nifes - 2002 - undertaking an industrial energy survey

7/27/2019 NIFES - 2002 - Undertaking an Industrial Energy Survey

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Advice for end users on finding energy cost savings

Good Practice Guide 316

Undertaking an industrial

survey



this guide GWhy and how to use this guide

finding savings G

Topic guides on common industrial processes, related topics and site services

survey pro formas and reporting GData sheets for recording survey data and results

reference GSupporting data, and sources of further advice

Appendix A ReportingAppendix B Selecting and briefing a consultant



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why and how to use this guide



1.1 Purpose of this guide

1.2 Energy surveys in perspective

1.3 Surveys and audits

1.4 Doing your own energy survey

why and how to use this guide



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1Financial

Energy bills are often regarded as an overhead charge to be paid ‘on the nod’ without rigorousscrutiny.This view can be challenged. Energy costs may be a small proportion of total costs, but theyare a significant proportion of controllable costs, and furthermore carry a high risk of being partlyunnecessary.The cost of eliminating avoidable excess energy expenditure can be much lower thanthe cost of ignoring it, and cost savings of 5%-25% are generally achievable. Moreover, for acompany operating on slender margins, this small saving on energy can give a disproportionateboost to profit. An equivalent boost to profit might be achieved by increasing sales; but that wouldobviously entail far higher costs (otherwise the company would already be doing it) and mightrequire investment in extra production facilities.

2Environmental

Most scientists believe that global warming is a real threat. In a busy industrial site, such globalconsiderations may seem remote. But your workforce may be sympathetic to the environmentalmessage, and may even include enthusiasts who would welcome their employer adopting a sociallyresponsible, proactive stance. Green credentials may also influence customers, and relations withlocal communities may benefit. If you have environmental certification, you will need a continuous

flow of quantifiable improvements if you are to retain your status; an energy-saving campaign isone of the few ways of guaranteeing demonstrable year-on-year improvement. It will also help if your company is applying for ISO14001 or a similar environmental management certification.

3Operational

Active energy management often results in reduced plant running hours, bringing reducedmaintenance costs, less frequent breakdowns, and less noise and unwanted heat. Sometimes,working conditions are improved as well. For example, modern high-frequency fluorescent lamps areflicker free as well as cheaper to run, and heating systems recommissioned to operate economicallysometimes work more effectively too.These factors improve staff morale and productivity. Even asmall reduction in electricity demand can be valuable because of the reduced peak demands; this

has enabled some factories to avoid paying for costly upgrades to supply transformers when extracapacity is needed. And advanced techniques of energy management can even inform and enhanceother cost-reduction activities.

4LegislativeIf your company is covered by Part A of the Pollution Prevention and Control (PPC) Regulations youwill find that you are under a legal obligation to save energy.And if you are a party to a ClimateChange Agreement (CCA), you could lose a valuable Climate Change Levy (CCL) discount by failingto make progress against your agreed energy saving targets. Loss of CCL discount would typicallybe the equivalent of a fine equal to more than 10% of your non-oil energy bills. Finally, the newBuilding Regulations compel businesses to incorporate energy-efficiency measures when evenrelatively minor work is carried out on existing buildings.

Background

The UK industrial sector uses the equivalent of about 36 million tonnes of oil each year,

and the service sector 21 million. Between them, they spend over £10 billion a year and

account for over a third of total inland energy consumption.Transport uses a similar

amount.There is now little doubt that the resultant carbon dioxide emissions

contribute to global warming, and the Government is committed to reducing our

output of CO2 to 20% below 1990 levels by 2010. So what? How does this big picture

relate to your everyday business needs, when you are focused on costs, and energy

probably doesn’t account for even 2% of your overall business purchases? Four reasons:

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The role of senior management

A successful energy saving campaign demands the

active support of senior management.There is nosuggestion that energy saving should enjoy ‘special

pleading’ unless the company’s policy says otherwise.

You will need to create the right corporate conditions

for progress:

G The company should appoint an ‘energy manager’ -

somebody (possibly acting part time) whose task it will

be to originate and coordinate energy-saving projects

and procedures.

G The appointed energy manager must be allowed

reasonable specialist training to make them fully

effective, and their knowledge and experience must

be respected.

G The company must back the appointed energy manager

when they cannot get the required help and information

from department heads.

G If levels of service provided by energy systems areinadequate, the company must be willing to

resolvethese issues. Otherwise there will be no support

for energy-saving initiatives.

G The company must be prepared to adopt an energy

policy, in the interests of curtailing argument about

whether and how certain things should be done.

G When faced with proposals for spending on energy

saving projects, the company must assess the financial

case fairly. Just because a cost-reduction project

increases profit without increasing sales should not

count against it.



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Section 1Contains

introductory

material

Section 2Contains a series of

survey topic

guides, each

focussed on a

particular factory

service or generic

process.There are

also four

management topic

guides.

Section 3Provides guidance

on reporting

including examples

of usefull tables

Section 4Contains reference

material

...you are a general manager, please focus on:

Section 1 and the management topic guides

2.a to 2.d

...you are given an energy management

responsibility please start on

Sections 1 and 2 and then move on to

the other sections

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1.1 PURPOSE OF THIS GUIDE

The purpose of this guide is to help you find

practical opportunities to save energy in

your business. It is based on the assumption

that while you may know little about

energy, you nevertheless have eyes and ears,

and common sense.The guide provides a

structured framework for a simple ‘walk-

through’energy survey, supported by ‘topic

guides’which deal with the more common

industrial processes and factory services.

The survey which you will carry out with the help of this guide is only a first step on the journey to lower energy costs, improved environmental performance,and all the other incidental benefits of active energymanagement. It will be a snapshot – with all thelimitations that implies. But it will be a start, and inthe course of your survey you will probably makeimmediate economies by detecting and rectifyingsome obvious things which are wasting money.

You will also establish how much energy you are usingthrough the year, and how much it is costing. You maybe able to attribute some of the consumption tospecific processes or activities and if consumption is

driven by production and/or other factors, you willhave calculated a headline performance ratio which you will be able to use for tracking future progress.

Saving energy requires action.A survey will provide alist of opportunities with associated costs and savingsfrom which priorities can be determined. Somemeasures will involve no expenditure (eg resettingheating controls). Some will require investment.

Once you have listed a number of opportunities for further investigation, you will know where to turn for more information and advice on a particular topic. Insome cases, using the ‘tips and tricks’mentioned insome of the topic guides, you will have been able toestimate current energy losses and associated costs.This will put you in a stronger position when assessingthe viability of solutions proposed to you by suppliersof energy-saving equipment and services.

This guide does not set out to provide tuition in theprinciples of energy management, nor to act as asubstitute for the wealth of useful information publishedby the Energy Efficiency Best Practice Programme.

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1.2 ENERGY SURVEYS IN

PERSPECTIVE

Energy surveys are important because they identify

how savings can be achieved. But there is more toenergy management than surveys alone. This diagramstructures the task of saving money through energymanagement, and thereby sets surveys in perspective:

Fig 1.1 Energy management- an overview

Improve

underlyingefficiency

This is the activity for which an energy

survey is mostrelevant, especiallywhere money isavailable to carry outremedial works or modifications.Thesurvey explicitlyreveals theopportunities for suchphysical changes,which also have thebenefit of reducing theenvironmental impact

of an organisation.

Prevent

foreseeablewaste

During an energysurvey, examples of

bad practice may berevealed.These willoften have ‘no-cost’or ‘low-cost’ solutions.The question alsoneeds to be asked: arethere procedures inplace which wouldprevent these thingshappening again?

Detect,

diagnose andrectify

unexpectedwaste

A one-off energysurvey is of limited usein support of thisactivity because it isonly a snapshot. Thedetection of randomly-occurringwaste is best dealtwith by regular long-term routinemonitoring andtargeting. However,

periodical snapinspections based onenergy surveyprinciples couldprovide some measureof defence.

Purchase

competitivelyand monitor for

billing errors

Because energysurveys focusexclusively on thephysical aspects of energy consumption,they have littlerelevance to thisactivity – with onemajor exception.Where costs aredependent to anyextent on peak demand, the energysurvey may reveal

opportunities toimprove load factor and thereby cut thepeak-demand elementof energy charges.

Reduce quantity purchasedand environmental impact

Reduce cost per unit

Reduce avoidable waste

Save money



1.3 SURVEYS AND AUDITS

Introduction

At the beginning of an energy management initiativeit is important to determine the current position.Once this has been established it is then possible toset goals and priorities for future improvement.

To determine the current position it is important to beable to answer questions such as:G What types of energy are used?G How much is being used?G How much does it cost?G Where is the energy being used?G How efficiently is energy being converted,

distributed and used?

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Energy survey: a technical investigation of the controland flow of energy in a:G Building…G Process/manufacturing unit…G Piece of equipment…G Site…

…with the aim of identifying cost-effectiveenergy saving measures.

Energy surveys can be conducted on entire sites,individual manufacturing units, utility systems or

specific items of equipment.Usually surveys include an examination of:G Energy conversion: where energy is converted from

one form to another, eg heaters, boilers, furnaces,refrigeration units, compressors, turbines, etc.

G Energy distribution: where energy is distributed,eg electricity, gas, steam, air, water, hot oil systems.

G Energy end use: where energy is used in plant,equipment and buildings.

G Management systems: how information isobtained, analysed, and used. Managementand people issues.

Example

This example is from a food manufacturing site with data from a 12-month period:

Consumption Cost Average cost

Energy type kWh % £ % p/kWh

Natural gas 5,856,979 67.2 39,375 25.1 0.672

Gas oil 202,967 2.3 3,398 2.2 1.674

Electricity 2,662,700 30.5 114,187 72.7 4.288

Total 8,722,646 100 156,960 100 1.799

G What are the potential savings?G How can they be achieved?G How much will it cost to achieve the savings?G What are the priority areas?

All the questions posed are important and can beanswered by conducting an energy survey.

DefinitionEnergy audit: a study to determine the quantity andcost of each form of energy to a:G Building…G Process/manufacturing unit…G Piece of equipment…G Site…

…over a given period, usually a year.



An energy survey will usually give a managementsummary and divide recommendations into threemain categories:

G No-cost measures (good housekeeping).

G Low-cost measures.G High-cost measures.

Examples of these three categories aregiven below:

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Install dehumidifier in building 10 670 40,870 400 0.6

Insulate boiler headers 150 9,120 350 2.3

Totals 820 49,990 750 0.9

Overhaul flue gas dampers, flow isolationcontrols and sequence control on main boilers 2,000 122,000 1,000 0.5

Presence-detector control of lighting 480 6,000 1,000 2.1

Insulate valves on heating pipework 320 19,800 900 2.8

Total 2,800 147,800 2,900 1.0

NO-COST MEASURES

Reset cooling plant time switch controls 3,237 45,278 - Immediate

Reset AHU time switch controls 16,712 233,611 - Immediate

Reset conditioned areas temperature setpoint during summer 1,390 19,444 - Immediate

Isolate skirting heating during cooling season - - - Immediate

Reinstate AHU heating coils (1,027) (97,778) - Immediate

Switch off air conditioning plant 3,100 95,833 - Immediate

Total 23,412 296,388 - Immediate

Estimated annual saving

£ kWhMeasureEstimated costs

£

Simplepayback

years

LOW-COST MEASURES



£

Simplepayback

years



£

Simplepayback

years

HIGH-COST MEASURES



BE YOUR OWN CONSULTANT

When an outside consultant does an initial energysurvey to identify likely avenues for further

investigation, they will usually cover the followingground:

G gather base data on monthly consumptionand expenditure over the last year;

G become familiar with the site and the work done there;

G become familiar with how energy iscurrently managed;

G study the main services facilities(boilers, compressed air, lighting, etc) searchingfor energy saving opportunities;

G review opportunities for saving energy at thepoint of use;

G estimate likely implementation costs, savings,and paybacks, usually from insufficient data;

G write a report in a prescribed format and haveit checked for accuracy.

The consultant’s advantages are primarily depth of technical expertise, breadth of experience, andfreedom from urgent interruptions. The consultant canlook at your site and its problems and opportunitieswith a fresh pair of eyes.An appropriately-chosen

consultant will have surveyed many sites and willknow the likely sources of possible energy savings in

your sector. But he or she usually has limited time:perhaps only one day on site and two days for analysisand reporting.Your ability to take your time, spreadingthe work over a longer period if you wish, is only oneadvantage which you enjoy. Here are the others:

G You will already be familiar with the site andits activities.

G You will be freer to come and go, and won’tneed an escort.

G You know who has the information you need,and if you overlook something, you can go back at any time.

G You can ask others to help you, parcel out someparts of the survey to more appropriate colleaguesif you want, or mobilise a workplace study groupin the style of a quality improvement team.

G If there are other surveys going on(on safety, quality, or environmental themes),

you may be able to join forces.

G If the base data which you need is not

forthcoming, you can ‘pull strings’ or even getinto the ledgers yourself – or simply busy yourself with other aspects while the data works its waythrough the system.

G You are not obliged to write a formal report(although it would be unwise not to record your findings, calculations and recommendations for others to read later; you may also need asummary to obtain funds for investment inenergy saving measures).

G You can legitimately build on the work of othersbefore you.

G You can elect to ignore whole aspects.

G You can improvise measurement techniques, eventurning things on and off (within reason) to gaugetheir effect on consumption.

G You may be able to experiment with variationsto processes.

This guide has been designed so that you can work within the limits of your own expertise. Once youneed to go beyond those limits, or cannot devote thenecessary time, using the guide will not only equip

you better to brief an outside expert; it will havehelped you establish that his or her fee is justified.

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Establish current patterns of overallconsumption and expenditure atsite level.

Continue to monitor performancesystematically in order to track andverify subsequent savings.

Does a meaningful yardstick energyratio exist for your industrial sector?

YES

YES

NO

Tabulate where in the works youhave examples of particular processes and services(eg compressed air, treatment vats).

Visit each area or department inturn. Using the appropriate topicguides as a prompt, look for thingswhich are obviously wrong and needto be corrected.

Report your findings, and put intoeffect whatever low-cost and no-costmeasures you have identified.

