BOILER REPLACEMENT. and Associated Works PERFORMANCE SPECIFICATION. Sussex Lodge London W2 & 16 Stanhope Terrace London W2

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1 and Associated Works PERFORMANCE SPECIFICATION Sussex Lodge London W2 & 16 Stanhope Terrace London W2 BPME Consulting Engineers Tel: Doc ref: 0075/D1 JUNE Page 1 of 29

2 1. GENERAL REQUIREMENTS Preliminaries Standards Existing Services Quality Assurance Site Safety Insurance Valuations Defects liability period and Maintenance Electricity and Water Access Provisional and Contingency Sums General technical requirements Manufacturing Standards Labels and Number Plates Fixings Fire Precautions Radio Interference Tests SCOPE OF WORKS Program of works Visiting site and costing NEW INSTALLATION Boilers Flue system Condensate system Combustion air supply Pipework Air venting and Safety valves Bracketing Insulation and Painting Valves & Cocks Plate heat exchangers and Buffer vessel Plate heat exchanger Buffer vessel Pumps Pressure Set / Expansion / Dosing system Pressure / expansion set Dosing Pot Gas Ventilation ELECTRICAL WORK Power and light Controls Equipotential Bonding Lightning Protection REMOVAL AND MODIFICATIONS TO EXISTING Boiler room Page 2 of 29

3 4.2. Roof tank room venting Venting Oil tank room Modifications to existing systems BUILDING WORK New Boiler room Gas meter area COMMISSIONING. WATER TREATMENT AND DOCUMENTATION Commissioning Water treatment Operating and maintenance instructions Record information and certificates SCHEDULE OF PRICES FORM OF BID Page 3 of 29

4 1. GENERAL REQUIREMENTS This specification covers the work required to replace the boiler plant at Sussex Lodge, Sussex Place, London W1, part of which building is known as 16 Stanhope Terrace W2, including all necessary Mechanical, Electrical, Plumbing and associated Builders work as specified. This specification shall be read in conjunction with Drawings Nos 0075 / M01 and 0075 / M02. Outline of project The building known as Sussex Lodge was originally served with heating and hot water from oil fired boilers installed approximately 40 years ago. A reasonable life expectancy is normally taken as 25 to 30 years. Only two of the original four boilers are now serviceable, the boiler serving the hot water having been removed and a temporary oil fired unit situated outside the boiler room is currently providing hot water. The existing boilers are oil fired from a daily service tank which is fed from a main tank room adjacent to the boiler room.. It is planned to install new high efficiency condensing gas fired boilers in the basement car park area and remove all redundant plant and services from the existing boiler room. Some of the existing distribution mains in the basement and the entire existing boiler room are insulated with asbestos. This will be removed under a separate contract prior to the work described in this specification commencing. The existing Hot Water Service distribution is installed in galvanised pipe and the heating in black steel. It is not planned to renew the distribution mains at this time hence the connections from the new hot water generator will be installed using galvanised pipework and fittings to serve until the distribution system is renewed. When this work is carried out the entire hot water system will be replaced with copper pipe and fittings Preliminaries Standards Full compliance is required with the following: (i) Current British and European Standards and Codes of Practice Page 4 of 29

5 (ii) IEE Regulations for Electrical Installations 16th Edition (BSS 7671) (iii) Health and Safety at Work Act 1974 (iv) Electricity at Work Regulations 1989 (v) Low Voltage Electrical Equipment (Safety) Regulations 1989 (vi) Standard Engineering specifications M & E 3 and 100 (vii) Gas Safety (Installation and Use) Regulations 1984 and Amendments 1990 (viii) Building Regulations 1989 and (ix) Control of Substances Hazardous to Health Regulations 1988 (x) Water regulations (xi) CIBSE Lighting Code: Sports 1990 (xii) CIBSE Lighting Code: The Outdoor Environment 1992 (xiii) CIBSE Guide 1986 (xiv) CIBSE TM12 Emergency Lighting 1986 (xv) CIBSE TM13 Minimising the Risk of Legionnaires Disease 1987 (xvi) CIBSE TM16 Fire Precautions 1990 (xvii) CIBSE TM17 Maintenance Management for Building Services 1990 (xviii) Inland Water Authority Requirements (xix) Local Public Health Office (xx) CIBSE TM18 Health, Safety and Welfare 1990 (xxi) Fire Safety and Safety of Places Sports Act 1987 (xxii) Local Government (Miscellaneous Provision) Act 1992 (xxiii) Fire Precaution Act 1974 (xxiv) HS(G) 70 Control of Legionella including Legionnaires Disease 1992 (xxv) The construction (Design and Management) Regulations 1994 (CONDAM) (xxvi) Low Voltage Electrical Equipment (safety) Regulations Existing Services Heating and Hot Water Service is currently distributed from the existing boiler room via high level mains in the basement garage area. It is planned to cut into these mains and serve them from the new boiler plant. As the existing system is old and in poor condition care shall be taken to ensure that the pressure exerted on the old system is not permitted to increase above the current operating pressure. Page 5 of 29

