CHAPTER 3. MARKET AND TECHNOLOGY ASSESSMENT

TABLE OF CONTENTS

3.1 Introduction

................................ ................................ ................................ ............. 3

- 1

3.1.1 Equipment Definitions, Scope of Coverage and Background

.................... 3

- 1

3.1.2 Equipment Classes

................................ ................................ ...................... 3

- 3

3.1.2.1 Existing Equipment Classes

................................ ......................... 3

- 3

3.1.2.2 New Equipment Classes

................................ .............................. 3

- 4

3.2 Market Assessment

................................ ................................ ................................ . 3

- 6

3.2.1 Trade Association

................................ ................................ ....................... 3

- 6

3.2.1.1 Air

- Conditioning, Heating, and Refrigeration Institute

............... 3

- 6

3.2.1.2 American Boiler Manufacturers Association

............................... 3

- 7

3.2.1.3 Additional Manufacturers

................................ ............................ 3

- 7

3.2.2 Regulatory Programs

................................ ................................ .................. 3

- 8

3.2.2.1 Current Federal Energy Conservation Standards

......................... 3

- 8

3.2.2.2 State Energy Conservation Standards

................................ .......... 3

- 9

3.2.2.3 Canadian Energy Conservation Standards

................................ ... 3

- 9

3.2.3 Non

- Regulatory Programs

................................ ................................ ........ 3

- 10

3.2.3.1 Energy Star Program

................................ ................................ .. 3

- 10

3.2.3.2 Federal Energy Management Program

................................ ...... 3

- 10

3.2.3.3 Rebate Programs

................................ ................................ ........ 3

- 11 Minnesota Energy Resources.

................................ .................... 3

- 11 Pacific Gas and Electric Company.

................................ ........... 3

- 11 San Diego Gas and Electric Company.

................................ ...... 3

- 12

Southern Cal ifornia Gas Company.

................................ ........... 3

- 12

3.2.4 Shipments

................................ ................................ ................................ .. 3

- 13

3.2.5 Equipment Lifetime

................................ ................................ .................. 3

- 13

3.2.6 Market Performance Data

................................ ................................ ......... 3

- 13

3.2.6.1 Small (300kBtu/h

- 2,500kBtu/h) Gas

- Fired Natural Draft Hot Water Commercial Packaged Boilers

................................ ........ 3

- 17

3.2.6.2 Large (>2, 500kBtu/h) Gas

- Fired Natural Draft Hot Water Commercial Packaged Boilers

................................ ................... 3

- 20

3.2.6.3 Small (300kBtu/h

- 2,500kBtu/h) Oil

- Fired Natural Draft Hot Water Commercial Packaged Boilers

................................ ........ 3

- 22

3.2.6.4 Large (>2,500kBtu/h) Oil

- Fired Natural Draft Hot Water

Commercia l Packaged Boilers

................................ ................... 3

- 24

3.2.6.5 Small (300kBtu/h‒2,500kBtu/h) Gas

- Fired Natural Draft Steam Commercial Packaged Boilers

................................ ................... 3

- 24

3.2.6.6 Large (>2,500kBtu/h) Gas

- Fired Natural Draft Steam Commercial Packaged Boilers

................................ ................................ ........ 3

- 27

3.2.6.7 Small (300kBtu/h

- 2,500kBtu/h) Oil

- Fired Natural Draft Steam Commercial Packaged Boilers

................................ ................... 3

- 29

3.2.6.8 Large (>2,500kBtu/h) Oil

- Fired Natural Draft Steam Commercial Packaged Boilers

................................ ................................ ........ 3

- 32

3.2.6.9 Small (300kBtu/h

- 2,500kBtu/h) Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

................................ ........ 3

- 33

3

- i3.2.6.10 Large (>2,500kBtu/h) Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

................................ ................... 3

- 38

3.2.6.11 Small (300kBtu/h ‒ 2,500kBtu/h) Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

................................ ........ 3

- 42

3.2.6.12 Large (>2,500kBtu/h) Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

................................ ................... 3

- 44

3. 2.6.13 Small (300kBtu/h‒2,500kBtu/h) Gas

- Fired Mechanical

- Draft Steam Commercial Packaged Boilers

................................ ........ 3

- 46

3.2.6.14 Large (> 2,500kBtu/h) Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers

................................ ................... 3

- 49

3.2.6.15 Small (300kBtu/h‒2,500kBtu/h) Oil

- Fired M echanical Draft Steam Commercial Packaged Boilers

................................ ................... 3

- 51

3.2.6.16 Large (>2,500kBtu/h) Oil

- Fired Mechanical Draft Steam

Commercial Packaged Boilers

................................ ................... 3

- 53

3.3 Technology Assessment

................................ ................................ ........................ 3

- 55

3.3.1 Boiler Equipment

................................ ................................ ...................... 3

- 55

Construction Materials

................................ ............................... 3

- 56

Tank /Pressure Vessel

................................ ................................ . 3

- 56

Burner

................................ ................................ ........................ 3

- 56 Heat Exchangers

................................ ................................ ........ 3

- 56

Controls

................................ ................................ ...................... 3

- 58

Draft

................................ ................................ ........................... 3

- 58

3.3.2 Technology Opt ions that Improve Combustion Efficiency and/or Thermal Efficiency

................................ ................................ ................................ .. 3

- 59 Jacket Insulation Optimization (Thermal Efficiency Only)

....... 3

- 59 Heat Exchanger Improvements (Including Condensing Heat Exchanger)

................................ ................................ ................. 3

- 60 Burner Derating

................................ ................................ ......... 3

- 62 Improved Burner Technology

................................ .................... 3

- 62

Combustion Air Preheaters

................................ ........................ 3

- 63

Economizers

................................ ................................ ............... 3

- 63 Blowdown Waste Heat Recovery

................................ .............. 3

- 63 Integrated, High

- Efficiency Steam Boilers

................................ 3

- 64

3.3.3 Technology Options to Reduce Seasonal Boiler Energy Consumption

... 3

- 64

3

- iiLIST OF FIGURES

Figure 3.1.1. Proposed Commercial Packaged Boiler Equipment Classes

...................... 3

- 5

Figure 3.2.1. Qualifying Checks on Air

- Conditioning, Heating, an d Refrigeration Institute Database for Commercial Packaged Boilers

................................ ... 3

- 16

Figure 3.2.2. Distribution of Small Gas

- fired Natural Draf t Hot Water Commercial Packaged Boilers Based on Input Rating

................................ . 3

- 17

Figure 3.2.3. Distribution of Small Gas

- Fired Natural Draft Ho t Water Commercial Packaged Boilers Based on Thermal Efficiency

...................... 3

- 19

Figure 3.2.4. Comparison of Average Thermal Efficiency with Small Gas

- Fired Natural Draft Hot Water Commercial Packaged Boilers Sub Category Based on Input Rating

................................ ................................ ................... 3

- 19

Figure 3.2.5. Distribu tion of Large Gas

- Fired Natural Draft Hot Water Commercial Packaged Boilers Based on Input Rating

................................ . 3

- 20

Figure 3.2.6. Distribution of Large Gas

- Fired Natural Draft Hot Water Commercial Packaged Boilers Based on Combustion Efficiency

................ 3

- 21

Figure 3.2.7. Comparis on of Average Combustion Efficiency with Large Gas

Fired Natural Draft Hot Water Commercial Packaged Boilers Sub Category Based on Input Rating

................................ ................................ ... 3

- 22

Figure 3.2.8. Distribution of Small Oil Fired Natural Draft Hot Water Boilers Based on Input Ratings

................................ ................................ ................. 3

- 22

Figure 3.2.9. Distribution of Small Oil

- Fired Natural Draft Hot Water Commercial Packaged Boilers Based on Thermal Efficiency

...................... 3

- 23

Figure 3.2.10. Comparison of Average Thermal Efficiency of Small Oil

- Fired Natural Draft Hot Water Commercial Packaged Boilers Sub Category Based on Input Rating

................................ ................................ ................... 3

- 24

Figure 3.2.11. Distribution of Small Gas

- Fired Natural Draft Steam Commercial Packaged Boilers Based on Input Rating

................................ ...................... 3

- 25

Figure 3.2.12. Distribution of Small Gas

- Fired Natural Draft Steam Commercial Packaged Boilers Based on Thermal Efficiency

................................ ........... 3

- 26

Figure 3.2.13. Comparison of Average Thermal Efficiency of Small Gas

- Fired Natural Draft Steam Commercial Packaged Boilers Sub Category Based on Input Rating

................................ ................................ ................... 3

- 27

3

- iiiFigure 3.2.14. Distribution of Large Gas

- Fired Natural Draft Steam Commercial Packaged Boilers Based on Input Rating

................................ ...................... 3

- 27

Figure 3.2.15. Distribution of Large Gas

- Fired Natural Draft Steam Commercial Packaged Boilers Based on Thermal Efficiency

................................ ........... 3

- 29

Figure 3.2.16. Comparison of Average Thermal Efficiency of Large Gas

- Fired Natural Draft Steam Commercial Packaged Boilers Sub Category Based on Input Rating

................................ ................................ ................... 3

- 29

Figure 3.2.17. Distribution of Small Oil

- Fired Natural Draft Steam Boilers Based on Input Ratings

................................ ................................ ............................ 3

- 30

Figure 3.2.18. Distribution of Small Oil

- Fired Natural Draft Steam Commercial Packaged Boilers Based on Thermal Efficiency