Might funding be available for energy-saving projects?

NO

Obtain quotations for possibleenergy-saving solutions.

Calculate the financial viability of theprojects you are proposing, and presentrecommendations for those most likelyto receive approval.

Identify opportunities which mayapply to your site in particular.

By measurement, experiment, or inference, estimate present energyconsumptions of affected plant, andlikely savings in each case.

Calculate the figurefor your site.

You can use the topic matrix at the beginning of Section 2as a guide.

Common generic processes and services are each covered by asurvey topic guide sheet in Section 2.If you are not sure what to look at first, start with the principalcentral services and the largest process users.

There is a selection of pro forma recording sheets in Section 3.

1.4 DOING YOUR OWN ENERGY

SURVEY

This provides a backdrop to your eventual findings and helps to

set the subject in a meaningful context for generalmanagement. Copies of energy invoices should be available in your accounts department, but suppliers will sometimesprovide historical summaries.

Systematic monitoring against targets cansave money in itself, by revealing the onsetof unexpected hidden waste.Further advice on this topic is in managementtopic guide sheet C.

Implement approved projects.



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topic guides on common industrial processes and site services

2



2.10 Fans and pumps

2.11 Burners

2.12 Steam systems

2.13 Crushing and grinding

2.14 Mixing and blending

2.15 Drying

2.16 Baking and curing

2.17 Machining, forming, and fabrication

2.18 Tanks and vats

2.19 Treatment booths and cabinets

2.20 High temperature processes

2.21 Cooling systems

2.22 Heat recovery

2.23 Mechanical handling

2.24 Motor transport

2.25 On-site catering2.26 Building fabric

2.a Management topic guide a:

Organising energy management

2.b Management topic guide b: People

aspects of energy management

2.c Management topic guide c:

Targeting and monitoring

2.d Management topic guide d:

Making the case

2.1 Lighting

2.2 Ventilation

2.3 Boilers

2.4 Space heating

2.5 Air conditioning

2.6 Hot water services

2.7 Compressed air services

2.8 Central vacuum services2.9 Electric motors and drives

topic guides on common industrial processes and site services



A ‘zone’ might be a boiler house or plant room, anentire production floor, a store,a canteen block, or however you decide to define it. Take the matrix with

you on your initial walk-round and tick off which topicguides you will need for each zone.The completedmatrix will help ensure that you later investigate (andreport) every aspect.

The site can be zoned however you wish. Illustration(A) shows just two zones – production and non-production. (B) has six buildings split into eightdistinct zones,while (C) is a geographical split.

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2 FINDING SAVINGS

SURVEY TOPIC GUIDES

The topic guides in this section provide a framework for your survey.They are structured as follows.

Each deals with a generic industrial process (boilers,for example) or a site service such as lighting or compressed air.

Each starts with a list of things to look for. These arethings which are often amiss, where common senseand local knowledge will normally be sufficient todictate an appropriate remedy, and where it should bequick and cheap – or even free – to put the problemright. This may be as far as you need to go.

For those who want to go further, each topic guidehas a selection of tips and tricks.

Next comes a list of potential opportunities. Theseonly apply if you are prepared to contemplatemoderate to high cost remedial works.

Finally, each topic guide includes references to furtherinformation. Much of this is free information fromthe Energy Efficiency Best Practice Programme.

Note: other common sources of information

are listed in Section 4, ‘Sources of

Assistance’.

Before carrying out any experiments or modifications,prepare a method statement and assess the risk of unintended consequences.

Not all of your site will feature every kind of processand service covered by the topic guides.You can usethe matrix to record which topics are relevant where.First divide the establishment into appropriate zonesand label each column of the matrix accordingly.

P R O D U C T I O N 1

B O I L E R

H O U S E

O F F I C E S


PRODUCTION 3

A B

STORES


B O I L E R

H O U S E

O F F I C E S


PRODUCTION 3

STORES


B O I L E R

H O U S E

O F F I C E S


PRODUCTION 3

STORES

C



Assessment and goal-setting

The energy management matrix (fig 2.1) is dividedinto six key organisational aspects of energymanagement:

G Policy

G Organising

G Training

G Performance measurement

G Communicating

G Investment

To obtain an indication of the current state of theorganisational aspects on your site complete thematrix by putting one cross in each column. The box

you mark under each column should represent thecurrent status on your site.Then join your crossesacross the columns to produce your organisationalprofile. This will show your strengths and weaknesses.Weaknesses can undermine strengths so the idealprofile is one which is relatively flat. From thatposition it is important to advance on all aspectsup the matrix.

Some companies find it useful to copy the matrix andget a group of managers to individually complete thematrix in a meeting and then compare findings.It provides useful management overview in a pictorialform and highlights points for further action.

In the rest of this section each of the organisationalaspects are covered briefly with pointers to further information.

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2.a MANAGEMENT TOPIC GUIDE:ORGANISING ENERGYMANAGEMENT

Success factors to look for

G An enthusiastic champion.

G A motivated and energy-aware workforce.

G A culture of engagement and co-operation.

G Support from senior management.

G True accountability for energy costs.

G Corporate willingness to rectify problems withexisting energy-related services.

G Training for those whose day-to-day work impinges on energy efficiency.

G A team approach on the part of therelevant players.

G Continuous feedback of results and achievements.

G Opportunities created by external factors(eg supply capacity constraining growth).



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Fig 2.1 Energy management matrix

Further information on energy policy

G GPG 186 Developing an effective energy policy

G GPG 200 A strategic approach to energy andenvironmental management

Further information on organisingenergy management

G GPG 119 Organising energy management - acorporate approach

G GPG 167 Organisational aspects of energymanagement: a self-assessment

manual for managers

G Standards for managing energy

Further information on energy training

G GPG 85 Energy efficiency training anddevelopment

G GPG 235 Managing people, managing energy

Further information on measuring energyperformance

G FEB 13 Waste avoidance measures

G GPG 112 M&T in large companies

G GPG 125 M&T in small and mediumsized companies

G GPG 231 Introducing information systemsfor energy management

Further information on communication

G GPG 84 Managing and motivating staff tosave energy

G GPG 172 Marketing energy efficiency -raising staff awareness

G GPG 235 Managing people, managing energy

G GPG 251 Maintaining the momentum

G Running an awareness campaignaction pack

Further information on energy-saving investment

G GPG 69 Investment appraisal for industrialenergy efficiency

G GPG 75 Financial aspects of energymanagement in buildings

G GPCS 251 An energy management andinvestment campaign in a

Energy Policy,action plan andregular review haveactive commitmentof top management

Policy

Fully integrated intomanagementstructure with clear accountability for energyconsumption

Appropriate andcomprehensive staff training tailored toidentified needs,with evaluation

Comprehensiveperformancemeasurementagainst targets witheffectivemanagementreporting

Extensivecommunication of energy issues withinand outsideorganisation

Regular staff briefings,performancereporting andenergy promotion

Resources routinelycommitted toenergy efficiency insupport of businessobjectives

Organising Training Performancemeasurement

Communicating Investment

Formal policy butno activecommitment fromtop

Clear linemanagementaccountability for consumption andresponsibility for improvement

Energy trainingtargeted at major users followingtraining needsanalysis

Weeklyperformancemeasurement for each process, unit,or building

Same appraisalcriteria used as for other costreduction projects

Some use of companycommunicationmechanisms topromote energyefficiency

Unadopted policy Some delegation of responsibility butline managementand authorityunclear

Ad-hoc internaltraining for selectedpeople as required

Monthly monitoringby fuel type

Low or mediumcost measuresconsidered if shortpayback period

Ad-hoc informalcontacts used topromote energyefficiency

Unwritten set of guidelines

Informal mainlyfocused on energysupply

Technical staff occasionally attendspecialist courses

Invoice checkingonly

Only low or no costmeasures taken

No communication

or promotion of energy issues

No explicit energy

policy

4

3

2

1

0 No delegation of

responsibility for managing energy

No energy related

staff trainingprovided

No measurement

of energy costs or consumptions

No investment in

improving energyefficiency



Training

On every site there are key people who can have alarge influence on energy consumption because of their job function.These people need to be identified

along with their training needs so that they receiveappropriate training to be energy efficient. Individualsare usually saving energy or wasting it and there israrely any neutral ground. In many industrial sites thePareto principle rules: 20% of the workforce control80% of the energy.

If energy efficiency investment measures are notsupported by appropriate training then potentialsavings will not be fully realised because of poor operation, control and maintenance practices.

Investment in vocational training for key staff (e.g.boiler or plant operators) not only saves energy but

also improves environmental performance andstandards of health and safety.The specialised needsof the individual energy manager must not beoverlooked. Note that since 1997 when the NationalVocational Standards for Managing Energy wereintroduced, it has been possible for individual energymanagers to gain a National Vocational Qualification(or a Scottish NVQ) by compiling an evidenceportfolio based on their work.

In addition, the Standards may help you review or specify the energy management function within

your organisation.

A framework for training needs

In a large operation, an integrated programme of training may be worth developing.This will need toaddress three categories of training need, and thematrix below shows what topics might typically becovered and at what level:

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2.b MANAGEMENT TOPIC GUIDE:PEOPLE ASPECTS OF ENERGYMANAGEMENT

Communicating

Every employee can make a contribution to savingenergy. Often, contractors should also be included.Two key aspects are required: awareness andmotivation.

Raising awareness covers the knowledge and skills sothat people see the potential for saving energy as anintegral part of their daily work. Awareness is knowingwhat to do.

Motivation is more complex. It varies from person to

person. Key factors include ‘external’ motivators, e.g.incentives, targets, competition to perform and‘internal’ motivators related to personal outlook andvalues (e.g. concerns for the environment).

Good housekeeping campaigns need to be integratedinto other energy management initiatives if momentum is to be maintained.



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Operatives and Engineers and General

maintenance line managers management and

fitters technical services

Overview of energy efficiency and energy

management; Climate Change Levy, grant schemes A A A

Energy billing and procurement A V

Performance monitoring and targeting A V,T T

Meter reading V T

Energy considerations specific to the process used

at the target site A V,T ABoiler operation V T A

Steam distribution, utilisation, and condensate recovery V T A

Pumps and fans A V,T A

Electric motors and drives A V,T A

Compressed air services V T A

Lighting A V,T A

Heat recovery V,T A

AudienceSubject

Key:

V Vocational. Material directed at improving skills,enabling trainees to do their jobs better. Likely toinclude some practical element.

T Theoretical. Material aimed at improvingknowledge and understanding, enabling better analysis and decision making.

A Awareness. Brief coverage to help traineesunderstand other people’s objectives andactivities, to put their own contribution in context,and to defuse potential conflicts.

Case studies

At a small injection-moulding plant,about £2,000 was spent on meters

to make staff more aware of where and how energy was being used.

They saved £21,000 in the first year.

A manufacturer of decorative tiles persuaded its suppliers to donate

prizes for an energy awareness campaign.



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2.c MANAGEMENT TOPIC GUIDE:MONITORING AND TARGETING

Purpose

An energy survey can only ever be a snapshot. It istherefore best at detecting opportunities for permanent modifications to plant, equipment,buildings, and operating procedures. However, your organisation may be incurring considerable hiddencosts through avoidable waste occurring at randomand remaining undetected. Examples could include

G Timeswitches and other self-acting controls failingin the ‘on’ position.

G Maintenance errors, such as fitting an oversizedreplacement motor.

G Operating errors, such as running an air compressor against a closed isolation valve.

G Lax discipline, for example leaving auxiliaries torun when not required.

G Leaks.

A management technique called monitoring andtargeting (M&T) is the most effective defence againstthese kinds of loss, which a one-off survey would miss.The next-best option - a regular programme of routine

energy inspections – would be a more costly exercise,and would anyway miss many kinds of energy-wastingfault because they are frequently of an unforeseen nature.

M&T works by combining regular consumption data(usually weekly or monthly) with corresponding dataon production throughput, weather, or other drivingfactors (called ‘variables’ in the older literature).AnM&T scheme is primed with targets for each streamof consumption, these targets being related to therelevant driving factor, so that given the level of activity in the facility, a ‘correct’ ration of energy canbe estimated at each point of use.The deviationbetween actual and expected consumptions indicatesthe extent of any unexpected loss, which can then beconverted to its implied cost in order to establishits significance.

When a fault detected in this way proves persistent,the pattern of deviation can be analysed as an aidto diagnosis.

An effective M&T scheme provides, in effect, acontinuous review of the site’s performance, and aswell as revealing random unexpected losses, it can beused to monitor and verify the effectiveness of other energy conservation measures.Verification is doublysignificant if your company is engaged in

emissions trading.

Common shortcomings

If any of the following apply in your organisation, your ability to manage the consumption of energy will becompromised:

G Unable to provide routine weekly assessment of performance and losses.

G Prime drivers of consumption(eg production flows) not catalogued.

G Quantitative relationship between eachconsumption stream and its drivers not known.

G ‘Best achievable’ relationships betweenconsumptions and drivers not used as targets.

G Regular records of driver values not kept insynchronism with consumption data.

G Inadequate submetering of significant processes.

G No regular in-house meter readings or other consumption figures.

G No stocktake of bulk-delivered commodities insynchronism with meter readings.

G Analysis and reporting starts afresh each year (instead of being continuous).

G Reliance on crude ‘specific energy ratios’ as targetsfor management control.

G Reliance on same-period-last-year as a basis

for comparison.G Focus on percentage deviations

(instead of their absolute cost).

G No system for initiating and pursuinginvestigations into unexplained deviations.

Specialist advice should be sought to rectify anysuch shortcomings, and thereby maximise the valueto be obtained from regular meter readings andother returns.

Case studies Steam losses worth £9,000 a year were detected at a paper mill.

Someone had left a bypass valve open on a steam trap.

At another paper mill, losses of £13,000 a year were detected when it

was found that an oversized replacement motor had been fitted to a

vacuum pump following a breakdown.



be done as a ‘before-and-after’ calculation(based on, say, a change in running hours) or apercentage reduction can be assumed.Equipment and service providers will often helpwith such estimates,but check their assumptionsand arguments critically – remember they havean optimistic bias.

