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Abse lev1 2_102-202_launch(full permission)

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    Abse lev1 2_102-202_launch(full permission) Abse lev1 2_102-202_launch(full permission) Document Transcript

    • This chapter covers the learning outcomes for:In this chapter you will learn about:■ energy conservation legislation■ application of energy sources■ energy conservation andcommissioning■ reducing waste and conserving energy■ safe disposal of materials■ conserving and reducing the wastageof water.City & Guilds unit number 102 and L2 202; EAL unit code QACC1/02and L2 QBSE2/03; ABC unit code A03 and L2 A07.Building services engineering has a vital role to play in the protection ofthe environment, waste reduction and conserving energy. There is also therequirement for correct waste disposal, both of recyclable materials and anymaterial that is potentially hazardous. You will explore these responsibilitiesfurther in this chapter.There is an increasing amount of legislation on energy conservation that isrelevant to building services engineering. There is also a wide variety of newtechnologies, which can be incorporated into building projects, that aim toreduce waste and conserve energy. In this chapter you will look at how thesenew, green technologies can help to reduce carbon emissions, conservenatural resources and encourage recycling.L2 Understand how to apply environmental protection measureswithin building services engineeringUnderstand fundamental environmental protection measures withinbuilding services engineering3 Environmental protectionmeasures
    • 68Access to Building Services Engineering Environmental protection measuresL2 Energy conservationlegislationCarbon is present in all fossil fuels, such as coal ornatural gas. Burning fossil fuels releases carbon dioxide,which is a greenhouse gas linked to climate change.Energy conservation aims to reduce the amount ofcarbon dioxide in the atmosphere. The idea is to do thisby making buildings better insulated and, at the sametime, make heating appliances more efficient. It alsomeans attempting to generate energy using renewableand/or low or zero carbon methods.Building Regulations (2010)In terms of energy conservation, the most important UKlaw is the Building Regulations (2010), particularly Part L.The Building Regulations:■ list the minimum efficiency requirements■ provide guidance on compliance, the main testingmethods, installation and control■ cover both new dwellings and existing dwellings.A key part of the regulations is the Standard AssessmentProcedure (SAP), which measures or estimates theenergy efficiency performance of buildings.Local planning authorities also now require that all newdevelopments generate at least 10% of their energyfrom renewable sources. This means that each newproject has to be assessed one at a time.Did you knowNew minimumrequirements cameinto force in October2010. There wererevisions to PartsG, F, J and L of theBuilding Regulations.Key termsRenewable source:An energy sourcethat is constantlyreplaced and willnever run out, suchas water, wind andsolar energy.Access to Building Services Engineering Environmental protection measuresAccess to Building Services Engineering
    • 69Environmental protection measuresL2 Water RegulationsIn the UK, the Water Supply (Water Fittings) Regulations(1999) aim to prevent water contamination as well asthe waste and misuse of water.With regard to the building services, this legislationhas led to a number of new developments and existingdwellings incorporating waste water reuse and therecycling of rainwater.Energy conservation – who isresponsible?By law, each local authority is required to reduce carbondioxide emissions and to encourage the conservation ofenergy. This means that everyone has a responsibility insome way to conserve energy.■ Clients, along with building designers, are requiredto include energy-efficient technology in the build.■ Contractors and sub-contractors have to follow thesedesign guidelines. They also need to play a rolein conserving energy and resources when actuallyworking on site.■ Suppliers of products are required by law to provideinformation on energy consumption.In addition, new energy-efficiency schemes andBuilding Regulations cover the energy performance ofbuildings. Each new build is required to have an EnergyPerformance Certificate. This rates a building’s energyefficiency from A (very efficient) to G (least efficient).Some building designers have also begun to adoptother voluntary ways of attempting to protect the
    • 70Access to Building Services EngineeringAccess to Building Services EngineeringApplication of energysourcesTypes of energyWhen we look at energy sources, we consider theirenvironmental impact in terms of how much carbondioxide they release. Accordingly, energy sources can besplit into three different groups:■ High carbon – those that release a lot of carbon dioxide■ Low carbon – those that release some carbon dioxide■ Zero carbon – those that do not release any carbondioxideFig. 3.1 The Energy Saving Trust encourages builders to useless wasteful building techniques and more energy-efficientconstructionTrade tipYou can find outmore about theEnergy SavingTrust at: www.energysavingtrust.org.ukL2environment. These include BREEAM, which is anenvironmental assessment method, and the Codefor Sustainable Homes, which is a certification ofsustainability for new builds.Access to Building Services EngineeringKey termsSustainability: Interms of buildingservices engineering,this is aboutreducing a building’senvironmental impactover its lifetime.
