION ABSORBERS

8. SILENCERS

9. INSPECTION OPENINGS

10. CLEANING

11. MARKING

12. PROTECTION OF COMPONENTS

13. DRAINING

14. ELECTRICAL ENGINEERING AND INSTRUMENTATION

15. DESIGN INFORMATION TO BE SUBMITTED

16. DOCUMENTATION

Issue No.: 01 2 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

1. GENERAL

This standard describes the design methodology for ES HVAC Systems.

1.1 SCOPE OF SUPPLY

HVAC systems to be installed shall be capable of performing the following functions:

. Removing the heat emitted by process and electrical equipment and by human beings . Removing contaminated air and explosive gas mixtures . Conditioning the room air with respect to temperature, humidity, purity, pressure, flow rate, fresh air rate, noise level.

The supply shall include, but not be limited to: air conditioners, ventilators (natural or forced), fresh and exhaust air fans, heating and cooling registers, radiators, air ducts, air intakes and ejectors, weather screens, louvers, relief dampers, fire dampers, air filters, piping for water, refrigerant, instrument and compressed air, valves, air and water balancing devices, refrigerators with air-cooled condensers, air intakes on the roofs, duct and pipe insulation, control cabinets, measuring systems, switchgear and control gear, cables between control cabinets and consumers, supporting structures and roof mounted frames for HVAC equipment, installation and fixing materials, wear and spare parts, and all parts required to make a complete installation.

1.2 DESIGN CONDITIONS

When designing the mechanical HVAC system, special attention shall be paid on the material and equipment selection, with special attention to the iron & steel industry environment, in order to obtain trouble-free, operation with minimum maintenance and economical life expectancy.

HVAC equipment shall preferably be installed indoors, i.e. inside mechanical services plant rooms.

Fire interlocking shall be provided through fire alarm signal for local HVAC systems or, in the case of central HVAC systems, divided into separate zones/applications equipped with fire dampers.

1.2.1 GENERAL DESCRIPTION

Rooms/spaces shall be provided with air-conditioning (A/C) or partial air-conditioning, as directed in the particular specification. A/C shall be implemented using compact cabinet- type appliances and, for larger applications, air handling unit (AHU) -type appliances, containing all necessary components. Appliances shall include fans, refrigerators and heaters, and as appropriate, steam humidifiers. The plant's room temperature and humidity shall be controlled automatically by means of sensors arranged in the conditioned space or return air duct as appropriate. Fresh air and recirculated air shall be provided to the different rooms via ducts made of galvanized steel sheet with grilles provided as required.

Issue No.: 01 3 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

The A/C unit - the Air Handling Unit (AHU) in the case of chilled water system or direct expansion (DX) system - shall preferably be accommodated in a separate mechanical room which allows proper maintenance access for cleaning, removing cooling coils, maintaining the fans, dampers etc.

Sound attenuators (silencers) are provided in the fresh air and waste air inlets and outlets as necessary to keep the sound level in air-conditioned rooms as low as possible.

The air shall be humidified by automatic steam air humidifier. Steam shall be produced by electric heating.

Waste air shall be exhausted from toilets through exhaust grilles. Exhaust fans shall be provided for extraction.

The gable roofs shall be provided with additional waste air fans in order to avoid heat build-up.

As sandstorms may occur in the region, fresh air shall be taken from a point above the roof of the building and led over suitable air baffles to separate the coarse sand prior to filtering. Convenient facilities for manual removal of coarse sand shall be provided. The pre-filtered air shall then be cleaned by additional oil bath filters.

An overpressure of approximately 5 mm WG shall be maintained in all air-conditioned rooms to prevent the ingress of dust through windows and doors and through other openings (cable passages).

Air intakes shall be provided with gas detectors to warn of gas ingress in rooms where persons are employed. The gas detection system shall be capable of shutting the fresh air supply ventilation system down.