................................ ........... 3

- 31

Figure 3.2.19. Comparison of Average Thermal Efficiency of Small Oil

- Fired Natural Draft Steam Commercial Packaged Boilers Sub Category Based on Input Rating

................................ ................................ ................... 3

- 31

Figure 3.2.20. Distribution of Large Oil

- Fired Natural Draft Steam Commercial Packaged Boilers Based on Input Rating

................................ ...................... 3

- 32

Figure 3.2.21. Distribution of Large Oil

- Fired Natural Draft Steam Commercial Packaged Boilers Based on Thermal Efficiency

................................ ........... 3

- 33

Figure 3.2.22. Comparison of Average Thermal Efficiency of Large Oil

- Fired Natural Draft Steam Commercial Packaged Boilers Sub

- C ategory Based on Input Rating

................................ ................................ ................... 3

- 33

Figure 3.2.23. Classification of Small Gas Fired Mechanical Draft Hot Water Commercial Package d Boilers Based on Material Used in the Primary Heat Exchanger

................................ ................................ ............................. 3

- 34

Figure 3.2.24. Classification of Small Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Condensing Boilers Based on Material Used in the Primary Heat Exchanger

................................ ................................ ......... 3

- 35

Figure 3.2.25. D istribution of Small Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Based on Input Rating

................................ . 3

- 35

Figure 3.2.26. D istribution of Small Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Based On Thermal Efficiency

..................... 3

- 37

Figure 3.2 .27. Comparison of Average Thermal Efficiency of Small Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Sub Category Based on Input Rating

................................ ................................ ... 3

- 38

3

- ivFigure 3.2.28. Classification of Large Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Based on Material Used in the Primary Heat Exchanger

................................ ................................ ............................. 3

- 39

Figure 3.2.29. Classification of Large Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Condensing Boilers Based on Material Used in the Primary Heat Exchanger

................................ ................................ ......... 3

- 39

Figure 3.2.30. Distribution of Large Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Based on Input Rating

................................ . 3

- 40

Figure 3.2.31. Distribution of Large Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Based On Combustion Efficiency

............... 3

- 41

Figure 3.2.32. Comparison of Average Combustion Efficiency of Large Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Sub Categ ory Based on Input Rating

................................ ................................ ... 3

- 42

Figure 3.2.33. Distribution of Small Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boil ers Based on Input Rating

................................ . 3

- 42

Figure 3.2.34. Distribution of Small Oil

- Fired Mechanical Draft Hot Water Commercial Packaged boilers Based on Thermal Efficiency

....................... 3

- 43

Figure 3.2.35. Comparison of Average Thermal Efficiency of Small Oil

- Fired

Mechanical Dr aft Hot Water Commercial Packaged Boilers Sub Category Based on Input Rating

................................ ................................ ... 3

- 44

Figure 3.2.36. Distribution of Large Oil

- Fired M echanical Draft Hot Water Commercial Packaged Boilers Based On Input Rating

................................ 3

- 45

Figure 3.2.37. Distribution of Large Oil

- Fired M echanical Draft Hot Water Commercial Packaged Boilers Based On Combustion Efficiency

............... 3

- 46

Figure 3.2.38. Comparison of Average Com bustion Efficiency of Small Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Sub Category Based on Input Rating

................................ ................................ ... 3

- 46

Figure 3.2.39. Distribution of Small Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based on Input Rating

................................ . 3

- 47

Figure 3.2.40. Distribution of Small Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based on Thermal Efficiency

...................... 3

- 48

Figure 3.2.41. Comparison of Average Thermal Efficiency of Small Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Sub Category Based on Input Rating

................................ ................................ ................... 3

- 48

3

- vFigure 3.2.42. Distribution of Large Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based on Input Rating

................................ . 3

- 49

Figure 3.2.43. Distribution of Large Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based on Thermal Efficiency

...................... 3

- 50

Figure 3.2.44. Comparison of Average Thermal Efficiency of Large Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Sub Category Based on Input Rati ng

................................ ................................ ................... 3

- 51

Figure 3.2.45. Distribution of Small Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based On Input Rating

................................ 3

- 51

Figure 3.2.46. Distribution of small oil

- fired mechanical draft steam commercial packaged boilers based on thermal efficiency

................................ .............. 3

- 52

Figure 3.2.47. Comparison of Average Thermal Efficiency of Small Oil

- Fired Mechanical Draft Steam Commercial Packaged Boile r Sub Category Based on Input Rating

................................ ................................ ................... 3

- 53

Figure 3.2.48. Distribution of Large Oil

- Fired Mechanical Draft Steam Commercial Package d Boilers Based On Input Rating

................................ 3

- 53

Figure 3.2.49. Distribution of Large Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based On Thermal Efficiency

..................... 3

- 54

Figure 3.2.50. Comparison of Average Thermal Efficiency of Large Oil

- Fired

Mechanical Dr aft Steam Commercial Packaged Boilers Sub Category Based on Input Rating

................................ ................................ ................... 3

- 55

Figure 3.3.1. Fin

- tube heat exchanger with louvered fins12

................................ ......... 3

- 61

3

- viLIST OF TABLES

Table 3.1.1. Existing Equipment Classes for Commercial Packaged Boilers

................. 3

- 4

Table 3.2.1. Commercial Packaged Boiler Manufacturers Represented in the Air

Conditioning, Heating, and Refrigeration Institut e Ratings Directory 1

.......... 3

- 7

Table 3.2.2. Current Federal Energy Conservation Standards for Commercial Packaged Boilers under 10 CFR 431.87

................................ ......................... 3

- 8

Table 3.2.3. Canadian Energy Conservation Standards Proposed by NRCan

– updated on November 2011

................................ ................................ ............ 3

- 9

Table 3.2.4. FEMP Recommended Thermal Efficiency Levels for Commercial Packaged Boilers

................................ ................................ ........................... 3

- 10

Table 3.2.5. Rebate Offered by PG&E for Commercial Space Heating Boilers

........... 3

- 11

Table 3.2.6. Rebates offered by SoCalGas for Space Heating Boilers

.......................... 3

- 12

Table 3.2.7. Rebates offered by SoCalGas for Process Heating Boiler

......................... 3

- 13

Table 3.2.8 Numb er of Boiler Models in each Equipment Class

................................ .. 3

- 14

Table 3.2.9. New Equipment Standards with Existing Minimum Efficiency Levels

.... 3

- 1 5

Table 3.2.10. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Small Gas

- Fired Natural Draft Hot Water Commercial Packaged Boilers

.............................. 3

- 18

Table 3.2.11. List of Companies in the Air

- Conditioning, Heati ng, and Refrigeration Institute Directory that Manufacture Large Gas

- Fired Natural Draft Hot Water Commercial Packaged Boilers

.............................. 3

- 20

Table 3.2.12. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Small Oil

- Fired Natural Draft Hot Water Commercial Packaged Boilers

.............................. 3

- 22

Table 3.2.13. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Small Gas

- Fired Natural Draft Steam Commercial Packaged Boilers

................................ ..... 3

- 25

Table 3.2.14. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Large Gas

- Fired Natural Draft Steam Commercial Packaged Boilers

................................ ..... 3

- 28

Table 3.2.15. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Small Oil

- Fired Natural Draft Steam Commercial Packaged Boilers

................................ ..... 3

- 30

3

- viiTable 3.2. 16. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Small Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

....................... 3

- 36

Table 3.2.17. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Large Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

....................... 3

- 40

Table 3.2.18. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Small Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

....................... 3

- 43

Table 3.2.19. List of Companies in the A Air

- Conditioning, Hea ting, and Refrigeration Institute Directory that Manufacture Large Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

....................... 3

- 45

Table 3.2.20. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Small Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers

.............................. 3

- 47

Table 3.2.21. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Large Gas

- Fired

Mechanical Draft Steam Co mmercial Packaged Boilers

.............................. 3

- 49

Table 3.2.22. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Dire ctory that Manufacture Small Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers

.............................. 3

- 52

Table 3.2.23. List of Companies in the Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Large Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers

.............................. 3

- 54

3

- viii

### CHAPTER 3. MARKET AND TECHNOLOGY ASSESSMENT

3.1 INTRODUCTION

This chapter details the market and technology assessment that the U.S. Department of Energy (DOE) has conducted in support of the preliminary analysis for the

energy con servation standards rulemaking for commercial packaged boilers.

The goal of the market assessment is to develop a qualitative and qua ntitative characterization of the commercial packaged boiler industry and market structure, based

on information that is publicly available and on data submitted by manufacturers and other interested parties. Issues addressed include commercial packaged bo iler characteristics, market share and equipment classes; existing regulatory and non

regulatory eff iciency improvement initiatives; overview of historical eq uipment shipments and lifetimes and trends in the equipment markets. The technology assessment

is a n investigation into technologies that will improve the energy efficiency of commercial packaged boilers, and results in a preliminary list of technologies that can improve the thermal and/or combustion efficiency of commercial p ackaged boilers

. In addition, technology options which can improve seasonal efficiency are also discussed as part of this assessment.

A c ommercial packaged boiler (CPB)

, which is defined later in this chapter (see section 3.1.1)

, is a boiler designed to provide space heating or hot water to commercial

institutions

. These boilers are differentiated from residential boilers by their rated input capacity. Residential boilers have a n input capacity up to (but not equal to) 300 thousand British thermal units p er hour ( kBtu/h ) , whereas commercial packaged boilers have capacities of 300 kBtu/h or more

. This chapter further describes the scope of the assessment and divides commercial packaged boilers into various equipment classes. These equipment classes are dire ctly analyzed by DOE to understand various aspects of the CPB market such as number of models under each equipment class, types of boilers ( e.g. , modulating or condensing), heat exchanger materials, and potential technology options for enhancing efficiency etc. The equipment classes created by DOE to analyze

boilers are based on general characteristics of boilers and are discussed in detail in later

sections

.

