**United States Environmental Protection**  **Agency EPA 231-R-98-014**  **July 1998 Office of Policy Planning & Evaluation**  **(2126)**



# Climate Wise 

# Wise Rules for Industrial Efficiency Wise Rules for Industrial Efficiency

A T OOL 

# K IT FOR 

# E STIMATING 

# E NERGY 

# S AVINGS AND 

# G REENHOUSE 

# G A S 

# E MISSIONS 

# R EDUCTIONS

# CLIMATE WISE Wise Rules for Industrial Efficiency A Tool Kit for Estimating Energy Savings and Greenhouse Gas Emissions ReductionsF or mor e information on the Climate W ise P r ogram, call the W ise L ine at 1-800-459-WISE. Climate W ise would like to thank the follo wing people for their assistance and input:
■ M ichael R. M uller , D ir ector , O ffice of I ndustrial P r oductivity & E nergy Assessment, R utgers U niversity

. ■ S teven C. Schultz, E nergy E ngineering S pecialist, 3M Company

. ■ K enneth F . Kraly , D ir ector of E ngineering, Cosmair , I nc. ■ H arry A. Kauffman, D ir ector E nergy and F ir e Policy M anagement, J ohnson & J ohnson. ■ Lee Link and R ob Penney , E nergy I deas Clearinghouse, W ashington S tate E nergy O ffice. ■ G eorge M. Wheeler , D ir ector , I ndustrial Assessment Center, O r egon S tate U niversity

.
This document was dev eloped for the U.S. E nvir onmental P r otection Agency under contract number EP A 68-W6-0029.

# T able of C ontents

1. Intr oduction....................................................................................................................... .......................................................................1 The ClimateW ise P r ogram ............................................................................................................................... ............................. .......1 Overview ............................................................................................................................... ......................................................... .......1 I nformation S our ces ............................................................................................................................... ....................................... .......1 U

sing the T oolkit

............................................................................................................................... ............................................. .......3 2. Boilers..................................................................................................................... .................................................................................5 I ntr oduction

............................................................................................................................... ................................................... .......5 Boiler Load M anagement ............................................................................................................................... ............................... .......6 T

une-U p and Air/F uel Ratio O ptimization

............................................................................................................................... ..... .......6 B urner R epalcement

............................................................................................................................... ....................................... .......7 S tack H eat Losses and W aste H eat R ecovery ............................................................................................................................... ... .......7 B low down Contr ol and W aste H eat R ecovery .............................................................................................................................. .......7 S ummary of W ise R ules for Boiler S ystems ............................................................................................................................... ... .......8 3. Steam Systems............................................................................................................... .......................................................................10 I ntr oduction

............................................................................................................................... ................................................... .... . 10 M aintenance of S team T raps ............................................................................................................................... ........................... .... . 10 R

educing Leaks

............................................................................................................................... ............................................... .... . 11 R

educing H eat Losses

............................................................................................................................... ..................................... .... . 11 V

apor R ecompr ession

............................................................................................................................... ..................................... .... . 11 Condensate

............................................................................................................................... ..................................................... .... . 11 S ummary of W ise R ules for S team S ystems ............................................................................................................................... ... .... . 12 4. Pr ocess Heating.................................................................................................................. ...................................................................14 I ntr oduction

............................................................................................................................... ................................................... .... . 14 I nsulation and H eat Containment

............................................................................................................................... ................. .... . 14 Combustion Air Contr ol

............................................................................................................................... ............................... .... . 15 P r ocess W aste H eat R ecovery ............................................................................................................................... ......................... .... . 15 S pecific P r ocess H eat A pplications

............................................................................................................................... ................. .... . 15 D ir ect H eating

............................................................................................................................... ............................................... .... . 16 S ummary of W ise R ules for P r ocess H eating

............................................................................................................................... . .... . 16 5. W aste Heat Recover y and Cogeneration............................................................................................................. .................................18 I ntr oduction

............................................................................................................................... ................................................... .... . 18 W

aste H eat R ecovery ............................................................................................................................... ..................................... .... . 18 Cogeneration

............................................................................................................................... ................................................... .... . 19 S ummary of W ise R ules for H eat R ecovery and Cogeneration

.................................................................................................... .... . 20

Table of Contents Wise Rules Page iPage ii Wise Rules Table of Contents 6. Compr essed Air Systems

............................................................................................................................... .......................................22 I ntr oduction

............................................................................................................................... ................................................... .... . 22 U

se Cooler I ntake Air

............................................................................................................................... ..................................... .... . 23 M atch Compr essor with Load R equir ement ............................................................................................................................... ... .... . 23 R

educe Compr essor Air P r essur e ............................................................................................................................... ................... .... . 23 R

educe or E liminate Compr essed Air Use ............................................................................................................................... ..... .... . 24 Eliminate Air Leaks

............................................................................................................................... ......................................... .... . 24 R

ecover W aste H eat ............................................................................................................................... ....................................... .... . 24 F ilters and Coolers

............................................................................................................................... ......................................... .... . 25 S ummary of W ise R ules for Compr essed Air S ystems .................................................................................................................. .... . 25 7. Pr ocess Cooling.................................................................................................................. ...................................................................27 I ntr oduction

............................................................................................................................... ................................................... .... . 27 E nergy E fficient Chillers and R efrigeration Units

.......................................................................................................................... .... . 27 Cooling T ow er W ater ............................................................................................................................... ..................................... .... . 28 R

efrigeration and Chillers

............................................................................................................................... ............................... .... . 28 F r ee zing

............................................................................................................................... ........................................................... .... . 28 V

ariable S peed D rives ............................................................................................................................... ..................................... .... . 29 S ummary of W ise R ules for P r ocess Cooling S ystems .................................................................................................................. .... . 29 Appendix A: Sector -Specific Ener gy Savings Potential ...........................................................................................................................31 Appendix B: Conversion Factors and Emission Coef ficients

................................................................................................................. . 52 Appendix C: Summar y of W ise Rules.......................................................................................................................... .............................55 Appendix D: Key Refer ences & Resour ces ............................................................................................................................... ...............601. Introduction Wise Rules Page 1 

# 1. I ntroduction The Climate Wise Pr ogram 

# C limate W ise is a par tnership initiativ e sponsor ed b y the U.S. EP

A, with technical suppor t fr om the U.S. DOE, designed to stimulate the v oluntar y r eduction of gr eenhouse gas emissions among par ticipating manufacturing companies. Climate W ise hopes to spur inno vation b y encouraging br oad goals, pr oviding technical assistance, and allo wing organizations to identify the most cost-effectiv e ways to r educe gr eenhouse gas emissions. Climate W ise curr ently has mor e than 400 par tners, r epr esenting about 12 per cent of U.S. industrial energy use. As par t of their Climate W ise commitment, par tner companies acr oss the countr y develop compr ehensive A ction P lans that describe their energy efficiency and pollution pr evention goals, the specific actions under taken to achiev e these goals, the time frame for implement

ing commitments, and estimates of the impacts on energy , costs, and emissions fr om these actions. T o date, Climate W ise P ar tner companies have submitted Action P lans detailing mor e than 1,000 individual actions to r educe gr eenhouse gas emissions and pr event pollution. A bout half of these actions per tain to energy efficiency measur es in industrial operations such as: boiler and steam sys

tems, compr essed air systems, energy management operations, motor systems, process heating, and process impr ovements. P ar tner companies also pursue non-pr ocess energy efficiency mea

sur es such as lighting, HV A

C, and building shell impr ovements, as well as water conser vation, r ecy cling, pollution pr evention and educational outr each. 

# Over view The W ise Rules for I ndustrial E fficiency – “ W ise R ules T ool Kit ” – was developed to help par tners make the most of their Climate W

ise par ticipation and generate inter est and commitment in suppor t of energy efficiency and pollution pr evention effor ts. I t pr ovides Climate W ise P ar tners with simple r ules for estimating energy savings and gr eenhouse gas emissions r eductions fr om a wide range of industrial energy efficiency measur es, based on a large number of r esour ces. I nformation on typical cost savings and paybacks ar e also pr ovided. The W ise R ules focus on six pr ocess energy end-uses including boilers, steam systems, pr ocess heating, waste heat r ecovery and cogeneration, compr essed air systems, and pr ocess cooling. S ix chapters describe energy efficiency measur es and pr ovide W ise R ules on typical energy and cost savings for each of these major pr ocess end-uses. This information can help y our company identify and ev aluate alternativ e energy efficiency activi

ties. I t can also help you to develop your Climate W ise A ction P lan — y our statement of commitment under y our Climate W ise P ar ticipation Agr eement. Climate W ise will update this document periodically as w e gather new information on industrial energy efficiency measur es. W e w el

come y our feedback and input on the W ise R ules T ool Kit, includ

ing other r ules that you have found useful and would like to shar e, or r equests for ne w W ise R ules for specific end-uses. P lease phone in y our comments to the W ise L ine at 1-800-459-WISE, fax them to 703-934-3968, send them via electr onic mail to: W

iseLine@ICFKaiser.com, or mail them to:

Climate W ise c/o ICF Kaiser Consulting G r oup 9300 Lee H ighway F air fax, V irginia 22031 

# Infor mation Sour ces The W ise R ules T ool Kit is a compilation of some of the best infor

mation available on industrial energy efficiency

. These r ules ar e based on energy efficiency r esear ch and engineering principles, the experience of Climate W ise Par tners, and government sour ces such as the U.S. D epar tment of E nergy ’ s I ndustrial Assessment Center (DOE/IAC) energy audit database. These r esour ces pr o vide a wealth of energy efficiency and other information in the manufacturing sector , including energy , cost, and operating data. The W ise R ules captur e br oad categories of efficiency impr ove ments such as “ air compr essor efficiency measur es ” and mor e detailed actions such as “ optimiz e boiler air-to-fuel ratio .” The W

ise R ules also pr ovide multiple perspectiv es on efficiency oppor

tunities b y expr essing energy savings as a per cent of a par ticular end-use ’ s energy consumption (e.g., optimizing air-to-fuel ratioPage 2 Wise Rules 1. Introduction can r educe boiler fuel use b y two to 20 per cent), as a per cent of a facility ’ s total energy use (e.g., steam trap maintenance can reduce a facility ’ s total energy use b y 3.4 per cent), or per unit change in a physical parameter (e.g., for ev ery one psi decr ease in air compr es sor pr essur e, energy use is reduced b y 0.7 per cent). T o make them as useful as possible, the W ise R ules ar e pr esented in a variety of formats, including graphs, bullets, and tables. I n addition, we have pr ovided a handy r efer ence guide to identify energy efficiency oppor tunities for specific manufacturing sectors (see Appendix A). The DOE/IAC energy audit database was an impor tant sour ce of information for the T ool Kit. The database contains information fr om industrial energy assessments conducted at small-to-medium siz ed manufacturing facilities b y teams of faculty and students fr om accr edited engineering schools in 30 univ ersities acr oss the country . The W ise R ules T ool Kit includes information on the expected impacts fr om appr o ximately 27,000 specific impr ove ments and upgrades fr om 4,300 detailed facility audits conducted between 1990 and 1997. The majority of the auditors' r ecom mendations had r elatively shor t (1 to 2 y ear) payback periods and
w

er e expected to be implemented within two y ears of the audit. The impacts fr om br oad categories of efficiency r ecommendations in the DOE/IAC audits ar e summariz ed in I ntroduction T able 1

. F or example, boiler efficiency measur es wer e r ecommended dur

ing 20 per cent of the 4,300 audits and w er e expected to save on average 2.8 per cent of a facility ’ s total energy use, or an av erage of 2,600 MMBtu per year. The average cost of implementing boiler efficiency measur es was expected to be $5,300 with average firsty

ear savings of $7,200 for an expected av erage simple payback of nine months. Compr essed air efficiency measures wer e r ecom mended during 68 per cent of the audits. The average savings fr om


### Intr oduction T able 1: Summar y of Ef ficiency Measur es fr om the DOE/IAC Database* End Use Recommendation A verage A verage A verage A verage A verage Rate Annual Annual Implementation Cost Simple (% of audited facilities) 

### Ener gy Savings Ener gy Savings Cost Savings Payback (% of total facility (MMBtu) (months) energy use) Boilers 20% 2.8% 2,600 $ 5,300 $ 7,200 9 S team Systems 13% 2.0% 2,400 $ 3,300 $ 7,100 6 F ur naces & Ov ens 4% 2.8% 2,500 $ 5,500 $ 8,100 8 Process H eating 1% 2.2% 3,600 $ 7,500 $ 12,200 7 H eat Containment 22% 1.5% 1,100 $ 1,100 $ 5,100 9 H eat R eco v

er

y 26% 4.6% 3,700 $ 16,500 $ 12,500 16 Cogeneration** 3% 9.1% 31,000 $667,500 $233,600 34 Air Compr essors 68% 0.4% 300 $ 1,600 $ 4,300 5 Process Cooling 6% 1.1% 1,000 $ 18,900 $ 11,200 20 * Based on DOE/IAC estimates at audits of 4,300 manufacturing companies (1/90-7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-site po werplants for purchased electricty. Definition of Terms: The recommendation rate is equal to the number of facilities receiving a particular recommendation (e.g., repair steam leaks) divided by the total number of facilities audited ( ≈ 4,300). Average percent energy savings are defined as the average reduction in a facility’s total energy use from a specific recommendation. Average annual energy and cost savings reflect first year savings. Cost savings are primarily based on energy cost savings, but also may inclu de other cost savings. The average simple payback is the average implementation cost divided by average annual cost savings, times 12 (months per year).air compressor efficiency measur es w ere 0.4 per cent of total facility energy use, or an average 300 MMBtu annual r eduction in each facility ’ s energy use. The average cost of implementing compr essed air efficiency measur es was expected to be $1,600 with av erage first-year cost savings of $4,300 for an av erage simple payback of five months. S imilar r ules developed for a range of other br oad actions as well as mor e detailed measur es ar e pr esented in the body of the W ise R ules T ool Kit. The estimated audit impacts for spe

cific industr y sectors ar e pr esented in A ppendix A. 

# Using the T ool Kit The W ise R ules w ere dev eloped to help y ou take full advantage of y

our par ticipation in the Climate W ise P rogram. As y ou begin to dev elop y our Climate W ise A ction P lan, the W ise R ules can help y

ou and y our Climate W ise team generate ideas for energy savings oppor tunities in y our facilities. The T ool Kit pr o vides a quick scan of measures along a number of dimensions, including potential energy savings, implementation costs, energy costs savings, and pay

back. U se the W ise R ules, along with information on the pr ocesses in y our operations, to scr een a br oad range of efficiency measur es and to eliminate less attractiv e options based on y our company ’ s key criteria. The T ool Kit pr o vides backgr ound information on all of the W

ise R ules so that Climate W ise Par tners will have a better under

standing of how and when to use them. W e hav e also pr o vided references to the primary data sour ce for every W ise R ule so that par tners can learn mor e if they desir e. A ppendix D of the T ool Kit contains a summary of key references and r esour ces. O nce measur es have been identified, you can use the W ise R ules to estimate pr oject-level energy savings and CO 2 emissions r eductions to be r epor ted on y our Climate W ise A ction P lan. While y ou will want to r efine these estimates o ver time and track actual r esults for completed pr ojects, the W ise R ules can serve as place-holders until y

our experience pr ovides y ou with better , site-specific data. Y ou may also find that you want to develop y our own r ules based on y

our engineering analyses and meter ed data. I n this way y ou can tailor W ise R ules for pr ocesses specific to your company or based on y our company ’ s operations, energy prices, and other factors. The T ool Kit also pr ovides information r equir ed to calculate CO 2 emissions r eductions, as r equir ed in y our Climate W ise A ction P lan. CO 2 emission factors pr ovided in A ppendix B of the T ool Kit can be used with the energy savings estimates based on the W ise R

ules to estimate total emissions r eductions fr om y our actions. I t is impor tant to keep in mind a number of points when using the W ise R ules:
■ The T ool Kit pr ovides savings estimates for many impor

tant efficiency measur es, but it is not a exhaustiv e list of industrial efficiency oppor tunities. A number of pr ocess es and end-uses ar e not included her e that may offer sav

ings to your company (e.g., lighting and motors). Ther e may also be attractiv e measur es — including pollution pr evention measur es — applicable to your specific pr ocesses and operations that y our company should con

sider. M or eover , many of the W ise R ules r eflect efficien

cy r ecommendations with r elatively shor t (1 to 2 y ear) payback periods. Y our company ’ s payback r equir ement may be longer for some types of pr ojects. When identify

ing energy efficiency and pollution pr evention oppor tu nities, it is impor tant not to limit your actions to those measur es included her e. ■ The W ise R ules can pr ovide simple savings estimates but they cannot take the place of detailed engineering analy

ses based on site-specific data and operating parameters. The W ise R ules ar e based on typical experience and gen

eral engineering obser vations fr om a number of sour ces. The energy audit data r eflect the energy and cost savings estimates (not actual experience) acr oss many industr y gr oups, over several years and acr oss many par ts of the country . B e sur e to consider y our company ’ s unique cir

cumstances when applying W ise R ules. F or many pr o jects, mor e detailed analysis will be desirable.
■ S ome W ise R ules may be only applicable under specific operating conditions (e.g., only to equipment of a cer tain siz e or within a specific temperatur e range). S ome effi

ciency measur es for the same or r elated end-uses may interact, such that the total energy savings fr om complet

ing two measur es may be less (or more) than the sum of the two measur es ’ individual impacts. B ecause W ise R

ules ar e drawn fr om a variety of sour ces, savings esti

mates may not be comparable, ev en when the energy effi

ciency measur es ar e similar. F or example, some W ise R

ules expr ess savings for an energy efficiency measur e on the basis of specific equipment energy consumption, while others ar e expr essed as a per cent of a facility ’ s total energy savings. S uch r ules may not be comparable,

1. Introduction Wise Rules Page 3Page 4 Wise Rules 1. Introduction because they may assume differ ent specific measur es, implementation lev els, or contributions of the end use to total facility energy-use.
■ All W ise R ules ar e expr essed as “ energy savings ” to allo w easy comparison acr oss measur es. H owever , many of the key r efer ences and r esour ces ar e based on efficiency impacts — a closely r elated measur e. ■ A compr ehensive analysis of efficiency oppor tunities should also examine secondar y impacts of savings mea

sures. These include impacts on operations, maintenance, pr oductivity , and the envir onment. F or example, changes in boiler operating parameters may hav e secondary effects on emissions of nitr ogen o xides, par ticulates, or carbon mono xide. These may all be impor tant decision criteria for y our company . ■ E nergy savings estimates based on the W ise R ules cannot take the place of measuring the r esults of implemented pr ojects. F or some pr ojects, y ou may want to implement energy tracking and/or metering systems to ev aluate the success of y our Climate W ise effor ts and the r eturn on y

our investments. This information can later be used to develop W ise R ules for your company .industrial boilers can ex ceed 7,500 hp (250 MMBtu/hr). T ypical boiler efficiencies range fr om about 70 to 85 per cent depending on fuel type, configuration, and heat r ecovery capability


### . 2 S everal boiler efficiency measur es may be of inter est to Climate W

ise P ar tners: boiler load management, burner r eplacement, upgraded instr umentation, tune-up and air/fuel ratio optimiza

tion, stack heat loss pr evention, waste heat r ecov ery , and blow down contr ol. Boiler F igur e 1 illustrates the potential energy savings fr om boiler efficiency measur es based on IA C audit r ecommenda

tions. Boiler efficiency measur es with an average savings of about thr ee per cent of facility energy use, and a simple payback of nine months wer e r ecommended at 20 per cent of the 4,300 facilities audited. Boiler load management measur es have a r elatively high

2. Boilers Wise Rules Page 5 Energy Savings Recommendation Rate Boiler Maintenance 

### Boiler FIgure 1 

### Energy Savings from Boiler Efficiency Measures* Recommendation Rate

Energy Savings Rate (percent of total facility energy use) All Boiler Measures (9 month payback) Boiler Load Management (23 month payback)

(5 month payback) Combustion Air Preheating (8 month payback)
Boiler Blowdown

(11 month payback) 0% 6% 12% 20% 2% 4% 8% 10% 14% 16% 18%

0% 6% 2% 4% 8%
* Results from the DOE/IAC Database (1/90-7/97). The IAC data reflect average potential impacts from energy efficiency measures at small-to-medium sized manufacturing

facilities across all sectors and regions of the country. Most IAC audit recommendations are expected to be implemented within two years and typically have a one-to-two year payback period. (See Chapter 1.) 