G Multiply the reduction in units by the unit costof energy saved. Remember that the cost per unitsaved will often be less than the overall averageunit price.

G Add any quantifiable incidental savings,such as inmanpower, maintenance, or capacity charges.

G Note any additional costs which will offset theexpected savings.

Assembling the information

Before making a proposal the energy manager needs toknow the following:

G The cost of the proposed work.

G Any subsequent recurring costs.

G The expected savings.

G Risks and incidental benefits.

G The criteria against which other capital expenditureprojects are assessed.

Presenting the case

An effective proposal will have the following attributes:G There should be a single unequivocal

recommendation (not a selection of choices).

G The full costs must be stated.

G Known risks must be disclosed and accounted for.

G Against the risks, incidental benefits must bepresented as bonuses.

G The method of analysing the financial return mustbe as used for all other projects.

G The proposed investment must satisfy thecompany’s current criteria.

A proposal will always stand a better chance of acceptance if it can be aligned with the goals of anycurrent corporate campaign. Energy projects for example often have beneficial environmental impactsand can improve reliability.

Further Information

G GPG 69 Investment appraisal for industrialenergy efficiency

G GPG 75 Financial aspects of energymanagement in buildings

G GPCS 251 An energy management andinvestment campaign in a glass plant.

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2.d MANAGEMENT TOPIC GUIDE D:MAKING THE CASE

Most organisations can achieve significant energysavings through low and no cost measures, such asgood housekeeping.At some point investmentwill be needed.

Energy is one of the few cost elements present in themanufacture of every industrial product. It is also one of the key measurable and controllable contributors tocost in at least 80% of all industrial production.Commercially available equipment exists to reduce UKenergy consumption by 25%.

Barriers to energy-saving investment

There are three main barriers to overcome:G the low priority given to energy efficiency in

most organisations;

G application of inappropriate standards of investment appraisal;

G decision taken at wrong level in the organisation.

Investment appraisal is merely a rational method of making choices.Any healthy commercial enterpriseought to be able to identify more viable opportunitiesthan it can afford to fund. It therefore has to choosewhich projects are priorities for investment.

Very often energy managers use simple payback as thecriterion,even when promoting large projects. Moresophisticated methods are needed if the people judgingthe case, who will usually have an accountancy or business management training, are to take it seriously.Suitable methods are explained fully in GPG 69(see details below).

Assessing costs and savings

A short energy survey carried out by a consultant canoften provide nothing more than indicative payback periods for each recommended energy-saving measure.As the end user (and therefore the potential customer)

you are in a better position to get more definite figures,and indeed it is in your interests to do so if your proposal for capital expenditure is to be acceptable.Thesources of cost information are, in descending order of preference:

G Estimates or quotations from suppliers.

G Knowledge gained from other people who havedone similar projects.

G Generic estimates from engineers’ yearbooks.

The procedure for calculating savings is

G Estimate the reduction in unit consumptionachieved by each proposed measure.This can either



G P G


1. Lighting

2. Ventilation

3. Boilers

4. Space heating

5. Air conditioning

6. Hot water services

7. Compressed air

8. Central vacuum

9. Electric motors and drives

10. Fans and pumps

11. Burners

12. Steam systems

13. Crushing and grinding

14. Mixing and blending

15. Drying

16. Baking and curing

17. Machining and fabrication

18. Tanks and vats

19. Treatment booths/cabinets

20. High temperature processes

21. Cooling systems

22. Heat recovery

23. Mechanical handling

24. Motor transport

25. On-site catering

26. Building fabric

Copy the matrix if you need to define more zones.

A. Identify appropriate zones

B. Check which topic guides are needed for each zone

S e r v i c e s

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Things to look for

G People not even knowing where the lightswitches are.

G Tungsten filament lamps running more than four hours per day.

G Excessive light levels for the type of work being done.

G Large banks of lights controlled by a single switch.

G Lack of labels on switches controllingshared workspace.

G Outside lights on fixed timeswitch or manual

control.G Dirty or discoloured diffusers and shades.

G Empty areas lit unnecessarily.

G Dirty rooflights or other opportunities to usemore daylight.

G Artificial lighting in areas with sufficient daylight.

Survey tricks and tips

G Estimate the lighting load by means of acontrolled test with the building unoccupied: readthe electricity meter at (say) ten-minute intervalsfirst with lights off, then with lights on.

G Make a point of examining areas which have hada change of use.

G Subject to safety considerations, turn off somelights and see if anyone notices.

G Walk the site at night or during shutdowns to seewhat lights get left on.

G An inexpensive light meter will give enoughaccuracy to establish if lighting is in line with thefollowing ‘adequate’ levels:

Type of use LuxClose detailed work 1,000-2,000

Offices 400

Workshops 300

Stairs and corridors 200

Rest rooms 100

Street lighting 20

Security lighting 5

G Use time-lapse video recording to studyintermittently-occupied spaces.

Potential opportunities

Note: the new Building Regulations compel you totreat replacement lighting systems as if the buildingwere a new one.

G Brief security staff and cleaners to turn off lightswhen leaving unoccupied areas.

G Improve labelling of switches, combined with astaff awareness and motivation campaign.

G Replace lamps with more efficient equivalents(e.g.T12 tubes with T8 tubes if fittings are suitable).

G Convert fluorescent lights to high frequency fittings.

G Fit more switches per bank of lights, if wiring permits.

G Fit automatic lighting controls (carefully chosen to

suit the circumstances) especially in infrequentlyoccupied rooms. Photocells can be used for external lighting.

G Fit more effective reflectors and remove aproportion of lamps.

G In areas where colour rendering is unimportant,use high-pressure sodium discharge lighting.

Further information

G FEB 21 Simple measurements for energyand water efficiency in buildings

G CIBSE Guide F Energy Efficiency in Buildings,

Section 19.6G GPCS 169 Energy efficient lighting in factories

G GPCS 309 Energy efficient lighting inindustrial buildings

G GPG 158 Energy efficiency in lighting for industrial buildings

G GPG 159 Converting to compact fluorescentlighting - a refurbishment guide

G GPG 199 Energy efficient lighting - a guidefor installers

G GPG 272 Lighting for people, energyefficiency and architecture - anoverview of lighting requirementsand design

G CIBSE AM5:1991-Energy Audits and Surveys

G www.lightswitch.co.uk - grants for lightingefficiency improvements for small and medium enterprises

Case histories A cosmetics manufacturer invested £17,000 on automatic lighting

controls. Even with today’s lower electricity prices the project would

have yielded about 20% internal rate of return. A plastics moulding factory refurbished its very inefficient lighting at a

cost of £9,640 and saved £47,750 a year. G P G

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G Interlock local extract ventilation to occupancyand/or activity.

G

Where dampers are used to control air flow rates,consider variable speed control of the fans(or even just two-speed motors) instead.

G Fit high-efficiency motors to fans.

G If excessive ventilation rates are confirmed, reducefan speed by changing pulley ratios.

Further information

G CIBSE Guide F Energy Efficiency in Buildings,Section 19.3

G GPG 257 Energy-efficient mechanical

ventilation systemsG GPG 139 Draught-stripping of existing

doors and windows

Case study

A pigment manufacturer was discharging extract air containing water

vapour and traces of fine powder.A spray condenser, fitted at a cost of

£284,000, recovered the heat and scrubbed the powder from the

extract air.At today’s fuel prices the investment would have realised an

internal rate of return close to 50%.

2.2 VENTILATION

What to look for

G Local extract ventilation likely or able to run whennot required.

G Eroded or fouled fan blades.

G Clogged or obstructed grilles or filters.

G Stuck or overridden dampers.

G Failure to exploit any existing air-recirculationfacilities.

G Inappropriate timeswitch settings.

Survey tips and tricks

G If fans are not visible or audible, air movement canbe detected by various means, includingimprovising with a child’s bubble maker. Thin stripsof tissue paper can be suspended near extractgrilles to provide a more permanent ‘tell-tale’.

G Pay special attention to areas which have had achange of use where the original ventilationrequirements were more demanding.

G To make a rough estimate of air flow into abuilding through an air handling unit (AHU)measure the cross-section of its inlet duct andassume an average air velocity of 1.5 m/s. The AHU

may also carry a rating plate stating its designcapacity. Commissioning test reports may exist.

G In the absence of other evidence, assume air handling plant was designed to prevailing designcodes for the type of use.



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G Isolate boiler capacity in excess of peak requirements,fitting isolation valves if necessary.

G

Fit flue dampers if heat loss from idle boilers cannot beprevented by other means.

G Rectify faults in boiler sequence control if low heatingloads are being shared by more than one boiler.

G Improve control so that boilers are only enabledwhen there is demand from one or more of the circuitsserved.

G On boilers serving space heating on optimumstart control, ensure that there is a separate timingsignal for domestic hot water,which will require a fixedstart time.

G Optimise high/low firing sequences to minimise the

number of ignition purge cycles.

G Apply weather-compensated boiler temperaturecontrol if feasible.

G Fit one condensing boiler to operate as the lead unit or;

G Evaluate a small combined-heat-and-power (CHP)unit to substitute for the lead boiler.

Further information

G CIBSE Applications Manual Condensing Boilers

G CIBSE Guide F Energy Efficiency in Buildings,

Section 19.6G GPG 30 Energy efficient operation of

industrial boilers

G FEB 17 Economic use of coal-fired boiler plant

G FEB 15 Economic use of gas-fired boiler plant

G FEB 14 Economic use of oil-fired boiler plant

G GPG 43 Introduction to large-scale combinedheat and power (revised)

G GPG 115 An environmental guide to small scalecombined heat and power

G GPG 227 How to appraise CHP - a simpleinvestment appraisal methodology

G GPG 226 The operation and maintenance of small scale CHP

Case history

A water company had numerous old cast-iron heating boilers.It conducted

a campaign to improve combustion efficiency through a standard retrofit

modification.The same project at today’s fuel prices would yield

70% internal rate of return.

2.3 BOILERS

Note: this section deals with water-circulation boilers

only, as commonly found on space heating systems. For issues specific to steam boilers, see survey topic sheet12, steam systems.

What to look for

G Damaged or insufficient insulation on boilers andassociated pipework, valves or flanges.

G Check for water losses by assessing the water make up rate (which should be zero: see Surveytips and tricks).

G Check whether multiple boilers are sharing lowloads,when one unit ought to suffice.

G Could boilers be running when there is no demandother than their own standing losses?

G Check if idle boilers are dumping heat up the chimney.

G Is heating-boiler time control dictated by hot-water service preheat time (see Opportunities)?

G See also the section on burners.


G A significant system-water leak will be evident fromthe continual filling of the feed and expansion tanks.

G Low leakage volumes can be detected by suspendinga small weighted container (such as a seasidebucket) under the ball-valve spigot. If subsequentlyfound full, it signifies that the feed-and-expansiontank must have been emptying.

G To assess the degree to which boilers are oversizedand therefore likely to be incurring avoidablestanding losses, observe their firing cycles with astop-watch for about an hour, noting the ignitionand shutdown times for each boiler.

G On space heating boilers, noting the outside air temperature and the observed load factor, it will be

possible to extrapolate to peak demandconditions (say -3°C outside).The alternative is to notehow monthly fuel consumption varies with degree daysand use this to estimate total demand on the peak day.

G To assess whether idle boilers are dumping heat upthe chimney, check for air flow through the boiler, andif confirmed,measure the stack temperature to see if it is elevated (this technique is notalways practical).

G Check water temperature in off-line boilers toconfirm that they are isolated. If feeding a commonflow header, relate common flow temperature toindividual boiler flow temperatures to estimate the

proportion of flow through idle boilers.



G P G


G The rate of heat loss from a building can be estimatedfrom the rate of temperature decay when the heating,lights and equipment are turned off at the end of the day.


G Fit improved heating system controls including possiblyzone isolation.Additional features could include optimumstart and weather compensation.

G Fit de-stratification fans to prevent warm air poolingat high level.

G Fit fast-acting roller shutter doors,or secondary doorsto create an air lock.

G Ventilation fans controlled on indoor air quality(eg CO2 sensing).

G Interlock loading-bay doors with heating.

G Use docking seals around vehicles duringloading/unloading.

G In high-bay buildings, replace convective ‘blown air’heaters with radiant tube or plaque heaters.

G Have the heating system rebalanced to prevent someareas having to be overheated in order to satisfy others.

G Replace electromechanical thermostats with electronicequivalents,which give more precise control.Use theopportunity to locate the thermostats in moreappropriate positions.

G Fit thermostatic radiator valves in rooms which suffer from overheating.

G Fit black-bulb sensors to thermostats in areas served byradiant heaters.

G Where there is occasional out-of-hours working, providean extension timer to avoid having to reset the maintime control.

G Fit a seven-day programmable controller if circumstanceswarrant it.These can be applied not only to heatingsystems but also to mechanical ventilation.

G In mechanically-ventilated buildings, investigate thepossibility of increased recirculation.

G Possibly recover heat from air compressors (for example).

G Implement two-stage frost protection (eg when belowzero outside, start circulation pumps only;boilers not tofire until internal temperature falls below say 5ºC)

Further information


G FEB 7 Degree days

G FEB 3 Economic use of fired space heaters for industry and commerce

G FEB 16 Economic thickness of insulation for existing industrial buildings

G FEB 10 Controls and energy savings

G GPG 132 Heating controls in small commercialand multi residential buildings

G GPG 197 Energy efficient heat distribution

Case study A local authority halved the cost of heating its surveyor’s depot when someonediscovered that a maintenance contractor had left the heating running 24hours a day.

2.4 SPACE HEATING

Note: Survey Guide Sheets 2.2 (Ventilation) and 2.10 (Fansand Pumps) will also be relevant.

What to look for

See also the sections on hot-water boilers or steam-raisingplant, regarding inefficiency and losses in the boiler room.

G Heating outside working hours(whether deliberate or accidental).

G Excessive space temperatures(even if only in localised areas).

G Uncontrolled heat output from distribution pipework.

G Unauthorised supplementary electric heating.

G Circulation pumps running when no heat is required.