3.1.1 Equipment Definitions, Scope of Coverage and Background

The En ergy Policy and Conservation Act, as amended, (EPCA) defines a “packaged boiler” as “a boiler that is shipped complete with heating equipment, mechanical draft equipment, and automatic controls; usually shipped in one or more sections.” (42 U.S.C. 6311(11)(B)) DOE ’s regulations further refin ed the “packaged boiler” definition to exclude a boiler that is custom designed and field constructed. Additionally, if the boiler is shipped in more than one section, the sections may be produced by more than one manufacturer, and may be originated or shi pped at different

times and from more than one location. 10 CFR 431. 8 2

3

- 1In its regulations as set forth in 10 CFR 431.82, DOE defines a “commercial packaged boiler” as a type of packaged low pressure boiler that is industrial equipment with a capacity, ( rat ed maximum input) of 300,000 Btu/h or more which, to any significant extent, is distributed in commerce: (1) For heating or space conditioning applications in buildings; or (2) For service water heating in buildings but does not meet

the definition of a ‘ho t water supply boiler’ in [part 431].

A “packaged low pressure boiler” is defined as “a packaged boiler that is: (1) A steam boiler designed to operate at or below a steam pressure of 15 psig [pounds per square inch gauge]; or (2) A hot water boiler desig ned to operate at or below a water pressure of 160 psig and a temperature of 250 °F; or (3) A boiler that is designed to be capable of supplying either steam or hot water, and designed to operate under the conditions in paragraphs (1) and (2) of this defin ition.” 10 CFR 431.82.

On August 28, 2013, DOE released the Rulemaking Framework Document for Commercial Packaged Boilers (Framework document). On that same day DOE also issued the Notice of Public Meeting and Availability of the Framework Document for

co mmercial packaged boilers, which was published in the Federal Register on September 3, 2013. 78 FR 54197. As part of the Framework document and the notice of public meeting ( NOPM ) , DOE sought comments from interested parties and stakeholders on various asp ects of the rulemaking, such as scope of coverage, approach used, analyses methodologies etc. In respons e DOE received several responses which are summarized in chapter 2 of this Technical Support Document ( TSD )

.

DOE’s regulations for commercial packaged boilers that are currently in effect cover small and large, gas

- fired and oil

- fired, hot water and steam commercial packaged boilers that meet the definitions outlined above, as applicable. a DOE notes that although

F ederal energy conservation standards for electric commercial packaged boilers have not

been established , the definitions set forth above do not preclude DOE from adopting standards for such equipment if justified. In other words, electric commercial packaged boilers are within the scope of D OE’s authority under EPCA.

DOE plans to maintain the scope of coverage as defined by its current regulations for this analysis of amended thermal and combustion efficiency standards for commercial packaged boilers. However for the scope of the current rul emaking, DOE is not considering standards for electric commercial packaged boilers . This is primarily because

a review of the electric commercial packaged boilers market revealed that these boilers account for a relatively small number of annual shipments (approximately 1,500

- 2,100 units), and the efficiency of such equipment already approaches 100

- percent under the current metric ( i.e. , thermal efficiency). Thus, DOE believes that there is little to no room for improvement in efficiency, unless DOE were t o consider adopting levels requiring installation of heat pump technology (a technological leap when setting initial

a DOE’s regulations for commercial packaged boilers are divided into equipment classes based on input capacity ( i.e. , size category). Throughout this preliminary TSD, DOE refers to units with an input capacity
of ≥ 300,000 Btu/h and ≤ 2,500,000 Btu/h as “s mall” and units with an input capacity ≥ 2,500,000 Btu/h as “large.” For more information please refer to 10 CFR 431.87.

3

- 2standards). However, DOE did not consider heat pump technology in this rulemaking analysis, as it has not been demonstrated feasible for u se in electric commercial packaged

boilers

.

On August 13, 2013 , DOE published in the Federal Register a notice of proposed

determination (NOPD) of coverage to explicitly clarify its statutory authority to regulate natural draft commercial packaged boilers

. 78 FR 49202. As explained in the proposed

determination , under DOE’s interpretation of the relevant statutory provisions, natural draft commercial packaged boilers are currently included as covered equipment with standards at 10 CFR part 43 1 , subpart E. However, DOE is undertaking a coverage determination to explicitly clarify its statutory authority under EPCA to cover natural draft commercial packaged boilers. If the outcome of the NOPD is positive DOE will classify boiler models further into natural d raft and mechanical draft CPB s . Although outcome of NOPD is pending, DOE plans to cover natural draft boilers as part of this rulemaking. As a result, DOE has analyzed a total of 16 equipment classes for this TSD.

As noted previously in the discussion of d efinitions, c ommercial packaged boilers are defined as having an input capacity greater than or equal to 300,000 Btu/h. Currently

, there is no upper limit to the input capacity of a CPB

. As discussed in chapter 2 of this TSD, DOE received several comments on this topic, but has tentatively concluded that it

will not alter the scope of coverage for the rulemaking to exclude very large CPBs. Therefore, all CPBs having input capacity greater than or equal to 300,000Btu/h are covered under this rulemaking.

3.1.2 Equ ipment Classes

3.1.2.1 Existing Equipment Classes

EPCA

, as amended

, established mandatory F ederal energy conservation standards for certain commercial equipment , including CPB s, based on the American Society of Heating, Refrigerating and Air Conditioning Engine ers / Illuminating Engineering Society ( ASHRAE /IES ) Standard 90.1

, “ Energy Standard for Buildings Except Low

- Rise Residential Buildings

. ” Section 42 U.S.C 6313(a)(6) of EPCA provides that

, if

ASHRAE /IES Standard 90.1 is amended with respect to packaged boil ers, DOE shall publish in the Federal Register for public comment an analysis of the energy savings potential of amended energy efficiency standards. Further, EPCA requires DOE to establish an amended uniform national standard for commercial packaged boiler at the minimum level specified in the amended ASHRAE/IES Standard 90.1, unless DOE determines by rule and supported by clear and convincing evidence that adoption of a

more strin gent standard is technologically feasible and economically justified. In 2007, ASHRAE amended the efficiency levels of commercial packaged boilers. Subsequently,

i n July 2009, DOE published in the Federal Register a final rule (July 2009 final rule)

amendi ng the energy conservation standards for commercial packaged boilers to correspond to levels in ASHRAE 90.1

- 2007

. 74 FR 36312.

ASHRAE /IES Standard 90.1

‒ 2007 divides commercial packaged boilers into 10 equipment classes on the basis of fuel type ( i.e., oil or gas (natural or propane) ), size ( i.e.,

3

- 3small (300

- 2,500 kBtu/h) or large (>2,500 k Btu/h)) and heating media (steam or hot water). The gas

- fired steam boilers are further divided based on the draft type ( i.e. natural draft or mechanical draft). In the J uly 2009 final rule, DOE adopted efficiency levels and equipment classes based on Standard 90.1

‒ 2007 that required compliance beginning on March 2, 2012. Table 3.1

. 1 below shows the division of equipment classes based on

ASHRAE /IES Standard 90.1

‒ 2007.

As mentioned earlier, there are very few annual shipments and limited potential for improving efficiency for electric commercial packaged boilers, and therefore, this equipment class was not covered as part of the ASHRAE /IES Standard 90.1

‒ 2007 standards, or the July 2009 final rule. As discussed above, a preliminary investigation has shown that the market and technologies for th is equipment has not significantly changed

and

, thus, electric boilers were not considered for this preliminary analysis.

Table 3.1

. 1 . Existing Equipment Classes for Commercial Packaged Boilers Commercial Packaged Boiler Equipment Class Description of Characteristics

Small Gas

- Fired Hot Water Fuel input of 300

− 2,500 kBtu/h; fueled by propane or natural gas; hot water output

Small Gas

- Fired Steam All Except

Natural Draft Fuel input of 300

− 2,500 kBtu/h; fueled by propane or natural gas; steam outpu t; draft mechanism other than natural draft ( e.g., forced or induced draft mechanism)

Small Gas

- Fired Steam Natural Draft Fuel input of 300

− 2,500 kBtu/h; fueled by propane or natural gas; steam output; natural

draft mechanism

Small Oil

- Fired Hot Water Fu el input of 300

− 2,500 kBtu/h; fueled by oil; hot water output

Small Oil

- Fired Steam Fuel input of 300

− 2,500 kBtu/h; fueled by oil;
steam output Large Gas

- Fired Hot Water Fuel input of >2,500 kBtu/h; fueled by propane or natural gas; hot water output Large Gas

- Fired Steam All Except

Natural Draft Fuel input of >2,500 kBtu/h; fueled by propane or natural gas; steam output; draft mechanism other than natural draft ( e.g., forced or induced draft mechanism) Large Gas

- Fired Steam Natural Draft Fuel input o f >2,500 kBtu/h; fueled by propane or natural gas; steam output; natural draft

mechanism Large Oil

- Fired Hot Water Fuel input of >2,500 kBtu/h; fueled by oil; hot
water output Large Oil

- Fired Steam Fuel input of >2,500 kBtu/h; fueled by oil;
steam output

3.1.2.2 New Equipment Classes

3

- 4As a result of the August 2013 proposed determination of coverage , DOE

considered separate equipment class es for n atural draft commercial packaged boilers. Although, the outcome of the NOPD is pending, for the purpose of the rulemaking, DOE has tentatively decided to analyze separate equipment classes for natural draft boilers.