1.2.2 AMBIENT CONDITIONS

The complete mechanical HVAC system equipment shall be designed to operate satisfactorily under the following ambient conditions: i) Temperature from 0°C to 52°C. ii) Humidity 10 to 100% RH. iii) Sun exposure, about 300 days per year. iv) The prevailing wind blows generally at 10 to 40 km per hour and often carries a fine impalpable dust. It produces a humid, salty, dusty and sandy atmosphere. The frequency and intensity of storms are greatest during winter and early spring. During this time, the normal frequency of these storms is more than two per week. In-plant equipment is subject to additives, metallic and corrosive fugitive dust effects in the steel mill(s), direct reduction plant(s) (DR). v) The temperature may vary according to the in-plant conditions. If the mechanical HVAC system equipment is located in an area involved in the upper half of the production or process buildings, a design temperature of 70°C shall be used.

Issue No.: 01 4 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070 vi) The HVAC system installed in the overhead cranes in the production area shall conform to Standard 11 “Cranes & Hoists’ of the ESI Standards.

2.3 DESIGN CRITERIA

The heating and cooling load requirements for the HVAC system shall be based on the conditions detailed in ES Standard 02-000 “Site Information” (climate) document.

However, to ensure an adequate air-conditioning capacity for the critical facilities, such as computer centres, process cooling etc, the summer design ambient will be treated as 50°C dry bulb and 33°C wet bulb.

For the HVAC plant installed in the upper half of the process buildings such as Steel Plant, Hot Rolling Mills, Bar Mill etc., a design ambient of 70°C shall be used.

Ventilation requirements will be as per American Society of Heating, Refrigerating & Air Conditioning (ASHRAE) standards, and with respect to the space utilization.

All HVAC ducts will be according to Sheet Metal & Air Conditioning Contractor’s National Association Engineers (SMACNA) standard and plant utilisation that suits actual site conditions.

2.4 DESIGN SPACE CONDITIONS

In general, the space conditions shall conform to the ASHRAE standards with respect to space utilization and classifications. The space 'datum' may be comprised of the following nominal comfort conditions representing the residence or office buildings:

• Summer temperature 24°C ±1°C • Humidity 50% RH ±10% RH • Winter temperature 21°C ±1°C • Air flow rate in the area of workplaces <0.2 m/s • Max. noise level at the work place (offices), etc NR 40

There are many requirements for the other space conditions deviating from the 'datum' as determined by the space utilization and the requirements of the plant or equipment located in either normally occupied or unoccupied areas.

The complete details about the internal space parameters such as the temperature, the humidity, and the ventilations, etc. shall be submitted for discussion and prior approval.

The air distribution system shall be designed in such a way that it maintains a uniform zone of temperature. Each of the supply air diffusers shall be provided with a plenum box containing a volume control damper (for controlling the air flow) on the inlet duct spigot.

A separate return air grill for each supply diffuser shall be provided, connected to the main return air duct or main exhaust air duct as required.

2.5 SPECIAL REQUIREMENTS

Issue No.: 01 5 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

The various buildings and sections within buildings shall be heated, ventilated and conditioned according to the following concepts:

. Rooms with similar air conditions in the same building shall be supplied from a common centralized plant. . This centralized plant may belong to any of the following three groups:

(a) Full Air-Conditioning Systems for control rooms, computer rooms, offices, etc.

(b) Partial Air-Conditioning Systems for high-tension rooms, low-tension rooms, etc.

Rooms used for specific purposes shall have separate systems designed for the particular requirements of these rooms.

A hundred percent (100%) standby unit is required for all process cooling, control room, PLC and computer equipment rooms, and other similar units.

A minimum of 50 % standby unit is required for electrical room and other process related rooms. The units selected (the run units and standby) shall be with same model and size.

HVAC for rooms such as Level 3 Automation shall be operational throughout any power failure. A separate standby A/C unit connected to the emergency power supply shall be provided for these facilities.

To minimize the effects of sandstorms, fresh air shall be taken in at the highest point of the buildings.

Large buildings equipped with several HVAC systems shall have a common fresh air intake from which the air can be distributed via ductwork to the various HVAC systems.

The fresh air intake in large buildings shall be designed as a walkable air chamber consisting of two compartments. The compartment coming first in the direction of the air flow shall accommodate a sand trap and sand collector, the partition between the two compartments shall hold the pre-filter (for instance a continuous belt filter running through an oil bath), while the second compartment provides for the inlet to the fresh air distribution system.