6 The existing systems most likely contains sludge, and due to the age and condition of the existing pipework it is not considered prudent to high pressure flush or chemically clean the systems, also velocities of water flow in the existing mains shall remain approximately as existing. The existing heating system is fed from a feed and expansion tank situated at roof level. This will be replaced with an expansion vessel and pressurising set. The existing tank shall be empted, isolated and abandoned safe. The Contractor shall ensure that all existing open vents at roof level are replaced with automatic air valves arranged to discharge onto the roof Quality Assurance Site Safety The Contractor shall operate the project as though he is a Quality Assured Company in accordance with ISO Contractors and manufacturers of materials, equipment and spares used by the Contractor shall also comply with this criteria. If this is not possible the Tenderer shall state his method of working. The Contractor's attention is drawn to the Health and Safety at Work Act 1974, the Construction (Working Places) Regulations 1966, the Gas Safety (Installation and Use) Regulations 1984, the Control of Substances Hazardous to Health Regulations 1988, the Electricity at Work Regulations 1989 and the Construction (Design and Management) Regulations 1994 (CANDAM). The Contractor shall include in his price for the provision of all access equipment and all temporary barriers, butterfly tapes around the new boiler area, as appropriate, that are necessary for the safe execution of this contract. Mobile towers of quick erection type scaffolding must be used in accordance with the manufacturer's instructions as to securing to the building, bracing and movement. Scaffolding for chimney stack access to fit liner shall be erected and maintained by a specialist contractor who shall obtain all necessary approvals and consents. All erection, moving or dismantling of mobile towers /scaffolding shall only be carried out when the particular areas are unoccupied. The Contractor shall take all reasonable steps to avoid the creation of hazardous situations. Page 6 of 29

7 Where access equipment has to be employed in: (i) external areas - a temporary barrier fence 1.5 metres high shall be provided at a distance of approximately 2 metres where possible from the base of the access equipment in order to achieve segregation from the general public.. (ii) internal areas and basement - where access equipment has to be employed in areas not handed over to the Contractors sole use, but through which residents or visitors have to pass during the normal functions of the building, the Contractor shall employ temporary barriers, butterfly tapes or partial boarding of towers as appropriate, to deter encroachment or interference by unauthorised persons. Any partial obstruction of such areas necessary to progress the work shall be agreed with the Consulting Engineer Insurance Valuations The Contractor shall ensure that all tools and unfixed materials required to carry out the work are safeguarded during the course of the workday and are not left unattended on site. At night and during weekends all tools and loose materials shall be securely locked away. No tools or materials shall be stored in electrical distribution cupboards, corridors, access ways or any other areas where access for maintenance or means of escape are impeded or limited. The building owners, nor their agents shall take responsibility for loss of tools, materials or equipment. The contractor shall arrange and pay for all necessary scaffolding and associated safety requirements. All scaffolding being removed immediately the work to the chimney stack is completed and accepted by the client or his agent. Local authority and all necessary permissions being obtained and observed by the contractor Public liability insurance shall be maintained throughout the period of the works to at least 2,000, cover per incident. Proof of cover will be required. Prior to an order for the works to be undertaken the contractor shall issue a program of work on a weekly basis which shall give the value of the work on a fortnightly basis. Providing the work on site matches the programmed work and value, the programmed value will be paid, less 5% retention. On agreed practical completion 2.5% of the retention shall be released. The remaining 2.5% shall be paid at the end of the defects liability period of 12 months. Page 7 of 29

8 Defects liability period and Maintenance For a period of 12 months following practical completion, the contractor shall attend to all defects found in the new installation. At practical completion the contractor shall clean the main heating return strainer. The Contractor shall also include in his price to visit the site monthly for 6 months after practical completion and clean the strainer at each visit Electricity and Water Access Electricity and water for the works shall be made available free of cost but only from a point close to the basement garage entrance. All tools used on site shall be 110 volt operating Access for pricing purposes shall be arranged direct with the Chief Porter Mr Bob Mensforth Telephone or one of his assistants Provisional and Contingency Sums The contractor shall include a provisional sum for the lightning protection system in the sum of 1,000.00, gas meter reading requirements in the sum of and HWS pump as specified. The contractor shall also include a contingency sum of 5, for unforeseen requirements associated with the existing system. These sums may or may not be expended by the Client either in whole or part General technical requirements Manufacturing Standards Except where specified otherwise, all materials and equipment associated with the installations shall be handled and installed strictly in accordance with the manufacturer's recommendations and shall be handled and installed by workmen who have had previous experience of the equipment and materials, and who have, where necessary, attended a manufacturers course on use and installation. The Contractor shall ensure that any special tools recommended by the manufacturers for the installation of their materials and equipment are used by the workmen and sets left on site for use by the Client. Page 8 of 29