With the introduction of th ese equipment classes , all CPB s are divided into 16 categories (excluding electric boilers). The equipment classes are shown in the chart below ( Figure

3.1

. 1 )

Figure 3.1

. 1

. Proposed Commercial Packaged Boiler Equipment Classes

3

- 53.2 MARKET ASSESSMENT

The following market assessment identifies the manufacturer trade associations and domestic and international manufacturers of commercial packaged boilers. The market assessment also identifies existing regulatory and non

- regulatory programs fo r commercial boilers, and summarizes relevant characteristics and market performance data for each equipment class.

3.2.1 Trade Association

To gain insight into the commercial packaged boiler industries, DOE researched

various associations available to manufac turers, suppliers, and users of such equipment.

DOE identified the Air

- Conditioning, Heating, and Refrigeration Institute (AHRI) and the American Boiler Manufacturers Association (ABMA) as the only trade groups that support, or have an interest in, the com mercial packaged boiler industry.

3.2.1.1 Air

- Conditioning, Heating, and Refrigeration Institute

AHRI is a national trade association for manufacturers of heating, ventilation, air

conditioning, and refrigeration (HVACR) which includes commercial packaged boiler

manufacturers . AHRI was established in January of 2008 when the Air

- Conditioning and Refrigeration Institute (ARI) merged with the Gas Appliance Manufacturers Association (GAMA). AHRI develops and publishes technical standards for residential and

co mmercial air conditioning, heating, and refrigeration equipment using rating criteria and procedures for measuring and certifying product performance. AHRI maintains the Directory of Certified Product Performance , which is a database of ratings for all

ma nufacturers who elect to participate in the program (AHRI’s certified directory). AHRI

maintains a certified performance directory for commercial boilers. Table 3.2

. 1 shows the manufacturers of AHRI certified commercial boilers in the 2014 directory. The directory

consists of 2354 boiler models

. 1

DOE use d the data in this directory in its market assessment. DOE also examine d

other data sources such as manufacturer li terature, technical reports, and any other relevant information to provide a broad insight into the commercial packaged boilers

market.

3

- 6Table 3.2

. 1

. Commercial Packaged Boiler Manufacturers Represented in the Air

Conditioning, Heating, and Refrigeration Institute Ratings Directory 1

A.O. Smith Water Products Co. Heat Transfer Products Inc. Advanced Thermal Hydronics LAARS Heating Systems Company

AERCO International, Inc. Lochinvar Corporation

BIASI, S.p.A. c/o QHT, Inc. New Yorker Boiler Co., Inc. (Burnham Holdings, Inc.) Bosch Thermotechnology Corp. NY Thermal Inc.

Bradford White Corporation Parker Boiler Company Bryan Steam LLC P B Heat, LLC Burnham Commercial (Burnham Holdings, Inc.) Pennco (ECR International, Inc.)

Camus Hydronics Ltd. Raypak, Inc.

Cleaver

- Brooks RBI Water Heaters (Mestek, Inc.) Columbia Boiler Company of Pottstown Slant/Fin Corporation Crown Boiler Co. (Burnham Holdings, Inc.) Smith Cast Iron Boilers

De Dietrich Thermal Solutions Products, LLC (Burnham Holdings, Inc.) Dunkirk Boilers (ECR International, Inc.) Triangle Tube Phase III Inc. Fulton Heating Solutions Utica Boilers (ECR International, Inc.) Hamilton Engineering Inc. Viessmann Manufacturing Company, Inc.

Harsco Industrial Patterson

- Kelley Weil

- McLain

3.2.1.2 American Boiler Manufacturers Association

ABMA is a national, nonprofit trade association of commercial, institutional, industrial, and electricity

- generating boiler system manufacturing companies (> 400,000 Btu/h heat input), dedicated to the advancement and growth of the boiler and combustion equipment industry. b

DOE identified the following ABMA manufacturers as manufacturers of commercial packaged boiler equipment: Aesys Technologies, LLC; AJAX Boiler, Burnham Commercial; Cleaver

- Brooks; Johnston Boiler Company; Miura Boiler; Superior Boiler Works, Inc., Vapor Power International, LLC. c

3.2.1.3 Additional Manufacturers

DOE also reviewed the CSA

- International d and SC AQMD e boiler databases to identify commercial boiler manufacturers that may not be members of a trade association or actively participate in an efficiency certifi cation program . DOE identified 10

b See http://www.abma.com/

.

c For more information, visit http://www.abma.com/membership

- directory.html

d For more information, visit www.csa

- international.org/Default.asp?language=english

e For more information, visit www.aqmd.gov/

3

- 7additional boiler manufacturers from the two databases: Fulton Boiler; Parker Boiler;

Patterson

- Kelley Company (division of Harsco); Triad Boiler Systems; CAMUS Hydronics, Ltd.; Gasmaster Industries; General Boiler Co., In c.; Hurst Boiler; Lattner Boiler; and Unilux Boiler.

3.2.2 Regulatory Programs

The following section details current regulatory programs requiring energy conservation standards for commercial packaged boilers. Section 3 .2.2.1 addresses Federal energy conservation standards and section 3.2.2.2 provi des an overview of existing S tate standards. Section 3.2.2.3 reviews Canadian standards programs that may affect the companies servicing the North A merican market.

3.2.2.1 Current Federal Energy Conservation Standards

The existing F ederal energy conservation standards as set forth in 10 CFR 431.87 cover 10 equipment classes. Apart from gas

- fired steam boilers, no other equipment class

is currently divided based on draft type. As a result, both natural draft and mechanical draft boilers have the same energy conservation standard (except for gas steam boiler equipment classes) . Further, the energy efficiency descriptor for large hot water CPB equipment classe s is combustion efficiency

, while for all other equipment classes the descriptor is thermal efficiency. Table 3.2

. 2 show s the current energy efficiency

standards for c ommercial packaged boilers.

Table 3.2

. 2 . Current Federal Energy Conservation Standards for Commercial Packaged Boilers under 10 CFR 431.87

Equipment type Subcategory Size category (input) Efficiency

level

— Eff ective date: March 2, 2012*

Hot Water Commercial Packaged Boilers Gas

- fired ≥ 300,000 Btu/hr and

≤ 2,500,000 Btu/hr 80 % E T

Hot Water Commercial Packaged Boilers Gas

- fired >2,500,000 Btu/hr 82% E C

Hot Water Commercial Packaged Boilers Oil

- fired ≥ 300,000 Btu/hr and

≤ 2,500,000 Btu/hr 82% E T

Hot Water Commercial Packaged Boilers Oil

- fired >2,500,000 Btu/hr 84% E C

Steam Commercial Packaged Boilers Gas

- fired

— all, except natural draft ≥ 300,000 Btu/hr and

≤ 2,500,000 Btu/hr 79% E T

Steam Commercial Packaged Boilers Gas

- fired

— all, except natural draft >2,500,000 Btu/hr 79% E T

Steam Commercial Packaged Boilers Gas

- fired

— natural

draft ≥ 300,000 Btu/hr and

≤ 2,500,000 Btu/hr 77% E T * *

Steam Commercial Packaged Boilers Gas

- fired

— natural

draft >2,500,000 Btu/hr 77% E T **

Steam Commercial Oil

- fired ≥ 300,000 Btu/hr and 81% E T

3

- 8Packaged Boilers ≤ 2,500,000 Btu/hr

Steam Commercial Packaged Boilers Oil

- fired >2,500,000 Btu/hr 81% E T

* E T means “thermal efficiency.” E C means “combustion efficiency.” 10 CFR part 431.82. **On March 2, 2022 the minimum efficiency standard for small and large gas

- fired natural draft steam commercial packaged boilers will be 79% E T

.
3.2.2.2 State Energy Conservation Standards

Under EPCA, states may petition to have more

- stringent energy conservation

standards than those codified under subpart E of 10 CFR Part 431. (42 U.S.C. 6 316(b)(2);

6 297(d)). At this time, no states have been granted a petition from DOE to establish

more

- stringent energy conservation standards than th e levels EPCA established for commercial packaged boilers.

3.2.2.3 Canadian Energy Conservation Standards

In May 201 0 , the Natural Resources Canada (NRCan) Office of Energy Efficiency

, proposed energy conservation standards for gas

- and oil

- fired commercial packag ed boilers according to the standards set forth in ASHRAE 90.1

‒ 2007. After release of the propos ed standards , additional updates were published in August 2010 and

November 2011. As part of the August 2010 update, NRCan made three changes to its original pr oposal. NRCan changed its proposed near

- condensing efficiency level for

small gas

- fired boilers from 85

- percent to 84

- percent (t hermal e fficiency) and for large

gas

- fired boilers from 87

- percent to 86

- percent ( c ombustion e fficiency) . NRCan also

decided to allow boilers with near

- condensing efficiency levels only for replacement

market s and to require boilers to achieve efficiencies requiring condensation only for new

construction beginning in 2015.

