1、BSI Standards PublicationBS 5918:2015Solar heating systems fordomestic hot water Codeof practice for design andinstallationPublishing and copyright informationThe BSI copyright notice displayed in this document indicates when the documentwas last issued. The British Standards Institution 2015Publish
2、ed by BSI Standards Limited 2015ISBN 978 0 580 61963 2ICS 27.160, 97.100.99The following BSI references relate to the work on this standard:Committee reference RHE/25Draft for comment 12/30177610 DC, 13/30274184 DCPublication historyFirst published January 1980Second edition, February 1989Third (pre
3、sent) edition, January 2015Amendments issued since publicationDate Text affectedBS 5918:2015 BRITISH STANDARDContentsForeword iiiIntroduction 11 Scope 12 Normative references 23 Terms and definitions 34 General recommendations 75 Site inspections and technical pre-installation surveys 176 Provision
4、of customer information 187 Details of key components 198 Installation 369 Commissioning and documentation 3810 Maintenance 4011 Performance predictions 42AnnexesAnnex A (normative) Bacterial growth and safety in DHW systems 49Annex B (informative) Characteristics of an average UK household DHW usag
5、eprofile 53Annex C (informative) Example primary system layouts 55Annex D (informative) Site inspection 57Annex E (normative) Minimum wall thickness for high-temperature EPDM-basedrubber insulation 58Annex F (informative) Nominal amounts of DHW supplied by point-of-useappliances that are usually not
6、 available for solar preheating 58Annex G (informative) Example sizing of collector active area 58Annex H (informative) Worked example Expansion vessel sizing 59Annex I (informative) Troubleshooting 60Annex J (informative) Methods for calculating loss of irradiation due to shadingobstacles 61Bibliog
7、raphy 63List of figuresFigure 1 Schematic showing energy flows through the system 6Figure2Twotypes of storage vessel layout 9Figure 3 Schematic of the functional principle and fluid movements in a typicalsolar hot water system 10Figure 4 Example layouts illustrating dedicated solar storage within co
8、mmonDHW systems 11Figure 5 Means of primary circulation 14Figure6Variation of the solar energy, Qcol, with orientation and tilt 21Figure 7 Sizing of collector active area 25Figure 8 Expansion vessel 35Figure 9 Definitions and relationships of pressure in the system 36Figure 10 Example template commi
9、ssioning form handed to user 41Figure 11 Variation over the UK of the annual mean global irradiation on ahorizontal surface (in kWh/m2) 45Figure A.1 Specimen bacterial risk assessment overview such as forLegionella 50Figure B.1 Distribution of hot water delivery temperatures 53Figure B.2 Typical ran
10、ge of daily DHW consumption per person 54Figure B.3 Range of cold water feed temperatures 54Figure C.1 Simplified schematic primary system layouts (not to scale) 56Figure D.1 Site inspection example survey form 57Figure J.1 Example of sunpath viewer with shading objects sketched over 61BRITISH STAND
11、ARD BS 5918:2015 The British Standards Institution 2015 iList of tablesTable 1 Backup heat factor, F, for calculating effective solar storage 8Table2Technology classes according to collector performance factor(see 11.9) 24Table 3 Storage ratio according to collector size 28Table 4 Characteristics of
12、 common metallic joints 34Table 5 Default factors for orientation, OP, affecting annual mean daily globalirradiation on a horizontal surface, H, according to inclination of surface and itsazimuth, % 46Table6Typical collector parameters where BS EN ISO 9806 test data are notavailable 46Table 7 Reflec
13、tance values of surfaces and their likely effect on thevalue Rpanel48Table A.1 Specimen bacterial risk assessment for disinfection temperatures andtimes 51Table B.1 DHW profile: proportion of maximum hourly average peak flowrates 55Table E.1 Minimum wall thickness for high-temperature EPDM-based rub
14、berinsulation 58Table G.1 Example sizing of collector active area 58Table J.1 Default loss-of-sky area Zskyas related to the loss of irradiationfactor, Zpanel62Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv,pages 1 to 66, an inside back cover and a back c
15、over.BRITISH STANDARDBS 5918:2015ii The British Standards Institution 2015ForewordPublishing informationThis British Standard is published by BSI Standards Limited, under licence fromThe British Standards Institution, and came into effect on 31 January 2015. Itwas prepared by Technical Committee RHE
16、/25, Solar heating. A list oforganizations represented on this committee can be obtained on request to itssecretary.SupersessionThis British Standard supersedes BS 5918:1989, which is withdrawn.Information about this documentThis is a full revision of the standard.This standard is intended to help w