The quality of fresh air will be as follows:

The offices, pulpits, control rooms, laboratory, change room, and electrical rooms shall have systems with three-stage filtration:

. First Stage pre-filter 30 to 40% . Second Stage filtration 60 to 70% . Third (final) Stage 95%.

Issue No.: 01 6 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

This must ensure a dust-free environment, and maintain a positive pressure inside the space to be air conditioned.

A general emergency 'switch-off' point for all the equipment shall be provided for each building area.

The air cooled condensers for refrigeration plant shall be installed at ground floor level or at roof top level where necessary, having proper concrete foundation or steel platform and safe accessibility for maintenance.

The air intake openings in gas extinguisher stations shall have gas-tight check valves. Waste air outlets shall be provided at high and low points of the rooms.

The air intake openings in battery rooms shall be near the floor. Waste air outlets shall be arranged at high and low points of the room.

Fresh and waste air systems shall be protected against electrolytic effects and against electrostatic charges. No sparks shall be tolerated during normal operation, or during abnormal conditions of the fresh air and waste air systems, or under the effect of extraneous elements.

2.6 PLANT AND CONTROL ROOMS

The following conditions shall be taken as the minimum requirements in certain plant and control rooms, unless particular requirements are stated in the relevant plant area specifications.

. Plant control rooms, computer rooms, control pulpit, PLC etc. - temperature 25°C ±1°C, 50% RH ±10%.

. Electrical Switchgear (HT & LT), MCC rooms, PLC, cubicles and mechanical & electrical workshop – temperature maximum +30°C.

. Warehouse building, mechanical plant rooms, equipment rooms, , pump stations, compressor station, etc. - temperature maximum +40°C.

Preferably, chilled water shall be used as cooling medium (central/fan coil as applicable) for plant buildings.

Chilled water pipes shall not be run in computer rooms, control rooms, control pulpits, electrical switchrooms, PLC equipment rooms and the like.

Direct expansion (DX) systems may be used for small applications, with prior approval from ES.

2.7 TRANSFORMER ROOMS

Outside the plant building: suitable (filtered air) forced mechanical ventilation systems shall be provided.

Inside the plant building: fresh/filtered and chilled water cooling system, maximum temperature +50°C.

Issue No.: 01 7 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

2.8 ANALYZER ROOMS IN DRI PLANT

Analyzer rooms shall have an emergency ventilation system in addition to the normal HVAC system. This additional system shall ensure that leaking gases are sufficiently diluted with air to prevent explosive gas/air mixtures.

Overall, the HVAC and emergency ventilation systems shall have the following configuration:

(d) Air-conditioning unit installed in the A/C equipment room, with a connection to the fresh air intake on the roof of the building.

(e) Air supply duct from the A/C equipment room to the "room for analyses" and duct mounted ejector grills to blow the air into the room.

(f) Waste air exhausted through waste air inlets to the waste air duct and back to the air-conditioning unit.

(g) Exhaust air shall be discharged by explosion-proof exhaust grille to a vertical exhaust air duct with air inlets near the floor and near the ceiling. This system shall be connected to the atmospheric discharge opening.

It must be ensured that sufficient fresh air to maintain at least 5 air changes per hour can enter the "analyser room" when the air-conditioning unit is shut down and the emergency extractor system is operating.

While the emergency extractor system is operating and the air-conditioning unit is switched off (situation during gas alarm), sufficient fresh air shall enter the room by way of the air-conditioning unit and air ducts to prevent gas escaping the hazardous area and entering the non-hazardous areas.

As gas may leak into the "analyzer room", this room has been classified as hazardous (Zone 1).

The air-conditioning and the control cabinet for this unit shall be accommodated in a special room (A/C equipment room). They will not be explosion-proof (A/C equipment room shall be a non-hazardous area).

Gas detectors will be installed in the air-conditioning unit at suitable locations to monitor both the fresh air and the waste air from the room; the gas monitor will switch off the air- conditioning unit if a hazardous gas concentration is detected and will start the emergency extractor system - if it is not already running - to curb the increase in gas concentration within the room.