In the November 2011 update, NRCan amended efficiency level s and changed effective dates for certain equipment classes of boilers. The latest version of the proposed energy conservation standards for Canada is shown in the Table 3.2

. 3 below:

Table 3.2

. 3 . Canadian Energy Conservation Standards Proposed by NRCan

– updated on November 2011 2

Boiler Type Prescriptive Requirements Minimum Efficiency * Date of Manufacture

Small Gas Hot Water No standing pilot 80% E T March 2, 2012

Small Gas Hot Water No standing pilot 84% E T March 2, 2015

Small Gas Steam No standing pilot 77% E T March 2, 2012

Small Gas Steam No standing pilot 79% E T March 2, 2015

Small Oil Hot Water Nil 82% E T March 2, 2012

Small Oil Steam Nil 81% E T March 2, 2012
Large Gas Hot Water No standing pilot 82% E

c March 2, 2012
Large Gas Hot Water No standing pilot 85% E

c March 2, 2015
Large Oil Hot Water Nil 84% E

c March 2, 2012

Large Gas Steam No standing pilot 77% E T March 2, 2012
Large Gas Steam No standing pilot 79% E T March 2, 2015

3

- 9Large Oil Steam Nil 81% E T March 2, 2012

C

hanges from the May 2010 b ulletin are in bold and italic

. *E T refers to Thermal Efficiency; E C refers to Combustion Efficiency

3.2.3 Non

- Regulatory Programs

3.2.3.1 Energy Star Program

ENERGY STAR, a voluntary labeling program backed by the U.S. Environmental Protection Agency (EPA) and DOE, identifies energy efficient products through a qualification process

. f To qualify, a product must exce ed F ederal minimum standards by a specified amount, or if no F ederal standard exists, then exhibit selected

energy

- saving features. The ENERGY STAR program works to recognize the top quartile of products on the market, meaning that approximately 25

- percent of products on the market meet or exceed the ENERGY STAR levels. Currently, there is an ENERGY STAR program for residential packaged boilers, but there is no ENERGY STAR program for commercial packaged boilers.

3.2.3.2 Federal Energy Management Program

DOE’s Fe deral Energy Management Program (FEMP) works to reduce the cost and environmental impact of the Federal government by advancing energy efficiency and water conservation, promoting the use of distributed and renewable energy, and improving utility manageme nt decisions at Federal sites. g FEMP helps Federal buyers identify and purchase energy efficient equipment.

FEMP designates standards for commercial packaged boilers purchased by the Federal government. FEMP specifies different efficiency levels for comm ercial packaged boilers based on fuel type, size, and output. FEMP levels are specified using the thermal efficiency metric

. Table 3.2.4 presents the designated FEMP commercial packaged boiler

standards levels.

Table 3.2

. 4

. FEMP Recommended Thermal Efficiency Levels for Commercial Packaged Boilers 3

f For more information, visit www.energystar.gov

g For more information, visit www.e nergy.gov/eere/femp

3

- 10Equipment Class Recommended Thermal

Efficienc y (E T ) (%)

Small Gas

- Fired Hot Water 80 Large Gas

- Fired Hot Water 80

Small Gas

- Fired Steam 79 Large Gas

- Fired Steam 80

Small Oil

- Fired Hot Water 83 Large Oil

- Fired Hot Water 83

Small Oil

- Fired Steam 83 Large Oil

- Fired Steam 83

3.2.3.3 Rebate Programs

DOE has identified and reviewed various local utility rebate programs. Some of

the local utilities revie w ed by DOE include Minnesota Energy Resources, Pacific Gas and Electric Company (PG&E), San Diego Gas and Electric (SDG&E)

, and the Southern

California Gas Company (SoCalGas).

Minnesota Energy Resources.

The Minnesota Energy Resources Commercial Custom Rebate program offers businesses cash rebates as an incentive to install energy efficient commercial equipment, including

boilers and boiler retrofits. M innesota Energy Resources does not have a standard rebate amount; rather it individually reviews each application it receives. Rebate amounts are

awarded based on the type and efficiency of boiler

. Rebate amounts for hot water boilers having efficiency gre ater than 90

- are higher than those for efficiency greater than 85

- percent and less than 90

- percent . For steam boilers rebate is available for boilers having thermal efficiency greater than 83

- percent

. 4

Pacific Gas and Electric Company.

PG&E offers energ y efficiency rebates to commercial customers who use energy efficient space

- heating boilers in their businesses or commercial facilities. PG&E offers

different rebates amounts depending on the characteristics of the space

- heating boiler.

Table 3.2

. 5 below describes the rebates offered by PG&E for space

- heating boilers

. 5

Table 3.2

. 5 . Rebate Offered by PG&E for Commercial Space Heating Boilers
Description of Boiler Rebate Amount Space heating atmospheric water boiler thermal efficiency of ≥ 85% and input rating 300 kBtu /h and ≤ 2500 kBtu /h $1/k Btu/h

Space heating forced draft water boiler thermal efficiency of ≥ 85% and i nput rating 300 kBtu /h and ≤ 2500 kBtu /h $ 1/k Btu/h

Space heating condensing water boiler thermal efficiency of ≥ 94% and input rating 300 kBtu /h and ≤ 2500 kBtu /h $2/k Btu/h

Space heating atmospheric water boiler combustion efficiency of ≥ 85% and input rating > 2500 kBtu /h $1/k Btu/h

Space heating forced draft water boiler combustion efficiency of ≥ 85% or thermal efficiency of ≥ 83% and input rating > 2500 kBtu /h $1/k Btu/h

Space heating condensing water boiler thermal efficiency of ≥ 94% and input $2/k Btu/h

3

- 11rating > 2500 kBtu /h Space heating atmospheric steam boiler thermal efficiency of ≥ 85% and input rating 300 kBtu /h and ≤ 2500 kBtu /h $1/k Btu/h

Space heating forced draft steam boiler thermal efficiency of ≥ 85% and input rating 300 kBtu /h and ≤ 2500 kBtu /h $1/k Btu/h

Space heating atmospheric steam boiler combustion efficiency of ≥ 80% or

81% thermal efficiency and input rating > 2500 kBtu /h $1/k Btu/h

Space heating forced draft steam boiler combustion efficiency of ≥ 80% or

81% thermal efficie ncy and input rating > 2500 kBtu /h $1/k Btu/h

San Diego Gas and Electric Company.

SDG&E offers rebates and incentives to commercial customers through two

programs . The first program is its Energy Efficiency Business Incentive program. This

program provides cash incentives to businesses that improve boiler performance through replacement of boiler parts resulting in natural gas savings

. The incentive amounts to $1 per therm (~100 cu.ft of natural gas) of natural gas saved with the gas being supplied by SDG&E, PG&E or SoCal G as . This program is not offered to space

- heating commercial

boilers with input ratings ≤ 5,000 kB tu/h and process (non

- space

- heating ) boilers with input ratings < 10,000 k Btu/h for industrial end

- use customers

. 6

The second program offered is the Energy Efficiency Business Rebates program. This is available for a wide range of products and equipment from the agricultural,

commercial and industrial sector s . For comm ercial boilers, SDG&E provides a rebate of $0.5 per k Btu / h for any commercial space heating boiler having an input rating of 300

k Btu / h to 2,500 k Btu / h with a combustion efficiency greater than or equal 85

- percent

. For process boilers (non

- sp a ce

- heating) h aving an input rating more than 75,000 Btu / h and a thermal efficiency greater than or equal to 84

- percent , SDG&E offers a rebate of $0.5 per k Btu / h

. 7

Southern California Gas Company.

SoCalGas offers Energy

- Efficiency Rebates for Business (EERB) for replacing inefficient gas

- fired equipment with more

- efficient models. R ebates are offered for commercial, industrial or agricultural customer with an active, valid

, and non

- delinquent account. Eligible customers can receive rebates for space

- heating hot wa ter and process

heating boilers. For a space

- heating boiler

, which is installed by a licensed contractor and has an input rating greater than or equal to 300 kBtu/h, SoCal Gas offers the following

rebates:

Table 3.2

. 6

. Rebates offered by SoCalGas for Space Heating Boilers 8

**Type of Boiler Required Efficiency**  **Rebate Amount** Medium/Large

– steam ≥83% Combustion Efficiency $0.50/(kBtu/h) Medium/Large hot water (Tier I) ≥85% Combustion Efficiency $0.50/(kBtu/h)

Medium/Large hot water (Tier II) ≥90% Combustion Efficiency $4.00/(kBtu/h)

3

- 12For process heating boilers having a capacity of less than or equal to 10,000

kBtu/h , SoCalGas offers the following rebates:

Table 3.2

. 7 . Rebates offered by SoCa lGas for Process Heating Boiler 8

Type of Boiler Required Efficiency Rebate Amount

Steam ≥83% Combustion Efficiency $0.75 /(kBtu/h)

H ot water (Tier I) ≥85% Combustion Efficiency $0.75 /(kBtu/h)

H ot water (Tier II) ≥90% Combustion Efficiency $ 1

. 5 0/(kBtu/h)

3.2.4 Shipments

Information about annual equipment shipment trends allows DOE to estimate the impacts of energy conservation standards on the commercial packaged boiler industry. For commercial packaged boilers, very little information about historical shipments is publicly available. DOE used information from the 2009 commercial packaged boiler final rule analysis, along with information from the several other sources ( e.g ., the AHRI directory, Appliance Magazine, Energy) to develop its shipments model for commercial packaged boilers. 9 Additional details about commercial boiler shipment s are discussed in Chapter 9 of this TSD (Shipments Analysis)

.

