Underfloor Heating Specification CONTRACT 2
Underfloor Heating Specification October 2008 4 Pierhead Street, Capital Waterside, Cardiff CF10 4QP Tel +44 (0)29 2047 3727 Fax +44 (0)29 2047 2277 This report takes into account the particular instructions and requirements of our client. It is not intended for and should not be relied upon by any third party and no responsibility is undertaken to any third party www.arup.com Job number 122955
Document Verification Page 1 of 2 Job title Document title Job number 122955 File reference Document ref Revision Date Filename Bettws Underfloor Heating Spc T1.doc Draft 1 27/09/07 Description First draft Prepared by Checked by Approved by Name David Davies Matt Chambers Matt Chambers Signature Tender 1 15/01/08 Filename Description Bettws Underfloor Heating Spc T1.doc Issued for Tender Prepared by Checked by Approved by Name David Davies Matt Chambers Matt Chambers Signature Tender 2 15/01/08 Filename Description Bettws Underfloor Heating Spc T2.doc Prepared by Checked by Approved by Name David Davies Matt Chambers Matt Chambers Signature Contract 1 01/08/08 Filename Description Bettws Underfloor Heating Spc C1.doc Issued for Contract Prepared by Checked by Approved by Name David Davies Matt Chambers Matt Chambers Signature Issue Document Verification with Document HEATING SPC C2.DOC
Document Verification Page 2 of 2 Job title Document title Job number 122955 File reference Document ref Revision Date Filename Bettws Underfloor Heating Spc C2.doc Contract 2 31/10/08 Description Issued for Contract Prepared by Checked by Approved by Name David Davies Matt Chambers Matt Chambers Signature Filename Description Name Prepared by Checked by Approved by Signature Filename Description Name Prepared by Checked by Approved by Signature Filename Description Name Prepared by Checked by Approved by Signature Issue Document Verification with Document HEATING SPC C2.DOC
Contents Page 1 Introduction 1 2 Building Construction 2 2.1 Ground Floor Slab 2 2.2 First Floor Slab 2 3 System Design 2 3.1 Design Standards 2 3.2 Scope of Work 2 4 System Description 4 4.1 General 4 4.2 Mainfolds 4 4.3 Pipework & Pipework Routes 5 4.4 Controls 5 4.5 Thermal Insulation 6 4.6 Screed 6 5 Materials & workmanship 7 5.1 Valves 7 5.2 Gauge/Test Cocks 7 5.3 Automatic Control Valves 7 5.4 Instruments and Gauges 7 5.5 Self-Sealing Test Points 7 5.6 Leakage Testing 7 5.7 Test Procedures 8 6 Heat Loss & Zone Information 9 HEATING SPC C2.DOC
1 Introduction This specification has been compiled to detail the requirements of the underfloor heating for the proposed, Newport, South Wales. The underfloor package is being tendered as a stand alone package by Leadbitter (the main contractor) as it forms such a large element of the scheme. Underfloor heating is generally provided to all areas of the school at the ground and first floor levels. This document is only intended to provide technical details of the underfloor heating system and not contractual arrangements, sequencing of works or timescales. These should be discussed with the main contractor. For this contract the underfloor heating specialist shall be required to supply and install the floor insulation and screed in line with the requirements of this specification and the associated drawings. Page 1
2 Building Construction The building shall be a steel frame construction with concrete ground and first floor slabs with a lightweight roof as described below. 2.1 Ground Floor Slab The building ground floor slab shall be mainly a ground bearing slab on mass concrete foundations. 2.2 First Floor Slab The first floor slab shall be pre-cast hollow core concrete planks supported from the steel frame. There shall be no structural screed on these planks. 3 System Design The specialist underfloor heating contractor shall be responsible for the final design and installation of the underfloor heating system including; Pipework Manifolds Valve assemblies Thermal insulation Screed These shall be provided in accordance with this specification, the drawings and the heat loads as presented at the end of this document. The underfloor heating specialist shall be a single point of contact and responsibility for all of the above items. 