2.9 FIRE DAMPERS

Fire dampers shall be provided and installed in walls and ceilings. The dampers shall be equipped with limit switches and holding electromagnets.

Fire dampers status indication (open/close) shall be provided in a central control panel.

Issue No.: 01 8 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

2.10 REFRIGERATION

Refrigeration plant for HVAC systems shall have air-cooled condensers. Any plant application requiring water cooling must be discussed with and approved by ES.

Cooling systems shall utilise refrigerant fluids of low global warming potential and zero ozone depletion potential and be fully compatible with the refrigeration equipment.

2.11 MONITORING AND CONTROL

The main parameters of each room and zone and each HVAC unit shall be monitored and recorded by means of a Building Management System (BMS). The system shall consist of distributed plant input/output equipment and HMI workstations interconnected by a standard field bus network. Equipment shall be standardised with that in use on other ES plant. The selection of equipment, architecture and location of the HMI workstations shall be agreed with ES.

The minimum parameters to be monitored shall include:

. Unit status (running/stopped/fault) . Valve position . Motor trip . Fire alarm status . Room temperatures . Room high temperature alarms . Air and piped services (e.g. chilled water) flows, pressures and temperatures.

Control and monitoring for plant items such as Air Handling Units (AHUs) shall be by BMS local control unit to allow local and remote control and supervision. The unit shall be housed in an approved control panel and installed inside the AHU plant room. The panel shall provide following functions:

. Unit on/off and trip (indication & control). . Fresh air temperature (indication). . Fresh air relative humidity (indication) . Zone temperature (indication and control) . Zone relative humidity (indication and/or control) . Supply air temperature (indication and control) . Supply air relative humidity (indication and/or control) . Air input to AHU: temperature and humidity (indication) . Control valves/actuators (indication and control) . Alarm indication for filters, temperature, and humidity (if applicable)

3. MATERIAL SPECIFICATIONS

All the materials specifically used for the HVAC system mechanical equipments shall be fully compatible with heavy industrial applications such as in the steel plant conditions.

All the control system components will be selected to withstand the maximum temperature as specified in the concerned application, without affecting the efficiency and life expectancy of the system.

Issue No.: 01 9 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

The drive motors shall be 'TEFC' type and suitable for in-plant ambient conditions. Other accessories will be in accordance with requirements.

Valves (3-way or one-way), dampers and their actuators, etc. must all be suitable to plant ambient conditions.

All materials used shall be non-combustible or fire retardant.

All steel subject to corrosion shall be hot-dip galvanized with a uniform coating of not less than 200 g/m². Wherever galvanized parts have been damaged by welding or installation activities or for other reasons, they shall be painted over with 2 coats of rust inhibiting paint.

All insulation shall be vapour-proof. This requirement shall be strictly observed also for the insulation of air-conditioning units. The insulation shall be appropriately jacketed to prevent damage. Plastic jacketing is not acceptable.

All hangers, supports, etc. shall be appropriately designed to ensure that no direct contact is possible between the supporting part and the supported part. Inter-layers shall be provided having the same thickness as the insulation to avoid condensation.

All installations shall be appropriately arranged so that they can be conveniently inspected, repaired, replaced, etc. without interfering with other installations.

Air scrubbers (adiabatic cooling) shall not be used for air cooling. There use will only be accepted by special agreement give by ES and only if the wet bulb temperature of the outside air and the heat emission within the rooms to be cooled in relation to the desired room conditions (relative humidity) make this solution cost-effective in the long term. The fact that an air scrubber requires more maintenance than an air cooler coil must be taken into consideration.

Dielectric unions shall be provided at the joints between two different materials (for instance cooler piping, etc.) to avoid electrolytic corrosion.

All flange bolts shall be made of stainless steel. To prevent electrolytic corrosion, these bolts shall be run in plastic sleeves and have plastic washers.

The air condensers shall have a minimum fin spacing of 3 mm for the purpose of maintenance and longer equipment life.

The air condenser and AHU cooling coil shall be copper tube with copper fins.