G Mechanical ventilation runs (or able to run) when

building is unoccupied.G Irregular or irrational relationship between heating fuel

demand and prevailing weather.

G High ceilinged buildings in which warm air remainsat high level.

G Uncontrolled heat release from uninsulated distributionpipework,or from fan assisted convectors in the ‘idle’ mode.

G Temperature sensors and thermostats situated ininappropriate locations.

G Wrong thermostat type.

G Frost thermostats set too high.

G

Anything which restricts heat output.This includesblocked grilles, obstructed radiators,clogged air filters,and missing air filters which have allowed convector tubes to become fouled.

G Risk of cooling and heating being used simultaneously.

G Doors and windows which require draught proofingor repair.

G Automatic door closers not working.

G Holes in the building, for example under the eaves,through which warm air can escape.

G Walls and ceilings which have inadequate insulation.

G Vehicle access doors which may be left open for long periods.


G Check that monthly fuel demand varies in a rational waywith changing weather (as recorded in publisheddegree day figures).

G To measure temperature at high levels,use a digitalthermometer with a thermocouple on the end of a long pole.

G A 1ºC drop in average space temperature can cut fuelconsumption by about 8%.

G Temporary datalogging can provide valuable evidence.Asa minimum record the inside and outside air temperaturesat ten-minute intervals. In ‘wet’ systems record the boiler

casing or flue temperature to detect when the systemstarts and stops, and the circulation temperature tocheck that heat distribution is appropriately controlled.



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G Discontinue control of relative humidity if possible.

G Consider alternatives to electric evaporative

humidifiers.G Increase air re-circulation.

G Make maximum use of fresh air for cooling,including pre-cooling at night.

G Implement enthalpy control.

G Selectively inhibit out-of-hours ventilation tooptimise energy requirement.

G Provide ‘spot cooling’ systems for zones with year round cooling requirement, so that the maincentral system need only be operated seasonally.

Further information


G GPG 118 Managing energy use - minimisingrunning costs of office equipmentand related air-conditioning

G GPG 290 Ventilation and cooling optionappraisal - a client's guide

G GPG 291 A designer's guide to the optionsfor ventilation and cooling

2.5 AIR CONDITIONING

Note: Survey Guide Sheets 2.2 (Ventilation) and 2.10

(Fans and Pumps) will also be relevant.

Things to look for

G Excessively-low cooling set point (say below 22ºC).

G Lack of time control, excessive hours of operation,or risk of time-schedule being overridden.

G Excessively tight control of relative humidity.

G Blocked filters.

G Uninsulated supply ductwork.

G Portable electric heaters.

G Frost on pipework and fittings.

G Air-recirculation potential not exploited.

G Ventilation outside working hours(other than for free cooling benefit).

G Risk of simultaneous heating and cooling.

G Risk of doors and windows being left open, holesin building structure, or other infiltration routes.

G Risk of air exchange with non-conditioned spaces.

G Fouled evaporator or condenser coils.

G Electrical appliances (e.g. computer monitors)and lighting running unnecessarily.


G Log chiller run hours regularly to detect runningduring cool weather.

G Observe operating patterns of air conditioningchillers, cooling towers, etc., relative to outsideconditions; look for excessive running or frequenton/off cycling.

G Compare refrigerant suction/dischargetemperatures and condenser water temperatures

on similar plant items. Significant differences maypoint to physical problems or incorrect settings.




G If a hot water cylinder is fed from its own break tank you may be able to estimate the draw-off rate by shutting off the rising cold feed and timing

the fall in water level.

G Clamp-on ultrasonic flow meters can be hired butare very prone to error and should be calibrated insitu, at least approximately.

G When measuring hot water flow, remember toaccount for secondary recirculation if necessary.

G Run a hot tap which has not been used for a whileand time how long it takes to deliver hot water.

G Establish the number of full-time-equivalentoccupants and how they use hot water, in order to estimate their requirements.


G Fit point-of-use water heaters in order to dispensewith central storage and long distribution runs.These may be wall-mounted electric types inwashrooms, or direct gas fired for catering andother larger users.

G Fit flow restrictors to wash hand basins.

G Fit time control to point-of-use heaters,immersion-heater elements, and secondarycirculation pumps.

G If HW is generated from main heating boilers,consider alternative heat source for use outsideheating season.

G If central HW generation is to be retained look for alternative heat sources such as hot process drains(beware contamination risk), flash steam or hot condensate.

G Rationalise multiple storage cylinders if demand islow relative to stored volumes.

G Recover heat from water-cooled equipmentand processes.

Further information

G GPG 188 Maintaining the efficient operationof heating and hot water systems aguide for managers

G P G


2.6 HOT WATER SERVICES

What to look for

G Summer immersion heaters runningsimultaneously with boilers, or at risk of doing so.

G Long runs of uninsulated hot water pipework.

G Hot taps being allowed to run to overflow.

G Hot water being used where cold water would suffice.

G Poor insulation on hot water storage vessels.

G Excessive temperatures at hot taps(unless essential for control of legionella).

G Unreasonable quantities of hot water being used

(see Survey tips and tricks).



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2.7 COMPRESSED AIR SERVICES

Things to look for

G Air leaks; particularly on connectors, flanges, andflexible hoses.

G Are compressors running when there is no demandfor air?

G Air intakes drawing in warmer air than necessary.Use the coldest possible air source to maximisecompressor efficiency.

G Inappropriate uses. Low-grade duties (like swarf blowing, or agitating liquids in tanks) do not warrantclean, dry, air from the central system. See ‘Potentialopportunities’.

G Excessive distribution pressure. Higher pressuremeans greater losses through leaks and higher power

requirement for the same delivered air volume.G Dead legs on distribution pipework.These present a

leakage risk.

G Safety valves operating frequently, or leakingcontinuously.

G Manual drains left cracked open.


G Look and listen.Are air-pressure safety valvesoperating? If so, control is inadequate.Can you hear air escaping during meal breaks and after hours?Are compressors starting and stopping frequently?

G If the compressors have hours-run meters, read them

all at intervals through the day to see whether youhave more units running than necessary.

G Compare on-load hours against total run hours tocheck for idle running.

G If the air supply is metered, read regularly throughthe day to establish patterns of use relative toproduction activity. Look for unexplained idle losses.

G Air meters can be unreliable. If a meter provides achart recording, look for symptoms such as the tracebeing unexpectedly smooth, clipped off at maximum,or never returning to zero.

G After hours, shut off the compressors and either (a)record the rate at which pressure subsequently falls

or (b) time the load/unload periods.G A ten-percent air loss might be considered acceptable.

G Power delivered to air tools is ten times the cost of electricity to do the same job.

G Reducing air inlet temperature by 6ºC increasesoutput by 2%

G Ask how often the filters are replaced. Blocked filterscause pressure drop.


G Use low-pressure blowers for applications such as air knives, air lances,air agitation, blow guns, productejection, powder transfer, etc.

G Control pressure at the point of critical demand, notnecessarily at the compressor.

G Divert compressor cooling air to where heat isrequired. Look for a nearby application which could

benefit from air preheat. Even preheating boiler combustion air is beneficial.

G Heat rejected from oil coolers can assist hotwater generation.

G Fit improved control of central compressors.Computerised sequence controls could reducecompressor run hours and prevent air loss andwasted power through pressure overshoot.

G Fit zone-isolation valves.These can be under timecontrol, or interlocked to the packing/production lineserved, to enable parts of the site to operate out of hours without air going to the whole works. If combined with a pressure gauge, local leakage testswould be possible.

G To permit zone isolation it may be necessary torationalise air supply lines to eliminate cross-feedsbetween different production units.

G Install local air blowers for low-grade duties, for example, liquid agitation, where low pressure andhigh volumes of air are required without drying or filtering. A separate blower reduces demand on thecentral system and may permit a pressure reductionor reduced operating hours.

G Substitute alternatives for air tools.Would theoperators prefer electric tools (especially cordlessones) capable of doing the same job? This is mostbeneficial where a whole zone of air supply canbe cut out. But note: cordless tools are attractive

targets for theft.G When production is shut down, isolate constant

bleed pneumatic controls.

G Use actuators to time blowers instead of constantair flow.

G Use specially-designed nozzles for blowing applications.

G Replace timed receiver drains with water-sensingor float traps.

G Switch to high-performance lubricants.

G Consider high-efficiency motors and variable-speeddrives. See the Survey Guide Sheet 2.9 on Motorsand Drives.

Further information

G FEB 4 Compressed air and energy use

G GPG 126 Compressing air costs

G GPG 216 Energy saving in the filtration anddrying of compressed air

G GPG 241 Energy savings in the selection;control and maintenance of air compressors

Case history

In 1991 a vehicle manufacturer spent £32,000 on an automatic

sequence control of its air compressors. Although electricity was then

more expensive in real terms, the same project today would still yield aninternal rate of return of 70%.



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G Install variable-speed drive controls on vacuummanifold pressure.

G

Consider refrigeration circuits for liquid-ringwater cooling.

G Replace vacuum-pump motors with highefficiency equivalents.

G Upgrade complete vacuum pump sets with moreefficient units during replacement.

G Where vacuum is provided for local cleaning of components and assemblies at workbenches,alternative methods (e.g. dedicated local systemsor even brushes and pans) may be feasible (butconsult the user).

G Increase system working pressure.

Further information

G GPG 83 Energy efficient liquid ringvacuum pump installations inthe paper industry

G GPCS 127 Cooling and recirculating liquidring sealing water

2.8 CENTRAL VACUUM SERVICES

What to look for

G Air getting in through leaks.

G Ineffective closure flaps on vacuum hoses.

G Oversized nozzles on hoses.

G Redundant legs of vacuum pipework.

G Manual on/off control, with risk of out-of-hoursrunning.

G Seal water running to drain from liquid-ringvacuum pumps.


Run vacuum pumps against shut-off conditions, andmeasure air flow in the outlet duct.This equates toupstream air in-leakage. Measure vacuum at inletmanifold under these conditions and compare withmanufacturer’s load curve. Low vacuum at themeasured flowrate indicates loss of pump efficiency.

If necessary a manometer for low pressuredifferentials can be improvised from a length of transparent tubing bent into a ‘U’with water in thebottom, but beware any risk of water getting into themeasured system

Repeat these measurements at appropriate intervals

(quarterly or annually) depending upon the degreeof risk.



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2.9 ELECTRIC MOTORS AND DRIVES

Things to look for

G Driven equipment not doing a useful job.

G Oversized motors.

G Risk of unnecessary running.

G Voltage imbalance, low or high voltages, harmonicdistortion or poor power factor.

G Unusually hot or noisy gearboxes.

G Worn or slack V-belts.

G Individual belt broken on multi-belt drive.

G Misaligned pulleys or couplings.

G Worn bearings in motors, driven equipment,or intermediate drive train.


G Start with the largest motors and longest runninghours first.

G Pay particular attention to the noisiest machines.

G 3-phase motor power is derived from theammeter reading (I) by the following formula,where V is the supply voltage and PF is the power factor (typically 0.8 - 0.9)

Power = √3 x V x I x PF (kW)1000

Compare the result with the motor’s nameplaterating to see if it is only part-loaded.

G Thermal imaging equipment can help pinpointfrictional transmission losses.


G Introduce time switching.

G Fit automatic stop/start control(this might include motor load sensing).

G Substitute a high-efficiency motor whenreplacement is necessary.

G Consider soft-start controllers for intermittentrunning motors.

G Reduce losses in the driven equipment.

G Change pulley ratios to run driven equipmentat optimum speed.

G If permanently lightly-loaded, switch topermanent star connection or fit a smaller motor.

G On a part-loaded multi-belt drive, remove one or more belts to leave only the minimum required for the power actually being transmitted.

G Consider variable speed drive or multi-speed

motor depending on the circumstances.

G Where the duty toggles between high and lowload, consider replacement with a multi-speedmotor (up to four load steps may beaccommodated by MSM).

G When V-belt pulleys need replacing opt for wedgebelts (2% improvement) or synchronous, flat, or ribbed belts (5-6% improvement).

G Where possible replace gearboxes with variablespeed direct drives.

G Adopt high-performance lubricants.

Further information

G GPG 2 Energy savings with motorsand drives

G GPCS 215 Automatic switch-off of power presses

G GPCS 219 Two-speed motors onventilation fans

G GPCS 337 Low cost speed reduction bychanging pulley size

G

GPCS 170 Variable speed drives in achemical plant

G GPCS 222 Purchasing policy for higher efficiency motors

G GIL 56 Energy savings from motor management policies

Case history

Changes at a food manufacturer had left them with excessive capacity

on a pneumatic conveying system.They spent £58 on a new pulley for

the blower (to reduce its speed from 2,420 to 1,700 rpm) and claimed

annual savings of £4,960.



G P G


Further information

G GPG 2 Energy savings with motors and drives

G GPG 14 Retrofitting AC variable speed drives

G GPCS 88 Variable speed drives on water pumpsG GPCS 124 Variable speed drives on secondary

refrigeration pumps

G GPCS 170 Variable speed drives in achemical plant


G GPCS 219 Two-speed motors onventilation fans


G GPCS 232 Variable speed drives for wood dustextract fans

G GPCS 300 Energy savings by reducing the sizeof a pump impeller

G GPCS 337 Low cost speed reduction bychanging pulley size

Case history

An airport operator fitted variable-speed drives to chilled-water

circulating pumps in 1990, achieving payback of a £50,000 investment

in just under two years. Even at today’s lower real electricity prices,

payback would still be less than three years,with an internal rate of return approaching 30%.

2.10 FANS AND PUMPS

What to look for

G Unintended recirculation paths.

G Oversized motors.

G Excessive fan/pump speed.

G Excessive system resistance (for example becauseof dirty filters, stuck valves or dampers).

G Unbalanced distribution networks with excessiveflow in some branches at the expense of othersbeing starved of flow.


G Measure the flow and inlet/outlet pressures.Compare them not only with manufacturer’s databut with system design intent.

G Air movement can be detected with tissue paper,a smoke generator, or even a child’s bubble maker.