    • Environmental protection measures71Some examples of high, low and zero carbon energysources are given in the tables below.High carbon energy source DescriptionNatural gas or LPG Piped natural gas or liquid petroleum gas (LPG) stored inbottlesFuel oils Domestic fuel oil, such as dieselSolid fuels Coal, coke and peatElectricity Generated from non-renewable sources, such as coal-fired power stationsLow carbon energy source DescriptionSolar thermal Panels used to capture energy from the sun to heat waterSolid fuel Biomass such as logs, wood chips and pelletsHydrogen fuel cells Converts chemical energy into electrical energyHeat pumps Devices that convert low temperature heat into highertemperature heatCombined heat and power (CHP) Generates electricity as well as heat for water and spaceheatingCombined cooling, heat and power(CCHP)A variation on CHP that also provides a basic airconditioning systemZero carbon energy DescriptionElectricity/wind Uses natural wind resources to generate electrical energyElectricity/tidal Uses wave power to generate electrical energyHydroelectric Uses the natural flow of rivers and streams to generateelectrical energySolar photovoltaic Uses solar cells to convert light energy from the sun intoelectricityIt is important to try to conserve non-renewable energyso that there will be sufficient fuel for the future. The
    • 72Access to Building Services Engineeringidea is that the fuel should last as long as is necessaryto completely replace it with renewable sources, such aswind or solar energy.Install environmental technologies: Solar hot waterSolar photovoltaic electricityHeat pumpsWater harvesting and recyclingInsulate lofts and pipesInsulate walls (cavity and solid walls)Install double glazed windowsInstall draught-proofingFit low-flow taps/showersSwitch off lights and appliancesTurn heating thermostat downWash clothes at 30°Fit a smart meterEnergy advice/assessmentLow or zero carbon technologiesImprove efficiency:Fig. 3.2 Working towards reducing carbon emissionsactivity1. Think aboutwhere youlive. Does thedwelling aim toreduce demandand improveefficiency?2. How manyof the basicenvironmentaltechnologysystems are partof the dwelling?Use Figure 3.2 asa guide.Basic installation principlesEach environmental energy installation has its ownparticular operating principles. Many of them useenergy from different sources.Solar thermal systemsAt the heart of this system is the solar collector, whichis often referred to as a solar panel. The idea is thatthe collector absorbs the sun’s energy, which is thenconverted into heat. This heat is then applied to thesystem’s heat transfer fluid.
    • Environmental protection measures73The system uses a differential temperature controller(DTC) that controls the system’s circulating pump whensolar energy is available and there is a demand forwater to be heated.In the UK, due to the lack of guaranteed solar energy,solar thermal hot water systems often have an auxiliaryheat source, such as an immersion heater.To hot tapsCold inFig. 3.3 Solar thermal hot water systemDid you knowIf a dwelling makesits own electricity,this is calledmicro-generation.If it makes moreelectricity than itneeds, it can sellthat electricity to theNational Grid.L2 Biomass (solid fuel)Biomass stoves burn either pellets or logs. Some haveintegrated hoppers that transfer pellets to the burner.Biomass boilers are available for pellets, woodchips orlogs. Most of them have automated systems to cleanthe heat exchanger surfaces. They can provide heat fordomestic hot water and space heating.