# 2. B oilers Intr oduction 

# B oilers ar e one of the most impor tant energy uses in manufac

turing, typically comprising mor e than a thir d of total manu

facturing energy demand. A boiler generates hot water or steam, typically fr om the combustion of coal, oil, or natural gas. A net

work of pipes deliv ers steam (or hot water) to pr ovide heat for a
variety of pr ocess and heating applications. O nce the heat has been extracted fr om the water or steam, another networ k of pipes r eturns the condensed water back to the boiler wher e it is cy clical

ly r eheated. Ther e ar e several differ ent types of boilers including natural draft, for ced draft, hot water or steam, and fir e tube or water tube. The typical boiler used in small-to-medium siz ed industrial operations is a for ced draft steam boiler at 120-150 psi and appr o ximately 150 hp (equiv alent to 5 MMBtu/hr). 1 Largeexpected energy savings, eight per cent of total energy use, but these measur es wer e only r ecommended at one per cent of facilities audited and hav e a payback of about two years. Boiler mainte

nance measur e w er e r ecommended at 16 per cent of facilities audit

ed with average energy savings of two per cent and simple payback time of only fiv e months. Boiler T able 1 , at the end of this chap

ter

, summariz es the W ise R ules pr esented in this chapter , along with cost savings estimates, wher e available. 

# Boiler Load Management O ne of the most basic energy saving measur es is effectiv e boiler load management — pr operly sizing the boiler to meet the steam load. A good example of this is r eplacing a large boiler with sev er al smaller ones, allo wing for high efficiency operation during light and full load periods. The r elationship between boiler efficiency and firing rate is non-linear

. Ther efor e, in order to maximiz e over all efficiency , a boiler's output can be matched to load, based on its design and specifications. 3 Boiler W ise Rule 1 

### E ffective boiler load management techniques, such as operating on high fir e settings or installing smaller boilers, can save o v er 7% of a typical facility ’ s total energy use with an average simple payback of less than 2 years. 4 Boiler W ise Rule 2 

### Load management measur es, including optimal matching of boiler siz e and boiler load, can save as much as 50% of a boiler ’ s fuel use. 5 

# T

une-Up and Air/Fuel Ratio Optimization Periodic measur ement of flue gas o xygen, carbon mono xide, opac

ity

, and temperatur e pr ovides the fundamental data r equir ed for a boiler tune-up . I t is useful to have the follo wing instr uments on hand to best manage boiler operation: stack thermometers, fuel meters, make-up feedwater meters, o xygen analyz ers, r un-time r ecor ders, energy output meters, and r eturn condensate ther

mometers. 6 A typical tune-up might include a r eduction of ex cess air (and ther eb y excess o xygen, O 2 ), boiler tube cleaning, and r ecalibration of boiler contr ols. M aintaining a pr oper air-to-fuel ratio is very impor tant for optimizing fuel combustion efficiency

. I n a “lean ” mix (high air-to-fuel ratio), heat will be lost to the excess air , while in a “ rich ” mix (low air-to-fuel ratio), unburned fuel will be emitted with the exhaust gases. Each fuel type and fir

ing method has an optimal air/fuel ratio . F or example, optimum excess air for a pulveriz ed coal boiler is 15 to 20 per cent (3 to 3.5 per cent excess O 2 ), and optimum ex cess air for a for ced draft gas boiler is 5 to 10 per cent (1 to 2 per cent excess O 2 ). 7 The air/fuel ratio should be set to the manufactur er ’ s r ecommendations. B ecause it is difficult to r each and maintain optimal v alues in most boilers, actual excess air levels may need to be set higher than opti

mal. 8 When boilers ar e operating at lo w loads, ex cess-air r equir e ments may be gr eater than the optimal lev els and efficiency may be low er. 9 M anual or automatic o xygen trim can ensur e that the pr oper air/fuel mixtur e ratio is maintained. 10 S econdar y impacts of boiler efficiency measur es should be consider ed when evaluating a pr oject. F or example, adjustments of air/fuel ratio and other oper

ating parameters may affect emissions of nitr ogen o xides, par ticu

lates, or carbon mono xide. Boiler W ise Rule 3 

### An upgraded boiler maintenance program including optimizing air-to-fuel ratio, burner maintenance, and tube cleaning, can sav e about 2% of a facility ’ s total energy use with an av erage simple payback of 5 months. 11 Boiler W ise Rule 4 

### A compr ehensive tune-up with pr ecision testing equipment to detect and corr ect ex cess air losses, smoking, unburned fuel losses, sooting, and high stack temperatur es, can r esult in boiler fuel savings of 2% to 20%. 12 Boiler W ise Rule 5 

### A 3% decr ease in flue gas O 2 

### typically pr oduces boiler fuel savings of 2%. 13 Boiler W ise Rule 6 

### Using o v er fir e draft contr ol systems to contr ol ex cess air can save 2% to 10% of a boiler ’ s fuel use with typical equipment costs of $1,500. 14

Page 6 Wise Rules 2. BoilersBoiler W ise Rule 7 

### Using a characterizable fuel valv e to match the air/fuel ratios acr oss the load range can save 2% to 12% of a boiler ’ s fuel use at r elativ ely lo w cost. 15 

# Bur ner Replacement The method b y which fuel is delivered to the burner affects boiler efficiency . F uel atomization can add flexibility in fuel choice and can impro v

e lo w load operation. A tomizers suspend fine dr oplets of fuel on a cone of air or steam allo wing better contr ol of fuel delivery . 16 Boiler W ise Rule 8 

### Conv er ting to air or steam atomizing burners fr om conventional burners can r educe boiler fuel use b y 2% to 8%. 17 

# Stack Heat Losses and W aste Heat Recover y S tack heat losses ar e usually the largest single energy loss in boil

er operations. K ey measur es that minimiz e stack heat losses ar e air/fuel ratio optimization (see abov e), and stack gas heat r eco v er y for pr e-heating combustion air or boiler feedwater (see Chapter 5). 18 H eat r eco v er y may incr ease boiler-operating tem

peratur e, which may have secondar y effects of incr easing nitr o gen o xide emissions. T o maximiz e boiler efficiency and pr ev ent flue gas condensation, stack temperatur e should be 50 ° F to 100 ° F abo v e the water temperatur e. 19 Boiler W ise Rule 9 

### E

very 40 ° F r eduction in net stack temperatur e (outlet temperatur e minus inlet combustion air temperatur e) is estimated to sav e 1% to 2% of a boiler ’ s fuel use. 20 Boiler W ise Rule 10 

### S tack dampers pr ev ent heat fr om being pulled up the stack and can save 5% to 20% of a boiler ’ s fuel use. 21 Boiler W ise Rule 11 

### D ir ect contact condensation heat r eco v er y can save 8% to 20% of a boiler ’ s fuel use, but costs may be r el

atively high. 22 Boiler W ise Rule 12 

### P r eheating combustion inlet air can save about 3% of a facility ’ s total energy use with an average simple pay

back of 8 months. 23 

# Blowdown Contr ol and W aste Heat Recover y D issolved and suspended solids in boiler feedwater can deposit on heat transfer sur faces and r educe boiler efficiency . Boiler manufac

tur ers usually establish a maximum acceptable concentration of dissolved solids. T o maintain lo w concentration lev els, boiler water is periodically diluted in a pr ocess called “blo w down ” during which boiler water is drained off and ne w water is added. 24 H eat losses during blo w down ar e often overlooked because they ar e hard to measur e and facility personnel may not fully understand the water chemistr y . H ot water drained to the se w er and ex cess heat vented to the atmospher e contains unused energy

. 25 W arming make-up feedwater with blo w down waste heat can minimiz e heat losses. R eplacing manual blo w down valves with analyzing equip

ment and automatic v alves can also r educe blowdown losses. Boiler W ise Rule 13 

### M inimizing energy loss fr om boiler blowdo wn can sav e about 2% of a facility ’ s total energy use with an av erage simple payback of less than 1 y ear. 26 Boiler W ise Rule 14 

### R

emo ving a 1/32 inch deposit on boiler heat transfer sur faces can decr ease a boiler ’ s fuel use b y 2%; r emo v al of a 1/8 inch deposit can decr ease boiler fuel use b y o v er 8%. 27, 28 Boiler W ise Rule 15 

### B lo wdo wn heat r eco v er y is a pr o v en technology that can r educe a boiler ’ s fuel use b y 2% to 5%. 29 Boiler W ise Rule 16 

### F or ev ery 11 ° F that the entering feedwater temperature is increased, the boiler ’ s fuel use is reduced by 1%. 30

2. Boilers Wise Rules Page 7Boiler W ise Rule 17 

### Changing fr om manual blowdo wn contr ol to auto

matic adjustment can r educe a boiler ’ s energy use b y 2% to 3% and r educe blo wdo wn water losses b y up to 20%. 31 

# Summar y of Wise Rules for Boiler Systems U

se the W ise R ules in Boiler T able 1 (next page) to identify and estimate potential energy saving fr om boiler efficiency measur es. I n selecting alternative efficiency options and eliminating less attrac

tive measur es, consider the potential costs, savings, payback times and any secondar y effects. When using the W ise R ules, r emember that several of the measur es may ov erlap , or complement each other (e.g., tune-up and flue gas O 2 reduction) and energy savings rates of overlapping measur es may not be additive. I n addition, multiple W ise R ules may addr ess the same measur e fr om differ ent perspectives. F or example Boiler W ise R ule 1 expresses savings fr om boiler load management as a per cent of the boiler ’ s energy use, while Boiler W ise R ule 2 expr esses savings as a per cent of the facil

ity ’

s total energy use. S pecific W ise R ules may not be comparable with each other because they r ely on differ ent sour ces with differ

ent assumptions. A

djust the W ise R ules in Boiler T able 1 to match your cir cum stances. F or example, you may want to scale the gr oss fuel cost sav

ings to match your boiler siz e. T o calculate savings for a 10 MMBtu/hr natural gas boiler , multiply gr oss fuel cost savings b y a factor of ten. This scaling is applicable only to gr oss fuel cost sav

ings expr essed per MMBtu/hr , e.g., R ule 2, but not R ule 1 in Boiler T able 1 . I mplementation costs may not scale in a linear manner. S imilarly , y

ou can adjust the savings numbers on the basis of y our fuel prices and operating hours. F or example, if your boil

er uses coal at a price of $1.50/MMBtu, divide the cost savings
values in Boiler T able 1 b y the per MMBtu price of natural gas, e.g., $2.30, and multiply b y $1.50. 

### Boiler System Notes 1 Rutgers University, Office of Industrial Productivity and Energy

Assessment, Modern Industrial Assessments: A Training Manual , Version 1.0b, December 1995, p. 5-1. 2 O'Callaghan, P., Energy Management , McGraw-Hill, England, 1993, p. 198. 3 Taplin, H.R., Boiler Plant and Distribution System Optimization Manual , Fairmont Press, 1991, p. 122. 4 DOE/IAC Industrial Assessment Database, July 1997. 5 Taplin, p. 122. 6 Taplin, p. 129. 7 Turner, W.C., Energy Management Handbook , 3rd Edition, Fairmont Press, 1997, p. 90. 8 Rutgers, p. 5-12. 9 Turner, p. 90. 10 Garay, P.N., Handbook of Industrial Power and Steam Systems , Fairmont Press, 1995, p. 211. 11 DOE/IAC Database. 12 Taplin, p. 134. 13 3M Company, “ Rules of Thumb: Quick Methods of Evaluating Energy

Reduction Opportunities,” 1992, p. 8. 14 Taplin, p. 141. 15 Taplin, p. 140. 16 Taplin, p. 153. 17 Taplin, p. 153. 18 Taplin, pp. 11-18. 19 Rutgers, p. 5-12. 20 Garay, p. 219; Taplin, p. 15; Rutgers, p. 5-2. 21 Taplin, p. 15. 22 Taplin, p. 166. 23 DOE/IAC Database. 24 Garay, p. 271. 25 Taplin, p. 13. 26 DOE/IAC Database. 27 Garay, p. 271. 28 Rutgers, p. 5-10. 29 Taplin, p. 160. 30 Taplin, p. 33. 31 Taplin, p. 161; Turner, p. 109.

Page 8 Wise Rules 2. Boilers2. Boilers Wise Rules Page 9 a Percent of boiler energy use, unless noted. b Energy savings are expressed as a percent of total facility energy use. Cost savings (fuel, O&M, etc.) are expressed in dollars , not in dollars per MMBtu/hr of boiler size. c Based on a natural gas boiler with 80% efficiency, operating 5,000 hrs/yr, with a gas price of ≈ $2.30/MMBtu. These are gross fuel cost savings only and do not include capital, maintenance, or other costs or savings. 

### Boiler T able 1: Summar y of Boiler Ef ficiency Measur es Sour ce Measur e A verage Ener gy Savings a 

### A verage Annual Cost Savings (IAC recommendation rate) Savings per MMBtu/hr and (Payback) 

### All Ef ficiency Impr ovements I mplement typical efficiency 2.8% of total facility energ y use b $7,200 (9 months) b impro v

ements, which may include many or all of the measur es belo w (20%) 

### Boiler Load Management Rule 1 O perate on high fir e setting 7.4% of total facility energ y use b $19,900 (23 months) b or install smaller boilers (1%) Rule 2 O ptimize boiler size and boiler load 2% to 50% $230 to $5,750 c 

### T une-Up and Air/Fuel Ratio Optimization Rule 3 I mplement boiler maintenance (air/fuel 2.4% of total facility energ y use c $2,460 (5 months) b ratio optimization, burner maintenance, boiler tube cleaning) (16%) Rule 4 I mplement compr ehensiv e tune-up 2% to 20% $230 to $2,300 c Rule 5 D ecr ease flue gas O 2 2% per 3% decr ease in O 2 $230 c Rule 6 U tilize o v

er fir e draft control 2% to 10% $230 to $1,400 c Rule 7 U tilize characterizable fuel v alv

e 2% to 12% $230 to $1,400 c 

### Bur ner Replacement Rule 8 Conv ert to atomizing bur ners 2% to 8% $230 to $920 c 

### Stack Losses and W aste Heat Recover y Rule 9 R educe net stack temperatur e 1% to 2% per 40 ° F r eduction $140 to $230 c Rule 10 U tilize stack dampers 5% to 20% $580 to $2,300 c Rule 11 D ir ect contact condensation heat reco v

er

y 8% to 20% $920 to $2,300 c Rule 12 Pr eheat combustion air (3%) 2.6% of total facility energ y use b $5,200 (8 months) b 

### Blowdown Contr ol and Heat Recover y Rule 13 M inimize boiler blo w do wn (1%) 1.6% of total facility energ y

b $8,500 (11 months) b Rule 14 R emo v

e deposits from heat transfer surfaces 2% for 1/32 inch deposit, $230 to $920 c 8% for a 1/8 inch deposit Rule 15 U tilize blo w

do

wn heat r eco v

er

y 2% to 5% $230 to $580 c Rule 16 Pr eheat boiler feedwater 1% per 11 ° F incr ease $140 c Rule 17 U tilize automatic blo w

do

wn control 2% to 20% $230 to $2,300 c Source references for each Wise Rule are included in the chapter notes.Page 10 Wise Rules 3. Steam Systems audited with an av erage anticipated savings of two per cent of a facility ’ s total energy use and a simple payback of six months. I mpr oved steam line insulation was r ecommended at sev en per cent of the facilities audited with an expected av erage savings of one per cent of the facility’ s total energy use and a simple payback of ten months. S team T able 2 , at the end of this chapter , summa riz es the W ise R ules pr esented in this chapter , along with cost sav

ings estimates, wher e available. 