9 Labels and Number Plates Fixings All equipment shall be clearly and permanently labelled to the approval of the Engineer. Where labels are provided for making clear the method of the operation of apparatus they shall be concise and preferably diagrammatic in form. All labels shall be Traffolite and be fixed using screws. Labels, number plates and their fixing screws for outdoor use shall be stainless steel or other corrosion resistant material. Where the use of vitreous enamelled labels is approved, the whole surface including the back and edges shall be properly covered and protective washers shall be provided front and back on the fixing screws. Danger notices shall have red lettering on a white background. All other labels and number plates shall have black lettering on a white background. Generally, lettering for danger notices shall be 10mm high and all other lettering 6mm high. Labels for similar equipment shall be of uniform appearance and size, and the dimensions and size of lettering shall be to the approval of the Engineer. Fixings to brickwork and blockwork shall be made in the bricks and blocks and not in the bond. Wood screws shall be zinc coated and machine thread screws shall be solid brass or steel as appropriate, and greased before installation. Accessories mounted in fixed equipment shall incorporate adjustable slotted fixing holes. Heavy equipment shall be fixed with approved purpose-made clamp brackets, rag bolts or patent fixing bolts. Shot plugs shall not be used without the written agreement of the Engineer. No structural steelwork or concrete shall be drilled for any purpose without the written agreement of the Engineer. In general, all fixings to steelwork shall be by means of studs welded to the steelwork or by clamp-brackets or hook bolts. Exterior steelwork fixings shall be galvanised. The supply and fixings of all supports, brackets, clamps and spacers and any other steelwork, whether or not shown in detail on the drawings, required for the proper and effective fixing of any equipment, shall be considered to be included in the material and labour covered by the supply of that equipment. Where vibration may occur, nuts shall be locked in position with lock nuts, lock washers, or castle nuts and split pins, or other devices if Page 9 of 29

10 approved. Lock washers shall not be used above M24 except when a spring type is specially approved. No bolt or stud shall appear through it's nut by more than approximately 10mm or four threads, whichever is the less, except for terminals. Bolts, nuts and washers on outdoor equipment shall be of noncorroding material and where they are in contact with non-ferrous parts in conductor clamps and fittings, and elsewhere if specially required. Suitable special spanners shall be provided for bolts and nuts which are not properly accessible by any ordinary spanner Fire Precautions All apparatus, connections and cabling and piping shall be designed and arranged to minimise the risk of fire and any damage which might be caused in the event of fire Radio Interference Tests. All equipment shall be designed so as to minimise radio interference in the frequency range 0.15MHz to 30Mhz by means of suppression at source. Electrical The Services Contractor shall provide certificates from the manufacturers of the various classes of material and equipment being supplied to show that such material and equipment has been tested and inspected by the manufacturer. The Services Contractor shall carry out a visual inspection of the installation on completion. Tests shall be carried out on site by the Sub-Contractor upon completion of the work to ascertain: The Contractor shall carry out insulation tests on all M.I. cables, both immediately before and not less than 24 hours after the sealing glands are fitted. These tests shall be carried out using insulation testing equipment of the "megger" type at not less than 500 volts. An "infinity" reading between all cores and between each core and the cable sheath shall be obtained before the conductors are connected to any apparatus. The insulation resistance and early fault loop impedance of the conductors, cables, equipment, accessories and fittings. Page 10 of 29

11 The electrical continuity of the metal surrounding the conductors and all conductors. That all S.P. switches have been placed in the live wire and not in the neutral conductor. Volt drop acceptance tests. Mechanical All new water pipe, fittings and valve systems shall be tested to one and a half times working pressure. i.e. 5.4 Bar and held for 4 hours. During these tests the old existing system shall be isolated and left with an open end. Apparatus that is not designed to accept this pressure such as the boilers shall be isolated and left open. Further tests shall be carried out at the expiration of the guarantee / defects liability period and all faults found at the final test not due to fair wear and tear, shall be rectified by the Contractor at his own expense. The Contractor shall supply all labour and equipment necessary for carrying out the tests. Test instruments shall have recently been calibrated. The Contractor shall provide test certificates for each part of the project prior to handover SCOPE OF WORKS The scope of work shall include everything necessary to complete the installation and leave the heating and hot water systems working, including the following 1 Final detailed design of the systems in conjunction with the boiler and flue system manufacturer. 2 Isolating and draining the existing heating system where necessary avoiding the existing temporary hot water generator and leaving it operational 3 Removal and clearing from site all redundant plant, equipment, electrics leaving the existing boiler room clear. (this is a separate price and may or may not be carried out under this contract ) 4 Arranging for specialist sub contractor to decommission and de gas existing oil tanks and system and leave abandoned safe. 5 Building of walls with doors to form new boiler room Page 11 of 29