    • 74Access to Building Services EngineeringAccess to Building Services EngineeringStove providingroom heat onlyStove providingroom heat anddomestic hot waterStove providingroom heat, domestichot water and heatingFig. 3.4 Biomass stoves output optionsThere are a variety of different arrangements for each ofthe three main systems:■ Air source pumps operate at temperatures as low as−20°C. They have units that receive incoming airthrough an inlet duct.■ Ground source pumps operate on geothermal groundheat. They use a sealed circuit collector loop, which isburied either vertically or horizontally underground.■ Water source systems can be used where there is asuitable water source, such as a pond or lake.The heat pump system’s efficiency relies on thetemperature difference between the heat source andthe heat sink. Special tank hot water cylinders arepart of the system, giving a large surface-to-surfacecontact between the heating circuit water and the storeddomestic hot water.L2 Heat pumpsHeat pumps convert low temperature heat from air, groundor water sources to higher temperature heat. They can beused in ducted air or piped water heat sink systems.Key termsHeat sink: A heatexchanger thattransfers heat fromone source into afluid, such as inrefrigeration, airconditioning or theradiator in a car.Key termsGeothermal: Relatingto the internal heatenergy of the earth.Access to Building Services Engineering
    • Environmental protection measures75Fig. 3.5 Heat pump input and output optionsCombined heat and power (CHP) and combinedcooling, heat and power (CCHP) unitsThese are similar to heating system boilers, but theygenerate electricity as well as heat for hot water orspace heating (or cooling). The heart of the system is anengine or gas turbine. The gas burner provides heat tothe engine when there is a demand for heat. Electricity isgenerated along with sufficient energy to heat water andto provide space heating.CCHP systems also incorporate the facility to coolspaces when necessary.Wind turbinesFreestanding or building-mounted wind turbinescapture the energy from wind to generate electricalenergy. The wind passes across rotor blades of aturbine, which causes the hub to turn. The hub isconnected by a shaft to a gearbox. This increases theStirling engineand alternatorEngineburnerFlue outletCombustionpumpSupplementaryburner andheat exchangerFig. 3.6 Example of a microcombined heat and power(MCHP) unitAir sourceGroundsourceHeat pump Ducted airPiped waterWatersourceL2RotorbladesHubGearboxGeneratorTailfinNacelleFig. 3.7 A basic horizontal-axis wind turbine
    • 76Access to Building Services Engineeringspeed of rotation. A high-speed shaft is then connectedto a generator that produces the electricity.Solar photovoltaic systemsA solar photovoltaic system uses solar cells to convertlight energy from the sun into electricity. The solar cellsare usually made of silicon and are semi-conductors.The sunlight hits the solar cells and photons areabsorbed. This causes negatively charged electrons inthe cell to detach from their atoms and flow throughthe cell to create electricity. The electricity is directcurrent (DC). The DC current is then converted by aninverter to alternating current (AC), which is the typeof current used for mains electricity.Key termsSemi-conductor:A substance thatallows the passageof electricity in someconditions but not inothers.Photon: The basicunit of light orelectromagneticradiation.Electron: A tinyparticle that is partof an atom.Atom: The smallestunit of an element,made up of protons,neutrons andelectrons.Direct current (DC):An electric currentthat flows in onedirection only.Alternating current(AC): An electriccurrent where thedirection of currentreverses at regularintervals.IsolationswitchImportmeterConsumer unitInverterMeterAC/DCAC powerAC powerFig. 3.8 A basic solar photovoltaic system
    • Environmental protection measures77Guidance and advice on energy-savingand conservationThere are an increasing number of public and privateorganisations that can provide guidance and adviceon energy-saving and conservation techniques. A goodplace to start is the website of the Energy Saving Trust(www.energysavingtrust.org.uk) as it provides linksto several other organisations. They also have a networkof advice centres across the UK.Other sources of advice:■ Carbon Trust (www.carbontrust.co.uk) provides helpin cutting carbon and saving energy.■ Local councils or authorities all have energy andclimate change advisers or departments.■ The Department of Energy and Climate Change(www.decc.gov.uk) is responsible for governmentpolicy on energy and climate change.■ Local electricity suppliers.L2 Energy rating tables andcomponentsEnergy rating tables are used to measure the overallefficiency of a dwelling, with rating A being the mostenergy efficient and rating G the least energy efficient.Alongside this, an environmental impact rating (seeFig. 3.10) measures the dwelling’s impact on theenvironment in terms of how much carbon dioxide itproduces. Again, rating A is the highest, showing it has theleast impact on the environment, and rating G is the lowest.