G Compare the performance of identical duty andstandby units.


G Where fans and pumps have variable duties(controlled by dampers or valves), variable speed

drives should be considered as an option.G Inlet dampers are preferable to discharge dampers.

G Where fans or pumps are operating continuallyat part load, consider reducing the impeller size or changing the speed by using a different drive ratio.

G Avoid sharp bends in ducts or pipework andconsider low-friction pipework when refitting.

G On a pumped distribution network, reduce generalsupply pressure and use a small booster pump for the index circuit.

G Rebalance any distribution system in which

throttling valves or dampers are being used toregulate flow, so as to achieve design flow in allbranches with the minimum total flow.

G On primary heating and chilling systems, replacethree-port diverting valves with two-port valvesand use variable-speed control of pumps toregulate pressure.



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2.11 BURNERS

Things to look for

G Poor burner tuning resulting in flue losses throughexcess air or unburned fuel (evidence by yellowflame, soot in flue-ways, etc.).

G Unusual-shaped or unstable flame.

G Flame impingement.

G No probe-hole in exhaust flue, making combustiontests impossible.

G Results from earlier combustion tests chalkedup nearby.

G Combustion results identical from one testto another.

G Combustion test reports where the reportedefficiency is inconsistent with measured parameters.


G If testing for combustion efficiency by means of CO2 percentage, remember to test for smoke(in the case of oil and solid fuel) and carbonmonoxide (in the case of gas).Without thesemeasures it is impossible to say whether a givenpercentage of CO2 represents lean or richcombustion; a rich mixture will cause losses

in unburned fuel.G Compare similar units. Is one appreciably better

than the others?

G Where several items of combustion plant dischargeinto a common flue, beware the effects of variablesuction. Record draught-gauge measurements.

G With pressure-jet oil burners, ask when the nozzleswere last cleaned or replaced. It is ofteneconomical to replace them at every service;whereas ‘cleaning’ usually damages them.

G Look for hot spots on casings(may indicate impingement or refractory damage).

G Time on/off/purge cycles.


G Locate a source of preheated combustion air, suchas the exhaust from a dryer or other waste heat,or even just ducting from the roof space. But note:

if preheat is not consistent, this can cause theair:fuel ratio to vary.

G Consider direct recuperation.

G Reduce burner ratings to reduce stack exittemperature and minimise on-off cycling;or consider high/low or modulating burners.

G Use a larger number of smaller, self-proportioningburners.

G Improve combustion control; consider oxygen-trim control.

G Pressure-regulation of combustion chambers

enables tighter adjustment of air:fuel ratio.

G In some high-temperature furnace applications,using pure oxygen instead of air can beeconomical and may for example give a hotter flame or better product quality.

Further information

G GPCS 356 Conflict control of a combustion air fan on a large continuous furnace

G GPG 252 Burners and their controls

G GPCS 35 Variable speed drives on a boiler fan

G GPCS 125 Variable speed drive on a batchfurnace combustion air fan

Case history

In 1993 an engineering works installed recuperative burners,

improved burner control, and fitted low-thermal-mass insulation to

a heat treatment furnace. £21,000 investment was recovered in

1.5 years and the indicative internal rate of return at current fuel prices

is just under 50%.



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2.12 STEAM SYSTEMS

Things to look for

G Steam leaks.

G Missing, wet or damaged insulation.

G Flooding in pipe ducts.

G Steam traps passing steam.

G Steam traps not passing condensate.

G Condensate running to waste.

G Flash steam being lost from receivers and hotwell.

G Dead lengths of pipework, or long runs of pipework with very small users at the end.

G Potential water pockets caused by concentricreducers, large globe valves or wrongly-fitted strainers.

G Group trapping (several heat exchangers sharingone trap).

G Bypass valves on traps (not strictly necessaryand may be left cracked open).

G Manual temperature control of process items.

G Condensate overflowing to waste atcollecting points.

G Pipework which does not have a fall towards

drain pockets.

G Low feed tank temperature.

G Manual control of dissolved solids.

G Unnecessarily-low total dissolved solids.

G Insufficient reserve volume in feed tank to accommodate peak condensate returnduring start-up.


G Ask the boilerman about the frequency and

quality of maintenance.G Steam traps may be fitted with sight glasses or

‘Spiratec’ devices to verify operation.

G Thermodynamic traps may be heard opening andclosing frequently.



G It may be possible to divert condensatetemporarily downstream of the trap, into a bucketor barrel. Note the volume or weight at intervals,asa means of estimating steam demand.

The weighing vessel must contain cold water because of the potential hazard of flash steamfrom the condensate.

G If condensate is pumped from a receiver of knownvolume, intermittently, timing the pumping cycleswill provide a load estimate.

G Check the temperature of condensate pipework after each trap. If significantly below 100°C, thetrap is not working.

G Put a temperature logger on blowdown pipework to record timing and duration of blowdown.

G Estimate the percentage of condensate returnedto the boiler.

G Ineffective insulation in underground ducts canmanifest itself through the ground drying unusuallyquickly after rain, frost clearing sooner, etc.


G Consider dispensing with steam and adoptingalternative heating techniques.

G Rationalise pipework to reduce distances travelled(and reduce diameters where feasible).

G

Make alternative provision for small loads at theends of long dedicated pipe runs (or relocate them).

G Insulate fittings.

G Find a use for flash steam (e.g. sparging it intothe feedwater tank or cascading to lower-pressureusers) or use condensate coolers on calorifiersand heater batteries where feasible.

G Fit thermostatic air vents to reduce warmingthrough times.

G Measure warming-up time to establishthe minimun necessary

G Eliminate bypass valves on steam traps and if necessary fit better-matched traps.

G Fit automatic temperature controls in placeof manual valves.

G Use an engine or turbine for pressure reduction.

G Reduce steam pressure if possible, to giveimproved performance and less flash-steam loss.

G Recover heat from boiler blowdown.

G Implement automatic TDS control on boilers.

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G Reduce boiler pressure.

G Put a lid on the feed tank.

G Increase feed temperature to aid oxygen removal,

reduce dosing requirements andresultant blowdown.

G Where steam is exclusively used at high pressureand there is no use for flash steam, consider usingCBA pumps in a pressurised condensate returnloop directly injected into the boiler feedwater (see GPCS 153 under ‘Further information’).

G If condensate is all dumped because of potentialcontamination risk, fit automatic qualitymeasurement to control a diverting valve andrecover what is safe to reuse.

Further informationG ECG 66 Steam generation costs

G ECG 67 Steam distribution costs

G FEB 2 Steam

G GPCS153 Differential drainage and boiler return system

G GPG 18 Reducing consumption costs bysteam metering

G GPG 30 Energy efficient operation of industrial boilers

G GPG 197 Energy efficient heat distribution

Case histories

A tyre manufacturer installed flash steam recovery and improved

condensate collection,cutting boiler make-up from 70% to 10%. The

project cost £20,000 and (including the incidental savings on boiler

make-up water and chemicals) would yield an internal rate of return

exceeding 100% at today’s fuel prices.

A chemical company spent £21,000 insulating pipe fittings in 1994,

achieving a nine-month payback period (equivalent to an internal rate

of return of 170% at today’s values).

A food ingredients manufacturer noticed that a fluidised-bed spray

dryer was the only unit needing steam overnight.They fitted a standby electric air heater for overnight use, and proceeded to recover the

£1,350 installation cost eight times a year.



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2.13 CRUSHING AND GRINDING

Things to look for

G Mill speeds higher than necessary; continuousrunning at lower speed and throughput is moreefficient than intermittent operation at highspeed.

G Crushing techniques used on too small particles,or grinding used on oversized particles(30 mm is the approximate energy-efficientparticle size to change from crushing to grinding).

G Continuous stop/start operation because of downstream operations.


G Examine how size sampling is carried out.

G Question the method of control.


See also Survey Topic Guide 2.23, mechanical handling.

G Convert open to closed-circuit milling withefficient size separation.

G Fit higher-efficiency separators(on ball or roller mills).

G

Replace ball mills with roller-based systems if feed conditions permit; or use roller mill for pre-grinding.

G Optimise mill internals, feed/discharge system,and milling parameters such as speed and air flow.

G Use buffer store if downstream operations imposestop/start regime.

G Fit variable speed drives, especially on fans.

G Use soft start on main motors.

G Improve instrumentation and control(for example using laser fineness sensors).

G Use grinding aids if product conditions permit,especially if increased throughput is required.

Further information

G GPG 181 Energy efficient crushing andgrinding systems

G GPG 212 Reducing energy costs inflour milling



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2.14 MIXING AND BLENDING

What to look for

G Manual control of batch blending operation withinadequate end-point detection.

G Unnecessarily long mixing times.

G Lax ingredient control.

G Blade wear (increases mixing time).

G Inadequate insulation on mixing vessels.

G Use of compressed air to agitate mixtures.


G Record mixing times and look for suspiciousinconsistencies.

G Question the nature and frequency of end-point tests.

G Try to identify physical properties which could beused to determine completeness.


G Convert to low-loss stirrers.

G Fit high efficiency motors.

G Optimise stirring speed.

G Improve end-point detection and control.

G Use soft start motor control.

G Consider intermittent rather thancontinuous mixing.

G Convert batch mixing processes to continuous.

Further information

G ECG 20 Rubber compounding in therubber processing industry

G GIL 53 Optimising energy use in pulpers

and refiners

Case history

A manufacturer of rubber seals put a soft-start motor controller on a

100 kW mixing mill motor which was operating four minutes on, six

minutes off.The £1,600 investment (1990 prices) was paid back twice

in the first year.



G Two-stage drying may be more economical when theproduct contains both large and small particles.

G Investigate whether the output dryness specificationcan be relaxed.

G Are you drying product to stabilise for storage pendingsubsequent processes which add water? If so, canstorage be eliminated?

G Mechanical de-watering of powders (and subsequentdrying) can both be accelerated by reducing theproportion of fines.

G Where product is conveyed on perforated beltsor trays, reduce the blank supporting area under the product.

G Increase air velocity over the product.

G Subdivide or granulate the product.

G In direct-fired dryers,if dilution air is introduced beforethe combustion zone,mix it after the combustion zoneinstead to avoid flame chilling.

G Cascade chamber dryers from dry throughintermediate to wet,reheating as required toavoid condensation.

G Reduce supply air temperatures over weekend closuresif full of partially-dry product.

G On major processes use mechanical vapour recompression to recover exhaust heat.

G Consider matching CHP to a continuousdrying system.

Further information

G GPG 66 Rotary drying in the chemical industry

G GPG 149 Rotary drying in the food and drink industry (page 18 shows a method for calculating rough gas balances)

G GPG 185 Spray drying

G GPG 243 Drying of particulate solids - surveyfinding and auditing guide

G GPG 248 Energy efficient operation of dryers inthe ceramics industries

G GPG 343 Model-based predictivecontrol systems

Case histories

A chinaware manufacturer dispensed with ‘open-shop’drying in favour of amicrowave/vacuum dryer costing £562,500.The investment would have

yielded an estimated 45% internal rate of return at today’s prices.

A major sugar factory implemented model-based predictive control of dryers in 1996.The project gave energy savings,increased yield,and qualityimprovements which at today’s fuel prices equate to an internal rate of return of 120%.

An animal-feed producer eliminated some dryers completely by rebrandingthe product and selling it undried.

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2.15 DRYING

What to look for

G Product over-dried.

G Manual control of end-point at operators’discretion.

G Raw material moisture higher than necessary,for example because of damp storage conditions.

G Excess airflow into dryers.

G Hot external surfaces on dryers (missing insulation).

G Dryers actually running empty,or able to do so.

G Air filters clogged or ripped.

G Air leaks into or out of the dryer.

G Airflow imbalance on multiple tunnel dryers

(evidenced by wet or overdried product fromdifferent driers).


G In direct-fired dryers, variations in exhaust oxygencontent will indicate the degree of dilution byair ingress.

G Measure the moisture content of the dried productas it enters the next process stage,especially if itgoes through a buffer store. Drying below this‘natural regain’moisture level is pointless.

G Measure the energy input per kg of water evaporated.

Compare this against dryer manufacturer’s data sheets,or one dryer against another.

G Repeat the measurement from time to time to guardagainst future deterioration in performance.

G In theory a perfectly efficient dryer would require only0.63 kWh of input energy per kg of water removed.


G Prevent accidental moisture gains to feedstock.

G Mechanical de-watering (pressing, centrifuging, etc.)can reduce the need for thermal drying.

G Preheating the feedstock may aid drying.G Avoid high air supply temperatures and use more air

if necessary.

G Insulate dryer casings to reduce heat loss.

G Fit recirculation fans to improve internal velocities,reduce dead spots,and maximise relative humidityin exhaust.

G Recover heat from exhaust air. If contaminated bydust,etc., consider use as preheated combustion air.

G Control dryer end-point automatically, for exampleon exhaust relative humidity.



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2.16 BAKING AND CURING

Things to look for

G Part-loaded ovens or autoclaves.

G Excessive equipment preheat times.

G Oven doors left open longer than necessary.

G Air ingress especially at seals, sightholes,access panels.

G Potential useful heat gains to surrounding space.

G Plant in unnecessarily cold or exposed location.

G Incorrect damper settings.

G Excessive exhaust volumes.


G Use a datalogger to record local air temperatureabove oven doors.


G Optimise loading schedules to operate equipmentfor shorter periods at full capacity.

G Use combined heat and power.

G Review supply options, eg, substitute gas for steamor radiant tube; electric radiant; microwave;

gas radiant, etc.G Fit curtains to tunnel-oven entrances.

Further information

G GPG 271 Selecting and specifying new paintcuring and stoving ovens

G GPCS 387 Energy savings from optimisedoperation of painting andcuring lines

G GPG 309 Energy savings in industrialbakeries

Case study An aerospace components manufacturer operated a large autoclave for

curing resin-bonded components in relatively small batches. By

rescheduling operations to run it fully loaded, they not only reduced

energy costs, but cut 70% off their nitrogen demand.



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2.17 MACHINING, FORMING,ANDFABRICATION

What to look for

G Auxiliaries such as hydraulic packs, coolant pumps,waste removal, etc., running on idle machines.