# Maintenance of Steam T raps S team traps hold steam in the coil until the steam r eleases its heat energy and condenses. S team trap operation can be checked b y comparing the temperatur e on each side of the trap . I n pr operly

Energy Savings Recommendation Rate Repair Steam Leaks 

### Steam Figure 1 

### Energy Savings from Steam System Efficiency Measures* Recommendation Rate

Energy Savings Rate (percent of total facility energy use) All Steam Measures (6 month payback)
Steam T rap Maintenance

(2 month payback)

(3 month payback) Insulate Steam Lines (10 month payback)
Condensate Measures (8 month payback) 0% 13% 1% 2% 3% 4% 5% 8% 6% 7% 9% 10%

0% 1% 4% 2% 3% 11% 12% 

# 3. S team S ystems Intr oduction 

# S team system efficiency impr ovements ar e a logical complement to boiler efficiency measur es. U seful energy escapes fr om steam distribution systems fr om malfunctioning steam traps, steam leaks, and via radiativ e losses fr om steam lines, condensate lines, and storage tanks. Each of these ar eas pr esents oppor tunities for energy savings. S team system efficiency measur es that may be of inter est to Climate W ise P ar tners include: steam trap maintenance, r epairing steam leaks, insulation, condensate measur es, and vapor r ecom pr ession. S team F igur e 1 illustrates the potential energy savings fr om steam system efficiency measur es based on specific recom mendations in the DOE/IA C database. S team system efficiency measur es wer e r ecommended at 13 per cent of the 4,300 facilities

* Results from the DOE/IAC Database (1/90-7/97). The IAC data reflect average potential impacts from energy efficiency measures at small-to-medium sized manufacturing

facilities across all sectors and regions of the country. Most IAC audit recommendations are expected to be implemented within two years and typically have a one-to-two year payback period. (See Chapter 1.)3. Steam Systems Wise Rules Page 11 functioning steam traps, ther e will be a large temperatur e differ

ence between the two sides of the trap and no steam do wnstr eam of the trap . M alfunctioning steam traps waste steam and r esult in higher boiler fuel consumption. 1 T ypically , 15 to 60 per cent of the steam traps in a plant may be malfunctioning and wasting large amounts of energy

. 2 Steam W ise Rule 1 

### An effective steam trap maintenance pr ogram can sav e 3% of a facility ’ s total energy use with an average simple payback of 2 months. 3 Steam W ise Rule 2 

### An effective steam trap maintenance pr ogram can r educe a boiler ’ s fuel use b y 10% to 20%. 4 

# Reducing Leaks R

epairing leaks in steam pipes, condensate r eturn lines, and fit

tings can yield significant energy and cost savings. S team leaks incr ease boiler fuel use because additional steam must be generat

ed to make up for the wasted steam. Leaky condensate r eturn lines incr ease make-up water r equir ements and incr ease boiler fuel use because mor e energy is r equir ed to heat the cooler , make-up boiler feedwater than would be r equir ed to heat the r eturned con

densate. A ctual savings will depend on boiler efficiency , steam pr essur e, and annual operating hours. 5 Steam W ise Rule 3 

### R

epairing steam system leaks can save 1% of a facility ’ s total energy use with an average simple payback of 3 months. 6 Steam W ise Rule 4 

### A single high-pr essur e steam leak (125 psi) can r esult in energy losses costing fr om $660 to $2,200 per year (8,760 hrs). A single low-pr essur e steam leak (15 psi) can r esult in energy losses costing $130 to $480 per year (8,760 hrs). 7 

# Reducing Heat Losses O ften boiler and steam system insulation is r emoved to make r epairs and is not r eplaced. U ninsulated sur faces in boiler and steam systems can r each 450 ° F . S uch high temperatur es can thr eaten emplo y ee safety and can pose a fir e hazar d, as well as waste significant amounts of energy

.

Steam W ise Rule 5 

### I nsulating steam lines can save 1% of a facility ’ s total energy use with an average simple payback of 10 months. 9 

# V

apor Recompr ession When ther e is a need for low pr essur e steam, vapor r ecompr ession can double the pr essur e of vented steam using only a fraction of the energy r equir ed to generate the steam in a boiler

. 10 Steam W ise Rule 6 

### V

apor r ecompr ession saves 90% to 95% of the energy needed to raise the steam to the same pr essur e in a boiler

. 11 

# Condensate A number of measur es can be implemented to r educe heat losses fr om condensate — the water that forms after steam has been used. I ncr easing the amount of condensate r eturned to the boiler saves energy because it eliminates the need to heat cold make-up water. I nsulating steam lines, condensate lines and tanks, will pr e 

### Steam T able 1 

### Annual Costs of Heat Loss per 100 feet of Uninsulated Steam Pipe 8



### Steam Pr essur e Cost per 100 ft of pipe per year (8,760 hr) 25 psi $1,600 50 psi $1,900 75 psi $2,100 100 psi $2,300vent unnecessary heat loss thr ough the system. Collecting highpr essur e condensate after flash steam formation can pr ovide lowpr essur e steam for other purposes. Steam W ise Rule 7 

### M easur es to r educe heat loss fr om condensate in a steam system can save o v er 1% of a facility ’ s total ener

gy use with an average simple payback of 8 months. 12 

# Summar y of Wise Rules for Steam Systems U

se the W ise R ules in S team T able 2 (next page) to identify and estimate potential energy saving fr om steam system efficiency measur es. When identifying attractiv e options and eliminating
w

eak ones, consider potential costs, savings, payback periods and any secondar y effects. When using the W ise R ules, r emember that some measur es may interact or complement each other (e.g., steam trap maintenance and steam pipe insulation) and energy savings rates may not be additiv e. M ultiple W ise R ules may addr ess the same efficiency measure fr om differ ent perspectives. F or example, S team R ules 1 and 2 expr ess savings fr om steam trap maintenance as (1) a per cent of a facility's total energy use, and (2) as a per cent of boiler energy use. 

### Steam System Notes
1 Rutgers University Office of Industrial Productivity and Energy

Assessment, Modern Industrial Assessments: A Training Manual , Version 1.0b, December 1995, p. 5-19. 2 Turner, W.C., Energy Management Handbook , 3rd Edition, Fairmont Press, 1997, p. 149. 3 DOE/IAC Industrial Assessment Database, July 1997. 4 Taplin, H.R., Boiler Plant and Distribution System Optimization Manual , Fairmont Press, 1991, p. 276. 5 Rutgers, p. 5-17. 6 DOE/IAC Database. 7 Rutgers University OIPEA, “ Useful Rules of Thumb for Resource

Conservation and Pollution Prevention,” March 1996, #1 and #2. 8 Rutgers, “Useful Rules of Thumb,”#8. 9 DOE/IAC Database. 10 Bonneville Power Administration (BPA), Washington State Energy Office,

Electric Ideas Clearinghouse, “Vapor Recompression,” July 1992, p. 1. 11 BPA, p. 1. 12 DOE/IAC Database.

Page 12 Wise Rules 3. Steam Systems

### Steam T able 2: Summar y of Steam System Ef ficiency Measur es Sour ce Measur e A verage Ener gy Savings A verage Annual Cost Savings (IAC recommendation rate) (payback) 

### All Ef ficiency Impr ovements I mplement typical efficiency 2% of total facility energ y use $7,100 (6 months) impro v

ements, which may include many or all of the measur es belo w (13%) 

### Steam T rap Maintenance Rule 1 I mplement steam trap 3.4% of total f acility energ y use $17,400 (2 months) maintenance program (1%) Rule 2 I mplement steam trap maintenance pr ogram 10% to 20% of boiler fuel use 10% to 20% of boiler fuel costs 

### Leak Repair Rule 3 R epair steam leaks (2%) 1.0% of total facility energ y use $6,100 (3 months) Rule 4 R epair high pr essur e leaks (125 psi) $660 to $2,200 per leak R

epair lo w pr essur e leaks (15 psi) $130 to $480 per leak 

### Insulation T able 1 I nsulate steam lines (7%) $1,600 to $2,300 per 100 feet Rule 5 I mpro v

e steam line insulation 1.0% of total facility energ y use $2,800 (10 months) 

### Other Measur es Rule 6 R ecompr ess lo w pr essur e steam 90% to 95% of energ y needed to raise the steam in a boiler Rule 7 R educe heat loss from condensate (4%) 1.3% of total f acility energ y use $6,700 (8 months)

3. Steam Systems Wise Rules Page 13 Source references for each Wise Rule are included in the chapter notes.Page 14 Wise Rules 4. Process Heating Energy Savings Recommendation Rate 

### Process Heating Figure 1 

### Energy Savings from Process Heating Efficiency Measures*

Energy Savings Rate (percent of total facility energy use) All Furnace Heating Measures (8month payback)

All Process Heating Measures (7 month payback) Recommendation Rate 0% 1% 2% 4% 3%

0% 1% 2% 5% 3% Oven/Kiln Heat Recovery (16 month payback)

4% 

# 4. P rocess H eating Intr oduction 

# I ndustrial companies use furnaces, o vens, and kilns to raise the

temperatur e of a raw material or intermediate pr oduct as par t of a manufacturing pr ocess. I mpor tant pr ocess heating efficiency measur es include: insulation, combustion air contr ol, burner adjustment, automatic stack dampers, waste heat r ecovery , tem peratur e optimization, use of minimum safe v entilation, immer

sion heating, and enhanced sensitivity of temperatur e contr ol and cutoff . M inimizing equipment heat-up time can also sav e energy . F or example, many o vens need only 15 to 60 minutes to heat up , 1 but, in practice, may “warm up ” for an unnecessarily long period of time. The r emainder of this chapter pr ovides additional infor

mation on heat containment, pr ocess heating and dir ect heating. P rocess H eating F igur e 1 illustrates the potential energy savings fr om heating efficiency measur es based on IA C audit r ecommen dations. F urnace efficiency measur es wer e r ecommended at four per cent of the facilities audited with estimated av erage savings of thr ee per cent of the average facility ’ s total energy use and a simple payback of eight months. H eat r ecovery fr om ovens, kilns, and other equipment was r ecommended during only one per cent of

* Results from the DOE/IAC Database (1/90-7/97). The IAC data reflect average potential impacts from energy efficiency measures at small-to-medium sized manufacturing

facilities across all sectors and regions of the country. Most IAC audit recommendations are expected to be implemented within two years and typically have a one-to-two year payback period. (See Chapter 1.) the audits with estimated energy savings of almost fiv e per cent and average simple payback of 16 months. P rocess H eating T able 1 , at the end of this chapter, summariz es the W ise R ules pr esented in this chapter , along with cost savings estimates, wher e available. 

# Insulation and Heat Containment H eat loss can cause major r eductions in pr ocess heating efficiency

. H eat containment measur es include insulation of bar e equipment and open tanks, isolating hot or cold equipment fr om air condi

tioned ar eas, and r educing infiltration into hot or cold pr ocess equipment. N ew r efractory fiber material, with lo w thermal con

ductivity and heat storage, can pr oduce significant impr ovements in efficiency with minimal detriment to the wor k envir onment. T

ypical applications include furnace co vers, installing fiber liner between the standar d r efractor y lining and the shell wall, or installing ceramic fiber linings o ver the pr esent r efractor y liner

. R

eplacing standar d r efractor y linings with v acuum-formed r efrac

tory fiber insulation can also impr ove efficiency

. 2Pr ocess Heating W ise Rule 1 

### P r oper heat containment can save about 2% of a facility ’ s total energy use with an average simple payback of 9 months. 3 Pr ocess Heating W ise Rule 2 

### I nsulating a furnace with r efractor y fiber liners can impr o v e the thermal efficiency of the heating pr ocess b y up to 50%. 4 

# Combustion Air Contr ol M aintaining a pr oper air-to-fuel ratio is v ery impor tant for opti

mizing fuel combustion efficiency in pr ocess heating. I n a “lean ” mix (high air-to-fuel ratio), heat will be lost to the ex cess air , while in a “ rich ” mix (low air-to-fuel ratio), unburned fuel will be emit

ted with the exhaust gases. Aspirators can help maintain a pr oper air-to-fuel ratio for pr emix burners systems, while ratio-r egulating systems can do this for nozzle mix burners. 5 A utomatic burner contr ol is also an effective strategy for optimizing the air-to-fuel ratio . Contr ol systems technologies include pr ogrammable logic contr ollers, dir ect stack temperatur e monitors, and intelligent high-level computer contr ollers. 6 B e sur e to consider potential sec

ondary impacts fr om adjustments of air/fuel ratio or other operat

ing parameters, such as changes in emissions of nitr ogen o xides, par ticulates, and carbon mono xide. 

# Pr ocess W aste Heat Recover y Exhaust gas heat losses ar e another sour ce of pr ocess efficiency loss. H eat r eco v er y systems can r ecaptur e this heat and r eintr o duce it into pr ocessing heat or other end-uses. A r ecuperator extracts heat fr om furnace waste gases to pr eheat incoming com

bustion air. A r egenerator uses por ous ceramic beds for waste gas heat r eco v er y and shor t-term heat storage 

### . 7 Chapter 5, “ W aste H eat R eco v er y and Cogeneration,” describes additional waste heat r eco v er y measur es. Pr ocess Heating W ise Rul e 3 

### R

eco v ering waste heat fr om furnaces, o v ens, kilns, and other equipment can save 5% of a typical facility ’ s total energy use with an av erage simple payback of 16 months. 8 Pr ocess Heating W ise Rule 4 

### R

eco v ering waste heat thr ough a r ecuperator can r educe a kiln ’ s energy use b y up to 30%; r egenerators can save up to 50%. 9,10 

# Specific Pr ocess Heat Applications E nergy savings oppor tunities available in some sectors may be mor e br oadly applicable. F or example, in the lumber industr y, airdrying lumber befor e putting it in the kiln can reduce kiln energy use. U sing variable speed contr ols to r educe kiln fan po wer after the water has been driv en off can significantly r educe kiln energy use without affecting dr ying time or pr oduct quality

. 11 I n the cement industr y , advanced contr ol systems such as automated contr ols and exper t systems have shown significant energy savings. O ptimizing heat transfer conditions in the clinker cooler thr ough better distribution of clinker and air can also r esult in substantial energy savings. Pr ocess Heating W ise Rule 5 

### Each per cent of moistur e r emo v ed b y air dr ying lumber r educes the kiln ’ s energy use b y 50 to 85 Btu per boar d foot. 12 Pr ocess Heating W ise Rule 6 

### V

ariable fan speed contr ol in the lumber industry can r educe dr y kiln air flo w b y 20% and r educe the kiln ’ s energy used during sur face dr ying b y as much as 50%. 13 Pr ocess Heating W ise Rule 7 

### I nstalling exper t systems for kiln secondary contr ol can r educe a cement kiln ’ s energy use b y up to 3%. 14 Pr ocess Heating W ise Rule 8 

### N e w clinker cooler technologies that optimiz e heat transfer conditions can r educe a cement kiln ’ s energy use b y up to 6%. 15

4. Process Heating Wise Rules Page 15

# Dir ect Heating D ir ect heating is generally mor e efficient than indir ect heating because heat transfer losses fr om equipment and transfer media ar e eliminated. Examples of dir ect heating technologies include dir ect firing (generally with natural gas), infrar ed, micr o wav e, and dielectric heating. D ir ect heating also pr o vides other opera

tional benefits including faster drying times, r educed mainte

nance, easier installation, mor e pr ecise temperatur e contr ol, mor e uniform heating, and incr eased output. 16 Pr ocess Heating W ise Rule 9 

### D ir ect firing with natural gas in place of indir ect steam heating has the potential to save 33% to 45% of pr ocess heating energy use. P ayback times may range fr om a fe w months to 6 years. 17 Pr ocess Heating W ise Rule 10 

### D ir ect electric heating (infrar ed, micr o wav e, or dielec

tric) can r educe pr ocess heating energy use b y up to 80% with typical payback periods of 1 to 3 y ears. 18 

# Summar y of Wise Rules for Pr ocess Heating Use the W ise R ules in P r ocess H eating T able 1 (next page) to identify and estimate potential energy savings fr om pr ocess heat

ing efficiency measur es. When evaluating alternatives and elimi

nating options, consider the potential costs, energy savings, pay

back time, and any secondary effects. When using the W ise R

ules, r emember several of the measur es may o v erlap or comple

ment each other and energy savings rates fr om o v erlapping mea

sur es may not be additive. I n addition, multiple W ise R ules may expr ess savings for similar measur es fr om differ ent perspectives. F or example, some expr ess energy savings in terms of a typical facility ’s total energy use, while others ar e expr essed in terms of an end use ’s energy consumption.

Page 16 Wise Rules 4. Process Heating 

### Pr ocess Heating Notes 1 3M Company, “Laboratory Operations Energy Efficiency Guidelines,”

Feb. 1994. 2 Rutgers University Office of Industrial Productivity and Energy

Assessment, Modern Industrial Assessments: A Training Manual , Version 1.0b, December 1995, p. 5-36. 3 DOE/IAC Industrial Assessment Database, July 1997. 4 Rutgers, p. 5-37. 5 Rutgers, p. 5-34. 6 Centre for the Analysis and Dissemination of Demonstrated Energy

Technologies (CADDET), “Learning from Experiences with Process Heating in the Metals Industry,” Analyses Series No. 11, 1990. 7 CADDET, 1990. 8 DOE/IAC Database. 9 Bonneville Power Administration (BPA), Washington State Energy Office,

Electric Ideas Clearinghouse, “Dry Kiln Retrofit/Replacement,” October 1991. 10 CADDET, 1990. 11 BPA, “Dry Kiln Retrofit/Replacement.” 12 Bonneville Power Administration (BPA), Washington State Energy Office,

Electric Ideas Clearinghouse, “Optimizing Dry Kiln Operation,” October 1991. 13 BPA, “Dry Kiln Retrofit/Replacement.” 14 ICF Kaiser Consulting Group estimate based on cement industry data. 15 ICF Kaiser Consulting Group estimate based on cement industry data. 16 Mercer, A., Learning from Experience with Industrial Drying Technologies, Centre for the Analysis and Dissemination of Demonstrated Energy Technologies (CADDET), 1994. 17 Mercer, pp. 25-38. 18 Mercer, pp. 39-54.4. Process Heating Wise Rules Page 17 

### Pr ocess Heating T able 1: Summar y of Pr ocess Heating Ef ficiency Measur es Sour ce Measur e A verage Ener gy Savings A verage Annual Cost Savings (IAC recommendation rate) (payback) 

### All Ef ficiency Impr ovements I mplement typical efficiency 2.8% of total facility e nerg y use $8,100 (8 months) impro v

ements, which may include many or all of the measur es belo w (4%) 

### Insulation and Heat Containment Rule 1 I mpro v

e heat containment (22%) 1.5% of total facility energ y use $5,100 (9 months) Rule 2 I nstall fiber insulation 50% impro v

ement in ther mal efficiency 

### Pr ocess Heating W aste Heat Recover y Rule 3 R eco v

er fur nace, o v

en, and kiln 4.6% of total facility energ y use $13,000 (16 months) waste heat (1%) Rule 4 R eco v

er heat from kilns 30% to 50% r eduction in kiln energ y use 

### Specific Pr ocess Heating Applications Rule 5 Air dr y lumber 50 to 85 Btu per boar d foot for each 1% moistur e r

emo v

ed Rule 6 I nstall v ar

iable speed driv es (VSD) up to 50% of kiln energ y use for dr y kiln airflo w Rule 7 I nstall expert systems for up to 3% of cement kiln secondar y kiln controls energ y use Rule 8 O ptimize heat transfer conditions up to 6% of cement kiln energ y use 

### Dir ect Heating Rule 9 U se dir ect firing with natural 33% to 45% of the energ y (few months to 6 y ears) gas in place of indir ect heating r equir ement Rule 10 U se dir ect electric heating in 80% of heating energ y use (1 to 3 y ears) place of indir ect heating
Source references for each Wise Rule are included in the chapter notes.fuel inputs at off-site po w erplants for pur chased electricity) and the payback was about thr ee y ears. H eat R eco v

er

y/Cogen T able 2 , at the end of this chapter , summariz es the W ise R ules pr esented in this chapter , along with cost savings estimates, wher e available. 

