REPLACEMENT AIR CONDITIONING UNITS FOR BRITISH EMBASSY RESIDENCE

Transcription

1 REPLACEMENT AIR CONDITIONING UNITS FOR BRITISH EMBASSY RESIDENCE FOREIGN & COMMENWEALTH OFFICE BE BAHRAIN TEL: MAY TENDER ISSUE: 002/2014

2 1. GENERAL REQUIREMENTS

3 1.01 LOCATION OF SITE The British Embassy Bahrain is situated at 21 Government Avenue, Manama 306, Kingdom of Bahrain DESCRIPTION OF THE WORKS The scope of these works covers the removal of the existing R22 split air conditioning units and associated pipe work, insulation, controls etc. at the British Embassy, and the installation and commissioning of new R407C split air conditioning units and ancillaries. The works shall include all associated electrical, condensate drainage/plumbing and building works in connection with the installation. The installations shall comply strictly with the air conditioning unit manufacturer s drawings and specifications and the requirements of this specification. The existing air conditioning units shall remain operational throughout the works until such time as their phased removal. The contractor shall take special care to ensure that the protection is provided to the site and to the existing buildings/services and to members of staff throughout the duration of the works INSTRUCTIONS TO TENDERS Tender This specification and the manufacturer s drawings indicate the requirements for the installation works. The successful Contractor shall allow for all materials and labour to complete the works unless indicated otherwise including all electrical, builder s and plumber s works and protection to the site. The Contractor shall allow for installing all items indicated in the documents including any described as free issue.

4 Format of Tender The tender conditions and format of shall be in accordance with the requirements laid out by the FCO. The documents returned with the Contractor s tender shall include, but not necessarily be limited to the following:- (a) Details of key personnel who will be involved with the project (b) Health & Safety plan (c) Indicative programme of works (d) Completed tender summary (the works are to be undertaken as a lump sum contract) (e) The contractor shall allow for all costs Tender to Inform Himself It will be deemed that the Tenderer has thoroughly acquainted himself with the nature of the works and the conditions under which the work will be executed. The Contractor can, if deemed necessary, make arrangements to visit the Embassy via the British Embassy Estates Manager PROGRAMME The programme shall be agreed with the Estates Manager at the British Embassy, Bahrain prior to works commencing, but it is expected that all the works will be completed by 1 August The Embassy Compound will remain operational throughout the programmed works. It may be necessary to amend the programme due to daily operational requirements of the Embassy and the contractor should make some allowances for this within the tender. Indicative Working Hours Sunday Thursday 07:30 14:30 Friday and Saturday Closed (weekend out-of-hours working subject to agreement of Post) 1.05 GENERAL REQUIREMENTS Site Supervision

5 The Contractor shall keep a competent, English speaking Site Foreman who shall be in charge of the works during all working hours, who will be the duly accredited representative of the Contractor empowered to take instructions from the Estates Manager or her representative and to execute it Electrical, Builder s & Plumbing Works Requirements The Contractor shall carry out all necessary Electrical, Builder s and Plumbing Works associated with the Contract Disruption of Existing Services Any temporary disruption or disconnection of existing services which will be necessary to carry out the works shall only be made at such times as is agreed with the Estates Manager and/or his representative. This shall not be unreasonably withheld in order to allow the works to proceed in an economical manner. The programme and sequence of the works will be agreed with the Estates Manager prior to the works commencing INSPECTION, TESTING AND COMMISSIONING The installation shall be snagged by the Contractor and inspected by the Estates Manager or his representative, before final acceptance. The Estates Manager shall be offered the installations for witness testing upon completion of the works. The Contractor shall only offer the systems to the Estates Manager for final witnessing once he has satisfied himself that the systems are ready. The split air conditioning installations shall be tested and commissioned in accordance with the manufacturer s recommendations and shall include all control and safety devices. Prior to commissioning the Contractor shall provide a certificate of installation and electrical test certificates of the system to the Estates Manager or their representative.