G Hydraulics, compressors, chillers and other services or auxiliaries able to run when mainmachine is idle.

G Uninsulated cooling systems.

G Dirty skylights.

G Blunt tooling.

G Open or slow-acting vehicle access doors.

G Incorrect temperature settings on productcooling or baking.

G Worn extruder screw surfaces.

See also Survey Guide Sheets 2.1 (Lighting),2.7 (Compressed air), 2.8 (Central vacuum),2.18 (Treatment booths/cabinets)


G Fit run-hours meters (if not already present)and reconcile running hours of auxiliariesagainst work schedules.

G Compare similar machines and use the fastestor most efficient as the benchmark.

G Canvass the views of machine operators.

G Observe operations during meal breaks andother quiet periods.


G Interlock auxiliaries to the main machineswhich they serve.

G Use machines with lowest specific energy

consumption.G Fit high-efficiency motors when replacing

failed ones.

G Replace centralised heat supply with locallycontrolled gas radiant heaters.

G Fit power-factor correction capacitors if necessary.

G Implement zoning and variable speed pumpson central cutting-fluid systems.

G Recover waste lubricating oil for use asheating fuel.

G Fit quick-acting doors for vehicle access.

G Redecorate in lighter shades for improvedillumination.

G Fit destratification fans in high-bay buildings.G Insulate barrels of plastics extrusion presses.

G Change to near-final-size castings.

G Variable-speed AC drives to replace failedDC drives (for example on filament or filmuptake drives).

G Variable-speed drives on hydraulic packs to limitpressure or spill-back when off load.

G Optimise source of compressed air for blowing(eg poly bottles).

G Soft-start motor controllers.

G Additives to assist flow of polymers.

G Improved lubrication.

Further information

G GPG 48 Reducing electricity use ininjection moulding

G GPG 92 Reducing electricity use inextrusion-blow moulding of thermoplastic

G GPG 239 Energy efficient thermoplastics

extrusionG GPG 292 Energy in plastics processing –

a practical guide


Case histories

A company making metal pressings spent £630 on controls which

automatically turned off motors on presses which had been idle for a

preset period. At today’s prices the project would have yielded close

to 100% internal rate of return.

An injection moulding company put heat shields around heated press platens at a cost of £2,000. At today’s prices this project’s internal rate

of return would have been about 200%.

Another injection moulding company spent £500 in the early 1990’s

on timers to turn off the heaters on idle presses.They recouped their

investment once a month thereafter.



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2.18 TANKS AND VATS

Things to look for

G Tanks preheated for excessive periods.

G Tanks heated while not in use.

G Lack of insulation (including associated pipelines).

G Lack of lids on tanks.

G Oversized tanks or levels higher than needed.

G Excessive extract air velocities over exposed liquidsurfaces.

G Continuous uncontrolled top-up and overflowor run to waste.

G Excessive or unwarranted agitation.

G Agitation by compressed air from a high-qualitycentral source.

G Tank contents boiling when 95°C wouldbe effective.

G Steam blowing through directly-heatedtank contents.

G Local ventilation extract drawing air fromgeneral heated space.


G On vessels open to atmosphere, look for temperature controls set at 100°C(impossible to achieve without risk of boiling).

G Assess tank leakage by observing how the fluidlevel falls when not topping up.


G Reduce temperature if only being maintainedto assist drainage from treated parts; consider alternative methods of accelerating drainage

if necessary.

G Use lids or ball blankets to reduce heat lossand evaporation.

G Local fresh air supply duct to conserve heatedair in surrounding space.

G Use contra-flow arrangement for sequentialrinsing tanks.

G Where there are steam coils and condensateis dumped because of contamination risk,consider direct steam injection via sparge pipe.

G Consider switching to direct gas firing

where appropriate.

G Maintain lowest possible tank level.

G Insulate sides and bottoms of tanks.

G Recover heat from effluent fluid.

Further information

G FEB 19 Process plant insulation andfuel efficiency

G GPCS 133 External spray insulation onfurnace regenerators

G GPCS 30 Heat recovery fromcontaminated effluent

G NPCS 122 Reducing tank evaporativelosses using hexagonal floats

Case histories

A supplier of colours,glazes and clays to the pottery industry added

microprocessor control to reduce unnecessary stirring of agitator tanks.

Although the project cost £56,000 in 1985,it achieved a 1.3 year

payback and even at today’s lower real electricity prices it would give

an internal rate of return of 45%.

A manufacturer of decorative tiles went further and switched off

agitation of glaze tanks completely outside working hours, saving

£16,000 a year without prejudicing quality, and achieving 100% IRR.

A maker of metal tubing used floating hexagonal polypropylene shapes

to insulate the fluid surfaces of treatment tanks. For an investment of

£2,500 he saved an estimated £4,000 a year, giving an internal rate of

return of the order of 1,000%.



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2.19 TREATMENT BOOTHSAND CABINETS

Things to look for

G Lighting or air extract running, or able to run, whennot required (Note: containment booths need torun continuously).

G General ventilation relied on where local extractcould be applied.

G Local extract systems drawing heated air fromsurrounding space.

G Inadequate insulation if heated or cooled.

G Defective seals where airtightness is needed.

G Common air extract from multiple cabinets.G Unnecessarily high air extraction rates.


G Use smoke generator or strips of tissue to track air movement.

G Use the site’s list of local extract ventilation (LEV)equipment as a checklist.

G Observe pattern of use, especially during breaks.


G Arrange air extract and cabinet lighting to run ondemand, with automatic switch-off.

G Recover exhaust heat.

G Arrange dedicated extract for lightly-usedcabinets.

G Install dedicated fresh air supply ducts to avoiddrawing in heated air.

G Implement reduced or variable fan speed.

G Fit more-efficient fans.

Further information

G GPG 303 The designer’s guide to energyefficient industrial buildings



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2.20 HIGH TEMPERATURE PROCESSES

Things to look for

Note: see also Survey Guide Sheet 2.11 (Burners)

G Evidence of unnecessarily long preheat periods.

G Unnecessarily high processing temperatures.

G Extended holding periods at high temperature(for example while awaiting results of chemicalanalysis on product).

G Batch process plant maintained at temperaturebetween charges.

G Batch oven/furnace doors left open for longer than necessary.

G Evidence on external casing of hot gas leakage.G Product allowed to pick up moisture between

dryer and kiln.


G A thermocouple on the end of a pole can be usedto check surface temperatures on large plant.

G Use infra-red thermography to detect hot spots.

G Compare actual energy ratio per tonne withtheoretical requirement based on specific heatsand temperature rise.


G Maximise hearth loading.

G Automatic pressure control of furnaces permitstighter control of combustion efficiency.

G Reduce furnace temperatures if excessive.

G If heavy refractory lining is used in an intermittentfurnace, replace inner face with a ceramic-fibreinsulation blanket or tiles.

G Move stock into heated space if stored outside;

preheat further if suitable waste heat sourcesare available.

G Where parts need to be reheated for successiveoperations, use insulated transit containers.

G Fit permeable radiation walls in furnaces.

G Recover heat from exhaust.

G Reduce the mass of refractory furniture intunnel kilns.

G Optimise speed of kilning.

G Use direct gas firing if possible on furnaces withradiant tubes, or electric induction for metalheating or melting.

G Reduce air ingress into tunnel kilns using

end doors.

G Ensure sand traps create an effective seal.

G Subject to product requirements, aim for lowestoxygen content at exhaust.

G Use hot-gas recirculation to reduce temperaturestratification and promote heat transfer to product.

G Transfer clay goods direct to kiln from dryer toavoid moisture pickup.

Further information

G GPG 50 Efficient operation of corelessinduction furnaces

G GPG 77 Continuous steel reheatingfurnaces: operation andmaintenance

G GPG 164 Energy efficient operation of kilnsin the ceramic industries

G GPG 244 The use of low thermal massmaterials and systems in theceramic industries

G

GPG 252 Burners and their controlsG GPG 253 A manager’s guide to optimising

furnace performance

G GPG 255 Electroheating in industry:making the right choice

G GPCS 135 Furnace scheduling advisorysystem

G GPCS 160 Expert system improvesperformance of PLC controlled plant

Case histories

A forge installed a fluid-bed furnace for heating bar ends, replacinga less efficient conventional furnace.Their investment of £45,000 in

1984 offered a payback every 8 months, which translates into an

internal rate of return of 70% (in today’s terms).

A glass container manufacturer installed recuperative heat recovery

at a cost of £16,000, giving a present-day internal rate of

return exceeding 80%.



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Further information

G GPG 38 Commercial refrigeration plant:energy efficient installation

G

GPG 42 Industrial refrigeration plant:energy efficient operationand maintenance

G GPG 44 Industrial refrigeration plant:energy efficient design

G GPG 59 Energy efficient selectionand operation of refrigerationcompressors

G GPG 225 Industrial cooling water systems

G GPG 256 An introduction to absorptioncooling

G GPG 278 Purchasing efficient refrigeration –the value for money option

G GPG 279 Running refrigeration plantefficiently – a cost saving guidefor owners

G GPG 280 Energy efficient refrigerationtechnology – the fundamentals

G GPG 283 Designing energy efficientrefrigeration plant

G CG 7 Energy efficient cooling water systems in chemicals manufacture

G FEB 11 The economic use of refrigerationplant

G GIL 52 The engine of the refrigerationsystem: selecting and runningcompressors for maximumefficiency

G GPCS 301 Use of larger condensers toImprove refrigeration efficiency

G GPCS 302 Improving refrigerationperformance using electronicexpansion valves

Case history

An acid manufacturer installed heat recovery on an exothermic

process at a cost of £51,000.The equivalent internal rate of return

in today’s terms would be 10%.

2.21 COOLING SYSTEMS

What to look for

G Fouling of cooling tower.

G Uninsulated pipework and fittings.

G Excessively low chilling medium temperatures.

G For an air-cooled condenser, check for short-circuitair path to evaporator inlet.

G Air bypass or recirculation in cooling towers.

G Fouled coils, air filters, air inlet screens or coolingtower spray nozzles.

G Excessive cooling water flow rate and hencepumping power.

G Abnormal temperatures or pressures inrefrigeration circuit; avoid low evaporatingtemperatures.

G Multiple cooling towers with more units runningthan necessary.


G The temperature efficiency of a water cooledcondenser can be checked against themanufacturer’s specification.

G Measure refrigerant liquid temperature upstream

and downstream of the strainer.A high differentialimplies clogging.

G Excessive cooling water flow rate can be inferredfrom lower-than-expected temperature rise.


G Inhibit chillers below a certain ambienttemperature, or exploit other free cooling potential.

G Satisfy localised winter cooling demandwith dedicated package chillers instead of a central system.

G Fit a chiller load management system.

G Raise the chilled water temperature to itsfeasible limit.

G Where duty is shared by diverse chillers,optimise by letting the best take the lead.

G Use thermal storage to smooth the loadprofile, reduce start/stop cycling, maximiseuse of most efficient chiller, and possibly standdown excess capacity.

G Buy in liquid nitrogen rather than generating on site.



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2.22 HEAT RECOVERY

Note: heat recovery is itself sometimes an

opportunity.These points concern opportunities toimprove existing heat-recovery installations.

Things to look for

G Fouled heat exchangers.

G Fans fouled, worn, or even stopped.

G In air re-circulation systems verify operationof control dampers.

G Incorrect configuration or control of batchheat reclaim.

G Lost fluid or failed pumps in run-aroundcoil system.

G Dumping of heat because of mismatchedsources and loads.


G Check temperature differentials againstmanufacturer’s specification or originaldesign intent.

G Compare temperature efficiencies of similar units.

G Note the temperature and heat content of

the high-temperature stream at outlet, in casethere is potential for further heat recovery.


G On HVAC, inhibit heat recovery between 16-24°Cto prevent heat gain to chiller plant.

G Consider variable-speed drives on fans and pumps.

G Fit thermal storage to improve utilisation whereheat is being dumped because of mismatchedsupply and demand profiles.

Further information

G GPG 13 Guidance notes for theimplementation of heat recoveryfrom high temperature waste

streams

G GPG 242 Process integration

G GPG 89 Guide to compact heat exchangers

G GPCS 355 The use of pinch technology in afood processing factory

G GPG 141 Waste heat recovery in theprocess industries

G VI004 Low temperature heat recovery

Case histories

An animal-feed producer had bypassed a heat recovery unit because it was fouled and thought to be beyond repair.An enterprising employee

devised a method of unblocking it, which was done at a cost of £1,000

including equipment hire. Once recommissioned, it resumed saving

£30,000 a year.

A dairy ran into a constraint on increasing output because it appeared

to be short of chiller capacity for cooling the milk output from its

pasteurisers.However,on investigation, it was found that the

pasteuriser’s regenerator was performing well below industry norms.

The regenerator partly cools the milk output by exchanging heat with

the cold input stream. By improving the regenerator heat exchanger,at

a cost of £25,000, the company obviated the need to spend £150,000

on a new chiller and incidentally saved £10,000 a year on electricity.




G Reduce the thermal capacity of conveyingequipment and transit containers which gothrough heating or chilling equipment.

G Optimise carrying capacity; use buffer stores toisolate from downstream stoppages.

G Reduce distances and minimise or eliminatevertical lifts.

G Use control with sensors to enable conveyors to runonly on demand (ideally combined with short runs).

G Manually control to run intermittently at full loadrather than continuously at part load or empty.

G Replace pneumatic conveyors with bucketconveyors or other mechanical alternatives.

G Apply low-friction coatings to conveyors.G Where conveyors pass through heated process

equipment, insulate the return leg, route itthrough the heated equipment, or cool it topreheat air.

G Where product passes from heating to coolingzone, use separate conveyors.

G Fit purpose-designed nozzles and isolating valvesto air jets.

G If possible, charge truck batteries overnight; if thisis not possible, at least avoid charging on winter weekday afternoons.

Further information


G GPG 63 Metal distribution and handlingin iron foundries

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2.23 MECHANICAL HANDLING

Things to look for

G Conveyors running empty.