12 6 Provision of ventilation to boiler room.. 7 Cutting opening into existing brick chimney stack for new flue system 8 Installation of new boiler plant and associated systems. 9 Connecting gas from meter to new boiler plant and installation of gas safety system. 10 Provision of all power and controls to new boiler system including associated equipment. 11 Provision of condensate drainage system 12 Cutting into existing drainage system to accommodate condensate system. 13 Cutting into and connecting to existing distribution heating and hot water mains. 14 Cutting into existing cold water and connecting to new system. 15 Isolating, emptying and leaving safe existing feed system 16 Provision of thermal insulation to new system 17 Provision of new insulation to existing distribution mains in garage area. 18 Provision of flue systems as recommended by the boiler manufacturer. 19 Provision of lighting, emergency lighting, small power and equipotential bonding to new installation. 20 Provision of record documentation. 21 Testing and commissioning 1.4. Program of works The contractor shall formulate a simple program of work and submit it for comment or approval, the program shall incorporate the following sequence. 1 Install new boiler plant 2 new flues 3 gas connection 4 water connection 5 electrics 6 build boiler room 7 connect into existing heating 8 fire boilers 9 connect into existing hot water system 10 remove existing boiler plant 11 de commission oil tanks The Contractor may elect to build the plant room first to give reasonable security, and accept more difficult access. Page 12 of 29

13 Visiting site and costing Upon submitting a price it shall be deemed that the contractor made such visits to site that were necessary to fully acquaint himself with the requirements of the project such that he includes within his price for everything necessary to enable him to hand over a fully operational installation at practical completion. 2. NEW INSTALLATION 2.1. Boilers Three boilers shall be installed but space shall be left for a further one boiler at a later stage. The header connections and flues shall be installed now to facilitate the extension, i.e. all service connections installed for 4 No boiler rigs, but only 3 No rigs installed within this contract. Each boiler unit shall consist of four No modules and be as Keston Boilers Limited ( tel ) model ref 4xC55 rated at 220.8kW maximum output. The 4 No modules within each of the 3 rigs shall be factory preassembled, pre piped and wired, and shall permit a turn down to 13.9 kw output per rig The water content of each rig shall be 52.9 litres The boilers shall be suitable for a working pressure of 3.6 bar and factory test certified at 6.0 bar. Each module having a nominal output of 55 kw shall incorporate all safety features including :- Thermal fuse link Flow High limit thermostat Flow overheat thermostat Low water pressure switch low gas pressure switch Flue overheat thermostat The units shall be controlled such that the heating flow temperature is weather compensated, but on hot water demand a fixed flow temperature of 800C is maintained regardless of load up to the maximum duty of the plant, and include gas shut of valve, air pressure switch, RAM controller and high voltage ignition system. A switch shall be incorporated to change from weather compensation to fixed flow to auto. Page 13 of 29

14 To obviate duplicating headers and the restricted area of the boiler room, separate connections shall be taken from each module ( finally 32 No ) to the low loss header system to be installed at high level. The connections from / to the header system shall incorporate. the following Shunt pump ( supplied ready fitted by boiler manufacturer ) Safety valve (supplied ready fitted by boiler manufacturer, see also valves regarding a further safety valve to header ) Air eliminator valve Flow isolating valve Return isolating valve Strainer Binder test points Boiler drain point Gas cock ( provided loose by boiler manufacturer ) The boilers shall be arranged to operate nominally at 80 0 C flow and 60 0 C return water temperature. They shall also operate at 80 0 C flow and 69 o C return but at a lower efficiency Flue system To reduce the number of flues to be discharged at roof level and the length of flue run, a proprietary flue system shall be installed by Chimney and Canopy systems limited ( tel ) or equal and approved The system shall be as follows :- The existing brick chimney stack shall be cleaned and a liner installed as recommended by the boiler manufacturer A flue header duct shall run from the liner to the boiler area at high level. From each module the 50mm flue connection shall be enlarged to 100mm diameter stainless steel and connected to the high level flue header. The flue header shall incorporate a fan unit to overcome the resistance of the vertical liner within the brick stack. An air flow switch operating on differential pressure shall be incorporated such that no boiler can be enabled unless air or products of combustion is flowing. The flue fan shall be resiliently supported to ensure a maximum vibration transfer to the building structure of no more than 2%. Page 14 of 29