The chiller air condenser arrangement shall be vertical or "U" shape and shall be provided with fixed ladder and catwalk to give access to the condenser fans and motors.

All refrigeration pipes, plant and equipment subject to temperatures below ambient temperature shall be insulated and metal sheathed. The insulation used shall have a maximum thermal conductivity (K value) of 0.036W/m/°C with minimum of 25mm thickness or equivalent insulation. However, for the chiller evaporator, a similar K value with minimum of 38 mm insulation thickness is appropriate.

Issue No.: 01 10 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

The condenser fan motors shall be suitable for 60°C operation.

Double regulating valves (complete with volume flow measuring accessories and instruments including isolation and draining facilities) shall be installed in each branch of chilled water system, including the chillers.

Fin spacing in air condensers and AHUs shall be not more than 10 fins per inch.

Air condenser fin thickness shall be 0.3 mm minimum.

4. PIPING & DUCTING SYSTEMS

All water piping systems shall have a sufficient number of connections to permit thorough flushing of the piping prior to commissioning the systems.

Note: Control valves, air coolers or radiators must not be flushed. Interim bypasses shall be installed which shall be suitable to carry 1.5 times the water flow rate during future maximum load operation.

A minimum flow rate of 3.5 m/s in the piping system shall be ensured during the flushing operation.

All piping shall be tested with a pressure amounting to 1.5 times the maximum valve rating. This pressure shall be maintained over a period of three hours.

Strainers shall be provided upstream of all control valves and pumps

Copper tubes remain untreated unless they are in contact with soil, brickwork or concrete. In this case, at least two bitumen coats shall be applied to the tubes, provided that the contacting materials do not require any higher protection. Contact between copper tubes and other metals shall be prevented by an appropriate non-conducting insulation.

Wherever the piping penetrates brickwork, floors or other building components or materials, it shall be run through sleeves through the whole wall thickness. The sleeve material shall be the same as the pipe material. The inside diameter of the sleeve shall exceed the outside diameter of the insulated or non-insulated finished piping by 20 mm. The insulation shall not be damaged where it is run through the sleeves. The sleeves shall project by 20 mm beyond the penetrated material/component. The gap between the sleeve and the pipe shall be tightly packed with fire stopping material and then sealed with non-hardening transparent sprayed compound to depth of not less than 10mm at the sleeve ends.

Where air ducts penetrate other components, the procedure shall be the same as for piping, but the penetrations shall in addition be trimmed with 100x100 mm L-sections made of aluminium in exposed areas and of galvanized steel in concealed areas.

Note: Where aluminium foil is applied to the ducts as a vapour-proof barrier, the trimming frame shall in all cases be made of aluminium to prevent contact corrosion.

Where galvanized ducts are run through exposed areas, the trimming frame shall be made of aluminium with 3mm bitumen felt interlayer between the different materials to prevent contact corrosion.

Issue No.: 01 11 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

The sleeve for insulated ducts shall be large enough to ensure that the duct insulation can be run through it without detracting from the 10mm gap between the insulation and the wall sleeve.

Thermal expansion of piping, ducts or other systems shall be allowed for by appropriate fixed supports, expansion loops, etc. (no bellows expansion joints). Direct contact between the fixed supporting structure and the systems to be fixed should be avoided to forestall condensation; if this is not possible for technical reasons, such direct contact shall be limited to the absolute minimum.

Steel piping shall be supplied with a corrosion-inhibiting shop primer and shall be coated after installation as required by the Contract.

All exposed air ducts and HVAC plant room ducts shall have external metallic cladding of 0.6 mm GI sheet.

The supply air indoor duct shall be insulated with fibre glass or equal insulation of minimum thickness 40 mm and minimum density 32kg/m3, with aluminium foil surface finish.

All the exposed air ducts (exposed to sun, dust, fumes, humidity, etc) shall be provided with fibre glass or better insulation of minimum thickness 50 mm and minimum density 64 kg/m3, with aluminium foil surface finish.

Chilled water piping material shall be in accordance with ES Piping Specifications. A non- flammable, bonded proof insulating material must be supplied to ensure a maximum temperature rise of 1°C in the piping, and suitable GI sheet cladding etc. fitted.