G Motors running lightly loaded.

G Compressed air used for positioning or sortingwithout proper nozzles.

G Compressed air bleeding during inactive periods.

G Electric trucks charged during daytimetariff period.

In pneumatic handling systems:

G Dust on fan blades or filters.

G Air leaks.

G Transport velocities higher than necessary.


G Use infra-red thermography to detect hot spotscaused by friction.

G Listen for air being discharged when handlingsystem is idle.

G Stand and watch during production, at breaks,and during shift changes.



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2.24 MOTOR TRANSPORT

Things to look for

G Unexplained discrepancies in fuel consumption.

G Vehicles left with engines idling.


G Check vehicle mileage and fuelconsumption records.

G Analyse performance by driver if vehicles arepooled or shared.

G Check tyre pressures.

G Compare similar vehicles doing similar duties.

G Ask how routes and loads are planned.


G Provide driver training.

G Improve load and route planning.

G Improve vehicle aerodynamics.

G Use alternative-fuel vehicles, at least for intra-site duties.

G Outsource transportation.

Further information

G ECG 59 Fuel consumption in freighthaulage fleets

G ECG 64 Fuel consumption in UK car and van fleets

G FEB 20 Energy efficiency in road transport

G GPCS 311 Energy saving through improveddriver training

G GPCS 342 Fuel management for transportoperations

G GPG 218 Fuel-efficient fleet managementG GPG 307 Fuel management guide

Case history

A parcel delivery company provided driver training and achieved a 14%

reduction in fuel use.



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G If kitchen supplies are sub-metered, take frequentreadings throughout the day to establish patternsof demand.

G Visit directly after meal time to see if cookingequipment is still running.

G Observe activity during preparation period at startof working day.

G Gas consumption during summer months mayindicate catering demand.


G Provide energy training for catering staff.

G Fit soft-start motor controllers on freezers,

refrigerators, and chilled display cabinets.G Fit night blinds on open chilled display cabinets.

G Control vending machines, bains maries, heatedcabinets,and counter lighting by timeswitches.

G Heat recovery from kitchen extract.

G Motor controllers on refrigerators and freezers.

G Provide efficient fixed water boilers to obviatethe need for kettles.

G Replace conventional ovens with microwavecookers in mess rooms.

Further information

G GPG 222 Reducing catering costs throughenergy efficiency

G GPCS 223 Night blinds on refrigeratedcabinets

G GPCS 350 Strip curtains on chilleddisplay cabinets

G EEB002 Catering establishments

2.25 ON-SITE CATERING

Things to look for

G Kitchen ranges turned on before they are needed.

G Kitchen ranges used as source of space heating.

G Vending machines running 24 hours per day.

G Badly-fitting door seals on refrigeratorsand freezers.

G Hot water left running into kitchen sinks.

G Kitchen ventilation fans drawing heated air from dining area.

G No ‘night blinds’ on chilled display cabinets.

G Ovens and sterilisers preheated for excessive periods.

G Dishwasher running part-loaded or empty.

G Fridges and freezers next to heat sources.

G Inadequate ventilation for condenser units of cold rooms.

G Heated cabinets or counter display lightingleft running.

G Vigorous boiling of unlidded pans.



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2.26 BUILDING FABRIC

Things to look for

G Poorly-utilised space.

G Doors and windows propped open.

G Broken windows and rooflights.

G Dirty windows and rooflights.

G Holes in walls or roof.

G Substandard or damaged insulation.

G Damp which may have compromisedexisting insulation.

G Substandard or damaged draughtproofing.


G An infra-red camera can be used on cold nightsto detect hot spots (from outside) or cold spots(from inside).

G A bubble-maker or smoke generator can be usedto sense unwanted air movement.

G A building’s heat loss characteristics can beestimated from the rate of temperature decay atthe end of the working day, taking outsidetemperature into account.


G Repair holes and broken windows.

G Apply draughtproofing.

G Apply insulation.

G Clad and insulate over roof lights.

G Fit air-locks or high-speed doors.

Further information

G Building Regulations, Part L

G CIBSE Guide F Energy Efficiency in

Buildings, Section 19.1G CIBSE AM5:

1991 - Energy Audits and Surveys

G CIBSE TM22

G GPG 139 Draught stripping of existingdoors & windows

G GPG 303 The designer’s guide to energyefficient buildings for industry

G GPG 304 The purchaser’s guide to energyefficient buildings for industry

Case studyIn 1989 a steel company applied sprayed insulation to a corrugated

roof.Their investment of £235,000 would have yielded a 10% internal

rate of return at current fuel prices.



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data sheets for recording survey data and results

3



data sheets for recording survey data and results

3.1 Site energy consumption and

expenditure

3.2 Register of sources of data and

their ‘drivers’

3.3 Meter reading pro-forma

3.4 Schedule of identified opportunities



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Year: Jan-Dec 2001

Energy source Units of delivery Quantity Quantity Cost CO2

purchased purchased (£) (kg)

(in original (converted

units) to kWh)

Electricity kWh 46,789,012 46,789,012 £1,871,56020,119,000

Gas kWh 9,876,543 9,876,543 £79,012 1,876,000

Oil (35 second) litres 23,400 248,040 £4,680 6,000

LPG kg 5,000 68,900 £920 9,000

Totals 56,982,495 1,956,172 22,010,000

3.1 SITE ENERGY CONSUMPTIONAND EXPENDITURE

Tables like these can be used to record informationabout annual energy consumption and expenditure.Table 3.1.A is applicable in all cases, and is typical of the background information which would normallybe recorded in a consultant’s report.

Table 3.1.A: Site total statistics (actual)

A table in this form could be used to record statisticsfor at least the most recent year, and preferably two

years.The ‘quantity purchased’ and ‘cost’ columnscan be completed by aggregating data from invoicesfor the year(s) in question. The CO2 figure must bederived by applying the conversion factors shown

below, if necessary first converting quantities intokWh units.

Plant item description Utility Annual units consumed Annual cost

Air compressor Electricity 120,000 kWh £4,000

N/A N/A N/A

Curing Oven 1 Gas 230,000 kWh £2,000

Electricity 2,400 kWh £800

Etc. Etc.

Table 3.1.B Major energy-using equipment

Where possible, you should estimate the annualenergy used in major plant items (or in services suchas heating or lighting).This will later help you to

estimate likely savings.Where dedicated submetersare not fitted, it may be possible to infer consumptionfrom the equipment nameplate rating, by makingassumptions about annual running hours. Note thatsome equipment may be fitted with hours-runcounters to facilitate this.

The cost column can be calculated by multiplyingthe units consumed by the prevailing price.To avoidoverstating any likely savings, it is better to use themarginal unit price rather than the average cost per unit of energy.The marginal price is the amount savedby consuming one unit less than expected.

Table 3.1.A

Table 3.1.B



Note: The tables refer to EACs (energy accountablecentres). Some managers notionally split their businesses into EACs to improve energyaccountability. An EAC usually has these attributes:

G The ability to measure energy flows into it.

G The ability to measure production output from it(or some other determinant of demand).

G A person accountable for the energy used.

Table 3.2.A: Consumption drivers

Energy consumption depends upon the amount of work being done - be it production activity,or space heatingto provide comfort in cold weather.Consumptionpatterns cannot be analysed without reference to these

driving factors, and therefore if setting up an energymonitoring scheme, it will be necessary to record themas frequently as the meter readings.

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Consumption drivers Unit of measurement Where is the data Which EAC(s) does(eg production, (eg tonnes, degree available for routine this relate to?weather, etc) days, etc) weekly updates?

A1 Popcorn throughput Cartons Packing dept Packing

A2 Biscuit production Tonnes Bakery production planning Bakery

A3 Toffee production Tonnes Work study dept Confectionery

A4 Heating demand Degree days Web Offices and stores

3.2 REGISTER OF SOURCES OFDATA FOR CONSUMPTIONSAND THEIR ‘DRIVERS’

These tables provide a site-specific record detailingthe sources of data which might be needed for analysis or for future regular monitoring.Although notessential for the purposes of the survey, completingtables like these is good practice and will at least helpto ensure that all the requisite information could beobtained if needed later.

Failure to account for ‘drivers’ (the things whichdetermine demand), when analysing patterns of energy consumption, is a prevalent management fault.

These tables are provided as templates, and may not

give you enough room for your entries.You shouldprepare your own versions with more appropriatelayouts, and with provision for more than the four entries illustrated here.

Table 3.2.A



Table 3.2.B: Consumption streams – metered

This table catalogues the available energyconsumption meters.The information collectedabout individual meters could subsequently help,

for example, to resolve discrepancies in meter-reading records.

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Energy source Zone or Meter Serial Units Digits on EAC served

(eg electricity, gas) item served location number (eg kWh readout

x 10)

B1 Electricity Whole site Intake near ABC123XYZ

KW h 6 All

reception

B2 Gas Whole siteCanal gate DEF456 Hu cu ft 4 All

B3 Gas Main boilers Rear of boiler 9876543 M3

4 Heating

house

Energy source Location of storage Storage Units (eg litre) Method of EAC served(eg LPG, oil) capacity measuring stocks

C1 Oil Rear of staff car park 20,000 Litre Sight gaugeon tank Heating

C2 etc

C3

C4

Table 3.2.C: Consumption streams – unmetered

Some energy sources, notably oil, solid fuel andliquefied petroleum gas, are delivered in bulk andstored on site without any provision to meter thequantities used. Failure to measure the consumption,as opposed to deliveries, is a common managementfault. Completing this table will help to ensure thatconsumptions can be calculated from successivestock-level records after taking account of intervening deliveries.

Table 3.2.B

Table 3.2.C



The body of the form is in three parts:

G Determinants of demand (consumption drivers).

G Metered supplies.

G Unmetered supplies.

These correspond to the three tables in Section 3.2above, where the correspond static informationis recorded.

Note that the columns headed ‘Previous reading’ and‘Previous stock level’ in parts B and C may not benecessary if you are entering data into a database or spreadsheet where the previous data arealready stored.

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Name of person making the return Signature Date

Weekly energy return

Site nameDate of return

Time of readings

Part B: Metered supplies

Meter or submeter Units Current reading Previous reading

B1

B2

B3

B4

Part A: Consumption drivers

Description Units Quantity

A1

A2

A3

A4

Part C: Unmetered supplies

Commodity/delivery point Units Stock in hand Previous stock level Deliveries received

C1

C2

C3

C4

3.3 METER READING PRO FORMA

Regular recording of energy consumption (and of the

factors which determine how much energy is used)is fundamental to the good management of energyresources. The following pro forma weekly returnsheet should first be customised, by completing theshaded boxes only, to suit the specific site where itwill be used.The customised sheet can then be usedas a master copy for routine weekly return forms. If the design below does not suit your needs, use it asa template for your own design.



Note: this table is used merely to identify the possibleopportunities.As projects are accepted it will benecessary to identify an individual to acceptresponsibility for progressing each one.A suitable tablefor project tracking is available in CIBSE Guide F,Table18.4 (see Section 4.1, Sources of Assistance)

*For simplicity’s sake,simple payback is used here but it is recommended that more sophisticated financialassessments are used, eg internal rate of return.

See GPG 169: Investment Appraisal for Industry

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Measure identified Estimated Recurring Expected Simple payback*

implementation annual annual (years)cost costs thereafter cash savings

Destratification fans in

packing hall £3,000 £200 £1,200 3

Draughtproofing offices £2,000 Nil £1,000 2

Agitators in intermittent mode

at night £600 Nil £3,000 0.2

Etc.

3.4 SCHEDULE OF IDENTIFIEDOPPORTUNITIES

A table of this form can be used to register thepotential energy-saving projects for which fundingmight be sought. For example, one measure identifiedmight be a recirculation fan on a dryer. If this had animplementation cost of £4,000, recurring annual costsof £200 (for extra electricity) and expected annualcash savings of £1,200 (through reduced gasconsumption), it would offer a simple payback periodof 4,000/(1,200-200) = 4 years.



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supporting data, and sources of further advice

4



4.1 Sources of assistance

4.2 Recommended instruments and tools

4.3 Energy data and conversion factors

Appendix A Reporting

Appendix B Selecting and briefing

a consultant

supporting data, and sources of further advice



MACC2 (www.macc2.org.uk/whatis/index.htm)

MACC2 is a way of helping organisations improvetheir resource efficiency and environmentalperformance in a managed, targeted and transparent

way. It is designed to work equally well in industrial,commercial and public sector organisations.

MACC2 is a challenge to individual organisations tobring their use of resources and management of wasteinto line with targets which the Government has setfor reducing greenhouse gases and other emissionsand reducing, recycling and recovering waste.

BREEAM(http://products.bre.co.uk/breeam/default.html)

BREEAM is a tool that allows the owners, users anddesigners of buildings to review and improve

environmental performance throughout the life of abuilding. It is a widely accepted and respected schemethat sets a benchmark for environmental performanceand provides a wide range of benefits. It isindependent and authoritative,being based on many

years of construction and environmental researchcarried out at BRE together with the input andexperience of the construction and propertyindustries, government and building regulators

Energy Efficiency Accreditation Scheme(www.natenergy.org.uk/eeas.html)

This voluntary scheme enables an organisation toprove that it has met testing standards in its approachto energy efficiency. Reviews are carried out byindependent assessors using strict criteria, and periodicreaccreditation helps to ensure that momentum ismaintained. Being accredited provides qualitativeevidence in support environmental systemscertification and may help in relation to ClimateChange Agreements.

The Chartered Institution of Building ServicesEngineers (CIBSE)(www.cibse.org)

CIBSE is an international body that represents andprovides services to the building services profession.These services include publications and events.

Croner’s Energy Management(Croner.CCH Group,020 8247 1175)

This loose-leaf manual provides a wide range of information and reference material on energymanagement topics. It is supplemented by a monthlyupdate newsletter, including monthly and weeklydegree-day figures, and its content is subject toregular amendments.

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4.1 SOURCES OF ASSISTANCE

The Environment and Energy Helpline

(0800 585794)This service can provide quick answers to simplequestions related to energy efficiency and isparticularly useful as a starting point for those new toenergy saving. Contact the Helpline for free adviceand publications from the EEBPP.