3.2.5 Equipment Lifetime

During manufacturer interviews, estimates of commercial packaged boiler

lifetime typically ranged from 25 to 30 years, with an average lifetime expected to be roughly 25 years. For its analysis of lifetime, DOE used national survey data, published studies, and projections based on manufacturer shipment data to calculate the distribution of commercial packaged boiler lifetimes. More information about commercial packaged boiler equipment lifetime can be found i n the life

- cycle cost and payback period analyses

section in C hapter 8 (Life

- Cycle Cost and Payback Period Analysis) and Appendix 8

- F of

th is TSD.

3.2.6 Market Performance Data

DOE reviewed performance data for commercial packaged boi lers currently on

the marke t. DOE reviewed c ommercial packaged boiler equipment literature available

from manufacturers , including those listed as ABMA and AHRI members

. However for the analysis, DOE decided to use a database of boiler models which are certified by

AHRI

. Many of the non

- AHRI manufacturers reviewed by DOE had an efficiency metric listed but did not specify the type listed efficiency ( i.e. , whether combustion efficiency or thermal efficiency)

. U nder 10 CFR 431.86, Federal energy conservation standards requi re efficiency ratings to be determined using the Hydronics Institute BTS

- 2000 Testing

Standard , “Method to Determine Efficiency of Commercial Space Heating Boilers. ” 10

However, the efficiency ratings listed by non

- AHRI boiler manufacturers were often

deriv ed using the American Society of Mechanical Engineering

– Power Test Code (PTC 4) test method that may not be directly comparable with BTS

- 2000. Considering these issues DOE obtained a directory comprising 2

, 35 4 models manufactured by 33 companies from AHR I ’s website 1

. The directory provides a list of AHRI certified

3

- 13commercial boilers with important performance related information

, such as type of fuel, input ca pacity, draft type and heating medium listed for each boiler model. T o initiate the analysis, DOE categorized the entire list into the 16 equipment classes which are

mentioned in Table 3.2

. 8 . DOE identified the number of CPB s in each equipment class.

Table 3.2.8 below shows t he distribution of boiler models under each equipment class.

Table 3.2

. 8 Number o f B oiler Model s in e ach E quipment C lass

Full Name Abbreviation Number of Models Small (≥300,000 Btu/h and ≤2,500,000 Btu/h)

Gas

- fired Natural Draft Hot Water CPB SGNDHW 236

Large (>2,500,000 Btu/h) Gas

- fired Natural

Draft Hot Water CPB LGNDHW 35

Small (≥300,000 Btu/h and ≤2,500,000 Btu/h)

Oil

- fired Natural Draft Hot Water CPB SONDHW 55

Large (>2,500,000 Btu/h) Oil

- fired Natural

Draft Hot Water CPB LONDHW 6

Small (≥300,000 Btu/h and ≤2,500,000 Btu/h)

Gas

- fired Natural Draft Steam CPB SGNDST 347

Large (>2,500,000 Btu/h) Gas

- fired Natural

Draft Steam CPB LGNDST 163

Small (≥300,000 Btu/h and ≤2,500,000 Btu/h)

Oil

- fired Natural Draft Steam CPB SONDST 52

Large (>2,500,000 Btu/h) Oil

- fired Natural

Draft Steam CPB LONDST 95

Small (≥300,000 Btu/h and ≤2,500,000 Btu/h)

Gas

- fired Mechanical Draft Hot Water CPB SGMDHW 757

Large (>2,500,000 Btu/h) Gas

- fired Mechanical

Draft Hot Water CPB LGMDHW 127

Small (≥300,000 Btu/h and ≤2,500,000 Btu/h)

Oil

- fired Mechanical Draft Hot Water CPB SOMDHW 48

Large (>2,500,000 Btu/h) Oil

- fired Mechanical

Draft Hot Water CPB LOMDHW 24

Small (≥300,000 Btu/h and ≤2,500,000 Btu/h)

Gas

- fired Mechanical Draft Steam CPB SGMDST 98

Large (>2,500,000 Btu/h) Gas

- fired Mechanical

Draft Steam CPB LGMDST 106

Small (≥300,000 Btu/h and ≤2,500,000 Btu/h)

Oil

- fired Mechanical Draft Steam CPB SOMDST 95

Large (>2,500,000 Btu/h) Oil

- fired Mechanical

Draft Steam CPB LOMDST 107

Residential Boilers (Input Rating <300kB tu /h) N/A 3

Total 2,35 4

M any boiler models ha ve the capabilit y to deliver both hot water and steam and

often have only one efficiency rating listed in the AHRI database. In such instances, DOE classified these boilers into steam equipment classes because boilers capable of delivering both steam and hot water can be tested and rated for performance in only the steam mode, if the manufacturer chooses

. ( See 10 CFR 431 .86 ) In view of existing

3

- 14energy conservation standards, steam equipment classes have lower efficiency standards compared to corresponding hot water equipment classes and thus it is likely that the rating in steam mode is more conservative

.

After sorting the boiler models, DOE ver ified listed efficiency levels of the

models with equipment literature. I n the previous rulemaking, DOE combined natural draft and mechanical draft boilers into a single equipment class (except for gas

- fired steam boilers). With the introduction of new equ ipment classes, formed by dividing these equipment classes further based on draft type, the existing energy conservations standards will apply to the six new equipment classes. The se standards served as a baseline for conducting various analyses for this r ulemaking. Table 3.2

. 9

. shows all 16 equipment classes along with their corresponding energy conservation standards or baseline

efficiencies.

Table 3.2

. 9

. New Equipment Standards with Existing Minimum Efficiency Levels
Size Category Abbreviation Efficiency Standard
Small (≥300,000 Btu/h and ≤2,500,000 Btu/h) SGNDHW 80 % E T Large (>2,500,000 Btu/h) LGNDHW 82 % E C Small (≥300,000 Btu/h and ≤2,500,000 Btu/h) SONDHW 82 % E T Large (>2,500,000 Btu/h) LONDHW 84 % E C Small (≥300,000 Btu/h and ≤2,500,000 Btu/h) SGNDST 77% E T Large (>2,500,000 Btu/h) LGNDST 77% E T Small (≥300,000 Btu/h and ≤2,500,000 Btu/h) SONDST 81% E T Large (>2,500,000 Btu/h) LONDST 81% E T Small (≥300,000 Btu/h and ≤2,500,000 Btu/h) SGMDHW 80% E T Large (>2,500,000 Btu/h) LGMDHW 82% E C Small (≥300,000 Btu/h and ≤2,500,000 Btu/h) SOMDHW 82% E T Large (>2,500,000 Btu/h) LOMDHW 84% E C Small (≥300,000 Btu/h and ≤2,500,000 Btu/h) SGMDST 79% E T Large (>2,500,000 Btu/h) LGMDST 79% E T Small (≥300,000 Btu/h and ≤2,500,000 Btu/h) SOMDST 81% E T Large (>2,500,000 Btu/h) LOMDST 81% E T * E T refers to Thermal Efficiency and E C refers to Combustion Efficiency

During its review of the commercial packaged boiler performance data, DOE noticed that some boiler models did not have their relevant efficiency listed in the database. These models were rejected from the analysis. DOE also found several models

with effici ency ratings below the Federal requirements and did not include those units in its analysis. Lastly, DOE found three boiler models listed among AHRI data, which were below input ratings for qualifying as a commercial packaged boiler

, as defined by under

10 CFR 431.82, and these models were also removed from the analysis. Figure 3.2

. 1 below shows the numbers of boiler models which were rejected and the remaining ones

whi ch were used for analysis.

3

- 15Figure 3.2

. 1

. Qualifying C hecks on Air

- Conditioning, Heating, and Refrigeration

Institute D atabase for C ommercial P ackaged B oilers

T o analyze each equipment class in terms of efficiency level, input rating

, and manufacturer, listed models within each equipment class were further categorized b y input rating. S mall

- size boiler models had input rating categories of 100 kBtu/h step sizes ( e.g. , 300 kBtu/h

– 400 kBtu/h, 400 kBtu/h

– 500 kBtu/h, etc.). The lower limit of each input rating category was i ncluded within category range while the upper limit was excluded ( e.g. , 300 kBtu/h

– 400 kBtu/h has a range of ≥ 300 kBtu/h to 400 kBtu/h). For the last input rating category for small boilers

, however, DOE made an exception to include the upper limit within the range of the category ( i.e.

, 2,400 kBtu/h

– 2,500 kBtu/h had a range of ≥ 2,400 kBtu/h to ≤ 2,500 kBtu/h). This exception allowed boilers having

a 2,500 kBtu/h input rating to be included as part of the last input rating category for small boilers rather than having a separate input rating category altogether.

Similarly, DOE classified large commercial packaged boiler equipment classes.

I nput rating categories set up for such boilers had a step size of 1,500 kBtu/h . Also, unlike the input rating categories of small boilers, these input rating categories exclude the lower limit of the category and include the upper limit ( e.g. , 2,500 kBtu/h

– 4,000 kBtu/h has a range defined by >2,500 kBtu/h to ≤4,000 kBtu/h). As such

, DOE created 22 input rating categories for small CPB equipment classes and 11 input rating categories for large CPB equipment classes. The distribution of commercial packaged boilers within

these input rating rang es is shown in the figures appearing later in this section.