# W aste Heat Recover y H eat reco v

ery is often a viable r etrofit option for existing equipment. V

entilation and exhaust fr om pr ocess heating or combustion equip

ment are some common sour ces of potentially r eco v

erable energy

. H eat reco v

ery is beneficial only if the heat can be used else where and if it is available when it is needed. T ypical applications of waste heat include pr ocess heating, combustion air pr eheating, boiler feedwater preheating, and space heating. 1 B e sure to consider any secondar y effects fr om adjustments of combustion parameters, such as emis

sions of nitr ogen o xides, par ticulates, and carbon mono xide.

Page 18 Wise Rules 5. Heat Recovery & Cogeneration Energy Savings Recommendation Rate

Heat Containment 

### Heat Recovery/Cogen Figure 1 

### Energy Savings from Heat Recovery and Cogeneration Efficiency Measures* Recommendation Rate

Energy Savings Rate (percent of total facility energy use) W

aste Heat Recovery (16 month payback) Cogeneration** (34 month payback)

(9 month payback) 0%

0% 6% 26% 3% 9% 12% 15% 18% 22% 24% 24%

2% 10% 4% 6% 8%
* Results from the DOE/IAC Database (1/90-7/97). The IAC data reflect average potential impacts from energy efficiency measures at small-to-medium sized manufacturing

facilities across all sectors and regions of the country. Most IAC audit recommendations are expected to be implemented within two years and typically have a one-to-two year payback period. (See Chapter 1.) ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-site po werplants for purchased electricity. Off-site

power generation is assumed to have a heat rate of about 10,000 Btu/kWh. Savings are calculated by dividing total energy savings, including powerplant inputs, by total facilityenergy use. 

# Intr oduction 

# H eat exchangers r ecov er useful energy that would or dinarily be lost. G enerally , a heated gas or liquid leaving a pr ocess passes thr ough a heat exchanger to pr eheat another gas or liquid entering a pr ocess or an HV A

C system. Cogeneration takes heat r ecov ery a step fur ther b y recovering heat that would normally be wasted in the pr ocess of po w er generation and steam pr oduction. Cogeneration systems can r each efficiencies that can triple, or ev en quadr uple, conventional power and steam generation. H eat R

eco v

er

y/Cogen F igur e 1 illustrates the potential energy savings fr om heat r ecovery and cogeneration measur es based on IAC audit recommendations. W aste heat r ecovery measur es w ere r ecom mended at 26 per cent of the 4,300 IAC audits conducted fr om 1990 thr ough mid-1997 and were estimated to save almost five per cent of the average facility ’ s total energy use with a simple pay

back of 16 months. Cogeneration was r ecommended at few er facil

ities (thr ee per cent), but the average expected energy savings w ere much higher (nine per cent of the facility ’ s energy use, including 

# 5. W aste H eat R eco v ery and C ogenerationHeat Recovery/Cogen W ise Rule 1 

### R

eco v ering waste heat can r educe a typical facility ’ s total energy use b y about 5% with an average simple payback of 16 months. 2 Heat Recovery/Cogen W ise Rule 2 

### R

educing net stack temperatur e (outlet temperatur e minus inlet combustion air temperatur e) b y 40 ° F is estimated to r educe the boiler ’ s fuel use b y 1% to 2%. 3 Heat Recovery/Cogen W ise Rule 3 

### P r eheating furnace combustion air with r eco v er ed waste heat can save up to 50% of the furnace ’ s energy use. H eat R ecov ery/Cogen T able 1 summariz es typi

cal fuel savings for a natural gas furnace. 4 Air-to-air heat ex changers transfer heat fr om a hot air str eam to a cold one. U sing air-to-air heat ex changers to pr eheat ventilation air in the winter or for pr ecooling in the summer can add to the air distribution system’ s pr essur e losses and may requir e larger ven tilation fans. 6 I n heat pipes, hot and cold air str eams flow in oppo

site dir ections. H eat pipes typically ar e used in the range of 150 ° F to 850 ° F and r ecover betw een 60 and 80 per cent of the heat fr om the exhaust air str eam. H eat wheels ar e por ous disks with high heat capacity that r otate between a cold-gas duct and a hot-gas duct. They can r ecover fr om 70 to 90 per cent of the heat fr om the exhaust air str eam. G lass fiber ceramic heat wheels can be used at temperatur es up to 2,000 ° F

. 7 E conomiz ers ar e used primarily to pr eheat boiler feedwater with flue gas waste heat. The boiler feed

water flows thr ough the economiz er and is heated b y the hot exhaust gases fr om the boiler

. The higher the waste gas tempera

tur e, the gr eater the possible energy savings. E conomiz ers can be used at gas temperatur es up to 1,800 ° F


### . 8 Heat Recovery/Cogen W ise Rule 4 

### Using an economiz er to captur e flue gas waste heat and pr eheat boiler feedwater can r educe a boiler ’ s fuel use b y up to 5%. 9 H eat exchanger efficiency is dir ectly pr opor tional to the sur face ar ea that separates the heated and cooled fluids. I f heat exchanger sur faces become fouled with films, deposits, or corrosion, exchanger efficiency suffers. I f heavy fouling is expected, contam

inated str eams may need to be filter ed, or the design may need to be modified to include differ ent materials or to allo w easy access to sur faces for fr equent cleaning. 10 Heat Recovery/Cogen W ise Rule 5 

### R

emo ving a 1/32 inch deposit on boiler ’ s heat transfer sur faces can r educe a boiler ’ s energy use b y 2%; r emo ving a 1/8 inch deposit can r educe a boiler ’s energy use b y o v er 8%. 11,12 

# Cogeneration Cogeneration is the simultaneous pr oduction of electric po w er and thermal energy fr om a single fuel. I n a typical configuration, an industrial boiler is r eplaced b y a gas turbine. The turbine is used to generate electricity , and the waste heat is used to generate steam in a heat r ecovery steam generator (or HRSG). O ther cogeneration configurations combine boilers and steam turbines, or gas turbines and steam turbines (combined cy cle units). T wo emerging technologies that ar e applicable to cogeneration ar e the use of fuel cells and the Kalina cy cle — a vapor heat engine cycle using an ammonia-water wor king fluid. 13 Cogeneration is often a mor e efficient way of pr oviding electrici

ty and pr ocess heat than pr oducing them independently giv en the overall efficiency gain, as w ell as a potential fuel shift. A verage effi

ciencies for traditional cogeneration systems can range fr om 70

5. Heat Recovery & Cogeneration Wise Rules Page 19 

### Heat Recover y/Cogen T able 1 

### Fuel Savings fr om Pr eheating Combustion Air 5



### Fur nace Outlet Combustion Air Pr eheat T emperatur e T emperatur e 400 ° F 600 ° F 800 ° F 1000 ° F 1200 ° F 2600 ° F 22% 30% 37% 43% 48% 2400 ° F 18% 26% 33% 38% 43% 2200 ° F 16% 23% 29% 34% 39% 2000 ° F 14% 20% 26% 31% 36% 1800 ° F 13% 19% 24% 29% 33% 1600 ° F 11% 17% 22% 26% 30% 1400 ° F 10% 16% 20% 25% 28% Based on a natural gas furnace with 10% excess air.Page 20 Wise Rules 5. Heat Recovery & Cogeneration per cent to mor e than 80 per cent. 14 Cogeneration makes most sense in facilities wher e steam and electrical demand ar e balanced with the typical output of the cogeneration unit. Ther e ar e generally economies of scale inv olved with cogeneration systems, with larger units having lo w er costs (per installed kW) and higher efficiencies. A verage-siz ed cogeneration units range fr om 10 to 50 MW, though units as small as 3 MW can be costeffective. 15 Cogeneration economics depend on system utiliza

tion. 16 Ther efor e, it is impor tant to closely match the system’ s output to the facility’ s steam and electrical load. When electricity pr oduction is in ex cess of on-site consumption needs, it can typi

cally be sold to others and should be accounted for when ev aluat

ing the feasibility and economics of cogeneration. I t is a good idea to examine the steam load prior to assessing electrical needs in evaluating a potential cogeneration pr oject. B e sur e to consider any secondar y impacts fr om new combustion equipment such as nitr ogen o xide emissions fr om gas turbines. Heat Recovery/Cogen W ise Rule 6 

### G as turbines with heat r eco v er y equipment typically cost fr om $600 to $1,000/kW . Larger gas turbines may be available for half the cost per kW

. 17 Heat Recovery/Cogen W ise Rule 7 

### A typical cogeneration pr oject may r educe primar y energy consumption (including fuel inputs at off-site po werplants for pur chased electricity) for steam and electricity generation b y 10% to 15%. 18 Heat Recovery/Cogen W ise Rule 8 

### Cogeneration systems can save about 9% of a typical facility ’ s primar y fuel inputs for on-site energy use (i.e., including fuel savings at off-site powerplants for pur chased electricity) with an average simple payback of 34 months. 19 

### (S avings ar e calculated b y dividing total energy savings, including powerplant inputs, b y total facility energy use.) 

# Summar y of Wise Rules for W aste Heat Recover y and Cogeneration U

se the W ise R ules in H eat R eco v

er

y/Cogen T able 2 (next page) to identify and estimate potential energy saving fr om heat reco v

ery and cogeneration. Consider potential costs, savings, payback time, and any secondary effects in order to analyz e different efficiency alterna

tiv

es and eliminate less attractiv e options. When using the W ise R

ules, remember that several of the measur es may interact or com plement each other and energy savings rates may not be additive. 

### W

aste Heat Recover y and Cogeneration Notes 1 Rutgers University Office of Industrial Productivity and Energy

Assessment, Modern Industrial Assessments: A Training Manual , Version 1.0b, December 1995, pp. 5-21 and 5-22. 2 DOE/IAC Industrial Assessment Database, July 1997. 3 Garay, P.N., Handbook of Industrial Power and Steam Systems , Fairmont Press, 1995, p. 219; Taplin, H.R., Boiler Plant and Distribution System Optimization Manual , Fairmont Press, 1991, p. 15; Rutgers, p. 5-2. 4 Rutgers, p. 5-21. 5 Rutgers, p. 5-21. 6 Bonneville Power Administration (BPA), Washington State Energy Office,

Electric Ideas Clearinghouse, “Exhaust Air Heat Recovery Systems,” May 1992, p. 1. 7 Rutgers, p. 5-23. 8 Rutgers, p. 5-22. 9 O'Callaghan, P., Energy Management , McGraw-Hill, England, 1993, p. 198. 10 Turner, W.C., Energy Management Handbook , 3rd Edition, Fairmont Press, 1997, pp. 207-208. 11 Garay, p. 271. 12 Rutgers, p. 5-10. 13 Orlando, J.A., Cogeneration Design Guide , American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., 1996, pp. 62-63. 14 Stromberg, Jan, Gas-Turbine-Based CHP in Industry , Centre for the Analysis and Dissemination of Demonstrated Energy Technologies (CAD DET), 1993, p. 6. 15 McIntire, Margaret E., “Trigen Dispersed Energy Services for the MidSized Industrial and Commercial Market,” Nineteenth National Industrial Energy Technology Conference Proceedings , 1997, pp. 117-124. 16 Payne, F.W., Cogeneration Management Reference Guide , Fairmont Press, Inc., 1997, p. 6. 17 Rutgers, p. 5-40. 18 ICF Kaiser Consulting Group estimate. 19 DOE/IAC database. Off-site power generation is assumed to have a heat

rate of about 10,000 Btu/kWh.

### Heat Recover y/Cogen T able 2: Summar y of Heat Recover y and Cogeneration Ef ficiency Measur es Sour ce Measur e A verage Ener gy Savings* A verage Annual Cost Savings (IAC recommendation rate) (payback) 

### W

aste Heat Recover y Rule 1 R eco v

er waste heat (26%) 4.6% of total facility energ y use $12,500 (16 months) Rule 2 R educe stack waste heat losses 1% to 2% per 40 ° F r eduction Rule 3 Pr eheat fur nace combustion air U p to 50% Rule 4 Pr eheat boiler feedwater up to 5% of boiler energ y use Rule 5 Clean heat ex changers 2% for 1/32 inch deposit, 8% for a 1/8 inch deposit 

### Cogeneration Rule 6 I nstall gas turbine cogeneration C apital Cost: $600-$1,000/kW Rule 7 I nstall cogeneration system 10% to 15% of primar y energ y consumption Rule 8 I nstall cogeneration system (3%) 9.1% of total facility energ y use** $233,600 (34 months) Source references for each Wise Rule are included in the chapter notes. * Percent of equipment energy use, unless noted. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-site powerplants for purchased electricity. Off-site

power generation is assumed to have a heat rate of about 10,000 Btu/kWh. Savings are calculated by dividing total energy saving s, including powerplant inputs, by total facility energy use.

5. Heat Recovery & Cogeneration Wise Rules Page 21Page 22 Wise Rules 6. Compressed Air Systems S everal compr essed air system efficiency measures may be of inter

est to Climate W ise P ar tners, including using cooler intake air, optimizing load, r educing pr essur e, eliminating or r educing air use, r epairing leaks, r ecovering waste heat, r eplacing filters, and cleaning coolers. T ypical energy savings for these types of air com

pr essor measur es ar e illustrated in Compr essed Air F igur e 1, based on specific r ecommendations in the DOE/IA C database. Air com

pr essor efficiency measur es can be made at most facilities and w er e

Energy Savings Recommendation Rate Upgrading Screw Compressor Controls 

### Compressed Air Figure 1 

### Energy Savings from Air Compressor Efficiency Measures*

Energy Savings Rate (percent of total facility energy use) Entire Compressed Air System (5 month payback) Using Cooler Intake Air (5 month payback)

(8 month payback) Compressor Pressure Reduction (4 month payback) Eliminating or Reducing Compressed Air Use (6 month payback) Recommendation Rate 0% 30% 10% 20% 50% 40% 60% 70%

0% Repairing Air Leaks (3 month payback) Air Compressor W aste Heat Recovery (10 month payback)
1.8% 0.3% 0.9% 0.6% 1.2% 1.5% 

# 6. C ompressed A ir S ystems Intr oduction 

# C ompr essed air is used to power tools and machines, to r egu late HV AC systems, and for drying or cleaning various items. The two main types of air compr essors ar e r ecipr ocating com

pr essors and scr e w compr essors. Scr e w compr essors generally use mor e energy than r ecipr ocating compr essors, especially when they ar e o v ersiz ed. Compr essor energy use is a function of many
v ariables including compr essor type, par t-load efficiency , and contr ol mechanisms. 1

* Results from the DOE/IAC Database (1/90-7/97). The IAC data reflect average potential impacts from energy efficiency measures at small-to-medium sized manufacturing

facilities across all sectors and regions of the country. Most IAC audit recommendations are expected to be implemented within two years and typically have a one-to-two year payback period. (See Chapter 1.)r ecommended at 68 per cent of the 4,300 IA C audits conducted fr om 1990 to mid-1997. Using cooler intake air and r epairing air leaks wer e r ecommended at mor e than a thir d of facilities audited. A

verage expected savings ar e r elatively small — less than a half per cent of a facility ’ s total energy use. H ow ever , these measur es tend to have r elatively shor t payback periods (about 5 months) and r educe electricity use, a relatively expensive energy sour ce with high CO 2 emission rates in many r egions. S ome measur es have higher impacts. F or example, air compr essor waste heat r ecovery can r educe facility energy use b y almost two per cent. Compr essed Air T able 2 , at the end of this chapter, summariz es the W ise R ules pr esented in this chapter , along with cost savings estimates, wher e available. The range of compr essor efficiency measur es is br oad. Air com

pr essor energy use may r epr esent 5 to 15 per cent of a typical facil

ity

’ s energy use, depending upon pr ocess needs.

Compr essed Air W ise Rule 1 

### E fficiency impr o v ements can r educe compr essed air system energy use b y 20% to 50%. 2 Compr essed Air W ise Rule 2 

### E fficiency impr o v ements to compr essed air systems can save appr o ximately one-half per cent of a facility ’ s total energy use. 3 

# Use Cooler Intake Air The amount of energy r equir ed to compr ess air is a function of the intake air temperatur e, with warm air r equiring mor e energy to compr ess than cool air

. Ther e is a potential for energy savings when cooler air , typically fr om outside, is used in place of warmer compr essor r oom air. O ften piping can be installed to supply cool

er outside air to the compr essor intake. E nergy and cost savings for this measur e will depend on compr essor siz e, load factor , and the number of hours of operation. 4 Compr essed Air W ise Rule 3 

### Using cooler intake air for compr essors can r educe compr essed air system energy use b y 1% per 5 ° F r educ

tion in intake air temperatur e. 5 

### The payback period for this measur e is usually less than two years. 6 Compr essed Air W ise Rule 4 

### Using cooler intake air for compr essors can save almost one-half per cent of a facility ’ s total energy use with an average simple payback of 5 months. 7 

# Match Compr essor with Load Requir ement M atching the compr essor siz e with load can r esult in significant energy savings. B ecause air compr essors can consume 16 to 100 per

cent of full load pow er at low loads, it is a good idea to optimiz e compressor loading to minimiz e operation at low output levels. 8 This optimization can be achieved with unloading contr ols, auto

matic shutdown timers, and manual or automatic compr essor sequencing. U nloading contr ols cost about $500 to install at the factory and about $1,000 to r etrofit; automatic on/off timers cost about $300 to install. Y ou might also consider pur chasing a small compressor for smaller loads to av oid lo w-load operation of a large compressor . 9 Compr essed Air W ise Rule 5 

### I nstalling or adjusting unloading contr ols can r educe compr essed air system energy use b y about 10%. 10 Compr essed Air W ise Rule 6 

### U

pgrading contr ols on scr e w air compr essors can r educe a facility ’ s total energy use b y about 1% with an av erage simple payback of 8 months. 11 

# Reduce Compr essor Air Pr essur e Air is often compr essed to a higher pr essur e than r equir ed b y the pr ocess equipment. Lo w ering air pr essur e r educes compr essor demand and energy use. B e sur e to determine the minimum r equir ed pr essur e befor e implementing this measur e. Consider r educing compr essor operating pr essur e if it is higher than 10 psi above that r equir ed b y the pr ocess equipment (ex cept with long delivery lines or high pr essur e dr ops). 12 E nergy savings depend on the compr essor type, pow er rating, load factor , use factor , horse

pow er r eduction factor , and the pr oposed pr essur e change. 13

6. Compressed Air Systems Wise Rules Page 23Page 24 Wise Rules 6. Compressed Air Systems Compr essed Air W ise Rule 7 

### R

educing air compr essor pr essur e can r educe a facili

ty ’

s total energy use b y about one-half per cent with an av erage simple payback of 4 months. 14 Compr essed Air W ise Rule 8 