17、ith the design and installation of solarheating equipment for domestic hot water (DHW). It is especially intended tohelp fill the gap for fitted systems that have not been tested to BS EN 12976 orBS EN 12977. Note that the use of the term “custom systems” in these standardstends to refer to a functi
18、onal system provided by a single final supplier ormanufacturer. An assembly comprising solar energy collection and storagecomponents, and supplied or assembled by multiple providers, can be consideredan “ad-hoc” system which is considered in this standard.The documents available as downloads from th
19、e sites referenced in theBibliography were last accessed on 19 January 2015.WARNING. This British Standard calls for the use of substances and/or proceduresthat can be injurious to health if adequate precautions are not taken. It refersonly to technical suitability and does not absolve the user from
20、 legal obligationsrelating to health and safety at any stage.Copyright is claimed on Figure 11. Copyright holders are the Met Office, FitzRoyRoad, Exeter, Devon, EX1 3PB.Use of this documentAs a code of practice, this British Standard takes the form of guidance andrecommendations. It should not be q
21、uoted as if it were a specification andparticular care should be taken to ensure that claims of compliance are notmisleading.Any user claiming compliance with this British Standard is expected to be able tojustify any course of action that deviates from its recommendations.It has been assumed in the
22、 preparation of this British Standard that theexecution of its provisions will be entrusted to appropriately qualified andexperienced people, for whose use it has been produced.Presentational conventionsThe provisions of this standard are presented in roman (i.e. upright) type. Itsrecommendations ar
23、e expressed in sentences in which the principal auxiliaryverb is “should”.Commentary, explanation and general informative material is presented insmaller italic type, and does not constitute a normative element.The word “should” is used to express recommendations of this standard. Theword “may” is u
24、sed in the text to express permissibility, e.g. as an alternative tothe primary recommendation of the clause. The word “can” is used to expresspossibility, e.g. a consequence of an action or an event.BRITISH STANDARD BS 5918:2015 The British Standards Institution 2015 iiiNotes and commentaries are p
25、rovided throughout the text of this standard.Notes give references and additional information that are important but do notform part of the recommendations. Commentaries give background information.Contractual and legal considerationsThis publication does not purport to include all the necessary pro
26、visions of acontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legalobligations.BRITISH STANDARDBS 5918:2015iv The British Standards Institution 2015IntroductionThis code of practice applies to solar domestic water heating syste
27、ms thatincorporate a primary circuit that is indirect, such that the collected solar energyis transferred through a heat exchanger into storage that includes a volumededicated to solar input. This applies to most systems that are available in theUK at present.There are other system designs on the ma
28、rket that fall outside the scope, butthe code of practice does not restrict or limit the installation of such designs.The methods and algorithms presented in this document that estimate thesystem performance do not apply to such designs. Nevertheless, several clausesare also relevant to system desig
29、ns outside the scope. These include the clausesrelating to the mounting of solar panels, safety issues and those relating to theprovision of information to customers.1 ScopeThis British Standard gives recommendations and guidance for the installation ofcommon indirect solar domestic hot water (SDHW)
30、 systems for all types ofbuilding in the UK. It includes recommendations and guidance for design,handling, installation, commissioning, handover, maintenance, decommissioningand fault-finding.NOTE 1 SDHW is domestic hot water (DHW) that has intentionally received heatderived from solar radiation via
31、 a solar collector.The standard covers systems:a) in which solar radiation is converted to heat that is primarily intended fordomestic hot water preparation;b) that contain solar collector(s) intended to transfer heat using anaqueous-based liquid medium;c) whose solar collectors conform to BS EN 129
32、75-1 and BS EN ISO 9806;d) which contain collectors that provide up to 20 kW instantaneous peakpower output measured leaving the collector, when tested in accordancewith BS EN ISO 9806 at 800 W/m2perpendicular to the collector apertureplane;NOTE 2 Depending on the characteristics of the system, this
33、 typically equatesto a gross collector area of up to approximately 30 m2.e) in which heat is primarily stored in aqueous-based liquid media; andf) in which the primary circuit is indirect with a heat exchanger that is internalto the solar storage vessel and which separates the primary heat transferf