Boilers were also grouped and examined based on efficiency. The efficiency groupings were created by rounding off the relev a nt efficiency metric for every boiler of each equipment class to the ne arest integer. For example, all efficiency values between

79.5 and 79. 9

- percent were rounded to 80

- percent

, while all efficiency values equal to or

less than 79.4

- percent were rounded to 79

- percent

. Examining boiler models by efficiency levels helped DOE a nalyze the influence of boiler characteristics (condensing, modulating, material used etc.) on efficiency. Commercial Packaged
Boilers Database [2354]

Accepted CPBs [1989] Rejected CPBs [365]

Missing Relevant Efficiency Metric [227] Below Minimum Efficiency Level [135] Below 300kBtu/h Input Rating [3]

3

- 16Using the aforementioned equipment classes, baselines, input rating categories

, and efficiency groupings , DOE conducted its market analysis for each equipment class based on input rating, distribution of boilers based on efficiency levels, equipment offering by each company

, and variation of efficiency with respect to input rating. DOE also gave due consideration to important characteristics of boiler s , such as condensing, modulating or material type

, and assessed how these factors influence input rating and efficiency. The following sections describe equipment class es and the results of the

market assessment for each class.

3.2.6.1 Small (300k Btu /h

- 2,500k Btu /h) Gas

- Fired Natural Draft Hot Water Commercial Packaged Boilers

Approximately 10

- percent of the boiler models in the AHRI directory of commercial packaged boiler performance are included in th e small gas

- fired natural draft

hot water equipment class. Under the existing standards

, these boilers must have a minimum thermal efficiency of 80

- percent

.

Nearly 50

- percent of qualified boilers in this equipment class have a copper heat exchanger

, while the rest have a heat exchanger made of cast iron. Becau se these boilers vent to the atmosphere through natural draft, none of the boilers were condensing type.

The information from the AHRI database also revealed that none of the boilers had modulating burners. Figure 3.2

. 2 below shows the distribution of input ratings for boilers

with cast iron and copper heat exchangers

.

Figure 3.2

. 2

. Distribution of S mall G as

- fired N atural D raft H ot W ater C ommercial

P ackaged B oilers B ased on I nput R ating



### Manufacturers.

There are 10 AHRI

- member manufacturers which currently produc e boilers of this equipment class. Raypak was the only company to produce boilers of all input rating 0 5 10 15 20 25 30300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Number of Models

Input Ratings Category [kBtu/h] Distribution of Boilers Based on Input Ratings

Cast Iron Copper

3

- 17categories. Table 3.2.10. below

, shows different manufacturers of small gas

- fired hot

water CPB s and the size s which they manufacture.

Table 3.2

. 10

. List of Companies in the Air

- Conditioning, Heating, and Refrigeration

Institute Directory that Manufacture Small Gas

- Fired Natural Draft

Hot Water Commercial Packaged Boilers

Name of M anufacturer300 kBtu/h-500kBtu/h500kBtu/h-700kBtu/h700kBtu/h-900kBtu/h900kBtu/h-1100kBtu/h1100kBtu/h-1300kBtu/h1300 kBtu/h-1500kBtu/h1500kBtu/h-1700kBtu/h1700kBtu/h-1900kBtu/h1900kBtu/h-2100kBtu/h2100kBtu/h-2300kBtu/h2300kBtu/h-2500kBtu/h

A.O. Smith Water Products Co. X X X X X X X X
Bosch Thermotechnology Corp X X X X X X X X X

Burnham Commercial X X
Lochinvar Corporation X X

Mestek, Inc. X

P B Heat, L LC X X

Raypak, Inc. X X X X X X X X X X X

RBI Water Heaters Division o f Mestek, Inc. X X X X X X X X

Slant/Fin Corporation X X X

U.S. Boiler Co., Subsidiary o f Burnham Holdings,Inc X



### Characterization of Boilers Based on Efficiency.

For the distribution of equipment based on energy efficiency levels , DOE compared boilers having cast iron heat exchangers with those having copper heat

exch anger s. The analysis shows that most of the cast iron boilers were well spread out over different efficiency levels from 80 to 84

- percent . M ost boilers in this equipment

class are rated 82

- percent efficient, while 90

- percent of these boilers had a copper heat

ex c hanger . Some boilers also had efficiencies as high as 85

- percent ; all these boilers were made from copper. The chart below ( Figure 3.2.3 ) shows distribution of boiler models with respect to thermal efficiency levels.

3

- 18Figure 3.2

. 3

. Distribution o f Small Gas

- Fired Natural Draft Hot Water Commercial Packaged Boilers Based o n Thermal Efficiency



### Variation of Average Efficiency with Input Rating.

DOE analyzed the distribution of thermal efficiencies with respect to input capacity . Performance of copper and cast iron were considered separately. Findings indicate higher thermal efficiencies for copper boilers as compared to cast iron.

In general, t he thermal efficiencies for boilers of all input sizes are fairly

consistent

. Comparisons indicate that c ast iron boilers have lower efficiency when compared to copper boilers at the same input ratings

. However, a s boiler capacity increases, cast iron boiler efficiency shows an increase

. Figure 3.2

. 4 below shows the variation of average thermal efficiency with input size.

Figure 3.2

. 4

. Comparison of Average Thermal Efficien cy with Small Gas

- Fired

Natural Draft Hot Water Commercial Packaged Boilers Sub Category

Based o n Input Rating 0 10 20 30 40 50 60 70

80 81 82 83 84 85Number of Models

Thermal efficiency [%] Distribution of Boilers Based on Thermal Efficiency

Cast Iron Copper

78.00 79.00 80.00 81.00 82.00 83.00 84.00 85.00300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Average Thermal Efficiency [%]

Input Rating Category [kBtu/h] Average Thermal Efficiency Based on Input Rating

Cast Iron Copper

3

- 193.2.6.2 Large (>2,500kBtu/h) Gas

- Fired Natural Draft Hot Water Commercial Packaged Boilers Large gas

- fired natural draft hot water CPBs are required under 10 CFR 431.87 to
have a minimum efficiency standard of 82

- percent combustion efficiency. A ll boiler

models in this class are non

- condensing and non

- modulating. They are either made from cast iron or copper. Copper boiler models were found to have hig her capacities than cast iron boilers. A review of AHRI’s database suggests that the models of this equipment class available on the market span input rating s from 2,500 kBtu/h to 5,500 kBtu/h. Only 21 models were included in this equipment class. Figure 3.2

. 5 below shows distribution of boilers based on input rating.

Figure 3.2

. 5

. Distribution o f Large Gas

- Fired Natura l Draft Hot Water Commercial Packaged Boilers Based o n Input Rating



### Manufacturers.

There are four manufacturers in the AHRI directory that produce boilers of this equipment class. While all these manufacturers produce boilers having an input rating of 2,500kBtu/h to 4,000kBtu/h, only one manufacturer produces boilers having input s that range from 4,000kBtu/h to 5,500kBtu/h. Table 3.2.11. below shows a list of manufacturers which produce boilers of this equipment class.

Table 3.2

. 11

. List of Companies in the Air

- Conditioning, Heating, and Refrigeration

Institute Directory that Manufacture Larg e Gas

- Fired Natural Draft

Hot Water Commercial Packaged Boilers

Name of Manufacturer 2500

- 4000 [kBtu/h] 4000

- 5500 [kBtu/h]
Laars Heating Systems Company X X

Raypak, Inc. X

RBI Water Heaters Division Of Mestek,

Inc. X

Slant/Fin Corporation X 0 5 10 15 20

2500 - 4000 4000 - 5500Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

Cast Iron Copper

3

- 20

### Characterization of Boilers Based on Efficiency.

The distribution of boilers based on combustion efficiency shows that most of the

boilers in the large gas

- fired natural draft hot water equipment class operate at 82

- percent combustion efficiency

, with a smaller portion operating at 83

- percent combustion efficiency . Analysis shows that a major portion of the boilers at 82

- percent are copper boilers , while all boilers at 83

- percent are cast iron

. Figure 3.2.6 below shows the distribution of boiler models based on combustion efficiency levels.

Figure 3.2

. 6

. D istribution o f Large Gas

- Fired Natural Draft Hot Water Commercial Packaged Boilers Based on Combustion Efficiency



### Variation of Combustion Efficiency with Input Ratin g.

The c ombustion efficiency of boilers in this equipment class appears to vary moderately with input size , but this may be due to the limited amount of data available

. Figure 3.2.7 below shows this trend in the form of a bar

- graph. 0 2 4 6 8 10 12 14 16

82 83Number of Models

Combustion Efficiency [%] Distribution of Boilers Based on Combustion Efficiency

Cast Iron Copper

81.6 81.8

82 82.2 82.4 82.6 82.8

2500 - 4000 4000 - 5500Average Combustion Efficiency[%]

Input Rating Category [kBtu/h] Average Combustion Efficiency Based on Input Rating

Cast Iron Copper

3

- 21Figure 3.2

. 7

. Comparison of Average Combustion Efficiency with Large Gas

- Fired

Natural Draft Hot Water Commercial Packaged Boilers Sub Category

Based o n Input Rating

3.2.6.3 Small (300k Btu /h

- 2,500k Btu /h) Oil

- F ired Natural Draft Hot Water Commercial Packaged Boilers

Under 10 CFR 431.87, the small oil

- fired natural draft hot water commercial packaged boilers are required to have a minimum efficiency of 82

- percent

. AHRI’s Directory of Certified Product Performance indicates that a small perc entage of these boilers are made from steel, while the rest are made from cast iron. The steel boilers were

found to have low er input ratings than the cast iron boilers

. Figure 3.2

. 8 below shows distribution of boiler models for different input rating categories.

Figure 3.2

. 8

. Distribution of Small Oil Fired Natural Draft Hot Water Boilers Based

o n Input Ratings



### Manufacturers

Out of 33 manufacturers in the AHRI directory , only 5 produce these types of

boilers. Table 3.2

. 12

. below shows the different manufacturers and size of boilers produced by each manufacturer

.