### R

educing air compr essor pr essur e b y 2 psi can r educe compr essor energy use b y 1% (at 100 psi). 15 

# Reduce or Eliminate Compr essed Air Use I n some facilities, compr essed air use can be r educed or eliminated entir ely . Less expensive alternatives may exist for pr ocesses such as cooling, agitating liquids, or mo ving pr oducts. I n addition, some air-pow ered tools (e.g., grinders) can be r eplaced b y high fr equen cy electric tools. R educing compr essed air use may r esult in an exist

ing compr essor operating at r educed load and lo w er efficiency . I f the r eductions ar e significant, you may need to r e-optimiz e loading sequence or contr ols, or change to a smaller compr essor . Compr essed Air W ise Rule 9 

### E liminating or r educing compr essed air usage for cer

tain activities can r educe a facility ’ s total energy use b y mor e than one-half per cent, with an average simple payback of 6 months. 16 

# Eliminate Air Leaks Compr essed air distribution system leaks along piping, ar ound valves, fittings, flanges, hoses, traps, and filters can r esult in signif

icant energy losses in manufacturing facilities. T ypical leakage rates range fr om two to 20 per cent of system capacity . I n poorly main

tained systems, leakage rates can be as high as 40 per cent. 17 The cost of compr essed air leaks incr eases exponentially as the siz e of the hole incr eases. Compr essed Air T able 1 presents average energy losses for air leaks of v arious siz es. Leaks ar e often audible when the system is pr essuriz ed but equipment is not r unning (e.g., during breaks or after hours). Wher e y ou suspect a slow leak, use a soapy water solution or an ultrasonic detector to pinpoint its location. 18 When r epairing compr essed air leaks, it is impor tant to consider the effect on compr essor loading. I f the r eductions ar e significant, y

ou may need to r e-optimiz e loading sequence or contr ols. Compr essed Air W ise Rule 10 

### R

epairing air leaks can r educe compr essed air system energy use b y 30% or mor e. 19 Compr essed Air W ise Rule 11 

### R

epairing air leaks can r educe a facility ’ s total energy use b y about one-half per cent, with an average simple payback of 3 months. 20 Compr essed Air W ise Rule 12 

### I t takes appr o ximately 2.5 to 5.0 kWh to compr ess 1,000 ft 3 

### of air to 100 psi. 21,22 

### Each psi r eduction in compr essed air loss fr om the distribution system (at 100 psi), r educes the compr essor ’ s energy use b y mor e than one-half per cent. 23 

# Recover W aste Heat S ixty to 90 per cent of the energy of compr ession is available as heat that can be recover ed. 25 R ecover ed waste heat may be used for space heating or to supply heat to a manufacturing pr ocess. The amount of heat energy that can be r ecover ed depends on com

pr essor characteristics and use factor

. W aste heat r ecovery will be most cost-effectiv e when the compr essor is located near the pr ocess in which the heat is to be used. 26 Air compr essors 100 hp and larger ar e often cooled with water fr om a cooling to wer. The temperatur e of the water leaving the compr essor cooling coils may be high enough that heat can be extracted and applied else wher e. 

### Compr essed Air T able 1 

### Ener gy Losses and Cost Impacts of Compr essed Air System Leaks 24



### Hole Leak Rate Ener gy Loss Cost of Diameter W asted Ener gy (inches) (cubic feet/min.) (kWh per year) (dollars per year) 1/64" 0.5 635 $20 1/32" 1.8 2,500 $90 1/16" 7.2 10,800 $350 1/8" 29.0 43,800 $1,500 1/4" 115.8 174,100 $5,900 3/8" 260.6 392,000 $13,200 Based on a 115 psi system with 8,520 hours of compressor operation. Electricity price is assumed to be $0.034 per kWh.6. Compressed Air Systems Wise Rules Page 25 F or example, boiler feedwater could be pr eheated b y the compr es sor cooling water

. Compr essed Air W ise Rule 13 

### Air compr essor waste heat r eco v er y can r educe a facil

ity ’ s total energy use b y about 2% with an average simple payback of 10 months. 27 

# Filters and Coolers Compr essed air system efficiency suffers as compr essed air system filters and coolers become soiled. When filters ar e obstr ucted with pipeline contaminants, significant pr essur e dr ops can develop , r equiring an incr ease in compr essor discharge pr essur e. As a r esult of the pr essur e incr ease, air leaks will become mor e costly

. 28 Compr essed Air W ise Rule 14 

### F or ev er

y 1 psi increase in air compressor pressure gained by periodic filter changes, air compr essor energy use is reduced by about one-half per cent. 29 

### Changing dry er fil

ters at 8 or 10 psi dr op per filter can eliminate this waste. Compr essed Air W ise Rule 15 

### F or ev ery 11 ° F decrease in air compressor wor king tem

perature, gained by careful maintenance of intercoolers, air compr essor energy use will decreased by 1%. 30 

# Summar y of Wise Rules for Compr essed Air Systems U

se the W ise R ules in Compr essed Air T able 2 (next page) to iden

tify and estimate potential energy saving fr om air compressor effi

ciency measur es. When ev aluating efficiency options, consider potential costs, savings, payback and any secondar y effects. While some of the measur es in Compr essed Air T able 2 yield modest potential savings as a per cent of total facility energy use, the cost and CO 2 savings can be significant because most air compr essors are dri

v

en by electricity

. When using the W ise R ules, remember that sev

eral of the measur es may ov erlap or complement each other and energy savings rates may not be additiv e. I n addition, W ise R ules for similar measur es are addressed fr om different perspectives. S ome are stated in terms of the air compr essor ’ s energy use, others in terms of a facility ’ s total energy use, or as a function of a physical parameter (e.g., change in energy use with a change in pr essure). 

### Compr essed Air Notes 1 Talbott, E.M., Compressed Air Systems: A Guidebook on Energy and Cost Savings, 2nd Edition, Fairmont Press, 1992, p. 160. 2 Oregon State University, AIRMaster Compressed Air System Audit and Analysis Software, “ How to Take a Self-Guided Tour of Your Compressed Air System, ” 1996 revised in 1997, p. 2. (SelfGuided Tour) 3 DOE/IAC Industrial Assessment Database, July 1997. 4 Rutgers University, Office of Industrial Productivity & Energy Assessment (OIPEA), Modern Industrial Assessments: A Training Manual, Version 1.0b, 1995, p. 6-28. 5 Oregon State University, Self-Guided Tour, p. 5. 6 Rutgers, p. 6-28. 7 DOE/IAC Database. 8 Oregon State University, AIRMaster Compressed Air System Audit and Analysis Software Version 1.4, “ Analysis Methodology Manual for AIRMaster,” 1996 revised in 1997, p. 32. 9 Oregon State University, AIRMaster Compressed Air System Audit and Analysis Software, “ Case Studies: Compressed Air System Audits Using AIRMaster,” 1996 revised in 1997 pp. 20-21. 10 Oregon State University, AIRMaster Case Studies, p. 12. 11 DOE/IAC Database. 12 Rutgers, p. 6-17. 13 Rutgers, p. 6-17. 14 DOE/IAC Database. 15 Oregon State University, Self-Guided Tour, p. 8. 16 DOE/IAC Database. 17 Talbott, E.M., p. 112. 18 Oregon State University, Self-Guided Tour, p. 8. 19 Oregon State University, Self-Guided Tour, p. 8. 20 DOE/IAC Database. 21 ICF Kaiser Consulting Group estimate based on Talbott, p. 77; 3M, “Compressed Air Optimization,” 1994, p. 9. 22 Bonneville Power Administration, Industrial Compressed Air System Energy Efficiency Guidebook, 1996, p. 2-2 and p. 4-5. 23 Talbott, p. 93. 24 Rutgers, p. 6-22. 25 Talbott, p. 91. 26 Rutgers, p. 6-16. 27 DOE/IAC Database. 28 Oregon State University, Self-Guided Tour, p. 9. 29 3M, “ Compressed Air Optimization,” 1994, p. 9. 30 3M, p. 9.Source references for each Wise Rule are included in the chapter notes. * Percent of compressed air system energy use, unless noted. ** Based on compressed air system pressure of approximately 100 psi.

Page 26 Wise Rules 6. Compressed Air Systems 

### Compr essed Air T able 2: Summar y of Compr essed Air Ef ficiency Measur es Sour ce Measur e A verage Ener gy Savings* A verage Annual Cost Savings (IAC recommendation rate) (payback) 

### All Ef ficiency Impr ovements Rule 1 I mplement typical efficiency impr o v

ements, 20% to 50% which may include many or all of the measur es belo w Rule 2 I mplement typical efficiency impr o v

ements, 0.4% of total facility energ y use $4,300 (5 months) which may include many or all of the measur es belo w (68%) 

### Use Cooler Outside Air Rule 3 U se cooler air for intakes 1% per 5 ° F r eduction less than 2 y ears Rule 4 U se cooler air for intakes (37%) 0.2% of total facility energ y use $1,400 (5 months) 

### Optimize Load Rule 5 I nstall or adjust unloading contr ols 10% Rule 6 U pgrade scr ew compr essor controls (1%) 0.8% of total f acility energ y use $7,900 (10 months) 

### Reduce Compr essor Air Pr essur e Rule 7 R educe compr essor pr essur e (15%) 0.4% of total facility energ y use $2,800 (4 months) Rule 8 R educe compr essor pr essur e 1% per 2 psi r eduction** 

### Eliminate /Reduce Compr essed Air Use Rule 9 E liminate/r educe some uses of air (5%) 0.6% of total facility energ y use $7,300 (6 months) 

### Eliminate Air Leaks Rule 10 R epair air leaks 30% or mor e Rule 11 R epair air leaks (36%) 0.4% of total facility energ y use $3,900 (3 months) Rule 12 R educe air leaks in distribution system 0.7% decr ease in compr essor energ y use per 1 psi loss r eduction** T able 1 R epair 1/16" leak 7,560 kWh per leak per yr $360/yr 

### Recover W aste Heat Rule 13 R eco v

er waste heat from compr essors (8%) 1.8% of total facility energ y use $2,700 (10 months) 

### Change Filters and Clean Coolers Rule 14 Change dr y

er filters at 8 to 10 psi drop 0.5% per av oided 1 psi drop in pr essur e Rule 15 Clean intercoolers to r educe 1% per 11 ° F r eduction compr essor wor king temperatur e

# Ener gy Ef ficient Chillers and Refrigeration Units Ther e ar e sev eral energy efficiency options available when installing ne w chilling equipment. F or example, oversizing con

denser water supply pipes can r educe head pr essur e and pumping r equir ements. E vaporative cooled chillers consume considerably less energy per ton of cooling capacity then water- and air-cooled chillers. Using high efficiency compr essors can also r educe chiller energy use. Pr ocess Cooling W ise Rule 1 

### I nstalling energy efficient chillers and r efrigeration systems can save about 1% of a facility ’ s total energy use with an average simple payback of 23 months. 1

7. Process Cooling Wise Rules Page 27 Energy Savings Recommendation Rate Chillers and Refrigeration 

### Process Cooling FIgure 1 

### Energy Savings from Process Cooling Efficiency Measures* Recommendation Rate

Energy Savings Rate (percent of total facility energy use) Process Cooling (20 month payback) Cooling T ower Measures (14 month payback)

(23 month payback) 0%

0% 1% 2% 6% 3% 4% 5%

1.2% 0.2% 0.6% 0.4% 0.8% 1.0% 

# 7. P rocess C ooling Intr oduction 

# M any manufacturing pr ocesses r equir e that materials or com

ponents be cooled to lo wer temperatur es. Chillers, heat pumps and other r efrigeration equipment used as heat sinks for a
variety of industrial pr ocesses. Efficiency measur es for pr ocess cooling include using cooling to wer water in place of r efrigeration or chilling, modifying the r efrigeration system to operate at a lo w er pr essur e, incr easing chilled water temperatur es, and using variable speed drives ( VSDs). P rocess Cooling F igur e 1 illustrates the potential energy savings fr om pr ocess cooling efficiency measur es based on specific recom mendations in the DOE/IAC database. P r ocess cooling measur es w

er e r ecommended during six per cent of the IAC audits with esti

mated savings of about one per cent of a facility ’ s total energy use and a simple payback of 20 months. Cooling to w er measur es wer e r ecommended at thr ee per cent of audited facilities, with estimated energy savings of almost one per cent and a 14 month simple pay

back. P rocess Cooling T able 2 , at the end of this chapter , sum mariz es the W ise R ules pr esented in this chapter , along with cost savings estimates, wher e available.

* Results from the DOE/IAC Database (1/90-7/97). The IAC data reflect average potential impacts from energy efficiency measures at small-to-medium sized manufacturing

facilities across all sectors and regions of the country. Most IAC audit recommendations are expected to be implemented within two years and typically have a one-to-two year payback period. (See Chapter 1.)

# Cooling T ower W ater Using cooling tower water in place of a chiller can dramatically r educe cooling energy use when the outside temperatur e is lo w enough to achiev e the r equir ed pr ocess temperatur e. This method of cooling is r eferr ed as “ fr ee cooling ” because the chiller is not used. Pr ocess Cooling W ise Rule 2 

### “F r ee cooling ” with cooling tower water can r educe a facility ’ s total energy use b y about 1% with an average simple payback of 14 months. 2 Pr ocess Cooling W ise Rule 3 

### F ree cooling can reduce cooling system energy use by as much as 40% depending on location and load profile. 3 

# Refrigeration and Chillers R

educing the cooling load is a dir ect appr oach to cutting chiller energy use. A cooling system audit may identify oppor tunities for impr oving insulation and eliminating unnecessar y heat sour ces. Raising the chilled water set temperatur e can also r educe chiller energy use. B y monitoring the minimum r equir ements on the chilled water temperatur e, the chiller can be r eset appr opriately to meet the demands of the system without wasting energy

. R

efrigerant subcooling decr eases the load on the compr essor and r educes chiller energy use. Ov ersizing or continuous operation of cooling tow ers can lower condenser cooling water temperatur e and r educe cooling system energy use. Car eful system maintenance and r emoval of non-condensable fluids can lo w er operating pr es sur e and save energy . Pr ocess Cooling W ise Rule 4 

### I ncr easing chilled water temperatur e b y 1 ° F 

### r educes chiller energy use b y 0.6% to 2.5%. 4 

### (S ee P r ocess Cooling T able 1 for data on specific chiller types.) Pr ocess Cooling W ise Rule 5 

### R

educing condenser pr essur e b y 10 psi can decr ease r efriger ation system energy use per ton of r efrigeration (kW/ton) b y about 6%. 6 Pr ocess Cooling W ise Rule 6 

### F or each 1 ° F decr ease in condenser cooling water temperatur e, until optimal water temperatur e is r eached, ther e is a decr ease in chiller energy use b y up to 3.5%. 7 

# Fr eezing The fr ee zing pr ocess in a manufacturing facility can be made mor e efficient b y r educing heat loss thr ough the use of impr oved insu

lation (such as air locks) and b y fr ee zing pr oducts in batches rather than continuously

. Pr ocess Cooling W ise Rule 7 

### E liminating heat losses fr om leaks and impr oper defr osting can r educe r efriger ation system energy use b y 10% to 20%. 8 Pr ocess Cooling W ise Rule 8 

### F r ee zing pr oducts in batches rather than continuously can r educe fr eezing pr ocess energy use b y up to 20%. 9

Page 28 Wise Rules 7. Process Cooling 

### Pr ocees Cooling T able 1 

### Ener gy Savings fr om Incr easing Chilled W ater T

emperatur e 5 

### Chiller T ype Ener gy Savings (Energy Savings per 1 ° F Increase in Temperature) Scr ew Compr essor 2.5% Centrifugal Compr essor 1.7% R

eciprocating Compr essor 1.2% A

bsorption Chiller 0.6%

### Pr ocess Cooling Notes 1 DOE/IAC Industrial Assessment Database, July 1997. 2 DOE/IAC Database. 3 ICF Kaiser Consulting Group estimate based on D. Murphy, “Cooling

Towers Used for Free Cooling,” ASHRAE Journal , June 1991, pp. 16-26. 4 Clevenger, L. and J. Hassel, “Case Study: From Jump Start to High Gear –

How DuPont is Cutting Costs by Boosting Energy Efficiency,” Pollution Prevention Review , Summer 1994, p. 304. 5 Clevenger and Hassel, p. 304. 6 Bonneville Power Administration (BPA), Washington State Energy Office,

Electric Ideas Clearinghouse, “Improving Industrial Refrigeration Energy Efficiency,” October 1991, p. 3. 7 Bonneville Power Administration (BPA), Washington State Energy Office,

Electric Ideas Clearinghouse, “Optimizing Cooling Tower Performance,” November 1991, p. 1. 8 Centre for the Analysis and Dissemination of Demonstrated Energy

Technologies (CADDET), Newsletter No. 4 December 1996, p. 16. 9 CADDET, p. 16. 10 York International, “HVAC&R Engineering Update: Examining Part-Load

Performance Gives You the Full Story on Chiller Efficiency,” 1994. 

# V

ariable Speed Drives The application of v ariable speed driv es ( VSD) can r educe energy use when cooling loads v ary over time. VSDs can be applied to the compr essor within the chiller or , in some situations, utiliz ed in chilled water distribution. Pr ocess Cooling W ise Rule 9 

### I nstalling variable speed drives in place of constant speed systems can r educe cooling system energy use b y 30% to 50%, depending on load pr ofile. 10 

# Summar y of Wise Rules for Pr ocess Cooling Systems P rocess Cooling T able 2 (next page) summariz es P r ocess Cooling W

ise R ules contained in this chapter

. These W ise R ules can be used to identify and estimate potential energy saving fr om boiler efficiency measur es. When evaluating options, consider potential costs, savings, payback times, and any secondar y impacts. When using the W ise R ules, r emember that sev eral of the measur es may overlap or complement each other and energy savings rates may not be additive. I n addition, multiple W ise R ules may expr ess savings for similar measur es fr om differ ent perspectives: in terms of a facility ’ s total energy use, an end-use ’ s or pr ocess ’ energy use, or as a function of a physical parameter such as temperatur e.