    • 78Access to Building Services EngineeringL2 A Standard Assessment Procedure (SAP) is used toplace the dwelling on the energy rating table. This willtake into account:■ the date of construction, the type of construction andthe location■ the heating system■ insulation (including cavity wall)■ double glazing.The ratings are used by local authorities and other groupsto assess the energy efficiency of new and old housing.Information on alternative energysourcesThere are various sources of funding, guidance andadvice on energy saving and conservation techniquesincluding the following:■ Energy Share (www.energyshare.com) encouragesways to set up renewable energy projects.■ The Renewable Energy Centre (www.therenewableenergycentre.co.uk) provides newsand links to designers, suppliers, trade associationsand government departments.■ Energy Saving Trust (www.energysavingtrust.org.uk) provides information about saving energy andreducing carbon emissions.■ Carbon Trust (www.carbontrust.co.uk) aimsprimarily to help businesses in the public sector saveenergy and cut carbon emissions.Fig. 3.9 SAP energyefficiency rating table. Theranges in brackets showthe percentage of energyefficiency for each bandingFig. 3.10 SAP environmentalimpact rating table(92–100)(81–91)(69–80)(55–68)(39–54)(21–38)(1–20)ABCDEFG(92–100)(81–91)(69–80)(55–68)(39–54)(21–38)(1–20)ABCDEFG
    • 79Environmental protection measuresL2■ BRE Trust (www.bre.co.uk) is a research group forthe built environment.■ National Energy Foundation (www.nef.org.uk) aimsto develop and implement energy efficient initiatives.■ Carbon Leapfrog (www.carbonleapfrog.org) is acharity that supports carbon reduction projects.■ Energy4All (www.energy4all.co.uk) aims to expandthe number of renewable energy cooperatives.■ Renewable Energy Association (www.r-e-a.net)represents the UK’s renewable energy industry.Energy conservation andcommissioningThe role of the commissioning processWhen a new environmental energy system is installedin a dwelling or a new build, it is important that theinstallers carry out a rigorous commissioning process.This is done in order to ensure that the system is workingto its full efficiency.Commissioning normally takes place once theinstallation has been completed. It is a process in whichthe installers can check all of the components of theinstallation before it is handed over to the buildingowner and signed off. The purpose is to check thesystem’s overall performance.Commissioning and handing over the system to thecustomer will ensure:activityVisit some of thewebsites listed hereand find out whocan offer grants orfunds to assist inthe installation ofrenewable energysystems in your area.
    • 80Access to Building Services EngineeringDid you knowAbout 18% of theUK’s electricityusage is for electriclighting, and about5% goes towardsreducing the heatfrom lights. (Source:Digest of UK EnergyStatistics 2010)L2■ the system operates in the most effective way fromthe very beginning■ it is the start of an ongoing and cost-effectivemaintenance programme■ the owner is satisfied and that it meets their needs.Commissioning should prevent minor errors fromdeveloping into serious problems.System handover procedureOne of the most important aspects of commissioningand the handover procedure is to provide the owner withaccurate documentation and technical reports. These serveas a benchmark for future system tests. Also, it is unlikelythat the owner has a thorough working knowledge of thesystem, so the handover needs to provide basic training forthem to operate and routinely maintain the system.Reducing waste andconserving energyWorking practicesThe expectation within the building services industryis increasingly that working practices conserve energyand protect the environment. Everyone can play a partin this. For example, you can contribute by turningoff hosepipes when you have finished using water, orunplugging equipment or power tools that you wouldusually leave on standby.
    • Environmental protection measures81Simple things, such as keeping construction sites neatand orderly, can go a long way to conserving energyand protecting the environment. A good way toremember this is:■ Sort – sort and store items in your work area,eliminate clutter and manage deliveries.■ Set – everything should have its own place and beclearly marked and easy to access. In other words,be neat.■ Shine – clean your work area and it will be easier tosee potential problems.■ Standardise – using standardised working practices,you can keep organised, clean and safe.Reducing material wastageReducing waste is all about good working practice. Byreducing wastage disposal and recycling materials onsite, you will benefit from savings on raw materials andlower transportation costs.Let’s start by looking at ways to reduce waste whenbuying and storing materials:■ Only order the amount of materials you actuallyneed, to reduce over-ordering and potential waste.■ Arrange regular deliveries so you can reduce storageand material losses.■ Think about using recycled materials, as they may becheaper.■ Consider if all the packaging is absolutely necessary.Can you reduce the amount of packaging?T O O L B O X T A L KSmall, regulardeliveries will helpto ensure thatmaterials storedon site are neitherdamaged nor stolen.