6 2. SCOPE OF WORK

7 2.01 STANDARDS All equipment and installation works shall be carried out strictly in accordance with this specification, the air conditioning unit manufacturer s drawings and specifications and the Foreign & Commonwealth Office Electrical Standards HSP 9.64 (copy attached.) 2.02 GENERAL REQUIREMENTS All general provisions contained within this, or any other section of the Specification shall be fully applicable to each and every other section. All work carried out on the installation shall be carried out in a neat, efficient and workmanlike manner to provide for proper operation, maintenance and repair. The work shall be in accordance with the requirements of these Specifications and shall fulfil their true intent and meaning. No deviations from these Specifications and/or the manufacturer s drawings/specification shall be made without the Project manager s written approval. The Specification forms a composite document intended for the selection and installation of equipment having the general and specific characteristics, as detailed. The specifications indicate the equipment to be supplied and installed by the Contractor. Where the equipment or services are to be supplied or installed by others, it is noted accordingly. Unless otherwise specifically stated, the installation shall be left complete, tested and operating in all respects and fully integrated and coordinated with all other construction and installation works. The Contractor shall make any temporary connections and carry out other temporary works, as required for the installation of the works. Adequate precautions shall be made to ensure that the installation and site is safe at all times COORDINATION The contractor shall be solely responsible for the proper co-ordination of all phases of the work and timely delivery to the site of all equipment and materials for proper execution of the work.

8 It is the contract s sole responsibility to fully co-ordinate the work with all, or any other disciplines, and to ensure proper phasing of the work to ensure continuity of all works under this Contract. If it becomes necessary to remake any part of these works or that of any other discipline or trade as a result of poor or badly timed co-ordination, then all costs associated with remaking those works shall be borne by the Contractor. The Contractor shall take into consideration all statutory and local requirements issued by the local authorities, water, telephone and telecommunications etc. Along with any other requirements to be considered for the correct and legal operation of the air conditioning installation or equipment connected to the installation as part of this Contract GENERAL TECHINCAL REQUIREMENTS Electrical Supply The low voltage electrical system is a 3 phase, 4-wire 400/240 volts, 50Hz Earthing Requirements The air conditioning installation earthing arrangements shall in all respects comply with the following:- (a) FCO HSP 9.64 (b) Any other requirements stated within this Specification. The earthing conductor (the final conductor by which the connection to the selected means of earthing is made) is to be of copper construction and comply with the requirements of HSP All extraneous conductive parts are to be protected by supplementary bonding in accordance with HSP Minimum conductor size 4mm Green/Yellow Climate Conditions Except as stated below, all equipment shall be rated for the local ambient dry and wet bulb temperatures likely to be experienced. When equipment is installed in direct sunlight, it shall either be shielded from direct radiation or suitably rated for additional solar gains. Cables and hoses shall always be shielded from direct sunlight, if necessary, by the installation of ventilated covers or ducts. All equipment shall be rated for continuous services throughout its normal rated life, except for necessary routine maintenance Accessibility All work shall be so installed as to be accessible for operation, maintenance and repair.

9 Storage of Materials and Equipment All materials and equipment, fixed or unfixed, shall be protected against corrosion, deterioration and ingress of foreign matter. Wooden bearers shall keep all equipment clear of the floor or ground or other means and shall be protected against the weather. The contractor shall be responsible for arranging any off-site storage of the air conditioning units and ancillaries until installation is due. Deliver to site, safe unloading and positioning of the air conditioning units and ancillaries will be the responsibility of the Contractor and will be at a time to be agreed with the Estates Manager DETAILED SCOPE OF WORK The Contractor shall supply, install, test, commission and set to work the split air conditioning installation as detailed within the specification. The installation will consist of 10 no. new R407C split air condition units mounted in the Residence of the British Embassy in Manama. The existing redundant R22 split air conditioning units, refrigerant piping, insulation, condensate drains, controls etc. shall be removed prior to installation of the new units the exact location and type of the new units shall be determined on site and agreed with the Estate Manager before any work commences. When decommissioning the existing air conditioning units the contractor shall ensure that all R22 refrigerant removed is properly evacuated to avoid any emissions to atmosphere. All new interconnecting copper pipe work and associated copper materials must be of suitable quality for refrigerant R407C and shall be as per the manufacturer s recommendations. Copper pipe work shall be run in existing pipe ducts where possible and suitably fixed and supported along its entire length. Fixings and/or supports shall allow for pipe work expansion. To minimise the number of joints between the system components, coiled copper shall be used in preference to straight lengths of half-hard copper. All joints shall be brazed as flare joints are prone to leaking. The copper pipe work shall be capped at all times (with outside cover and caps), except when being worked upon. All pipe work shall be cut square with a propriety pipe cutter to give a clean cut, without copper fragmentation. Hacksaws must not be used. When brazing, all pipe work must be purged with low-pressure, oxygen free nitrogen, above atmospheric pressure to prevent moisture from the surrounding air entering the system. When all site works have been completed the pipe work shall be flushed with oxygen free, high-pressure nitrogen to ensure that any moisture and debris are removed. Pipe fittings shall be kept to a minimum and swept bends should be formed using a bending tool with the correct dies/mandrill/spring to prevent reeking or barrelling. A structured pressure test procedure shall be carried out as part of the general commissioning procedure and records kept. The formal test will be a multiple test and include the site pipe work, indoor/outdoor units etc. All capillary, solenoid and expansion valves shall be opened for these tests, to ensure all parts of the system are subjected to the test.