7. Process Cooling Wise Rules Page 29

### Pr ocess Cooling T able 2: Summar y of Pr ocess Cooling Ef ficiency Measur es Sour ce Measur e A verage Ener gy Savings A verage Annual Cost Savings (IAC recommendation rate) 

### and (Payback)
I mplement typical efficiency impr o v

ements, 1.1% of total facility energ y use $11,200 (20 months) which may include many or all of the measur es belo w (6%) Rule 1 I nstall energ y efficient chillers and 1.2% of total facility energ y use $11,200 (23 months) r efr

igeration units (3%) 

### Cooling T owers Rule 2 U se cooling to w

er to r eplace 0.8% of total facility energ y use $11,000 (14 months) chiller for fr ee cooling (3%) Rule 3 U se fr ee cooling up to 40% of cooling system energ y 

### Refrigeration and Chillers Rule 4 I ncr ease chilled water temperatur e 0.6% to 2.5% r eduction in energ y input per 1 ° F incr ease Rule 5 R educe condenser pr essur e 6% decr ease in r efrigeration energ y use per ton for each 10 psi r eduction Rule 6 D ecr ease condenser wor king temperatur e 3.5% r eduction in chiller energ y for each 1 ° F decr ease 

### Fr eezing Rule 7 R educe heat loss and improper defrosting 10% to 20% decr ease in fr eezer energ y use Rule 8 U se continuous fr eezing 20% decr ease in fr eezer energ y use Rule 9 I nstall v ar

iable speed driv es 30% to 50% r eduction in cooling energ y use

Page 30 Wise Rules 7. Process Cooling Source references for each Wise Rule are included in the chapter notes.Appendix A Wise Rules Page 31 

### T

able A-1: SIC Code Definitions SIC Code Classification 20 F ood and Kindr ed P r oducts 21 T obacco* 22 T extile M ill P r oducts 23 A pparel and O ther T extile Pr oducts 24 L umber and W ood P r oducts 25 F urniture and F ixtures 26 Paper and Allied Pr oducts 27 P rinting and Publishing 28 Chemicals and Allied P r oducts 29 P etroleum and Coal Pr oducts 30 R ubber and M isc. P lastics Pr oducts 31 Leather and Leather P r oducts 32 S tone, Clay and Glass P r oducts 33 P rimar y M etal I ndustries 34 F abricated M etal I ndustries 35 I ndustrial M achiner y and E quipment 36 Electronic and O ther E lectric E quipment 37 T ranspor tation E quipment 38 I nstr uments and R elated Pr oducts 39 M isc. M anufacturing I ndustries *Only three IAC audits were conducted for SIC 21 (1/91-7/97). 

# A ppendix A S ector -S pecific E nergy P otential I n this appendix, we pr esent examples of sector-specific savings

fr om the DOE IAC database. The IAC audit database contains information on the expected impacts fr om energy efficiency measur es r ecommended at small-to-medium siz ed manufactur

ing facilities. IAC audits typically r ecommend measur es with shor t (one to two year) payback periods. The energy and cost savings r epr esent averages acr oss industr y gr oups, years, and r egions.

“ A

verage per cent energy savings ” ar e defined as the av erage r eduction in a facility ’ s total energy use r esulting fr om the imple

mentation of a specific r ecommendation. F or example, a typical facility in the food industr y (SIC 20) could expect to sav e about six per cent of their total facility energy use b y implementing the measures recommended during an IAC audit (refer to T able A-2 ). The average simple payback period is defined as the amount of time it takes to r ecover initial inv estment costs thr ough energy savings. T

able A-1 pr ovides the definition of the S tandar d I ndustrial Classification (SIC) codes for manufacturing industries.Page 32 Wise Rules Appendix A 

### T

able A-2: A verage Impacts of All Ener gy Ef ficiency Measur es Recommended by IAC Audits, by Sector* SIC Code & Manufacturing A verage Annual A verage Annual A verage A verage Annual A verage Classification Ener gy Savings Ener gy Savings Implementation Cost Savings Simple (% of total facility (MMBtu) 

### Cost (dollars) 

### Payback energy use) (dollars) (months) 20 Food and Kindr ed Pr oducts 6.2% 4,400 78,000 41,000 23 21 T obacco** 4.4% 8,800 85,000 52,000 19 22 T extile Mill Pr oducts 6.8% 8,300 103,000 64,000 19 23 Appar el and Other T extile Pr oducts 8.8% 1,700 22,000 21,000 13 24 Lumber and W ood Pr oducts 4.7% 7,600 86,000 56,000 19 25 Fur nitur e and Fixtur es 12.3% 3,700 47,000 29,000 20 26 Paper and Allied Pr oducts 8.5% 7,900 65,000 51,000 15 27 Printing and Publishing 7.1% 1,800 42,000 26,000 20 28 Chemicals and Allied Pr oducts 5.7% 6,200 66,000 37,000 21 29 Petr oleum and Coal Pr oducts 13.4% 16,400 189,000 80,000 28 30 Rubber and Misc. Plastics Pr oducts 4.2% 2,500 43,000 35,000 15 31 Leather and Leather Pr oducts 4.0% 1,300 25,000 18,000 16 32 Stone, Clay and Glass Pr oducts 5.2% 16,800 183,000 98,000 22 33 Primar y Metal Industries 7.0% 5,700 57,000 46,000 15 34 Fabricated Metal Industries 7.2% 2,900 33,000 27,000 14 35 Industrial Machinery and Equipment 5.9% 2,200 31,000 25,000 15 36 Electr onic and Other Electric Equipment 8.5% 3,200 51,000 39,000 16 37 T ransportation Equipment 7.3% 2,600 38,000 30,000 15 38 Instr uments and Related Pr oducts 8.8% 2,300 41,000 32,000 15 39 Misc. Manufacturing Industries 9.7% 2,300 30,000 24,000 15 * Based on DOE/IAC estimates at audits of 4,300 manufacturing companies (1/90-7/97). Savings may not be additive. ** Only three IAC audits were conducted for Tobacco companies (SIC 21).Appendix A Wise Rules Page 33 

### T

able A-3: Food and Kindr ed Pr oducts Sector*(SIC 20) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Miscellaneous Heat Recover y 1% 21.2% 18,500 144,300 54,800 32 Steam Operations 2% 8.2% 4,800 400 11,400 0 Cogeneration** 5% 5.5% 7,100 705,900 229,000 37 Boiler Har dwar e 3% 5.5% 2,000 15,200 7,600 24 Other Pr ocess W aste 7% 5.2% 3,700 19,600 13,600 17 Heat Recover y Heat Recover y fr om Equipment 15% 4.5% 2,700 15,600 10,000 19 Chillers and Refrigeration 12% 3.2% 1,900 26,300 15,200 21 Flue Gas Recuperation 8% 2.9% 2,300 11,700 7,100 20 Boiler Maintenance 36% 2.3% 2,000 1,200 5,600 3 Steam Condensate 9% 2.3% 1,300 3,100 6,900 5 Ther mal System Insulation 23% 2.2% 1,700 4,200 3,400 15 Steam Leaks and Insulation 20% 0.9% 900 1,600 3,200 6 Motor Har dwar e 62% 0.6% 470 11,300 6,300 22 Air Compr essor Operations 35% 0.5% 300 1,400 3,600 5 Lighting Har dwar e 75% 0.4% 250 5,800 4,200 17 * Calculations based on IAC estimates at audits of 527 companies in SIC 20 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Page 34 Wise Rules Appendix A 

### T

able A-4: T extile Mill Pr oducts*(SIC 22) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Cogeneration** 3% 16.0% 9,700 211,000 111,000 23 Steam Operations 2% 7.7% 15,400 9,000 42,000 3 Heat Recover y fr om 10% 5.6% 4,700 11,000 15,000 9 Equipment Other Pr ocess W aste 13% 4.1% 5,500 22,000 19,000 14 Heat Recover y Boiler Har dwar e 5% 3.4% 6,000 60,000 21,000 34 Steam Condensate 10% 2.6% 4,200 16,000 14,000 13 Flue Gas Recuperation 13% 2.2% 4,900 19,000 14,000 16 Boiler Maintenance 27% 1.8% 2,500 15,000 13,000 14 Ther mal System 26% 1.3% 1,200 4,000 5,000 10 Insulation Steam Leaks and 22% 0.8% 1,300 1,000 4,000 4 Insulation Lighting Har dwar e 77% 0.7% 850 38,000 13,000 35 Motor Har dwar e 64% 0.5% 700 26,700 9,200 34 Air Compr essor Operations 49% 0.5% 600 3,000 7,000 5 Air Compr essor Har dwar e 36% 0.5% 500 2,000 5,000 5 Motor Operations 49% 0.4% 600 11,000 7,000 18 * Calculations based on IAC estimates at audits of 144 companies in SIC 22 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Appendix A Wise Rules Page 35 

### T

able A-5: Appar el and Other T extile Pr oducts* (SIC 23) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Miscellaneous Cooling 1% 46.2% 4,000 240,000 84,600 34 Space Conditioning 19% 8.3% 600 2,200 4,500 6 Contr ols Flue Gas Recuperation 4% 6.7% 650 5,600 3,300 20 Building Envelope 4% 5.3% 450 1,200 2,500 6 Infiltration Air Cir culation Har dwar e 12% 4.9% 750 4,200 10,300 5 Space Conditioning 15% 4.3% 700 3,200 8,600 4 Operation Other Pr ocess W aste 5% 3.5% 350 1,700 2,100 9 Heat Recover y Heat Recover y fr om 19% 3.0% 350 2,000 1,400 17 Equipment Lighting Operation 21% 2.9% 400 8,200 7,600 13 Ther mal System 15% 2.7% 1,700 3,600 6,800 6 Insulation Lighting Har dwar e 81% 1.7% 300 10,300 5,800 21 Steam Leaks and 16% 1.6% 600 950 1,700 7 Insulation Boiler Maintenance 21% 1.2% 400 1,300 2,000 7 Motor Har dwar e 35% 0.7% 150 6,700 2,500 33 Air Compr essor 51% 0.5% 100 350 1,600 2 Operations * Calculations based on IAC estimates at audits of 113 companies in SIC 23 (1/90 - 7/97). Savings may not be additive.Page 36 Wise Rules Appendix A 

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able A-6: Lumber and W ood Pr oducts* (SIC 24) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Air Cir culation 1% 11.0% 1,000 11,900 4,800 30 Har dwar e Heating/Cooling 4% 8.0% 800 6,600 5,100 15 Har dwar e Boiler Maintenance 14% 7.0% 13,100 2,900 18,100 2 Boiler Operation 3% 4.8% 27,700 9,700 19,800 6 Cogeneration** 6% 4.6% 41,700 680,000 297,000 27 Heat Recover y 10% 2.0% 700 8,100 2,700 36 fr om Equipment Steam Leaks and 11% 1.7% 4,800 3,000 5,800 6 Insulation Space Conditioning 7% 1.4% 350 1,000 2,600 5 Contr ols Ther mal System 9% 0.8% 1,900 4,600 3,300 17 Insulation Air Compr essor 63% 0.3% 650 5,800 8,400 8 Operations Motor Har dwar e 74% 0.2% 450 17,000 7,000 29 Motor Operations 55% 0.2% 250 7,100 3,700 23 * Calculations based on IAC estimates at audits of 213 companies in SIC 24 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Appendix A Wise Rules Page 37 

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able A-7: Fur nitur e and Fixtur es* (SIC 25) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Cogeneration** 5% 17.4% 17,400 402,900 117,000 41 Boiler Har dwar e 2% 14.1% 15,600 2,300 38,700 1 General V entilation 8% 7.7% 3,000 19,800 10,800 22 Other Pr ocess 5% 7.7% 3,400 11,700 12,500 11 W

aste Heat Recovery Heat Recover y 21% 6.4% 1,800 4,700 6,200 9 fr om Equipment Ther mal System 11% 5.8% 2,500 14,000 7,400 23 Insulation Space Conditioning 16% 3.8% 700 4,100 5,000 10 Operation Space Conditioning 11% 3.8% 500 2,100 3,100 8 Contr ols Boiler Maintenance 9% 3.4% 800 1,000 1,500 9 Building Envelope 15% 2.9% 750 5,400 2,800 23 Infiltration Air Cir culation 10% 2.8% 550 6,500 3,500 22 Har dwar e Equipment Use 18% 2.1% 500 450 4,400 1 Reduction Lighting Har dwar e 77% 1.0% 200 7,500 4,500 20 Air Compr essor 60% 0.7% 250 950 3,400 3 Operations Motor Har dwar e 50% 0.5% 150 7,000 3,800 22 * Calculations based on IAC estimates at audits of 109 companies in SIC 25 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Page 38 Wise Rules Appendix A 

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able A-8: Paper and Allied Pr oducts* (SIC 26) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Mechanical System 1% 43.1% 62,500 219,400 161,000 16 Design Flue Gas-Other Uses 2% 19.2% 33,700 69,800 98,200 9 Cogeneration** 4% 11.0% 29,500 400,100 275,900 17 Other Pr ocess W aste 6% 7.5% 15,900 72,700 39,200 22 Heat Recover y Steam T rap Management 3% 7.0% 4,400 2,300 21,000 1 Heating/Cooling 4% 4.7% 1,200 35,200 9,900 43 Har dwar e Miscellaneous Building 4% 4.6% 2,400 19,700 6,500 36 Envelope Boiler Operation 7% 2.9% 2,300 3,000 8,200 4 Building Envelope 12% 2.5% 1,100 13,900 4,300 39 Infiltration Heat Recover y 15% 1.9% 2,500 10,300 7,600 16 fr om Equipment Space Conditioning 10% 1.9% 850 2,500 4,300 7 Contr ols Boiler Maintenance 25% 1.2% 1,900 4,200 6,100 8 Lighting Har dwar e 78% 0.5% 350 9,700 6,900 17 Air Compr essor 39% 0.5% 300 1,100 4,600 3 Operations Motor Har dwar e 61% 0.4% 450 14,600 8,200 21 * Calculations based on IAC estimates at audits of 226 companies in SIC 26 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Appendix A Wise Rules Page 39 

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able A-9: Printing and Publishing* (SIC 27) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Heating/Cooling Har dwar e 7% 5.6% 450 26,700 9,600 33 Flue Gas Recuperation 3% 4.2% 2,000 15,600 8,300 23 Space Conditioning 19% 4.0% 850 4,100 4,500 11 Contr ols Heat Recover y fr om 16% 3.5% 1,000 5,600 5,200 13 Equipment Boiler Har dwar e 4% 3.2% 800 12,200 4,300 34 Air Cir culation 7% 2.9% 400 4,900 2,300 25 Har dwar e Miscellaneous Building 10% 2.4% 800 16,000 5,000 37 Envelope Space Conditioning 25% 2.2% 300 3,000 2,900 13 Operation Equipment Use 12% 1.7% 600 46,100 4,700 118 Reduction Motor Har dwar e 42% 1.3% 300 6,900 5,400 15 Lighting Har dwar e 79% 1.0% 300 9,200 5,400 20 Building Envelope 15% 1.0% 250 1,100 1,300 11 Infiltration Air Compr essor 45% 0.8% 250 1,000 4,000 3 Operations Motor Operations 31% 0.5% 150 2,700 2,300 14 Lighting Contr ols 31% 0.4% 120 1,200 1,700 9 * Calculations based on IAC estimates at audits of 182 companies in SIC 27 (1/90 - 7/97). Savings may not be additive.Page 40 Wise Rules Appendix A 

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able A-10: Chemicals and Allied Pr oducts* (SIC 28) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Cogeneration** 4% 18.6% 11,400 772,000 147,900 63 General V entilation 1% 9.9% 900 1,500 3,700 5 Boiler Har dwar e 1% 9.9% 20,500 125,000 73,900 20 Flue Gas Recuperation 9% 5.1% 8,000 27,900 22,200 15 Heating/Cooling 5% 3.9% 1,900 56,300 19,600 34 Har dwar e Other Pr ocess W aste 7% 2.7% 7,400 13,000 21,000 8 Heat Recover y Boiler Maintenance 23% 2.2% 2,500 1,200 6,800 2 Space Conditioning 9% 2.2% 800 2,400 8,400 3 Operation Heat Recover y fr om 10% 1.9% 1,200 4,400 4,800 11 Equipment Steam Leaks and 17% 1.6% 4,600 2,300 8,800 3 Insulation Equipment Use 12% 1.5% 950 1,500 4,400 4 Reduction Air Compr essor 37% 0.8% 400 450 5,400 1 Operations Motor Har dwar e 62% 0.5% 450 15,000 6,000 30 Lighting Har dwar e 75% 0.3% 200 7,200 4,200 21 Motor Operations 34% 0.3% 500 1,700 2,700 8 * Calculations based on IAC estimates at audits of 191 companies in SIC 28 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Appendix A Wise Rules Page 41 

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able A-11: Petr oleum and Coal Pr oducts* (SIC 29) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Cogeneration** 3% 23.6% 262,200 4,815,000 1,247,700 46 Fur nace Operations 3% 19.6% 9,500 4,000 23,700 2 Other Equipment 3% 10.1% 16,000 47,900 46,000 13 Har dwar e Fur nace Har dwar e 3% 8.8% 950 0 3,800 0 Space Conditioning 3% 8.1% 2,000 400 7,000 1 Contr ols Flue Gas Recuperation 15% 7.8% 9,200 40,900 36,100 14 Boiler Har dwar e 6% 7.4% 2,300 11,000 6,400 21 Flue Gas-Other Uses 6% 5.3% 8,700 12,000 30,900 5 Heat Recover y fr om 6% 3.8% 15,300 117,900 44,400 32 Equipment Ther mal System 65% 3.7% 3,900 8,100 18,400 5 Insulation Steam T rap 6% 3.6% 3,300 4,700 9,500 6 Management Boiler Operation 12% 3.0% 2,300 6,700 7,500 11 Boiler Maintenance 21% 2.5% 2,900 3,300 9,500 4 Fur nace Maintenance 12% 1.7% 600 750 1,600 6 Steam Leaks and 32% 0.9% 1,200 1,400 6,200 3 Insulation * Calculations based on IAC estimates at audits of 34 companies in SIC 29 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Page 42 Wise Rules Appendix A 

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able A-12: Rubber and Misc. Plastics Pr oducts* (SIC 30) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Flue Gas Recuperation 4% 8.3% 8,000 19,800 20,600 12 Other Pr ocess W aste 3% 5.0% 2,300 24,200 11.600 25 Heat Recover y Other Equipment 7% 2.4% 650 20,100 11,300 21 Har dwar e Heating/Cooling 7% 2.3% 800 20,300 9,200 26 Har dwar e Boiler Maintenance 11% 2.2% 1,700 3,000 6,300 6 Heat Recover y 10% 2.2% 1,100 5,100 4,900 12 fr om Equipment Equipment Use 13% 2.1% 650 2,600 8,200 4 Reduction Space Conditioning 10% 2.0% 800 3,100 5,800 6 Operation Equipment Automation 13% 1.7% 450 2,800 7,400 5 Air Cir culation Har dwar e 10% 1.7% 650 6,900 4,300 19 Space Conditioning 12% 1.6% 500 1,300 3,700 4 Contr ols Ther mal System 33% 0.8% 500 3,000 6,300 6 Insulation Lighting Har dwar e 74% 0.5% 300 7,200 5,100 17 Motor Har dwar e 59% 0.5% 400 15,200 6,800 27 Air Compr essor 42% 0.4% 250 1,300 4,500 3 Operations * Calculations based on IAC estimates at audits of 440 companies in SIC 30 (1/90 - 7/97). Savings may not be additive.Appendix A Wise Rules Page 43 