3.1 Design Standards The underfloor heating system shall be designed in accordance with the following standards as well as Industry best practice and the Chartered Institute of Building Services Engineers (CIBSE) guides; BS EN 1264 Floor Heating - Systems and Components. Underfloor heating design and installation - HVCA - Heating and Ventilating Contractors' Association 2004. Underfloor heating systems: designers' guide - BSRIA - AG 12/2001. Underfloor heating systems: assessment standard for installations - BSRIA - AG 13/2001. Screeds with underfloor heating: guidance for a defect-free interface. Concrete Society/BSRIA. British Standards as applicable and as listed within the Materials & Workmanship section of this specification. 3.2 Scope of Work The scope of the work to be carried out by the underfloor heating specialist shall include, but not be limited to, the following; Verification and acceptance of the heat loss figures for the areas to have underfloor heating installed as given in the equipment data sheets section of this specification. Page 2
Preparation of detailed calculations and design drawings based on the design criteria and design information contained herein. To include, but not be limited to, sizing and locating manifolds, sizing and laying out underfloor pipe work circuits, floor surface temperatures, water flow rates, hydraulic resistance of under floor heating circuits including manifolds. Liaising with the design team during the design phase, and obtaining approvals from them in a manner to suit the programme. Obtain approval of and supply and installation of all necessary equipment and materials, including pipe work, pipe work fixing system, manifolds, manifold housings, floor insulation and screed. Installation of all necessary equipment and systems to provide a complete underfloor heating system, coordination with all other trades on site as necessary in a timely fashion so as to avoid undue delay. Liaise with the Main Contractor to ensure the work is carried out in accordance with the programme, and that all necessary information is available to other trades to allow them to complete their works where the underfloor heating installation may impact on their works. Carry out full testing and commissioning of the installation. Give adequate notice of testing and commissioning programme to allow interested parties the opportunity to attend. Provide assistance to the commissioning engineer in setting the maximum control valve opening limits to achieve the required design flow rates. Provide Operation & Maintenance Manuals for the entire underfloor heating system. 2 hard copies and an electronic copy shall be required. Provide support during defects liability period. Provide warranty/guarantee in accordance with this specification. The entire system shall be designed in accordance with the recommendations of the chosen specialist. If these recommendations differ from this specification in any way then these shall be raised with this tender return with the engineer and an agreement in writing reached. Page 3
4 System Description 4.1 General The underfloor heating system shall be fed from a dedicated underfloor heating circuit from the main boilers. This Low Temperature Hot Water (LTHW) circuit will be set to 50 C flow temperature and 40 C return temperature. The LTHW will distribute at high level within the exposed ground floor ceiling void. From here it will drop to low level to serve the ground floor manifolds and rise to first floor level to serve the first floor manifolds. From the point at which the LTHW pipework joins the manifold the responsibility for the underfloor heating system will be with the underfloor heating specialist. Each room as indicated as a zone on the drawings shall be provided with underfloor heating. Each zone shall be fed from a local manifold as indicated on the drawings and the datasheets at the end of this specification. 4.2 Mainfolds Manifold locations are currently indicated on the drawings making use of store rooms, cleaners rooms and mechanical risers to ensure concealment and to restrict access. On preparation of detailed circuit designs the specialist may determine that alternative locations would provide for a more efficient installation. If this is the case the specialist shall propose these alternative locations to the engineer prior to any design work for their consideration. The specialist shall seek approval for manifold locations on their design drawings from the architect and engineer prior to any installation commencing. Manifolds shall be provided with the following; Isolation valve on flow and return manifold Drain cock on flow and return manifold Automatic air vent on flow and return manifold Combined temperature and pressure gauge on flow and return manifold BMS operated control valves to each under floor pipe circuit Visual flow indicator to each under floor pipe circuit Proprietary bracketing system for wall fixing Purpose designed enclosures covering whole manifold assembly to protect them from impact or interference. Page 4
