1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS 8542:2011Calculating domestic waterconsumption innon-domestic buildings Code of practicePublishing and copyright informationThe BSI copyright notice displayed in this document
2、 indicates when the documentwas last issued. BSI 2011ISBN 978 0 580 71075 9ICS 13.060.20The following BSI references relate to the work on this standard:Committee reference B/504Draft for comment 11/30218883 DCPublication historyFirst published October 2011Amendments issued since publicationDate Tex
3、t affectedBS 8542:2011 BRITISH STANDARDContents0 Introduction 11 Scope 22 Normative references 33 Terms and definitions 44 Water consumption calculation methodology 55 Rainwater and greywater 186 Total calculated water consumption 207 Terminal fitting use factors 228 Domestic water consumption perfo
4、rmance indicators 22AnnexesAnnex A (informative) Example calculations Office buildings: baselinecalculation 23Annex B (informative) Default values for calculating water consumption 30Bibliography 37List of figuresFigure 1 Calculating water consumption using BS 8542 2List of tablesTable 1 Product per
5、formance data 8Table A.1 Water consumption calculator for offices: WCs 24Table A.2 Water consumption calculator for offices: urinals 25Table A.3 Taps (personal hygiene) 26Table A.4 Taps (staff kitchen cleaning) 26Table A.5 Kitchen canteen/restaurant: waste disposal 27Table A.6 Kitchen canteen/restau
6、rant: food preparation and cleaning 27Table A.7 Kitchen canteen/restaurant: dishwasher 27Table A.8 Softeners 28Table A.9 Total water consumption (per capita consumption occupieddays) 29Table A.10 Total water consumption (m3per annum per building) 29Table B.1 Default occupancy data staff 30Table B.2
7、Default use factors for office buildings 31Table B.3 Default use factors for retail buildings: visitors 32Table B.4 Default use factors for retail buildings: staff 33Table B.5 Default use factors for study bedrooms (e.g. in student halls ofresidence) 33Table B.6 Performance indicators 34Table B.7 De
8、fault performance data for terminal fittings 35Table B.8 Performance indicators for net water consumption in an officebuilding 36Summary of pagesThis document comprises a front cover, an inside front cover, pages i to ii,pages 1 to 38, an inside back cover and a back cover.BRITISH STANDARD BS 8542:2
9、011 BSI 2011 iForewordPublishing informationThis British Standard is published by BSI and came into effect on31 October 2011. It was prepared by Panel B/504/2/2, Water consumption inbuildings, under the authority of Technical Committee B/504, Water supply. A listof organizations represented on this
10、committee can be obtained on request toits secretary.Use of this documentAs a code of practice, this British Standard takes the form of guidance andrecommendations. It should not be quoted as if it was a specification andparticular care should be taken to ensure that claims of compliance are notmisl
11、eading.Any user claiming compliance with this British Standard is expected to be able tojustify any course of action that deviates from its recommendations.Presentational conventionsThe provisions in this standard are presented in roman (i.e. upright) type. Itsrecommendations are expressed in senten
12、ces 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.Contractual and legal considerationsThis publication does not purport to include all the necessary provisions
13、of acontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legalobligations.In particular, attention is drawn to the following regulations which may beamended from time to time. The commentary in this British Standard reflectsthe st
14、ate of the regulations in 2011.In this document, the following national regulations, which apply to plumbingsystems in premises to which a supply of public mains water has been provided,are referred to as the “Water Fittings Regulations” 1: The Water Supply (Water Fittings) Regulations 1999, in Engl
15、and The Water Byelaws 2004 (Scotland), in Scotland; The Water Supply (Water Fittings) Regulations (Northern Ireland) 2009, inNorthern Ireland.BRITISH STANDARDBS 8542:2011ii BSI 20110 Introduction0.1 GeneralCalculating water use in non-domestic buildings provides a means for estimatinga buildings imp
16、act on water consumption whether looking at the consumptionof new or existing buildings. Calculating water use in non-domestic buildingsalso provides a means for estimating the impact of a terminal fitting on anindividual basis to inform procurement choices. Figure 1 provides a guide on thecalculati
17、on procedure.There are common water uses between different building types, e.g. the use ofwash basin taps in a restaurant is similar to that found in an office or a hotel,but variations also exist, e.g. water use for showering.NOTE The domestic water use requirements for an employee may be simplifie