    • 82Access to Building Services EngineeringKey termsLow-risk waste:Waste that is not verydangerous but stillneeds to be disposedof carefully.Hazardous waste:Waste that couldcause great harmto people or theenvironment andneeds to be disposedof with extreme care.Fig. 3.11 Measuringaccurately can reducewastage■ Reject damaged or incomplete deliveries.■ Make sure that storage areas are safe, secure andweatherproof.■ Store liquids away from drains to prevent pollution.By planning ahead and accurately measuring andcutting materials, you will be able to reduce wastage.Safe disposal ofmaterialsL2 Statutory legislation for wastemanagementBy law, all construction sites should be kept in goodorder and clean. A vital part of this is the properdisposal of waste, which can range from low-riskwaste, such as metals, plastics, wood and cardboard,to hazardous waste, for example asbestos, electricaland electronic equipment and refrigerants.Waste is anything that is thrown away because it is nolonger useful or needed. However, you cannot simplydiscard it, as some waste can be recycled or reused,while other waste will affect health or the quality of theenvironment.Legislation aims not only to prevent waste from goinginto landfill but also to encourage people to recycle.For example, under the Environmental Protection Act(1990), the building services industry has the followingduty of care with regard to waste disposal:
    • Environmental protection measures83Fig. 3.12 Low-risk wasteDid you knowIf waste is notmanaged properlyand the duty of careis broken, then a fineof up to £5000 maybe issued.Trade tipYou can keep up todate with the latestdevelopments inenvironmental lawby using websitessuch as: www.environmentlaw.org.ukL2■ All waste for disposal can only be passed over to alicensed operator.■ Waste must be stored safely and securely.■ Waste should not cause environmental pollution.The main legislation covering the disposal of waste isoutlined in the table below.UK waste disposal lawsLegislation Brief explanationEnvironmental Protection Act(1990)Defines waste and wasteoffencesEnvironmental Protection (Dutyof Care) Regulations (1991)Places the responsibility fordisposal on the producer ofthe wasteHazardous Waste (Englandand Wales) Regulations (2005)Defines hazardous wasteand regulates the safemanagement of hazardouswasteWaste Electrical and ElectronicEquipment (WEEE) Regulations(2006)Requires those that produceelectrical and electronicwaste to pay for its collection,treatment and recoveryWaste (England and Wales)Regulations (2011)Introduces a system for wastecarrier registrationSafe methods of waste disposalIn order to dispose of waste materials legally, you mustuse the right method.■ Licensed waste disposal is carried out by operators oflandfill sites or those that store other people’s waste,treat it, carry out recycling or are involved in the finaldisposal of waste.
    • 84Access to Building Services EngineeringREMEMBERMetals, plastics, woodand cardboard can allbe recycled.Key termsFerrous: Metals thatcontain iron.Non-ferrous: Metalsthat do not containany iron.Foundry: A placewhere metal ismelted and pouredinto moulds.Fig. 3.13 Recycled metalswill be transported to afoundry■ Waste carriers’ licences are awarded to companiesthat transport waste; these may also be wastecontractors or skip operators. For example,electricians or plumbers that carry construction anddemolition waste would need to have this licence, aswould anyone involved in construction or demolition.■ Recycling of materials such as wood, glass, soil,paper, board or scrap metal is dealt with at materialsreclamation facilities. They sort the material, which isthen sent to reprocessing plants so it can be reused.L2■ Specialist disposal is used for waste such as asbestos,which has to be double-bagged and placed in acovered, locked skip, along with any personal protectiveequipment (PPE) that may have become contaminated.There are authorised asbestos disposal sites thatspecialise in dealing with this kind of waste.Approved processes for recyclingmaterialsMetalsScrap metal is divided into two different types:■ Ferrous scrap includes iron and steel, mainly frombeams, cars and household appliances.■ Non-ferrous scrap is all other types of metals,including aluminium, lead, copper, zinc and nickel.Recycling businesses will collect and store metals andthen transport them to foundries. The operators willhave a licence, permit or consent to store, handle,transport and treat the metal.
    • 85Environmental protection measuresL2PlasticsPlastic waste can include drums, containers or plasticpackaging. Different types of plastic are used fordifferent things, so they will need to be recycledseparately. Licensed collectors will pass on the plastics torecycling businesses who then remould the plastics.Wood and cardboardBuilding sites will often generate a wide variety of woodwaste, such as off-cuts, shavings, chippings and sawdust.Paper and cardboard waste can be passed on to anauthorised waste carrier, but it is important to keepwaste transfer notes for every load of waste passed on.The waste carrier must be registered or exempt fromregistration.Disposal of potentially hazardousmaterialsPotentially hazardous waste materials need to bedisposed of in the correct way. Legislation places a dutyon individuals to ensure that hazardous wastes do notrepresent a risk to health or the environment.AsbestosAsbestos needs to be double wrapped in approvedpackaging, with a hazard sign and asbestos codeinformation visible. The standard practice is to use a redinner bag with the asbestos warning and a clear outerbag with a carriage of dangerous goods (CDG) sign.Trade tipBefore collection,plastics should bestored on hard,waterproof surfaces,undercover andaway from watercourses.Trade tipYou can search forlicensed recyclingand waste disposalcompanies usingwebsites such as:www.wastedirectory.org.ukREMEMBERSites must onlypass waste on to anauthorised waste carrier,and it is important tokeep records of alltransfers.