15 Each module connexion shall incorporate a balancing damper and draught diverter. The entire system shall be designed, supplied and installed by Chimney and Canopy Systems Ltd. The hole to be cut into the existing brick stack shall be carried out to the requirements of a Chartered Structural Engineer. The contractor shall provide a spare motor for the flue fan and leave on site for possible future use Condensate system The boilers are condensing type and hence all flues and flue components shall be drained. A 32mm mupvc trapped drain shall be taken from each boiler rig to the existing rain water pipe cleaning eye. A further 32mm trapped point shall be taken from the base of the vertical flue liner or fan drain point. The traps shall be formed from standard bends such that the water seal depth is 200mm minimum Combustion air supply 2.3. Pipework A separate air supply shall be installed to each module. The supply shall be provided via 50mm mupvc pipework to BS 5256 from a position outside the boiler room and garage as recommended by the boiler manufacturer. Each air pipe shall terminate with a rain cowl as provided by the boiler manufacturer. Final location shall be agreed on site, but for costing purposes the location shown on the drawings shall be assumed to be correct. All pipework shall be installed as follows: External underground water Internal cold water Hot water Heating up to 50mm (2 ) Heating in Plant room PE80 Blue Copper EN 1057 Black label Galvanised heavy weight steel to BS1386 Copper EN 1057 Black label Page 15 of 29

16 over 50mm (2 ) Black heavy weight steel to BSS 1386 Gas external underground MPDE Gas internal up to 22mm Copper EN 1057 Black label Gas internal over 22mm (¾ ) Black as heating over 2 Waste connections from fittings to stacks MUPVC Safety valve discharges Copper to EN 1057 Air release valve discharges Copper to EN 1057 Condensate pipework MUPVC All fittings on copper pipe shall be non dezinkifiable and leadless soldered. Black steel pipe fittings of 65mm and above shall be welded. Unions shall be bronze faced conical seat pattern. Flanges on LTHW shall be to BS 4504 and rated at 10 Bar pressure, except where mating to plant items when matching flanges shall be used Air venting and Safety valves All high points shall be vented. A primary automatic air vent shall be fitted on the low loss header, located as shown on the drawings. This air vent shall be Charles Wynn & Co Type B. A 15mm copper discharge shall be run to waste with the outlet visible. The automatic air valve shall be installed upon an air bottle as shown on the drawings. A lock shield valve shall be fitted between the header or main and the automatic air valve. A further valved manual air vent shall be installed on the air bottle with venting cock at a suitable level. Other high points may be vented by means of manual air vents. Such manual air vents shall consist of an air bottle 150mm long x 38mm diameter; a 22mm gate valve shall be installed between the main and bottle. A discharge pipe 15mm diameter shall run to low level incorporating a vent cock in a convenient location. Safety valves shall be incorporated within each boiler module preset to 4 Bar by the boiler manufacturer. Additionally a further ½ NABIC pattern safety valve shall be installed on the low loss header complete with discharge to boiler room floor. This valve shall also be set at 4Bar. Page 16 of 29

17 Bracketing Steel pipework and valves shall generally be supported from the floor or from the concrete soffit by means of steel strap hangers so arranged to allow thermal expansion and contraction Copper pipework shall be supported by means of single ring clips of brass manufacture. The main low loss heating headers shall be supported from the floor, but stayed to the walls. Maximum spacing of supports Steel pipe 65mm (2 ½ ) & over4.5m vertical, 3.7m horizontal Copper pipe 15mm 1.2m vertical and horizontal 22mm 1.2m 28mm 1.8m 35mm 2.5m 42mm 2.5m 54mm 2.8m Full regard shall be given to expansion and contraction of the pipework by means of swing brackets where necessary, with anchors where necessary. The connections from the boilers to the header shall incorporate at least one right angled bend such that the boiler module is not stressed Insulation and Painting All pipework other than: Safety valve discharges Condensate systems Air eliminator discharges shall be insulated as required by section L of the Building Regulations and water supply regulations with mineral wool or equal sectional insulation having a thermal conductivity not exceeding W/mK and a thickness equal to the pipe external diameter up to a maximum of 40mm No insulation shall be applied until the systems have been tested, cleaned and painted one coat primer. All insulation shall have a smooth aligned finish, undulations and steps will not be accepted. Page 17 of 29

18 All insulation shall be non- combustible when tested as required by BS476 : Part 4, and the surface rated class O for flame spread in accordance with BS 476 : Part 7 No materials shall be incorporated which could emit toxic fumes or smoke in the event of fire. Polyurethane, PVC or other thermo-plastic materials shall not be used. All insulation shall comply with the following :- BS3958 Part 3, 4 and 5 BS All insulation finished surfaces shall be Aluminium foil finished with end caps and colour identification bands conforming to BS amended 1991 All valves over 50mm nominal diameter shall be insulated, valves 50mm and under, brackets and other steel components shall be painted with one coat primer, one under coat and one gloss coat to agreed colour Valves & Cocks All items of plant including pumps, boilers, heat exchangers, pressure set shall be fitted with valves to permit isolation. For plant isolation on the heating circuits up to and including 50mm (2 ), lever operated butterfly and ball valves will be acceptable except cold water stopcocks, which shall be BSS1010, and gas cocks which shall be plug cock type at the boilers and diaphragm type as Saunders Type A with type C diaphragms suitable for a working pressure of up to 1 Bar and suitable for natural gas at entry to the plant area. Valves 65mm nominal diameter and above on the heating circuits shall be flanged as Crane Ltd F624 ( tel ) or Holmes Valves Ltd equivalent ( tel ) Valves 65mm nominal diameter and above on the Hot Water secondary circuits shall be flanged as Crane Ltd F624or Holmes equivalent incorporating PN lining and stainless steel covered disc. All valves shall be suitable for an operating pressure of 10.0 Bar Drain cocks shall be fitted at all low points. Valves up to 50mm on hot water service shall be of bronze or stainless steel manufacture Page 18 of 29