10 Suggested pressures used for testing are: Stage 1 - Stage 2 - Stage 3 - Flush system 3 bar for 2-3 minutes (to indicate major leaks) 1 st pressure test 15 bar for 10 minutes (if 1% deviation check for leaks) 2 nd pressure test 28 bar for 24 hours (No deviation in pressure) After satisfactory completion of pressure testing, the system shall be put under vacuum. The pipe work shall be evacuated to -755mm Hg (or manufacturers recommended value) for 1-2 hours and the vacuum broken with oxygen free dry nitrogen, this process shall then be repeated and after a third evacuation refrigerant shall be used in place of nitrogen. Interconnecting pipe work lengths shall be kept to a minimum, however any additional refrigerant charge required shall be calculated in accordance with the manufacturers detailed instructions. All pipe work shall be insulated with preformed armaflex or equal and approved, class O fire rated and vapour sealed. Insulation thickness shall be 6mm for ¼ pipe size and 13mm for 3/8 and above. Condensate drainage shall be heavy duty PVC and joints shall be made with couplers and solvent cement. All condensate pipe work shall be installed with a minimum gradient of 1:100 and shall not terminate in foul drains. Access for pipe cleaning shall be installed at suitable positions to allow rod access event of blockage. Each new split air conditioning system shall be fed from existing electrical supplies, however the contractor shall ensure that the existing supply cables are adequately sized for the load and shall complete insulation resistance testing before installation new cables shall be installed should the test results not comply with FCO HSP Earth loop impedance testing shall be carried out on completion of each installation and protective device disconnection times shall be in accordance with FCO HSP Each split air conditioning installation shall be protected by a suitably rated Type C MCB at the main distribution board and shall have IP 65 rated, rotary lockable isolators at the external unit. Indoor units shall be fed via suitably rated double pole switches and all indoor/outdoor units shall be labelled for correct identification HEALTH & SAFETY PLAN The contractor shall provide method statements/plans detailing health and safety proposals for the following areas of work: Working at height; Working with refrigerants; Hot works; Personal Protective Equipment (PPE).

11 2.08 TESTING AND COMMISSIONING The air conditioning installations shall be tested in accordance with the manufacturer s recommendations and all supply circuits shall be tested in accordance with FCO HSP all test results shall be recorded on approved test sheets. The Estates Manager shall be offered the installation for witness testing upon completion of the works. The contractor shall only offer the systems to the Estates Manager for final witnessing once he has satisfied himself that the system/s are ready. Only an experienced commissioning engineer who has been trained on the specific system installed shall carry out the commissioning of the installation, ie, the manufacturer s commissioning engineer. Prior to commissioning the Contractor shall provide a certificate of installation and test certificates of the system to the Estates Manager or her representative. Once the Certificates have been witnessed, issue a typed Inspection, Completion Certificate.

12 3. TENDER SUMMARY

13 3.01 TENDER SUMMARY To provide materials and install split air conditioning units as per the specification, meeting the manufacturers installation requirements and FCO Electrical Standards HSP 9.64.

14 TENDER SUMMARY 1. Decommissioning and removal of existing R22 split air conditioning units at British Embassy 2. Installation of 2 new 1.5-ton wall mounted R407C split air conditioning units at British Embassy 3. Installation of 8 new 2-ton ceiling mounted R407C split air conditioning units at British Embassy 4. All associated builders/plumbing/electrical work 5. Testing, commissioning & handover of installations 6. Complete two years, 4-times, maintenance & servicing of all units Total BHD 6,940 SIGNED... POSITION... COMPANY NAME... DATE...