    • 86Access to Building Services EngineeringL2Asbestos waste should be carried in a sealed skip orin a separate compartment to other waste. Ideally, itshould be transported by a registered waste carrier anddisposed of at a licensed site. Documentation relating tothe disposal of asbestos must be kept for three years.Electrical and electronic equipmentThe WEEE Regulations were first introduced in the UK in2006. They were based on EU law – the WEEE Directiveof 2003.Normally, the costs of electrical and electronic wastecollection and disposal fall on either the contractor orthe client. Disposal of items such as this are part of theSite Waste Management Plans Regulations (2008), whichapply to all construction projects in England worth morethan £300,000.■ For equipment purchased after August 2005, it is theresponsibility of the producer to collect and treat thewaste.■ For equipment purchased before August 2005 that isbeing replaced, it is the responsibility of the supplierof the equipment to collect and dispose of the waste.■ For equipment purchased before August 2005 that isnot being replaced, it is the responsibility of either thecontractor or client to dispose of the waste.RefrigerantsRefrigerators, freezer cabinets, dehumidifiers and airconditioners contain fluorinated gases, known aschlorofluorocarbons (CFCs). CFCs have been linkedREMEMBERAsbestos waste includesanything that cannotbe decontaminated,including PPE andcloths.Fig. 3.14 PPE is essentialwhen dealing with asbestosKey termsFluorinated gas: Apowerful greenhousegas that contributesto global warming.
    • Environmental protection measures87Did you knowThe ozone layerprovides protectionagainst skin cancerby absorbingharmful UV radiationfrom the sun.Trade tipTo deal with theproblem of dust, usefine water spray ora sprinkler systemthat is capable ofreaching all parts ofthe site.Key termsOzone layer: Athin layer of gashigh in the earth’satmosphere.L2with damage to the earth’s ozone layer, so productionof most CFCs ceased in 1995.Refrigerants such as these have to be collected bya registered waste company, which will de-gas theequipment. During the de-gassing process, thecoolant is removed so that it does not leak into theatmosphere.Preventing damage to the environmentConstruction sites can be a major source ofenvironmental pollution or danger. Those working onconstruction sites, therefore, need to follow environmentallegislation and establish good pollution controlprocedures in order to prevent problems such as:■ noise ■ odour■ smoke ■ dust.We all need to consider how our work activities couldendanger the environment. Bonfires, for example, arenot permitted on most construction sites.Each site should have a nominated person who isresponsible for carrying out a risk assessment to identifypotential pollution incidents. The risk assessment needsto incorporate:■ how to stop the pollution occurring in the first place■ how to contain any pollution and prevent it fromspreading■ information on who needs to be informed ofpollution incidents
    • 88Access to Building Services Engineering■ consideration of how significant a pollution incidentmight be■ plans for how to clean up and dispose of anypollution or waste.Conserving water andreducing water wastageWater is a precious resource, so it is vital not to wasteit. To meet the current demand for water in the UK, it isessential to reduce the amount of water we use and torecycle water where possible.The construction industry can contribute to waterconservation by effective plumbing design and throughthe installation of water-efficient appliances and fittings.These include low- or dual-flush WCs, and taps andfittings with flow regulators and restrictors. In addition,rainwater harvesting and waste water recycling shouldbe incorporated into design and construction whereverpossible.L2 Statutory legislation for waterwastage and misuseWater efficiency and conservation laws aim to help dealwith the increasing demand for water. Just how this isapproached will depend on the type of property:■ For new builds, the Code for Sustainable Homesand Part G of the Building Regulations set new waterefficiency targets.T O O L B O X T A L KIf there is a pollutionincident on site youmust contact theEnvironment Agencyimmediately.