19 2.5. Plate heat exchangers and Buffer vessel Plate heat exchanger Hot water shall be provided from a constant flow plate heat exchangers. The plate heat exchanger shall be rated at 470 kw and supplied as a total package by Stokvis Energy Systems ltd ( tel ) type reference EconoplateE4B27. The unit shall have the following specification Primary water in Secondary water in Secondary water out Secondary flow rate Primary working pressure Secondary working pressure C C C 2.48 litres / sec 3.6 Bar 4.0 Bar The unit shall also be capable of heating 2.48 l/s water from C to C The unit shall include a primary water pump, 4 port modulating control valve and Secondary transfer pump. The control arrangements shall be factory pre packaged within the unit and shall enable the HWS flow temperature to be maintained to an accuracy of +/- 10 C and the set point variable between 500C and 650C A HWS return shall be connected at the cold feed point as shown on the drawings Hot Water Cold Water Feed is fed from roof top tank room see Cold Water Buffer vessel The hot water service cold feed is fed by gravity from the roof tank room. Due to the poor condition of the existing HWS distributing pipework it is not considered prudent to pump the system to give better flow rates within the flats. To overcome the high pressure drop of a plate heat exchanger the cold water feed shall only flow through a buffer vessel offering only a minimal resistance to flow. The buffer vessel shall be approximately 1.8m high x 600mm diameter having a nominal capacity of 500 litres and shall have internal sparge Page 19 of 29

20 2.6. Pumps arrangements to direct the hot water in the direction of flow within the vessel. The vessel shall be manufactured from stainless steel. Due to the restricted space in the plant area, the main circulating pumps shall be in line type but floor supported where necessary. The pumps shall have the duties shown on the drawing ref 0075 / 2 The following pumps shall be installed Nos 1 to 16 Boiler module circulating located in module new No 17 Heating circulating pipe line extg No 18 Stand by to No 17 pipe line extg No 19 HWS primary Flow unit 1 pipe line on unit new No 20 HWS Return* * pipe line new No 21 Stand by to No 20 pipe line new No 22 HWS secondary Flow In line new No 23 Stand by to No 22 in line new Note extg = Existing pumps to be re used ** = Provisional sum item, will only be installed if existing HWS return is found not to give satisfactory circulation The existing pumps to be re used shall be carefully removed from the existing system, overhauled and stored until required for the new installation. Should weather conditions demand that the existing oil fired boilers are temporary used for part of the winter, the existing pumps shall be removed and reinstalled with minimum down time Pressure Set / Expansion / Dosing system Pressure / expansion set A pressure fill / expansion system shall be installed. It is known that leakages in the old system occur, and may become more frequent. A normal fill / pressurising unit would require in the order of 1,500 litres of expansion vessel volume. Due to space limitations, possible future leakage, and age of the system a special fill / pressurisation unit shall be installed that can also monitor accurately the pressure exerted on the old pipework system to reduce future leaks as far as possible The pressure set shall be capable of maintaining a working pressure at 1.4 metres above boiler room floor level of 3.4 Bar including a static head of 2.5 Bar i.e. pressurisation of 0.9 Bar and to permit a leakage Page 20 of 29

21 Dosing Pot 2.8. Gas of 0.42 litres / minute. The capacity of the existing system can be taken as 12,000 litres ( estimated ). The unit shall consist of a frame, supporting :- 1 No 500 litre holding vessel 2 No pressurising pumps 2 No Transfer pumps 1 No break tank, ball valve & BS 1010 cock Control panel All interconnecting piping and wiring A 2 ( 50mm ) connection shall be taken from the outlet of the unit to a neutral pressure point on the low loss header as shown on the drawings. This pipe shall include a lock shield valve and drain cock. A 22mm copper cold main feed shall supply fresh water to make up tank ball valve, fitted with a BS 1010 stopcock A 22mm overflow shall be taken to a drain point The unit shall be as Armstrong ( tel ) reference Armex HMS2 4. A dosing pot shall be fitted across the heating pumps with a filling funnel and valves to enable inhibiting chemicals to be injected into the system all as Dosing Pot Technology Ltd ( tel ) or equal.. A new gas main and meter is being arranged by the building owner The location of the meter is as shown on the drawings. The contractor shall connect from the outlet cock at the meter and run a 75mm (3 ) supply at high level in the garage to serve the boilers. On entry to the boiler room a main gas shut off valve shall be installed followed by a fire shut off valve, all clearly labelled. The fire shut off valve shall be the same size as the gas main and arranged to close on power failure, a thermal fire detector shall be installed above each of the 4 boiler locations and wired in series with two manual knock off buttons which shall be wall mounted close to the doors. All gas pipework shall be tape marked GAS and painted gas yellow. Page 21 of 29