34、luid that passes through the collector from the DHW.This British Standard does not cover:1) applications that are primarily intended to provide heat for applicationssuch as space heating, cooling or swimming pools and any other than DHWpreparation;2) solar primary system layouts that use solar stora
35、ge vessels that are outsidethe building;3) solar primary system layouts with multiple collector fields;4) DHW systems that comprise multiple solar or multiple DHW storage vessels;or5) solar primary system layouts that incorporate a heat pump or other devicethat utilizes the Carnot cycle.BRITISH STAN
36、DARD BS 5918:2015 The British Standards Institution 2015 1NOTE 3 It is assumed in the calculations in this British Standard that there isuser-disinterest in the DHW settings, i.e. that default factory timer and thermostatsettings are present. Extra heating required for bacterial disinfection is not
37、assumedin these calculations.NOTE 4 Where stated in the standard, the pressure is that exceeding atmosphericpressure at sea level.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in thisdocument and are indispensable for its application. For dated refere
38、nces, onlythe edition cited applies. For undated references, the latest edition of thereferenced document (including any amendments) applies.BS 1566 (both parts), Copper indirect cylinders for domestic purposesBS 4213, Cisterns for domestic use Cold water storage and combined feed andexpansion (ther
39、moplastic) cisterns up to 500 l SpecificationBS 6213, Selection of construction sealants GuideBS 6920, Suitability of non-metallic products for use in contact with waterintended for human consumption with regard to their effect on the quality ofwaterBS 7671, Requirements for electrical installations
40、 IET Wiring RegulationsBS 8000 (all parts), Workmanship on building sitesBS 8000-15, Workmanship on building sites Part 15: Code of practice for hotand cold water services (domestic scale)BS 8558, Guide to the design, installation, testing and maintenance of servicessupplying water for domestic use
41、within buildings and their curtilages Complementary guidance to BS EN 806BS 8580, Water quality Risk assessments for Legionella control Code ofpracticeBS EN 806 (all parts), Specification for installations inside buildings conveyingwater for human consumptionBS EN 1990, Eurocode Basis of structural
42、designBS EN 1991-1-1, Eurocode 1 Actions on structures Part 1-1: General actions Densities, self-weight, imposed loads for buildingsBS EN 1991-1-3, Eurocode 1 Actions on structures Part 1-3: General actions Snow loadsBS EN 1991-1-4, Eurocode 1 Actions on structures Part 1-4: General actions Wind act
43、ionsBS EN 1993-1-1, Eurocode 3 Design of steel structures Part 1-1: General rulesand rules for buildingsBS EN 1995-1-1, Eurocode 5 Design of timber structures Part 1-1: General Common rules and rules for buildingsBS EN 12897, Water supply Specification for indirectly heated unvented(closed) storage
44、water heatersBS EN 12975-1, Thermal solar systems and components Solar collectors Part 1:General requirementsBS EN 12977, Thermal solar systems and components Custom built systemsBRITISH STANDARDBS 5918:20152 The British Standards Institution 2015BS EN 12977-3, Thermal solar systems and components C
45、ustom built systems Part 3: Performance test methods for solar water heater storesBS EN 12977-5:2012, Thermal solar systems and components Custom builtsystems Part 5: Performance test methods for control equipmentBS EN 14437, Determination of the uplift resistance of installed clay or concretetiles
46、for roofing Roof system test methodBS EN 60730-2, Automatic electrical controls for household and similar useBS EN 60730-2-9, Automatic electrical controls for household and similar use Part 2-9: Particular requirements for temperature sensing controlsBS EN ISO 11600, Building construction Jointing
47、products Classification andrequirements for sealantsBS EN ISO 9488, Solar energy VocabularyBS EN ISO 9806, Solar energy Solar thermal collectors Test methods3 Terms and definitionsFor the purposes of this British Standard, the terms and definitions given inBS EN ISO 9488, BS EN 12977 and the followi
48、ng apply.3.1 active areaeither the absorber or aperture area chosen dependant on collector typeNOTE 1 An active area is used for calculating or estimating system performance inthe design stage.NOTE 2 Some concentrating collectors with large reflective aperture areas do notwork as well in predominate
49、ly diffuse irradiation as found in the UK.NOTE 3 Aperture area is the preferred option for a collector which concentratessolar radiation.3.2 cold feedpipe that contains cold water intended to be eventually heated as DHW3.3 cold water storage (CWS)cistern located at a high location in the building filled with cold water via afloat valve3.4 compound parabolic concentrator (CPC) collectornon-imaging collector that uses parabolic reflector segments