18、d intokey water uses including water used for WC flushing and other sanitary purposes,water used for drinking, and water used in food/drink preparation and washing-up.With an increasing demand for water efficiency in non-domestic buildings, astandardized framework for reporting water consumption is
19、useful to allowdesigners, specifiers, building managers, water authorities and productmanufacturers to estimate and report water consumption in a consistent way.0.2 Non-domestic building typesThere is a wide range of building types that constitute non-household buildingsincluding, but not limited to
20、: offices; restaurants; retail buildings; industrial buildings; hotels; leisure buildings; education buildings.BRITISH STANDARD BS 8542:2011 BSI 2011 11 ScopeThis British Standard gives recommendations for calculating the volume of publicmains water that is consumed per head per day, per unit per da
21、y, or perbuilding per annum for domestic use in non-domestic buildings. It givesrecommendations for estimating the total water use from the buildingscomponents, allowing consumption to be indicated on a whole building levelagainst other buildings for best practice levels.This standard is not for use
22、 as a design guide.Figure 1 Calculating water consumption using BS 8542BRITISH STANDARDBS 8542:20112 BSI 2011It provides a framework for and details the development of water usecalculation methodologies in non-domestic buildings. It providesrecommendations for the quality of data used to calculate w
23、ater use for eachcomponent in non-domestic buildings and also standardized reporting forproduct performance data.It applies to both new and existing buildings and covers: water that is sourced from unwholesome sources such as rainwaterharvesting systems or greywater reuse systems; and water that is
24、sourced from wholesome sources including both hot and coldwater.This British Standard does not cover design, installation, testing andmaintenance of services supplying water for domestic use. Water use inindustrial processes or for agricultural, medical or fire suppression applicationsand external w
25、ater use such as irrigation or building services, e.g. airconditioning plant and cooling, are also not covered.It does not provide all data for calculating water use in non-domestic buildings,but provides recommendations for the data used to calculate water use innon-domestic buildings. This include
26、s the product performance data for eachterminal fitting and water use research data determining the frequency andduration of use for each terminal fitting.NOTE Total water use may be determined by metering the building, although itmight be difficult to differentiate between domestic water uses and w
27、ater use forother purposes unless these are sub-metered.2 Normative referencesThe following referenced documents are indispensable for the application ofthis document. For dated references, only the edition cited applies. For undatedreferences, the latest edition of the referenced document (includin
28、g anyamendments) applies.BS 8515:2009, Rainwater harvesting systems Code of practiceBS 8525-1, Greywater systems Part 1: Code of practiceBS EN 200, Sanitary tapware Single taps and combination taps for water supplysystems of type 1 and type 2 General technical specificationBS EN 817, Sanitary tapwar
29、e Mechanical mixing valves (PN 10) Generaltechnical specificationsBS EN 997, WC pans and WC suites with integral trapBS EN 1111, Sanitary tapware Thermostatic mixing valves (PN 10) Generaltechnical specificationBS EN 1286, Sanitary tapware Low pressure mechanical mixing valves Generaltechnical speci
30、ficationBS EN 1287, Sanitary tapware Low pressure thermostatic mixing valves General technical specificationsBS EN 13407, Wall-hung urinals Functional requirements and test methodsBS EN 14055, WC and urinal flushing cisternsBS EN 14743+A1, Water conditioning equipment inside buildings Softeners Requ
31、irements for performance, safety and testingBS EN 50242 (BS EN 60436), Electric dishwashers for household use Methods for measuring the performanceBRITISH STANDARD BS 8542:2011 BSI 2011 3BS EN 60456, Clothes washing machines for household use Methods formeasuring the performance3 Terms and definitio
32、nsFor the purposes of this British Standard, the following terms and definitionsapply.3.1 building terminal fittingsdifferent components of water demandNOTE This includes devices such as WCs, showers, baths, washing machines,dishwashers and taps.3.2 cisternfixed, vented container for holding water a
33、t atmospheric pressure3.3 collection areaplan area of the roof or other collection surface, which is to be drained to therainwater harvesting system3.4 covers per m2number of dining spaces per m23.5 domestic water useuse related to residential or similar dwellingsNOTE 1 Domestic potable water use in