Energy Efficiency Best Practice Programme(www.energy-efficiency.gov.uk)

Nearly all the documents cited in the ‘further information’ sections of this Guide are available freeof charge from this Government programme, and can

be ordered via the Environment and Energy Helplineor this web site. Many are even available online for immediate downloading. See Institute of Energy for how to obtain the Standards for Managing Energy.

Envirowise (www.envirowise.gov.uk)

This programme can help with wider aspects of wasteminimisation. It features a Fast Track visit, which is aconfidential on-site waste review, available tocompanies with fewer than 250 staff.Within the spaceof one day, a consultant will identify wasteminimisation opportunities, and help you plan to

make these savings a reality.

Action Energy (www.energy-efficiency.gov.uk)

This is a grant scheme to support the provision of energy-saving advice from consultants. It operates attwo levels. Site Energy Assessment (SEA) provides for a short general assessment of energy-savingopportunities, free of charge to the applicant. SpecificMeasures Assessment (SMA) can subsidise morefocussed in-depth help where the need has beenidentified in an SEA report or its equivalent.

Design Advice(http://collaborate.bre.co.uk/designadvice/)

Design Advice offers professional, independent andobjective advice on the energy-efficient andenvironmentally conscious design of buildings as partof the Energy Efficiency Best Practice Programme.Clients are offered a one-day general consultancy ontheir chosen building project, paid for by a cashback scheme.The consultancy recommendations, coveringenergy efficiency, environmental improvements andthe potential commercial benefits, are contained ina client report. More detailed specialist consultationswill also be supported under the service.



Gee’s Energy Saver(Gee Publishing, 020 7393 7666)

This loose-leaf reference manual provides a widerange of information on energy management topics.

Its content is subject to regular amendments,including updates to monthly degree-day data.

Energy Systems Trade Association(www.esta.org.uk)

As the trade association for suppliers of energy-efficiency equipment and services, ESTA provides auseful first point of call in the search for equipment,materials, and expert advice.

Institute of Energy (www.instenergy.org.uk)

The Institute is the UK's professional associationfor those active in the energy scene (whether assuppliers, users, or academics).As such it can provideenergy managers with useful individual contacts.Contact the Institute to get a copy of the Standardsfor Managing Energy.

CHP Club (www.chpclub.com)

The CHP Club is a new initiative under theGovernment's Energy Efficiency Best PracticeProgramme, aimed at helping users and potentialusers in getting the maximum benefits from CHP.It provides members with a free one-stop-shop, aunique combination of information, exchange of experience and advice facilities on CHP and relatedtopics that will give everybody what they need andwhen they need it.

Combined Heat and Power Association(www.chpa.co.uk)

In some circumstances, combined heat and power (CHP) can be an important contributor to energyefficiency.The CHPA exists to promote thistechnology and can provide a great deal of technicaland market information, as well as news on grants

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G A video camera can be very useful.An inexpensivePC-connectible camera can be used inmany instances.

G Pressure/vacuum gauges.

G Combustion analysis kit.This is one instrumentwhich ought to be calibrated against a traceablestandard. Although relatively expensive, this is agood long-term investment because it enablespoor combustion to be detected through regular checks.Always choose one with carbon monoxidemeasurement. If using oil or solid fuel, you will alsoneed a smoke pump.

G Anemometer to measure air velocities especially insupply and extract ducts.

G Smoke generator to detect air leaks.Alternatively,improvise with tissue-paper tell-tales or a child’sbubble maker.

G Torch.

G Stopwatch.

G Pocket tape measure.

G Crowbar (for access to water meter).

G Meter compartment keys.

G Walkie-talkie radio or mobile telephones tocoordinate ‘drop tests’ when one party is readingmeters while another starts and stops equipment.

G

Permanent metering should not be overlooked as asource of data. Manually read at frequent intervals,it can provide useful profile information. Do notforget that on equipment with fixed power demands, an elapsed-hours counter will provide arough estimate of demand.

Instruments which are too expensive to buy canbe hired.

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4.2 RECOMMENDED INSTRUMENTSAND TOOLS

For the purposes of energy surveys, it is not usuallynecessary to have traceable calibrated instrumentsbecause approximate measures usually suffice.Exceptions to this rule are noted below.

G Digital thermometers with type K thermocoupleprobes.You will need one instrument operating inthe range –50 to 200ºC, ideally with 0.1ºCresolution, and another for 0-500ºC with 1ºCprecision. For high-temperature applications arobust probe is needed. For lower-temperaturework, a ‘band’ probe designed for surfacemeasurements makes a good general-purposeinstrument capable also of measuring air temperatures. Even a bare thermocouple junctioncan be used.Thermocouples can be left in placeand read manually by connecting the instrumentwhen required. Compensating extension cable isnecessary if the probe will need to be used at adistance (on the end of a pole), for instance.

G A sling hygrometer enables a spot check to bemade on wet and dry bulb air temperatures.Alternatively, use a digital relative humidity probe,especially if moisture contents of product need tobe measured.

G Non-contact thermometers can be useful to giveapproximate temperatures of inaccessible surfaces,or to scan for hot spots.An infra-red camera canbe hired if large areas need to be assessed in detail.Results of infra-red thermography must beinterpreted with caution.

G Miniature data loggers which record temperature,relative humidity, voltage, or pulses, may beuseful for extended tests. Pulses may be loggedfrom a variety of sources including PIR sensors(logging occupancy levels) or even improvisedtemporary contacts on valve linkages and other moving equipment.

G A light meter.An inexpensive unit will suffice,capable of working over the 100-2000 lux range.Photographic light meters are not suitable.

G A clip-on power meter is useful for checking onlighting circuits, motor consumption and smallpower loads.

G A compact camera.An inexpensive 35mmcompact model is adequate, but a powerful flashis recommended.



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4.3 ENERGY DATA ANDCONVERSION FACTORS

Energy contents of fuels (gross colorific value basis)

Fuel Measured units To get kWh multiply by

Electricity kWh 1

Natural gas (typically) m3 10.86hundred cu ft 30.76KWh 1Therm 29.31

Class D oil (35s) Litre 10.83Class E oil (290s) (typical figures) Litre 11.53Class F oil (950s) Litre 11.63Class G oil (3500s) Litre 11.66

Propane Tonne 13,890Kg 13.89

Coal Tonne 7,970(typical industrial) Kg 7.97

Example

Fuel kWh CO2 ratio kg CO2

Gas oil 27,000 Litre = 293,220 0.25 73,305

Natural gas 140,000 0.19 26,600

Electricity 35,000 0.43 15,050

Total 114,955

CO2 equivalents of electricity and fuelsEnergy source kgCO2/kWh

Grid electricity (from 1998) 0.43

Coal , typically 0.30

Coke 0.37

Jet kerosene 0.24

Natural gas 0.19

Gas/diesel oil 0.25

Heavy fuel oil 0.26

Petrol 0.24Propane 0.21

Note that where figures quoted are ‘typical’, actual values will be available from your fuel suppliers.



APPENDIX A - REPORTING

Although not essential, it is a good idea to record your

survey findings in a formal report. It does not need tobe lengthy; just sufficient to inform others of what you found and how you arrived at your conclusions. Itcould also help you to remind yourself of these thingsshould you need to return to the subject at alater date.

If you are seeking authority to spend money onprojects, it is absolutely vital to present clear,unambiguous recommendations. Do not give thereader multiple options to choose between.Alwayssupport your recommendations with appropriatecalculations and estimates.

Your report should contain the following sections:

Introduction

G Background to the site and its operations.

G Energy consumption and expenditure statistics(see tables in section 3.3 above).

G If appropriate and available, the trend in specificenergy ratio (and comparison withpublished norms).

G Any special considerations supporting

subsequent recommendations.

Summary

G A table similar to that shown in section 3.4 above.

G Brief narrative introducing the findingsand recommendations.

Survey findings

G Detailed discussion of survey findings, presentedeither by production area, or by technology theme(eg lighting), or both.

Recommendations

G Measures to be taken.

G Expected costs.

G Estimated savings.

G Incidental benefits.

G Payback periods or internal rates of return.

AppendicesG Energy prices.

G Charts and diagrams.

G Data gathered during the survey.

G Calculations of savings.

G Any other information.

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APPENDIX B – SELECTING ANDBRIEFING A CONSULTANT

There are various circumstances in which you mightrequire the services of an energy consultant.

G In the course of your energy survey, you may findenergy-saving opportunities for which expert helpis required.

G After attempting a survey unaided, you mayconclude that it would be better to engage anoutside specialist to do the job for you.

G You may have surveyed only certain aspects of your site, or you may have other sites which youcannot survey in person.

G The terms of a grant scheme may require that aformal energy survey is first carried out by anaccredited person.

B1. SELECTING A CONSULTANT

There are several ways of finding a consultant if youdo not already know of one:

G Recommendations from contacts in your industryor from your trade association.

G Approaching expert authors writing in thespecialist press.

G Registers are maintained by independent bodiessuch as the Institute of Energy and the EnergySystems Trade Association (details in Section 4.1).

In making your shortlist selection, look forthese attributes:

G Relevant experience (not necessarily in your ownindustrial sector: many energy projects are generic).

G Relevant qualifications: Are they properlyqualified? Do they hold membership of arecognised professional body which has a code of

conduct? Is it important that they should bechartered engineers?

G True independence. The consultancy should not betied to any particular product or to any givenenergy supply company. Ask who owns them.

G Professional indemnity insurance.Ask for a copy of their current certificate.

G Quality system: Does the consultancy performwork to a recognised quality standard?

G Affordable rates. Most reputable consultants willquote a fixed fee,although some may quote on a‘shared-savings’ basis. Be circumspect aboutshared-savings offers.Apart from the high risk of costly disputes, there is a risk that the consultantwill ‘walk away’ from a job where he finds nothinghe is interested in doing. The other risk is of savings being much higher than promised, inflatingthe fee well above what was expected.

B2. BRIEFING AND MANAGEMENT

Having found one or more suitable candidates,describe your project and ask them about similar work they have done for other clients. If they are able toprovide satisfactory answers, ask for referencesand

follow them up.

When you are ready to commission the work,brief the consultant properly. The project must haveclear objectives and deliverables.Avoid ambiguitiesabout what is or is not included in the fee offer.A model brief for a consultant’s report is provided inSection B.4.

When the project has started, expect to spend timewith the consultant: perhaps half a day for every day

that he works on the project. Do not expect to see theconsultant on site for the whole of the project. Mostprojects would require the consultant’s attendance onsite for at most one day in three.

B3. FURTHER INFORMATION

G FL0089 Choosing an energy consultant

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B4. MODEL BRIEF FOR ANENERGY SURVEY

If you are briefing a consultant to do a general energysurvey of the kind dealt with by this Guide,The

following model brief can be adapted to suit your particular site’s circumstances. It is adapted fromCIBSE’s Energy Audits and Surveys AM5: 1991.

1. Objectives

The objectives of a concise energy audit andsurvey are:

G to identify opportunities for reducing energy costs;

G to estimate the potential savings, and whereapplicable, implementation costs;

G to provide an audit for the site on the basis of the

previous 12 months’ invoiced accounts.

Methods of achieving these objectives are:

G by observations and, where applicable, analysis of how efficiently energy-consuming equipment isbeing used;

G by considering possible improvements to energymanagement control.

2. Report format

A short report shall be written to outline the findings

and recommendations arising from the survey. Thereport shall be preceded by a summary outlining thepotential energy savings available at the site.Thesewill primarily be of the good housekeeping and low-cost type but will also indicate where further opportunities may exist.The body of the report shallcontain the following sections:

G Site information.

G Energy audit.

G Energy use.

G Energy management.

3. Scope of survey and report

The following shall be covered:

G Site information.

G The site, its functions and services, shallbe described.

G Energy audit.

Based on data obtained from the previous12 months’ fuel invoices, a table showing annual fuelconsumptions and costs shall be compiled of the site.Performance indicators against published benchmarksshall be determined and commented on.

4. Energy use

Boiler plant

Combustion efficiency, based on waste gas analyses,shall be assessed for the main boiler plant under operating conditions as found.The general conditionof the boiler plant and associated pipework insulationshall be checked. Recommendations for improvedenergy efficiencies within the boiler house shall be

based on the above analysis and observations.

Process/manufacturing equipment

Observations on:

G factors affecting consumption;

G product quantity/quality;

G controls;

G operation.

Compressed air

Observations on:

G generation;

G treatment;

G distribution;

G end use;

G controls.

Electrical power and lighting

Observations of power and lighting systems shall be

carried out to determine the following:G the condition of lighting equipment;

G any unnecessary use of lighting;

G the type of existing luminaires and possiblereplacement by higher-efficiency lighting;

G use of electric heating and its control;

G the operation and loading of refrigerators andair compressors;

G efficient use of large electric motors.

Recommendations to reduce energy costs shall be

made on the basis of the above observations.



G P G


p u b l i s h e d 0 2 / 0 2

Ventilation/air conditioning

The settings of existing time and capacity controlsshall be obtained and included in the report, together with comments on control, operation and potential

energy savings.

Space heating and domestic hot water

The heating and hot water systems shall be assessedand recommendations made on:

G the heating period compared withoccupancy periods;

G the condition, settings and siting of existingcontrollers and sensors;

G instantaneous temperature measurement takenduring occupancy periods;

G the condition of insulation on pipework, valvesand flanges;

G the condition and siting of heat emitters andany obstruction;

G HWS temperature.

Building fabric

Observations shall be made of:

G insulation standards;

G excessive air leakage into buildings due to badly

fitting doors and windows.

Recommendations shall be based on the aboveobservations.

5. Energy management

Existing energy management procedures shall beassessed, and outline recommendations shall bemade in any improvement which can be made to

the existing system.

Consideration should be given to:

G Energy purchasing/procurement.

G Energy policy.

G Management structure/responsibilities.

G Training of key staff.

G Management information systems (M&T).

G Awareness/motivation of employees.

G Investment strategy.

nifes - 2002 - undertaking an industrial energy survey

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