Typical Manifold Detail 4.3 Pipework & Pipework Routes Underfloor heating pipework shall run from the manifold positions within the floor screed to the area that it is serving. Underfloor heating pipework shall not be allowed to run from classroom to classroom. Where manifolds are installed in classrooms and this manifold serves adjacent classrooms, the pipework shall run into the corridor and then back into the adjacent classroom. Underfloor heating pipework shall also not allowed to be installed across any void within the school construction, it shall go around these voids to the area that it is serving. The underfloor heating pipework shall be mechanically fixed to the insulation during installation to the routes shown on the specialists design drawings. All pipework shall be fixed before the screed is laid. Underfloor heating is generally only proposed in areas where fixed furniture will not be used. However, during the detailed design the underfloor heating specialist shall superimpose the fixed furniture layout onto their drawings to check for clashes. This drawing shall be submitted to the engineer as part of the design submission for comment. Underfloor heating pipe work shall be either; Cross-linked high density polyethylene (PE-X) Polybutylene (PB) Metal/plastic multi layer composite The pipe work system must include an oxygen diffusion barrier to prevent the absorption of oxygen through the walls of the plastic pipe work as recommended by the Underfloor Heating Manufacturers Association. The pipe work shall comply with BS7291. 4.4 Controls Each underfloor heating zone shall be controlled separately so that the heating demand in each space can be met. The Building Energy Management System (BEMS) shall monitor the temperature in each zone through the use of wall mounted thermostats. The BEMS shall then signal the appropriate control valve on the underfloor heating manifold that controls that zone to open. Page 5
Each zone valve on the manifold shall be clearly labelled by the underfloor heating manifold during installation. 4.5 Thermal Insulation Floor and edge insulation shall be provided by the underfloor heating specialist to all rooms with underfloor heating. In addition it is required that insulation is to be provided to other areas of the school that does not have underfloor heating. These are indicated by a hatched area on the drawings. Any area on the drawings that is not identified as a zone or hatched does not require insulation. An insulation thickness of 50mm shall be used throughout the school on ground and first floor levels. The insulation shall have the following properties; Thickness = 50mm Thermal Conductivity = 0.037 W/mK R Value = 1.316 m 2 K/W Compression strength = 70 kpa 4.6 Screed The specialist underfloor heating contractor shall provide screed to all areas where insulation is provided. The total build up of insulation, underfloor heating pipework and screed shall be 125mm. The underfloor heating specialist shall provide details of their proposed screed within the tender return so that this can be evaluated by the team. Page 6
5 Materials & workmanship 5.1 Valves Valves shall be manufactured to BS EN ISO 9001, or BS EN ISO 9000/1, independently assessed, product-tested to British Standards stated and Kite marked. Isolating valves shall be line size unless otherwise indicated. Commissioning valves shall be selected in accordance with manufacturer's recommendations to ensure that adequate signals for measurement are generated. Bronze valves with drilled flanges shall be flat-faced for full face gaskets. Flanged copper items shall have IBC gaskets fitted between composite flanges. Check valves, strainers and uni-directional globe valves shall have arrow indication of flow. 5.2 Gauge/Test Cocks Pipeline instruments shall have a gauge cock fitted between the service pipe and the instrument. The bodies shall be bronze construction, polished finish and with parallel threads. Gauge cocks for low temperature hot water, shall be straight pattern, ground plug type with lever handle. 