22 2.9. Ventilation The special flue arrangements require that air is made available to the boiler room. The contractor shall include to install a natural ventilation duct from external to the plant room into the room. The duct shall be sized in accordance with the specialist flue system manufacturer s recommendations. A weather proof louvre shall be incorporated and a supply grille. The duct shall be painted, one primer, one undercoat and one top gloss coat to a colour selected by the Client. 3. ELECTRICAL WORK The contractor shall supply and install all necessary electrical systems associated with the new boiler plant, small power, lighting and controls as set out below and elsewhere in this document Power and light The Contractor shall obtain all necessary loads and requirements from the various equipment and plant suppliers and manufacturers as appropriate. The following is a guide list only, as different manufacturers vary in their power requirements Approx Total Phase kw each kw Power to boiler rigs ( allow 4 units ) Power to the following pumps No 17 Heating circulating No 18 Stand by to No 17 inc inc No 19 HWS primary Flow inc inc 1 No 20 HWS Return No 21 Stand by to No 20 inc inc No 22 HWS secondary Flow No 23 Stand by to No 22 inc inc Plate Heat exchanger Pressurisation set Flue fan gas valve small small Approximate estimated total plant 8.66 kw The existing electrical supply to the old boiler plant shall be used to supply the new plant. The cable feeding the old boiler house from the supply point shall be renewed and run to the new required location. Lighting shall be installed to the new boiler area consisting of 4 No twin fluorescent gas tight fittings set out to give uniform lighting level and switched from close to the door. Page 22 of 29

23 3.2. Controls One fitting closest to the door shall include an emergency battery pack which in the event of a power cut shall maintain escape lighting for 30 minutes. An escape route sign shall be affixed to the wall to indicate the escape route lit by the emergency light unit. 1 No double metal clad 240 volt switched socket outlets shall be installed close to the control panel. A control package shall be supplied by the boiler manufacturer capable of finally controlling 4 No boiler units but initially 3 No units The boiler units shall be arranged as 1 master unit with 4 (3 now ) slaves. The master unit shall have a separate supply for the control module such that the controls and sequencer still operate even if the master boiler is not enabled. A clear label shall be affixed CONTROL CIRCUITS LIVE WHEN UNIT IS SWITCHED OFF A sequencer temperature detector shall be mounted in the low loss header were required by the boiler manufacturer but approximately where shown on the drawings. The boilers and other plant shall not be enabled unless 1 the flue header fan is working and air flowing. A pressure differential stat shall be incorporated across the flue fan such that a pair of contacts make on air flow. 2 system pressure is satisfied at working pressure. When both of the above are satisfied the boilers and other plant shall be enabled. A control panel shall be provided, and shall have switches and lights to give the following facilities and information on the front panel Overall system on / off switch Weather compensation on / off / auto switch Control circuits live light Flue fan air flow OK light Pressure OK light Boiler unit 1 on / off switch Boiler unit 2 on / off switch Boiler unit 3 on / off switch Page 23 of 29

24 Boiler unit 4 on / off switch Pressure unit on / off switch Plate unit on / off switch Heating pumps No 1, No 2, Off switch HWS secondary pump No 1, No 2. Off switch 3.3. Equipotential Bonding All metal work shall be equipotentialy bonded strictly in accordance with I E E regulations for electrical Installations ( BS 7671 ) 3.4. Lightning Protection A provisional sum shall be included for bonding the flue liner in the sum of 1, This sum may or may not be expended by the Client either in full or part. 4. REMOVAL AND MODIFICATIONS TO EXISTING 4.1. Boiler room A separate cost is requested to remove the existing boiler plant together with all associated pipes, valves, pumps, oil system, iron flues, electrical installation and all other mechanical and electrical installations within the existing boiler room with the exception of the ventilation fan and lighting, which shall remain operating on completion. It should be noted that most existing larger valves are seized open. All removed plant and materials shall become the property of the contractor and totally removed from site and correctly disposed of or sold, leaving the area clear. The room will not be decontaminated within this contract Roof tank room venting The existing boiler plant is filled with water from a feed tank situated within a roof tank room, and a common open vent discharges over it originating from 3 way vent valves on the existing boilers. The contractor shall disconnect the tank feed at a suitable time during the contract period and blank safe. The tank shall be left empty and dry and abandoned in existing location. Page 24 of 29