### T

able A-13: Leather and Leather Pr oducts* (SIC 31) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Ther mal System 6% 7.3% 750 2,100 4,800 5 Infiltration Steam Maintenance 3% 5.9% 700 200 2,400 1 Steam T rap Management 6% 5.7% 1,400 1,700 4,500 5 Heating/Cooling 9% 5.3% 100 19,100 3,000 77 Har dwar e Space Conditioning 15% 3.8% 500 5,300 2,500 25 Operation Lighting Level 12% 2.3% 250 700 3,400 2 Steam Leaks and 21% 1.8% 1,200 1,600 4,100 5 Insulation Boiler Maintenance 21% 1.8% 1,100 2,500 3,400 9 Heat Recover y fr om 21% 1.4% 100 450 900 6 Equipment Lighting Har dwar e 61% 0.9% 300 18,100 7,700 28 Lighting Contr ols 18% 0.7% 200 1,000 1,700 7 Ther mal System 27% 0.6% 300 2,500 1,600 19 Insulation Air Compr essor 52% 0.5% 200 850 4,300 2 Operations Air Compr essor 58% 0.3% 70 600 1,400 5 Har dwar e Motor Har dwar e 39% 0.3% 200 7,700 5,000 18 * Calculations based on IAC estimates at audits of 33 companies in SIC 31 (1/90 - 7/97). Savings may not be additive.Page 44 Wise Rules Appendix A 

### T

able A-14: Stone, Clay and Glass Pr oducts* (SIC 32) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Miscellaneous Heat 1% 38.8% 7,400 32,300 36,900 11 Recover y Ther mal System 1% 23.7% 600 6,000 3,800 19 Isolation Cogeneration** 7% 10.2% 123,800 1,447,400 464,000 37 General Operations 1% 5.3% 1,000 6,000 4,600 15 Maintenance Flue Gas-Other Uses 6% 4.2% 27,700 46,100 65,800 8 Flue Gas Recuperation 9% 4.1% 14,800 54,300 33,400 19 Ther mal System 22% 2.4% 5,000 7,200 15,500 6 Insulation Heat Recover y 12% 2.3% 3,600 5,100 10,200 6 fr om Equipment Boiler Maintenance 11% 2.2% 2,300 1,000 8,900 1 Other Equipment 9% 2.2% 5,000 153,800 89,700 21 Har dwar e Other Pr ocess W aste 6% 2.2% 6,300 23,500 19,000 15 Heat Recover y Building Envelope 8% 1.4% 4,700 1,800 10,600 2 Infiltration Boiler Operation 4% 1.4% 2,600 3,400 7,600 5 Motor Har dwar e 70% 0.3% 1,100 30,800 15,000 25 Air Compr essor 56% 0.3% 850 3,200 9,800 4 Operations * Calculations based on IAC estimates at audits of 151 companies in SIC 32 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Appendix A Wise Rules Page 45 

### T

able A-15: Primar y Metal Industries* (SIC 33) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Cogeneration** 2% 12.1% 8,100 473,600 112,000 51 Boiler Operation 4% 7.0% 6,300 13,000 18,100 9 Fur nace Operations 3% 6.9% 11,500 2,900 26,400 1 Space Conditioning 4% 6.8% 3,300 18,700 8,900 25 Operation Flue Gas-Other Uses 8% 6.2% 10,700 106,400 52,400 24 Fur nace Maintenance 3% 6.2% 4,100 7,200 15,700 6 Flue Gas Recuperation 14% 5.9% 6,000 20,600 17,800 14 Building Envelope 6% 3.7% 1,600 10,600 6,200 21 Infiltration Heat Recover y fr om 12% 2.8% 1,600 8,500 6,800 15 Equipment Boiler Maintenance 10% 2.0% 1,400 1,600 5,500 3 Ther mal System 24% 1.7% 1,400 2,500 6,400 5 Insulation Equipment Use 11% 1.7% 2,000 1,100 7,600 2 Reduction Motor Har dwar e 62% 0.6% 500 11,000 7,000 20 Air Compr essor 45% 0.6% 450 2,300 6,600 4 Operations Lighting Har dwar e 70% 0.3% 250 6,000 3,800 19 * Calculations based on IAC estimates at audits of 263 companies in SIC 33 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Page 46 Wise Rules Appendix A 

### T

able A-16: Fabricated Metal Industries* (SIC 34) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Cogeneration** 2% 15.2% 13,000 323,000 121,000 32 Flue Gas-Other Uses 4% 8.2% 6,800 19,300 21,400 11 Heating/Cooling 7% 4.5% 950 20,100 5,300 46 Har dwar e Flue Gas Recuperation 5% 4.1% 4,200 20,700 11,000 23 Air Cir culation 8% 2.6% 800 5,400 4,500 14 Har dwar e Miscellaneous Building 7% 2.6% 1,100 17,100 5,400 38 Envelope Heat Recover y fr om 16% 2.5% 900 3,700 3,800 12 Equipment Boiler Maintenance 12% 2.5% 1,500 1,400 4,600 4 Space Conditioning 9% 2.1% 700 1,500 3,800 5 Operation Building Envelope 15% 2.0% 700 2,800 3,000 11 Infiltration Ther mal System 21% 1.8% 800 3,800 3,800 12 Insulation Space Conditioning 14% 1.5% 600 1,500 3,500 5 Contr ols Air Compr essor 55% 0.6% 250 890 4,300 2 Operations Lighting Har dwar e 75% 0.5% 200 6,700 4,800 17 Motor Har dwar e 54% 0.5% 200 6,600 3,900 20 * Calculations based on IAC estimates at audits of 570 companies in SIC 34 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Appendix A Wise Rules Page 47 

### T

able A-17: Industrial Machiner y and Equipment* (SIC 35) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Building Envelope 15% 4.3% 1,000 3,200 3,300 12 Infiltration General V entilation 7% 4.1% 900 2,800 4,300 8 Air Cir culation Har dwar e 9% 4.0% 750 6,600 4,200 19 Space Conditioning 15% 3.8% 900 3,100 6,000 6 Operation Heating/Cooling 8% 3.8% 700 35,000 12,600 33 Har dwar e Space Conditioning 13% 3.6% 750 1,700 3,800 5 Contr ols Miscellaneous Building 6% 3.2% 1,000 22,500 4,900 55 Envelope Other Equipment 7% 3.0% 400 6,500 5,600 14 Har dwar e Equipment Use 15% 2.8% 750 900 4,200 3 Reduction Heat Recover y fr om 21% 1.8% 600 3,200 2,800 14 Equipment Boiler Maintenance 10% 1.7% 600 1,000 2,300 5 Lighting Level 12% 1.4% 400 1,200 5,700 2 Lighting Har dwar e 82% 0.7% 250 9,800 5,000 23 Air Compr essor 55% 0.6% 250 1,000 3,700 3 Operations Motor Har dwar e 47% 0.6% 150 5,900 2,800 25 * Calculations based on IAC estimates at audits of 438 companies in SIC 35 (1/90 - 7/97). Savings may not be additive.Page 48 Wise Rules Appendix A 

### T

able A-18: Electr onic and Other Electric Equipment* (SIC 36) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Humidity Contr ol 1% 31.2% 16,000 143,400 97,000 18 Cogeneration** 1% 22.1% 47,000 286,800 303,600 11 Heating/Cooling 8% 6.2% 2,000 40,200 20,500 24 Har dwar e Heat Recover y fr om 20% 3.5% 1,000 6,400 5,400 14 Equipment Space Conditioning 17% 3.4% 1,000 4,000 8,400 6 Contr ols Other Pr ocess W aste 5% 3.1% 2,300 17,400 11,900 18 Heat Recover y Space Conditioning 14% 2.9% 850 8,300 7,800 13 Operation Air Cir culation 8% 2.8% 650 6,200 7,400 10 Har dwar e Other Equipment 7% 2.6% 600 19,200 7,700 30 Har dwar e Miscellaneous Building 6% 2.6% 550 15,300 5,100 36 Envelope Building Envelope 9% 2.4% 600 2,500 5,300 6 Infiltration Ther mal System 20% 1.2% 500 2,400 4,600 6 Insulation Lighting Har dwar e 77% 1.1% 400 15,100 8,000 23 Motor Har dwar e 55% 0.7% 250 9,100 5,000 22 Air Compr essor 43% 0.6% 200 1,300 3,600 4 Operations * Calculations based on IAC estimates at audits of 287 companies in SIC 36 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Appendix A Wise Rules Page 49 

### T

able A-19: T ranspor tation Equipment* (SIC 37) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Flue Gas Recuperation 3% 8.4% 7,000 20,000 19,800 12 Miscellaneous Building 5% 7.0% 1,000 9,700 4,600 25 Envelope Heating/Cooling 11% 5.8% 1,000 17,000 12,400 17 Har dwar e Space Conditioning 12% 3.7% 1,000 3,000 6,200 6 Operation Space Conditioning 18% 2.8% 1,000 2,600 6,100 5 Contr ols Building Envelope 9% 2.8% 850 2,600 4,200 7 Infiltration Heat Recover y fr om 21% 2.7% 1,000 7,100 4,000 22 Equipment Boiler Maintenance 9% 2.4% 2,000 1,200 5,100 3 Equipment Automation 14% 1.8% 400 2,000 3,200 7 Lighting Level 15% 1.2% 350 3,300 6,200 6 Air Compr essor 64% 1.0% 300 1,000 4,700 3 Operations Lighting Har dwar e 79% 0.9% 300 11,200 5,400 25 Motor Har dwar e 56% 0.8% 300 8,400 4,300 23 Motor Operations 31% 0.6% 250 2,800 3,100 11 Air Compr essor 39% 0.4% 150 1,200 2,200 7 Har dwar e * Calculations based on IAC estimates at audits of 214 companies in SIC 37 (1/90 - 7/97). Savings may not be additive.Page 50 Wise Rules Appendix A 

### T

able A-20: Instr uments and Related Pr oducts* (SIC 38) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Solar Loading 2% 10.3% 550 4,900 4,100 14 Other Equipment 5% 9.3% 1,000 60,600 26,600 27 Har dwar e Other Pr ocess W aste 5% 6.7% 4,000 13,400 19,000 8 Heat Recover y Space Conditioning 14% 5.3% 600 3,100 7,800 5 Operation Heat Recover y fr om 13% 4.7% 1,000 5,200 5,600 11 Equipment General V entilation 4% 4.6% 900 8,000 4,700 20 Equipment Use 14% 3.7% 700 600 4,400 2 Reduction Heating/Cooling 7% 2.6% 450 40,400 12,400 39 Har dwar e Lighting Har dwar e 83% 2.2% 450 18,900 10,300 22 Equipment Automation 19% 2.1% 400 2,900 3,900 9 Building Envelope 13% 1.7% 450 1,500 5,100 3 Infiltration Ther mal System 20% 1.1% 350 1,700 2,400 5 Insulation Motor Har dwar e 57% 0.9% 250 9,400 4,400 25 Air Compr essor 40% 0.7% 100 350 2,100 2 Operations Lighting Contr ols 34% 0.6% 150 1,700 2,400 8 * Calculations based on IAC estimates at audits of 95 companies in SIC 38 (1/90 - 7/97). Savings may not be additive.Appendix A Wise Rules Page 51 

### T

able A-21: Misc. Manufacturing Industries* (SIC 39) Measur e Recommendation A verage Annual A verage Annual A verage A verage A verage Rate Ener gy Savings Ener gy Savings Implementation Annual Cost Simple (% of total facility (MMBtu) 

### Cost Savings Payback energy use) (dollars) (dollars) (months) Alter nate Fossil 1% 25.5% 2,000 21,700 29,000 9 Fuel Switching Boiler Operation 3% 24.0% 7,000 15,100 5,900 31 Cogeneration** 1% 15.9% 8,000 165,000 54,000 37 Heating/Cooling 5% 10.3% 1,000 58,400 14,100 50 Har dwar e Solar Loading 4% 10.3% 700 13,900 4,400 38 Heat Recover y fr om 12% 7.0% 2,000 4,800 11,500 5 Equipment Flue Gas Recuperation 5% 6.2% 4,000 8,200 12,300 8 Boiler Maintenance 19% 5.6% 1,000 1,200 4,400 3 Miscellaneous Building 8% 4.6% 800 19,000 6,000 38 Envelope Space Conditioning 13% 3.9% 600 1,700 3,000 7 Operation Space Conditioning 13% 2.7% 1,000 2,800 7,800 4 Contr ols Lighting Har dwar e 88% 1.0% 250 8,000 4,600 21 Air Compr essor 48% 0.9% 150 950 3,100 4 Operations Motor Har dwar e 45% 0.7% 100 4,300 2,200 24 Air Compr essor 41% 0.5% 100 800 1,100 9 Har dwar e * Calculations based on IAC estimates at audits of 75 companies in SIC 39 (1/90 - 7/97). Savings may not be additive. ** Cogeneration energy savings are based on primary fuel savings from electricity generation, including fuel inputs at off-sitepowerplants for purchased electricity.Appendix B Wise Rules Page 52 

### T

able B-1: Helpful Conversion Factors T o Conver t T o Multiply By T ons Pounds 2000 T ons Metric T ons 0.9072 MMBtu Btu 10 6 kWh Wh 10 3 MWh kWh 10 3 kWh Btu 3413 Quads Btu 10 15 (quadrillion Btu) Quads kWh 2.93 x 10 11 (quadrillion Btu) Ther ms Btu 10 5 Horsepower (hp) kW 0.746 Btu Joule (J) 1055 kWh Joule (J) 3600 Carbon Carbon Dioxide 3.667 (mass units) (mass units) Carbon Dioxide Carbon 0.2727 (mass units) (mass units) Carbon Carbon Dioxide 4.042 (metr ic tons) (tons) Carbon Dioxide Carbon 1.237 x 10 -4 (pounds) (metr ic tons) 

# A ppendix B C onv ersion F actors and E mission C oefficients This appendix pr o vides the necessar y information to calculate CO 2 emissions r eductions fr om energy efficiency measur es. O nce you have qualified pr oject impacts (using W ise R ules, meter ed data, and/or engineering estimates), simply multiply the energy savings b y the appr opriate CO 2 emission coefficient. U se T

able B-2 to calculate CO 2 emission r eductions fr om fuel sav

ings and use T able B-3 to calculate CO 2 emissions r eductions fr om electricity savings. CO 2 emissions fr om electricity genera

tion ar e a function of po werplant efficiency and fuel use. The CO 2 emission coefficients in T able B-3 ar e av erage values that r eflect the mix of powerplants in each state. F eel fr ee to use your o wn site-specific information on fuel carbon content or pur

chased electricity CO 2 emissions in place of the averages pr esent ed her e. 

### Example 1: Boiler Fuel Savings Consider a boiler tune-up that is estimated to save 1,000 MMBtu of natural gas per y ear. M ultiply the 1,000 MMBtu savings b y the CO 2 emission coefficient for natural gas, 117.08 pounds CO 2 per MMBtu (T able B-2) to calculate annual savings of 117,080 pounds of CO 2 . T o expr ess the gr eenhouse gas emis

sions r eduction in metric tons of carbon, multiply the pounds of CO 2 sav ed b y 1.237 x 10 - 4 (T able B-1) to yield 14.5 metric tons of carbon. 

### Example 2: Air Compr essor Electricity Savings Consider a manufacturing facility in F lorida that implements compr essed air system efficiency impr o v ements that r esult in annual savings of 100 MWh. M ultiply the 100 MWh savings b y the CO 2 emission factor for electricity generated in F lorida, 0.587 metric tons CO 2 per MWh (T able B-3), to calculate annu

al savings of 58.7 metric tons of CO 2 . T o expr ess the gr eenhouse gas emissions r eduction in metric tons of carbon, multiply the metric tons of CO 2 sav ed b y 0.2727 (T able B-1) to yield 16.0 metric tons of carbon.Page 53 Wise Rules Appendix B 

### T

able B-2: Emission Coef ficients by Fuel T ype Fuel Emission Coefficients Pounds C O 2 per Unit Volume or Mass Pounds C O 2 per Million Btu 

### Petr oleum Pr oducts A viation Gasoline 18.355 per gallon 152.717 770.916 per barrel Distillate Fuel (No. 1, No. 2, No. 4 Fuel Oil and Diesel) 22.384 per gallon 161.386 940.109 per barrel Jet Fuel 21.439 per gallon 159.690 900.420 per barrel Ker osene 21.537 per gallon 159.535 904.565 per barrel Liquefied Petr oleum Gases (LPG) 12.200 per gallon 138.846 512.415 per barrel Motor Gasoline 19.641 per gallon 157.041 824.939 per barrel Residual Fuel (No. 6 Fuel Oil) 26.033 per gallon 173.906 1,093.384 per barrel 

### Natural Gas and Other Gaseous Fuels Methane 116.376 per 1000 f t 3 115.258 Flar e Gas 133.759 per 1000 f t 3 120.721 Natural Gas (Pipeline) 120.593 per 1000 f t 3 117.080 Pr opane 12.669 per gallon 139.178 532.085 per barrel 

### Electricity Varies depending on fuel used to generate electricit y * 

### Coal Anthracite 3852.156 per ton 227.400 Bituminous 4921.862 per ton 205.300 Subbituminous 3723.952 per ton 212.700 Lignite 2733.857 per ton 215.400 

### Renewable Sour ces Geother mal Ener gy 0 0 W

ind 0 0 Photovoltaic and Solar Ther mal 0 0 Hydr opower 0 0 W

ood and W ood W aste 

### ** 3814 per ton 221.943 Municipal Solid W aste 

### ** 1999 per ton 199.854 

### Nuclear 0 0 Source: DOE/EIA, Form EIA-1605 Voluntary Reporting of Greenhouse Gases, Instructions , 1997, Appendix B. *For average electric power emission coefficients by state, see Table B-3. **Fuel cycle emissions are likely to be less than the direct emissions because all or part of the fuel is renewable. These biof uels contain carbon that is part of the natural carbon balance and that will not add to atmospheric concentrations of carbon dioxide.Appendix B Wise Rules Page 54 

### State CO 2 

### Emission Factors lbs/kWh short tons/MWh metric tons/MWh

Alabama 1.369 0.684 0.621 Kentucky 1.930 0.965 0.869 Mississippi 1.075 0.537 0.487 T ennessee 1.335 0.668 0.606 