5. INSULATION

The insulating material shall be non-combustible. Expanded materials such as foamed styrene, polyurethane foam and the like are not acceptable.

Mineral fibre materials may be used, but it shall be ensured that the fibres of the mats, boards, etc. are arranged upright rather than horizontal.

The hardness of the insulating material shall be such that the loaded insulation is not compressed by more than 10% either by its own weight or by the weight of the insulated object (at supports etc).

Valves and other fittings in insulated piping shall be installed as follows:

(a) The piping insulation and vapour barrier shall be run up to the valve flange. The split, easily detachable aluminium valve cap shall be installed with a lap of not less than 50mm.

(b) The cap encloses the valve body up to the stuffing box in such a way that the installation thickness will not be less than 30mm after Class O (low smoke and fume) insulation foam injection. Stuffing boxes shall be covered by a conveniently removable cap, which is then also filled with Class O insulation foam.

Issue No.: 01 12 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

(d) When the valve is replaced, the foam insulation has to be removed by mechanical means and the new valve enclosed and insulated as described above.

6. LIFTING DEVICES

All units or components shall have a sufficient number of lifting eyes to ensure that they can be conveniently manipulated by hoists.

Lifting eyes or other suspension facilities shall be located so that adequate space remains between the lifting eye at the unit and the suspension system from which the unit is to be hung to attach a hoist and lift the unit or component at least 500mm above its operating location.

7. VIBRATION ISOLATION

The installation of vibration isolators shall be symmetric to the mass centre rather than the area centre.

All vibration absorbers shall be selected according to the manufacturer's instructions and their dimensions shall be such that a sufficient distance remains between the unit and its foundation during shutdown, acceleration, operation and slow down. Even if the unit it temporarily slanted owing to inertia, the "sufficient distance" at the closest point shall not be less than 30mm.

All large area structures such as equipment housings, etc. shall be appropriately stiffened to ensure that rhythmic vibrations or fluttering is safely prevented during all operating conditions.

8. SOUND ATTENUATORS

Sound attenuators for ventilation and air-conditioning systems shall be made of series produced components. It shall be possible to improve the silencing effect by adding on identical components in a modular system.

Attenuator elements and other sound-absorbing lining shall be made of non-combustible material; they shall resist abrasion and wear up to air flow rates exceeding the maximum design flow by 50%.

9. INSPECTION OPENINGS

Inspection openings shall be provided in the air ducts upstream and downstream of shut- off dampers, fire dampers, air heaters, air coolers, bends with installed deflectors and other internals that may reduce the duct cross section, but also along straight duct sections at intervals not exceeding 20m.

The size of the inspection openings shall not be less than 500x500mm (subject to the size of the ductwork). If this is not possible for technical reasons, a clearance of 500mm shall be maintained at least in one direction while the other dimensions shall be as large as possible according to local conditions.

Issue No.: 01 13 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

The inspection openings shall have hinged air-tight doors which can be easily opened by means of a sash bolt.

The insulation thickness on the opening doors shall be the same as for the ducts in which the doors are installed.

The opening doors shall be appropriately designed to prevent condensation at the frame and at all other parts.

Openings for the installation of detectors, sensors or other control devices as well as test holes shall have a clearance of 150x150 mm. They shall be closed air-tight and the lids shall be insulated to the same thickness as the ducts in which they are installed. To ensure convenient removal and refitting, the control devices shall be installed in these lids.

10. CLEANING

All installed items such as instruments, units, piping, ducts, insulations, insulation jackets, and all accessories shall be properly cleaned before the acceptance inspection.

11. MARKING

All piping, ducts, dampers, control units, valves and other components, whether they are exposed or concealed, shall be appropriately marked using a stencil and/or tag to indicate the following information by color and wording:

System Fluid (gas, liquid) Flow direction Hazardous or non-hazardous (for instance acid, pressure etc)

The description shall be entered in a numbering system to be used also on the respective data sheets and as-built drawings so that the respective component can always be conveniently identified and found.