25 Venting An advantage of removing the tank is to reduce the static pressure on the systems to assist in prolonging the life of the existing system and reduce leaks. The existing system is filled from a feed and expansion tank and vented by a series of approximately 11 No vent pipes extending above the roof level by up to approximately 3 metres These vent pipes shall be removed and replaced with air bottles fitted with automatic air vents as Charles Winn pattern B, 15 mm discharges shall be taken to the roof Oil tank room A price is requested to de-commission the existing oil tanks and area, including de gassing and warranting safe. It is not planned to remove the tanks and associated pipes and equipment within this contract, but the contractor shall blank safe the oil feed pipe exiting the tanks within the oil store area not the boiler house. Should the contractor find it more economical to remove than warrant the tank safe, this will be acceptable to the client. All removed materials shall become the property of the contractor and totally removed from site and correctly disposed of or sold, leaving the area clear. of debris Modifications to existing systems It will be necessary to modify, remove or cut into some existing services to enable the new work to be installed., including but not limited to the following Existing basin waste Existing Rain water pipe Existing heating and HWS mains where they currently exit from the existing boiler room. Cold water feed to HWS Cold water main for heating fill 5. BUILDING WORK 5.1. New Boiler room The boiler area of the garage shall be enclosed for safety reasons and to protect the plant and equipment from un-authorised tampering. Page 25 of 29

26 The walls as laid out on the drawing shall be constructed from 100mm concrete blocks, with standard timber doors. The door width shall be 1.2 metres and of sufficient height to enable all plant to be removed except for the main boiler rig frames. The door shall be painted primer, undercoat and top gloss to a colour selected by the client. The new walls shall be constructed from concrete blocks to BS having an average compressive strength of 7.0 N/mm2 and 215mm x 450mm face size. The block work shall be neat of appearance with unchipped arrises and cut with a masonry saw where cut edges will be exposed to view. The walls shall be built to an accuracy of +/- 15mm in a length of 5m and +/- 20mm in a length of 5 to 10m. The walls and ceiling inside the boiler room shall be painted white Gas meter area At the time of writing meter reading arrangements have not been agreed. A provisional sum shall be included within the Contractors price of This sum may or may not be spent in whole or in part by the Client. 6. COMMISSIONING. WATER TREATMENT AND DOCUMENTATION 6.1. Commissioning The Contractor shall carefully purge the gas installation and arrange for the boilers to be commissioned and first fired by the boiler manufacturer. The manufacturer shall issue a certificate excepting the installation complies with his requirements. The entire system shall be left operating to the satisfaction of the Engineer Water treatment The contractor shall employ a water treatment specialist as Aldus and Stamp or equal to dose the systems and disinfect the hot water new pipework. Page 26 of 29

27 The dosing of the heating and primary circuits shall be agreed in conjunction with the Engineer, great care being taken due to the age and condition of the existing systems Operating and maintenance instructions Clear operating and maintenance instructions shall be supplied to the Client and shall contain the following :- 1 General description of the installation 2 Clear simple English directions for switching on and off the plant. 3 Manufacturers information on all installed plant and equipment 4 Recommended schedule of required maintenance based on manufacturers recommendations. 5 What to do in an emergency and emergency telephone numbers. The information shall be bound into a quality binder having the Contractors and Consultant s name and contact information printed on the front cover Record information and certificates A CORGY certificate shall be issued. An NICE electrical test certificate shall be issued. Previously completed pressure test certificates shall be issued. The certificates shall be incorporated into the Maintenance Manual The contractor shall supply record information as follows. Record drawings of the installation in electronic format on 3 ½ floppy or compact disk and one set on paper to be incorporated into the maintenance instruction manual. Initially one set on paper shall be issued for approval or comment by the Engineer. Page 27 of 29

28 7. SCHEDULE OF PRICES The contractor shall indicate below how his total price is made up. 1 Isolating, draining, cutting into, refilling and dosing total systems 2 Provision and installation of new boiler plant 3 Provision and installation of flue and ventilation systems 4 Insulation of the new installation 5 Insulation to existing system where removed for asbestos reasons 6 Associated electrical work 7 Associated building work 8 Disconnection and leave safe existing feed / vent system 9 Removal of redundant plant to existing boiler room 10 Emptying, de-gassing and leaving safe oil tank area. p 11 Provisional sum Lightning protection Gas meter reading Contingency sum 5, Total to Form of Bid Options O1 Install new hot water system in Copper instead of galvanised pipe O2 Renew all garage Hot Water Service mains in copper As far as risers to flats Page 28 of 29

29 8. FORM OF BID I/We.... of.. are prepared to carry out the work outlined in specification reference 0075 / D1 dated June 2003 and drawings reference Nos 0075 / M01 and 0075 / M02. for the sum of ( in words ). Option 1 Option 2 Extra for copper HWS for the sum of.. Extra to renew garage distribution mains.. These prices exclude VAT and are open for acceptance for 1 month We have visited site and are fully aware of the requirements. Signed Position: Company: Telephone Date fax..... Page 29 of 29