    • Environmental protection measures89L2■ For existing buildings, Part G of the BuildingRegulations applies to all refurbishment projectswhere there is a major change of use.■ For owners of non-domestic buildings, tax reductionand grants are available for water efficiency projects.In addition, the Water Supply (Water Fittings) Regulations(1999) set a series of efficiency improvements for fittingsused in toilets, showers, washing machines, and so on.Water efficiency calculatorTo work out the water efficiency for a new build, youwill need the water consumption figures provided bymanufacturers for their products. This will determinethe consumption of each terminal fitting. These figuresare entered into a table to calculate the consumption ofeach fitting in litres per person per day. The total is thencalculated, which needs to comply with the Code forSustainable Homes and the Building Regulations 17.K.The key points to remember are:■ Regulation 17.K requires the average water usageper person per day does not exceed 125l.■ Calculations need to be based on data for the fittingsthat have actually been installed.■ Completed calculations have to be sent to thebuilding control body.Reducing water wastageThere are many different ways in which water wastagecan be reduced, as shown in the following table.Did you knowThe water efficiencycalculator for newdwellings can befound at the PlanningPortal (www.planningportal.gov.uk), thegovernment’sonline planning andbuilding regulationsresource for Englandand Wales.
    • 90Access to Building Services EngineeringMethods of reducing water wastageMethod ExplanationFlow-reducingvalvesWater pressure is often higher than necessary;by reducing the pressure, less waste water isgenerated when taps are left runningSpray taps Fixing one of these inserts can reduce waterconsumption by as much as 70%Low-flush WC These reduce water use from 13l per flush to6l for a full flush and 4l for a reduced flushMaintenance ofterminal fittingsand float valvesDripping taps or badly adjusted float valvescan cause enormous water wastage – adripping tap can waste 5000l a yearPromoting userawarenessUsers who are on a meter will make savingsif they improve their water efficiency, and theirenergy bills will reduce if they use less hot waterCaptured and recycled water systemsThere are two variations of captured and recycled watersystems:■ Rainwater harvesting captures and stores rainwaterfor non-potable use.■ Greywater reuse systems capture and store wastewater from baths, washbasins, showers, sinks andwashing machines.Rainwater harvestingIn this system, water is harvested usually from theroof and then distributed to an above-ground orunderground tank. Here it is filtered and then pumpedinto the dwelling for reuse. The recycled water is usuallystored in a cistern at the top of the building.Key termsNon-potable: Waterthat is unsuitable fordrinking.Greywater: Wastewater from washingmachines, sinks andbaths or showers.
    • Environmental protection measures91Mains watersupply (potable)RainwatercollectionGardentapFilterUndergroundstorage tankStoragetankCalmed inletOverflowSubmersible pumpwith floating extractionFig. 3.15 A typical rainwater harvesting systemGreywater reuseThe idea of this system is to reduce mains waterconsumption. The greywater is piped from points ofuse, such as sinks and showers, through a filter and intoa storage tank. The greywater is then pumped into acistern where it can be used for toilet flushing, wateringthe garden or sometimes to feed washing machines.Mains watersupply (potable)Greywaterinlet filterGreywatercollectionpipeworkGreywater supplyto storage tankType AA air gap toprovide backflowprotectionBack-up watersupply to storage tankOutlet tosupply pointsAccesscoverOverflowSubmersible pumpwith floating extractionCalmed inletFig. 3.16 Greywater system layout and key componentsactivityFig. 3.16 showsthe layout and keycomponents of agreywater system. (Itis not an installationdiagram.)Why might it beuseful to have thegreywater intlet filterabove ground?
    • 92Access to Building Services Engineeringcheck your knowledgeLevel 11. Identify and briefly describe two high carbon energy sources.2. Identify and briefly describe two new technologies that are classed as lowcarbon energy sources.3. What is the purpose of a DTC?4. Briefly describe the basic principles of a solar photovoltaic installation.5. Suggest and explain two ways in which you could reduce materials wastage.6. List as many types of material you can think of that can be recycled from anormal building site.7. How might a low-flush WC reduce water wastage?8. Why might grewater be less useful as recycled water compared to rainwater?check your knowledgeLEVEL 21. Identify and explain one energy conservation law that is relevant to thebuilding services industry.2. Identify and briefly explain three zero carbon energy sources.3. What is the main difference between CHP and CCHP?4. Identify and explain three key parts of a system handover procedure.5. Identify and explain two methods of conserving materials usage on site.6. Which type of material needs specialist disposal?7. Briefly explain the working principles behind a rainwater recycling installation.8. Explain why mains water should not be contaminated by greywater or rainwater.