Concealed fire dampers shall be appropriately identified on the concealing surface to ensure that they can be unambiguously identified by means of the respective data sheets.

12. PROTECTION OF COMPONENTS

12.1 PROTECTION PRIOR TO INSTALLATION

Wherever possible, the components shall be stored in sand-tight rooms. If this is not possible, they shall be protected against solar radiation and covered by plastic sheeting to keep off the sand and shall be stored not less than 300mm above the ground.

Easily damaged items such as accessories of the control system or louvered air coolers, etc. shall be replaced if they are damaged by sand or corrosion due to non-compliance with the storage instructions.

12.2 PROTECTION AFTER INSTALLATION

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HVAC System PRD-ES-070

All openings of components, units, piping or duct systems shall be tightly closed or covered to keep out dust during installation until the entire system is commissioned and handed over to ES.

The Contractor shall protect all items associated with his work – irrespective of the supplier - against damage and shall repair any damage that has occurred to the best of his ability or replace the damaged items by new ones.

Protective measures shall be prescribed and duly observed to ensure the air ducting is commissioned without special precautions. Appropriate measures shall be taken to prevent dust from being blown into the ventilated rooms when the system is first commissioned. This may be achieved, for instance, by using also the air supply system to extract air from the rooms and discharge it to the atmosphere when the system is operated for the first time.

13. DRAINING

All points where condensate may collect (air coolers, open valves, etc.) shall be drained to the foul water sewer. The connection between the drain and the sewer shall not be rigid. This system shall include:

. An odour trap with sufficient water level, and . A stainless steel intake funnel with male thread.

The odour trap shall be suitable for cleaning.

Condensate piping shall be insulated with a vapour-proof barrier.

Condensate drains at air coolers shall have a minimum diameter of 50mm. Each condensate pan shall have at least 2 drains.

Plugged drain nozzles shall be provided at the fans of air-conditioning units, installed downstream of cooling elements.

14. ELECTRICAL ENGINEERING AND INSTRUMENTATION

The electrical and instrumentation systems forming part of HVAC units shall conform to the requirements under Electrical Equipment and Instrumentation Standards.

Note: all equipment shall be designed for operation on the normal site supply voltage(s) given in the particular specification.

15. DESIGN INFORMATION TO BE SUBMITTED

All the proposed and recommended types, HVAC systems' equipment, models, and manufacturers' special features, if any, for all the refrigerating, air-conditioning, ventilation, heating, and process cooling equipment, etc. shall be based upon the actual required system performance and plant space allocated, allowing a safe and generous space/access for necessary maintenance and repair of such equipment, compatible to the plant safety standards.

Issue No.: 01 15 of 16 Issue Date: 01.06.2011 EMIRATES STEEL

HVAC System PRD-ES-070

The final selection of the manufacturer shall be after due consultation with ES. The designer shall provide all plant duties including the fan curves, identifying system selection etc.

The information to be provided by the designer shall also include, but not be limited to, the following:

a. Type of the system (chilled water cooled or DX type). b. Coil on/off; dry and web bulb temperature. c. Coil flow rates. d. Plant air volumes and external resistance. e. Humidification/dehumidification calculations. f. Standard of filtration. g. Maximum/minimum volumes and quality of fresh air. h. Air supply temperatures. i. Plant noise levels. j. Psychometric chart of system conditions. k. Total cooling/heating and ventilation load calculation for each plant. l. Air velocities throughout the system. m. Water flow rate/velocity - if applicable. n. Exhaust air & ventilation requirements. o. Electrical calculations related to the HVAC system. p. Pressurized water tap connection/compressed air for maintenance purpose. q. Annunciator panel for the area/building to include the complete HVAC system monitoring.

16. DOCUMENTATION

Documentation shall meet the requirements of EN/IEC standards.

The minimum requirements for engineering drawings and documentation shall be in accordance with Section 9 “Engineering Documentation’ of ES Site Conditions and Engineering Standards.

17. ISSUE HISTORY

Issue Date Page / s Revision Details Status 01 12/06/2011 16 Formatted as per ISO corporate standard

Issue No.: 01 16 of 16 Issue Date: 01.06.2011