34、cludes water for the kitchen sink,wash basins, bath, shower and dishwasher. Domestic non-potable water use includeswater for WC flushing, domestic washing machines and garden watering.NOTE 2 In commercial, industrial or public premises, “domestic use” is limited towater used for those applications/a
35、ppliances described above and excludes, forexample, water used for fire fighting, central heating or irrigation systems.3.6 effective flushing volumeaverage volume of water discharged from the flushing device during a flushcycle3.7 flushing devicedevice fitted to a cistern to provide controlled, mea
36、sured volume(s) of water toa WC suite or urinal for flushing3.8 flush-freeWC suite or urinal designed to operate without the use of a flushing device3.9 frequency of use factoraverage number of uses per day of a terminal fitting based on nominal usage3.10 greywaterdomestic wastewater excluding faeca
37、l matter and urineNOTE This British Standard covers systems using washroom and bathroomgreywater including greywater sourced from wash basins, showers and baths.3.11 hydraulic filter efficiencyloss of rainfall volume collected as a result of the filtering processBRITISH STANDARDBS 8542:20114 BSI 201
38、13.12 intensity of use factoraverage water use of a terminal fitting for each user event as a result of theduration of use and/or the proportion of a terminal fittings total capacity usedper event3.13 regeneration processpart of softener operating cycle, during which all the operations needed torest
39、ore the ion exchange capacity of a resin bed are carried out3.14 regeneration waterquantity of water, expressed in litres (or in cubic meters), necessary for acomplete regeneration process, including water used for the preparation of thebrine3.15 non-domestic buildingbuilding other than a dwellingNO
40、TE A dwelling is a self-contained unit designed to accommodate a singlehousehold.3.16 non-potable/unwholesome waterwater not suitable for human consumption that does not meet minimum legalrequirements for wholesome water3.17 per capita consumptionwater use in units of litres per person per day3.18 p
41、otable/wholesome waterwater suitable for human consumption that meets minimum legal requirementsfor wholesome water from mains or private extraction3.19 rainwaterwater arising from atmospheric precipitation3.20 softenercomplete installation necessary for the ongoing production of softened water3.21
42、softeningreduction of the hardness of water by exchange of alkaline earths ions (mainlycalcium and magnesium) with sodium ions, by passing through a bed of cationexchange resin in the sodium form3.22 terminal fittingwater outlet device3.23 yield co-efficientfactor that represents the loss of rainfal
43、l volume from wetting of the collectionarea as a result of pitch and surface type4 Water consumption calculation methodology4.1 GeneralThe total domestic water consumption in a non-domestic building should becalculated using the following four parameters:a) the performance of all terminal fittings a
44、s described in 4.7, e.g. the flowrate of a shower (L/min);BRITISH STANDARD BS 8542:2011 BSI 2011 5b) the frequency and intensity of use of the terminal fitting, e.g. the numberof showers taken per day and the duration of each shower (min);c) occupancy data, including the total occupancy, operating h
45、ours and male tofemale ratio; andd) the volume of unwholesome water available, including the yield anddemand for greywater and rainwater supply systems (L).Water consumption should be calculated using either of the following twoapproaches:1) calculated actual water consumption for the building; or2)
46、 nominal water consumption.The required use of the calculation should determine whether calculated actualwater consumption or nominal water consumption are used.Calculated actual water consumption should be used when: estimating the buildings average and total water consumption; and estimating the i
47、mpact of changing a buildings water terminal fittingspecification on total water consumption.Nominal water consumption should be used when: indicating water efficiency of the building; comparing the building to other buildings of the same type; and calculating the consumption of an individual termin
48、al fitting.4.2 Calculated actual water consumptionThe calculated actual water consumption for the building should be calculatedusing actual occupancy and product performance data for the building, see 4.7.Frequency and intensity of use factors for the building should also be usedwithin these calcula
49、tions.NOTE 1 Where this data and actual product performance data is not available,default performance data may be used as provided in Table B.1.All calculations in Clause 4 should be carried out to two decimal places.NOTE 2 The calculated actual water consumption is not comparable with in-usemetered consumption as metered consumption data can include additional waterusage, e.g. irrigation, building services, process water. Metered water consumptioncan demonstrate a