5.3 Automatic Control Valves Automatic control valves shall be to BS 7350. 5.4 Instruments and Gauges Branch extensions shall be provided to all instruments and gauges to carry the item and any isolating device clear of the insulation and covering The pressure gauge range shall be selected so that the indicator will be central at normal operating condition. The gauge shall have an adjustable reference pointer. Gauges shall be to BS EN 837-1. Dial face shall be white with black scale graduations and numbering. Gauges shall have overall accuracy of one per cent (1%) of scale range and shall comply with the table below. Pressure (bar) 10 4.5 3.0 2.5 1.5 Gauge (bar) 0-20 0-10 0-6 0-5 0-3 Figure Intervals (bar) 2 1 1 1 0.5 Intermediate (mbar) 500 100 100 100 100 Fixed thermometers shall be to BS 5235. 5.5 Self-Sealing Test Points Test points shall be dual purpose for pressure gauge and thermometer, be mounted on the sides of pipes, and shall repeatedly reseal. 5.6 Leakage Testing All piping systems shall be tested after completion with all branch piping installed, but before being concealed, insulated or equipment fixtures and fittings set and connected. Page 7
Where previously agreed, piping systems may be tested in sections but a final test shall be made on completion of all work. Test failures shall be rectified and the test repeated until a satisfactory result is achieved. 5.7 Test Procedures Test procedures shall be in accordance with HVCA "Guide to Good Practice for Site Pressure Testing of Pipework". Piping systems shall be tested with cold water and the test pressure maintained for two hours or sufficient to ensure inspection of all joints without further application of pressure and without visible leakage or drop in indicated pressure. Concealed or work to be permanently buried shall be tested at twice working pressure. Page 8
6 Heat Loss & Zone Information Zone Manifold Heat loss (kw) Flow Rate (l/s) 001 M001 1.5 0.0357 002 M001 8.1 0.1929 003 M003 5 0.1190 004 M002 0.3 0.0071 005 M002 0.8 0.0190 006 M002 1.5 0.0357 007 M002 0.8 0.0190 008 M005 7.3 0.1738 009 M003 0.4 0.0095 010 M003 0.35 0.0083 011 M004 1.5 0.0357 012 M003 0.35 0.0083 013 M004 0.4 0.0095 014 M004 0.7 0.0167 015 M005 0.7 0.0167 016 M005 2.1 0.0500 017 M006 1.7 0.0405 018 M006 1.6 0.0381 019 M006 2 0.0476 020 M007 1.9 0.0452 021 M007 1.7 0.0405 022 M007 1.9 0.0452 023 M009 0.8 0.0190 024 M009 1.8 0.043 024a M009 1.5 0.036 025 M009 0.4 0.0095 026 M010 1.6 0.0381 027 M010 2.9 0.069 028 M010 1.9 0.0452 029 M011 1.9 0.0452 030 M011 1.6 0.0381 031 M011 1.7 0.0405 032 M008 1.7 0.0405 033 M008 4.1 0.0976 034 M009 2.4 0.0571 035 M012 1.4 0.0333 036 M012 0.4 0.0095 037 M013 2.6 0.0619 038 M013 2.7 0.0643 039 M013 0.4 0.0095 040 M013 3.2 0.0762 041 M012 2.5 0.0595 042 M014 12.8 0.3048 043 M003 0.7 0.0167 044 M004 0.9 0.0214 045 M005 2.3 0.0548 046 M008 2.4 0.0571 047 M008 1 0.0238 048 M010 0.33 0.0079 049 M012 2 0.0476 050 M014 1.2 0.0286 Page 9
051 M001 0.84 0.021 101 M101 2.2 0.0524 102 M102 0.9 0.0214 103 M102 0.9 0.0214 104 M102 2 0.0476 105 M101 1 0.0238 106 M101 1.4 0.0333 107 M103 6 0.1429 108 M103 2.2 0.0524 109 M102 6.5 0.1548 110 M105 1.25 0.0298 111 M105 2.5 0.0595 112 M105 2.2 0.0524 113 M105 2.9 0.0690 114 M104 1.5 0.0357 115 M104 2.2 0.0524 116 M104 2.4 0.0571 117 M108 2.5 0.0595 118 M108 2.3 0.0548 119 M108 2.2 0.0524 120 M108 3.8 0.0905 121 M107 2.8 0.0667 122 M107 2.2 0.0524 123 M107 2.2 0.0524 124 M107 2.4 0.0571 125 M109 0.9 0.0214 126 M109 0.7 0.0167 127 M109 1.9 0.0452 128 M109 4 0.0952 129 M111 3.7 0.0881 130 M111 4.9 0.1167 131 M111 3.9 0.0929 132 M111 3.5 0.0833 133 M110 3.4 0.0810 134 M109 4.4 0.1048 135 M110 1 0.0238 136 M110 0.7 0.0167 137 M112 2.1 0.0500 138 M113 4.1 0.0976 139 M113 3 0.0714 140 M113 5.1 0.1214 141 M101 1.4 0.0333 142 M103 0.75 0.0179 143 M103 0.3 0.0071 144 M102 2.1 0.0500 145 M104 1.2 0.0286 146 M108 1.3 0.0310 147 M106 1.1 0.0262 148 M106 0.53 0.0126 149 M109 1.7 0.0405 150 M110 1.6 0.0381 151 M112 0.9 0.0214 152 M112 4.4 0.1048 153 M106 1.2 0.0286 Page 10
154 M106 1.6 0.0381 Page 11