### W

est-South Central Region Arkansas 1.286 0.643 0.584 Louisiana 1.388 0.694 0.629 Oklahoma 1.672 0.836 0.758 T exas 1.552 0.776 0.704 

### Mountain Region Arizona 0.798 0.399 0.362 Colorado 2.001 1.000 0.908 Idaho 0.269 0.134 0.122 Montana 1.553 0.777 0.704 Nevada 1.875 0.937 0.850 New Mexico 1.405 0.703 0.637 Utah 1.990 0.995 0.903 W

yoming 2.194 1.097 0.995 

### Pacific Region Contiguous Califor nia 0.756 0.378 0.343 Or egon 0.235 0.118 0.107 W

ashington 0.306 0.153 0.139 

### Pacific Region Non-Contiguous Alaska 0.031 0.016 0.014 Hawaii 

### State CO 2 

### Emission Factors lbs/kWh short tons/MWh metric tons/MWh 

### New England Region Connecticut 0.715 0.358 0.324 Maine 0.966 0.483 0.438 Massachusetts 1.459 0.729 0.662 New Hampshir e 0.852 0.426 0.386 Rhode Island 1.091 0.546 0.495 V er mont 0.159 0.080 0.072 

### Mid Atlantic Region New Jersey 0.774 0.387 0.351 New Y ork 1.036 0.518 0.470 Pennsylvania 1.286 0.643 0.583 

### East-Nor th Central Region Illinois 0.866 0.433 0.393 Indiana 2.171 1.086 0.985 Michigan 1.576 0.788 0.715 Ohio 1.807 0.904 0.820 Wisconsin 1.343 0.671 0.609 

### W

est-Nor th Central Region Iowa 1.686 0.843 0.765 Kansas 1.703 0.852 0.773 Minnesota 1.627 0.814 0.738 Missouri 1.783 0.891 0.809 Nebraska 1.288 0.644 0.580 Nor th Dakota 2.303 1.151 1.045 South Dakota 0.912 0.456 0.410 

### South Atlantic Region Delawar e 1.855 0.928 0.842 District of Columbia 2.649 1.324 1.192 Florida 1.294 0.647 0.587 Geor gia 1.220 0.610 0.553 Mar yland 1.356 0.678 0.615 Nor th Car olina 1.350 0.675 0.612 South Car olina 0.688 0.344 0.312 V ir ginia 1.107 0.554 0.502 W

est Vir ginia 2.005 1.003 0.909 

### T

able B-3: Electricity CO 2 

### Emission Factors by State

East-South Central Region

U.S. A verage Source: DOE/EIA, Form EIA-1605 Voluntary Reporting of Greenhouse Gases, Instructions , 1997, Appendix C. 1.291 0.646 0.586Boiler W ise Rule 7 

### Using a characterizable fuel valv e to match the air/fuel ratios acr oss the load range can save 2% to 12% of a boiler ’ s fuel use at r elativ ely lo w cost. Boiler W ise Rule 8 

### Conv er ting to air or steam atomizing burners fr om conventional burners can r educe boiler fuel use b y 2% to 8%. Boiler W ise Rule 9 

### E

very 40 ° F r eduction in net stack temperatur e (outlet temperatur e minus inlet combustion air temperatur e) is estimated to sav e 1% to 2% of a boiler ’ s fuel use. Boiler W ise Rule 10 

### S tack dampers pr ev ent heat fr om being pulled up the stack and can save 5% to 20% of a boiler ’ s fuel use. Boiler W ise Rule 11 

### D ir ect contact condensation heat r eco v er y can save 8% to 20% of a boiler ’ s fuel use, but costs may be r el

ativ ely high. Boiler W ise Rule 12 

### P r eheating combustion inlet air can save about 3% of a facility ’ s total energy use with an average simple pay

back of 8 months. Boiler W ise Rule 13 

### M inimizing energy loss fr om boiler blowdo wn can sav e about 2% of a facility ’ s total energy use with an av erage simple payback of less than 1 y ear. 26 Boiler W ise Rule 14 

### R

emo ving a 1/32 inch deposit on boiler heat transfer sur faces can decr ease a boiler ’ s fuel use b y 2%; r emo v al of a 1/8 inch deposit can decr ease boiler fuel use b y o v er 8%.
Appendix C Wise Rules Page 55 

# A ppendix C S ummary of W ise R ules Boilers Boiler W ise Rule 1 

### E ffectiv e boiler load management techniques, such as operating on high fir e settings or installing smaller boilers, can save o v er 7% of a typical facility ’ s total energy use with an average simple payback of less than 2 years. Boiler W ise Rule 2 

### Load management measur es, including optimal matching of boiler siz e and boiler load, can save as much as 50% of a boiler ’ s fuel use. Boiler W ise Rule 3 

### An upgraded boiler maintenance program including optimizing air-to-fuel ratio, burner maintenance, and tube cleaning, can sav e about 2% of a facility ’ s total energy use with an av erage simple payback of 5 months. Boiler W ise Rule 4 

### A compr ehensive tune-up with pr ecision testing equipment to detect and corr ect ex cess air losses, smoking, unburned fuel losses, sooting, and high stack temperatur es, can r esult in boiler fuel savings of 2% to 20%. Boiler W ise Rule 5 

### A 3% decr ease in flue gas O 2 

### typically pr oduces boiler fuel savings of 2%. Boiler W ise Rule 6 

### Using o v er fir e draft contr ol systems to contr ol ex cess air can save 2% to 10% of a boiler ’ s fuel use with typ

ical equipment costs of $1,500.Boiler W ise Rule 15 

### B lo wdo wn heat r eco v er y is a pr o v en technology that can r educe a boiler ’ s fuel use b y 2% to 5%. Boiler W ise Rule 16 

### F or ev ery 11 ° F that the entering feedwater temperature is increased, the boiler ’ s fuel use is reduced by 1%. Boiler W ise Rule 17 

### Changing fr om manual blowdo wn contr ol to auto

matic adjustment can r educe a boiler ’ s energy use b y 2% to 3% and r educe blo wdo wn water losses b y up to 20%. 

# Steam Systems Steam W ise Rule 1 

### An effective steam trap maintenance pr ogram can sav e 3% of a facility ’ s total energy use with an average simple payback of 2 months. Steam W ise Rule 2 

### An effective steam trap maintenance pr ogram can r educe a boiler ’ s fuel use b y 10% to 20%. Steam W ise Rule 3 

### R

epairing steam system leaks can save 1% of a facility ’ s total energy use with an average simple payback of 3 months. Steam W ise Rule 4 

### A single high-pr essur e steam leak (125 psi) can r esult in energy losses costing fr om $660 to $2,200 per year (8,760 hrs). A single low-pr essur e steam leak (15 psi) can r esult in energy losses costing $130 to $480 per year (8,760 hrs). Steam W ise Rule 5 

### I nsulating steam lines can save 1% of a facility ’ s total energy use with an average simple payback of 10 months. Steam W ise Rule 6 

### V

apor r ecompr ession saves 90% to 95% of the energy needed to raise the steam to the same pr essur e in a boiler

. Steam W ise Rule 7 

### M easur es to r educe heat loss fr om condensate in a steam system can save o v er 1% of a facility ’ s total energy use with an average simple payback of 8 months. 

# Pr ocess Heating Pr ocess Heating W ise Rule 1 

### P r oper heat containment can save about 2% of a facility ’ s total energy use with an average simple payback of 9 months. Pr ocess Heating W ise Rule 2 

### I nsulating a furnace with r efractor y fiber liners can impr o v e the thermal efficiency of the heating pr ocess b y up to 50%. Pr ocess Heating W ise Rule 3 

### R

eco v ering waste heat fr om furnaces, ov ens, kilns, and other equipment can save 5% of a typical facility ’ s total energy use with an average simple payback of 16 months. Pr ocess Heating W ise Rule 4 

### R

eco v ering waste heat thr ough a r ecuperator can r educe a kiln ’ s energy use b y up to 30%; r egenerators can save up to 50%. Pr ocess Heating W ise Rule 5 

### Each per cent of moistur e r emo v ed b y air dr ying lumber r educes the kiln ’ s energy use b y 50 to 85 Btu per boar d foot.

Page 56 Wise Rules Appendix CPr ocess Heating W ise Rule 6 

### V

ariable fan speed contr ol in the lumber industry can r educe dr y kiln air flo w b y 20% and r educe the kiln ’ s energy used during sur face dr ying b y as much as 50%. Pr ocess Heating W ise Rule 7 

### I nstalling exper t systems for kiln secondary contr ol can r educe a cement kiln ’ s energy use b y up to 3%. 14 Pr ocess Heating W ise Rule 8 

### N e w clinker cooler technologies that optimiz e heat transfer conditions can r educe a cement kiln ’ s energy use b y up to 6%. Pr ocess Heating W ise Rule 9 

### D ir ect firing with natural gas in place of indir ect steam heating has the potential to save 33% to 45% of pr ocess heating energy use. P ayback times may range fr om a fe w months to 6 years. Pr ocess Heating W ise Rule 10 

### D ir ect electric heating (infrar ed, micr o wav e, or dielec

tric) can r educe pr ocess heating energy use b y up to 80% with typical payback periods of 1 to 3 y ears. 

# W aste Heat Recover y and Cogeneration Heat Recovery/Cogen W ise Rule 1 

### R

eco v ering waste heat can r educe a typical facility ’ s total energy use b y about 5% with an average simple payback of 16 months. Heat Recovery/Cogen W ise Rule 2 

### R

educing net stack temperatur e (outlet temperatur e minus inlet combustion air temperatur e) b y 40 ° F is estimated to r educe the boiler ’ s fuel use b y 1% to 2%. Heat Recovery/Cogen W ise Rule 3 

### P r eheating furnace combustion air with r eco v er ed waste heat can save up to 50% of the furnace ’ s energy use. H eat R ecov ery/Cogen T able 1 summariz es typical fuel savings for a natural gas furnace. Heat Recovery/Cogen W ise Rule 4 

### Using an economiz er to captur e flue gas waste heat and pr eheat boiler feedwater can r educe a boiler ’ s fuel use b y up to 5%. Heat Recovery/Cogen W ise Rule 5 

### R

emo ving a 1/32 inch deposit on boiler ’ s heat transfer sur faces can r educe a boiler ’ s energy use b y 2%; r emo ving a 1/8 inch deposit can r educe a boiler ’s energy use b y o v er 8%. Heat Recovery/Cogen W ise Rule 6 

### G as turbines with heat r eco v er y equipment typically cost fr om $600 to $1,000/kW . Larger gas turbines may be available for half the cost per kW

. Heat Recovery/Cogen W ise Rule 7 

### A typical cogeneration pr oject may r educe primar y energy consumption (including fuel inputs at off-site po werplants for pur chased electricity) for steam and electricity generation b y 10% to 15%. Heat Recovery/Cogen W ise Rule 8 

### Cogeneration systems can save about 9% of a typical facility ’ s primar y fuel inputs for on-site energy use (i.e., including fuel savings at off-site powerplants for pur chased electricity) with an average simple payback of 34 months. 19 

### (S avings ar e calculated b y dividing total energy savings, including powerplant inputs, b y total facility energy use.)

Appendix C Wise Rules Page 57

# Compr essed Air Systems Compr essed Air W ise Rule 1 

### E fficiency impr o v ements can r educe compr essed air system energy use b y 20 to 50%. 2 Compr essed Air W ise Rule 2 

### E fficiency impr o v ements to compr essed air systems can save appr o ximately one-half per cent of a facility ’ s total energy use. Compr essed Air W ise Rule 3 

### Using cooler intake air for compr essors can r educe compr essed air system energy use b y 1% per 5 ° F r educ

tion in intake air temperatur e. 5 

### The payback period for this measur e is usually less than two years. Compr essed Air W ise Rule 4 

### Using cooler intake air for compr essors can save almost one-half per cent of a facility ’ s total energy use with an average simple payback of 5 months. Compr essed Air W ise Rule 5 

### I nstalling or adjusting unloading contr ols can r educe compr essed air system energy use b y about 10%. Compr essed Air W ise Rule 6 

### U

pgrading contr ols on scr e w air compr essors can r educe a facility ’ s total energy use b y about 1% with an av erage simple payback of 8 months. Compr essed Air W ise Rule 7 

### R

educing air compr essor pr essur e can r educe a facili

ty ’

s total energy use b y about one-half per cent with an av erage simple payback of 4 months. Compr essed Air W ise Rule 8 

### R

educing air compr essor pr essur e b y 2 psi can r educe compr essor energy use b y 1% (at 100 psi). Compr esse d Air W is e Rule 9 

### E liminating or r educing compr essed air usage for cer

tain activities can r educe a facility ’ s total energy use b y mor e than one-half per cent, with an average simple payback of 6 months. 16 Compr essed Air W ise Rule 10 

### R

epairing air leaks can r educe compr essed air system energy use b y 30% or mor e. Compr essed Air W ise Rule 11 

### R

epairing air leaks can r educe a facility ’ s total energy use b y about one-half per cent, with an average simple payback of 3 months. Compr essed Air W ise Rule 12 

### I t takes appr o ximately 2.5 to 5.0 kWh to compr ess 1,000 ft 3 

### of air to 100 psi. 21,22 

### Each psi r eduction in compr essed air loss fr om the distribution system (at 100 psi), r educes the compr essor ’ s energy use b y mor e than one-half per cent. Compr essed Air W ise Rule 13 

### Air compr essor waste heat r eco v er y can r educe a facil

ity’s total energy use b y about 1.8% with an average simple payback of 10 months. Compr essed Air W ise Rule 14 

### F or every 1 psi incr ease in air compr essor pr essur e gained b y periodic filter changes, air compr essor energy use is r educed b y about 0.5%. Changing dr y er filters at 8 or 10 psi dr op per filter can eliminate this waste. Compr essed Air W ise Rule 15 

### F or ev ery 11 ° F decrease in air compressor wor king tem

perature, gained by careful maintenance of intercoolers, air compressor energy use will decreased by 1%.

Page 58 Wise Rules Appendix C

# Pr ocess Cooling Pr ocess Cooling W ise Rule 1 

### I nstalling energy efficient chillers and r efrigeration systems can save 1.2% of a facility ’s total energy use with an average simple payback of 23 months. Pr ocess Cooling W ise Rule 2 

### “F r ee cooling ” with cooling tower water can r educe a facility ’s total energy use b y about 1 per cent with an av erage simple payback of 14 months. Pr ocess Cooling W ise Rule 3 

### F ree cooling can reduce cooling system energy use by as much as 40% depending on location and load profile. Pr ocess Cooling W ise Rule 4 

### I ncr easing chilled water temperatur e b y 1 ° F r educes chiller energy use b y 0.6% to 2.5%. 4 

### (S ee P r ocess Cooling T able 1 for data on specific chiller types.) Pr ocess Cooling W ise Rule 5 

### R

educing condenser pr essur e b y 10 psi can decr ease r efriger ation system energy use per ton of r efrigeration (kW/ton) b y about 6%. Pr ocess Cooling W ise Rule 6 

### F or each 1 ° F decr ease in condenser cooling water temperatur e, until optimal water temperatur e is r eached, ther e is a decr ease in chiller energy use b y up to 3.5%. Pr ocess Cooling W ise Rule 7 

### E liminating heat losses fr om leaks and impr oper defr osting can r educe r efrigeration system energy use b y 10% to 20%. Pr ocess Cooling W ise Rule 8 

### F r ee zing pr oducts in batches rather than continuously can r educe fr ee zing pr ocess energy use b y up to 20%. Pr ocess Cooling W ise Rule 9 

### I nstalling variable speed drives in place of constant speed systems can r educe cooling system energy use b y 30% to 50%, depending on load pr ofile.

Appendix C Wise Rules Page 59

# A ppendix D K ey R eferences
■ 3M Company , “R ules of Thumb: Q uick M ethods of E

valuating E nergy R eduction O ppor tunities,” 1992. ■ Clevenger , L. and J. H assel, “Case S tudy: F r om J ump S tar t to H igh G ear—H ow D uPont is C utting Costs b y Boosting E nergy E fficiency ,” P ollution P r evention R eview , S ummer 1994, p . 301-312. ■ G aray , P

.N., H andbook of I ndustrial P o wer and S team S ystems , F airmont P r ess. ■ M er cer , A., Lear ning fr om E xperiences with I ndustrial Dr

ying T echnologies , Centr e for the Analysis and D issemination of D emonstrated E nergy T echnologies (CADDET ), 1994. ■ O'Callaghan, P ., E nerg y M anagement , M cG raw-H ill, E ngland, 1993. ■ O r egon S tate U niversity , AIRM aster Compr essed Air S ystem A udit and Analysis S oftwar e. T o inquir e about the AIRM aster S oftwar e package, call the E nergy I deas Clearinghouse at 1-800-373-2139. ■ P ayne, F .W ., Thompson, R.E., E fficient Boiler O per ations Sour cebook , 4th E dition, F airmont P r ess, 1996. ■ R utgers U niversity , O ffice of I ndustrial P r oductivity & E nergy Assessment (OIP EA), M odern I ndustrial Assessments: A T r aining M anual , V ersion 1.0b , (pr epar ed for the U.S. DOE O ffice of I ndustrial T echnology and the U.S. EP A, 1995). A vailable at: http://oipea-www .r utgers.edu/site_docs/pdfdocstm.html ■ R utgers U niversity OIP EA, “U seful R ules of Thumb for R

esour ce Conservation and Pollution P r evention,” M ar ch 1996. ■ T aplin, H.R., Boiler P lant and Distribution S ystem O

ptimization M anual , F airmont P r ess, 1991. ■ T albott, E.M., Compr essed Air S ystems: A G uidebook on E

nerg y and Cost S avings , 2nd E dition, F airmont P r ess, 1992. ■ T urner , W .C., E nerg y M anagement H andbook , 3r d E dition, F airmont P r ess, 1997 ■ F or assistance in pr eparing your Climate W ise A ction P lan or your V oluntar y G r eenhouse G as E missions R

epor t (F orm EIA-1605), call the Climate W ise W

ise L ine at 1-800-459-WISE. ■ F or information on the U.S. EP A E nergy S tar P r ograms, call 1-888-ST AR-YES. ■ F or information on the U.S. EP A W aste W ise P r ogram, call 1-800-EP A-WISE. ■ F or information on U.S. DOE I ndustrial Assessment Centers, call 1-800-DOE-EREC. ■ F or information on the U.S. DOE M otor Challenge P r ogram, call 1-800-862-2086. ■ F or information on the U.S. DOE Compr essed Air Challenge, call 1-800-559-4776.

Appendix D Wise Rules Page 60 

# K ey R esources