Table 3.2

. 12

. List of Companies in the Air

- Conditioning, Heating, and Refrigeration

Institute Directory that Manufacture Small Oil

- Fired Natural Draft

Hot Water Commercial Packaged Boilers

Name of M anufacturer300 kBtu/h-500kBtu/h500kBtu/h-700kBtu/h700kBtu/h-900kBtu/h900kBtu/h-1100kBtu/h1100kBtu/h-1300kBtu/h1300 kBtu/h-1500kBtu/h1500kBtu/h-1700kBtu/h1700kBtu/h-1900kBtu/h1900kBtu/h-2100kBtu/h2100kBtu/h-2300kBtu/h

Bosch Thermotechnology Corp X X X X X X X X X 0 2 4 6 8 10 12 14300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

Cast Iron Steel

3

- 22New Yorker Boiler Co., Subsidiary

o f Burnham Holdings Inc. X X

Slant/Fin Corporation X X X X X X X

U.S. Boiler Co., Subsidiary o f Burnham Holdings,Inc X

Weil

- Mclain X



### Characterization of Boilers Based on Efficiency.

Figure 3.2.9 below shows a bar chart indicating distribution of boilers with respect to efficiency levels. As with other natural draft equipment classes, all boilers are

non

- condensing or non

- modulating.

Figure 3.2

. 9

. Distribution of Small Oil

- Fired Natural Draft Hot Water Commercial Packaged Boilers Based o n Thermal Efficiency



### Variation of Average Efficiency with Input Rating.

Based on AHRI’s directory, it may be noted that average thermal efficiencies of cast iron boilers increase with input capacity of the boiler. Figure 3.2

. 10 below shows average thermal efficiency of boilers for each input rating category. 0 2 4 6 8 10 12 14 16

82 83 84 85 86 87Number of Models

Thermal Efficiency [%] Distribution of Boilers Based on Thermal Efficiency

Cast Iron Steel

3

- 23Figure 3.2

. 10

. Comparison of Average Thermal Efficiency of Small Oil

- Fired Natural Draft Hot Water Commercial Packaged Boilers Sub Category

Based o n Input Rating

3.2.6.4 Large (>2,500k Btu /h) Oil

- Fired Natural Draft Hot Water Commercial Packaged Boilers

There are only six models of large oil

- fired natural draft hot wat er commercial packaged boilers in th e AHRI ’s Directory of Certified Product Performance for

commercial packaged boilers

. B oilers of this equipment class are required to have a combustion efficiency of at least 84

- percent . All boilers of this class have an input rating

between 2

, 500 kBtu/h and 4

, 000 kBtu/h. All of the boiler models are produced by Slant/Fin Corporation and have combustion efficiency in the range from 84

- percent to
86

- percent

.

3.2.6.5 Small (300k Btu /h ‒2 ,500kBtu/h) Gas

- Fired Natural Draft Steam

Comme rcial Packaged Boilers

DOE analyzed 254 small gas

- fired natural draft steam commercial packaged

boilers listed in AHRI’s Directory of Certified Product Performance . All boilers in this equipment class are cast iron and non

- condensing. Figure 3.2

. 11 below shows distribution of commercial packaged boilers with respect to boiler size. The distribution

shows that the majority of commercial boilers in th is equipment class are between 300

- 400 kBtu/h

. 78.00 80.00 82.00 84.00 86.00 88.00300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Average Thermal Efficiency [%]

Input Rating Category [kBtu/h] Average Thermal Efficiency Based on Input Rating

Cast Iron Steel

3

- 24Figure 3.2

. 11

. Distribution of Small Gas

- Fired Natural Draft Steam Commercial Packaged Boilers Based o n Input Rating



### Manufacturers.

There are 11 AHRI

- member manufacturers that produce boilers in this equipment

class. Table 3.2.13. below shows a list of manufacturers along with boiler size which these companies are able to produce.

Table 3.2

. 13

. List of Companies in the Air

- Conditioning, Heating, and Refrigeration

Institute Directory that Manufacture Small Gas

- Fired Natural Draft

Steam Commercial Packaged Boilers

Name of M anufacturer300 kBtu/h-500kBtu/h500kBtu/h-700kBtu/h700kBtu/h-900kBtu/h900kBtu/h-1100kBtu/h1100kBtu/h-1300kBtu/h1300 kBtu/h-1500kBtu/h1500kBtu/h-1700kBtu/h1700kBtu/h-1900kBtu/h1900kBtu/h-2100kBtu/h2100kBtu/h-2300kBtu/h2300kBtu/h-2500kBtu/h

Burnham Commercial X X X X X X X X X

Crown Boiler Co, Subsidiary

Of Burnham Holdings Inc. X X X X X X X X X X X

Dunkirk Boilers, ECR

International, Inc. X X X X X X X X X X X

P B Heat, L LC X X X X X X X X X X X
Pennco, ECR International,

Inc. X X X X X X X X X X X

Slant/Fin Corporation X X X X X X X

Smith Cast Iron Boilers X X X X X X

U.S. Boiler Co., Subsidiary o f Burnham Holdings,Inc X

Utica Boilers X X X X X X X X X X X
Utica Boilers, ECR International, Inc. X X X X X X X X X X X

Weil

- Mclain X X X X X X X X X X X 0 5 10 15 20 25300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

3

- 25

### Characterization of Boilers Based on Efficiency.

The baseline efficiency for this equipment class is a thermal efficiency value of

77

- percent

. A major portion of the boilers

– close to 67

- percent had reported thermal efficiency levels of 78

- percent

. Figure 3.2.12 below shows distribution of equipment

based on thermal efficiencies.

Figure 3.2

. 12

. Distribution of Small Gas

- Fired Natural Draft Steam Comme rcial Packaged Boilers Based o n Thermal Efficiency



### Variation of Average Efficiency with Input Rating.

The average thermal efficiency for each input rating was calculated to observe the dependence of efficiency on boiler size. Figure 3.2.13 below shows the variation of thermal efficiency with boiler input category. The average efficiency varies slight ly with input size , but always remains between 77

- percent and 78

- percent

. 0 20 40 60 80 100 120 140 160 180

77 78 79 80Number of Models

Thermal Efficiency Distribution of Boilers Based on Thermal Efficiency

3

- 26Fi gure 3.2

. 13

. Comparison of Average Thermal Efficiency o f Small Gas

- Fired

Natural Draft Steam Commercial Packaged Boilers Sub Category

Based o n Input Rating

3.2.6.6 Large (>2,500kBtu/h) Gas

- Fired Natural Draft Steam Commercial Packaged Boilers

Large gas

- fired natural draft steam commercial packaged boilers are required to have minimum thermal efficiency standard of 77

- percent . There are 163 boilers in this

class

, which is the largest representation of the large (>2,50 0kBtu/h) boiler equipment

classe s in the database. All boilers in this class are made of cast iron and are non

condensing and non

- modulating. Figure 3.2.14 below shows distribution of boiler models over various input rating categories.

Figure 3.2

. 14

. Distribution of Large Gas

- Fired Natural Draft Steam Commercial Packaged Boilers Based o n Input Rating 76.5 77.0 77.5 78.0 78.5 79.0 79.5300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Average Thermal Efficiency [%]

Input Rating Category [kBtu/h] Average Thermal Efficiency Based on Input Rating

0 20 40 60 802500 - 40004000 - 55005500 - 70007000 - 85008500 - 1000010000 - 1150011500 - 1300013000 - 1450014500 - 1600016000 - 1750017500 - 19000Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

3

- 27

### Manufacturers.

There are seven manufacturers listed in the AHRI Directory of Certified Product

Performance which produce boilers in this equipment class. Table 3.2.14. below shows different manufacturers and the sizes of boiler they are capable of manufacturing.

Table 3.2

. 14

. List of Companies in the Air

- Condit ioning, Heating, and Refrigeration

Institute Directory that Manufacture Large Gas

- Fired Natural Draft

Steam Commercial Packaged Boilers

Name of

M anufacturer2500-4000[kBtu/h]4000-5500[kBtu/h]5500-7000[kBtu/h]7000-8500[kBtu/h]8500-10000[kBtu/h]10000-11500[kBtu/h]11500-13000[kBtu/h]13000-14500[kBtu/h]14500-16000[kBtu/h]16000-17500[kBtu/h]17500-19000[kBtu/h]

Dunkirk Boilers,

E CR International,

Inc. X

P B Heat, LLC X X X X X
Pennco, E CR International, Inc. X

Smith Cast Iron

Boilers X X X X X X X X X X X

Utica Boilers X
Utica Boilers, E CR International, Inc. X

Weil

- Mclain X



### Characterization of Boilers Based on Efficiency

.

All boiler models were characterized based on thermal efficiency. Approximately

60

- percent of the boilers operate at an efficiency level of 78

- percent

. Figure 3.2.15. below shows distribution of boilers with respect to thermal efficiency levels.

0 20 40 60 80 100

78 79 80 81Number of Models

Thermal Efficiency [%] Distribution of Boilers Based on Thermal Efficiency

3

- 2 8Figure 3.2

. 15

. Distribution of Large Gas

- Fired Natural Draft Steam Commercial Packaged Boilers Based o n Thermal Efficiency



### Variation of Average Efficiency with Input Rating.

The average thermal efficiency for each input rating was calculated to assess impact of boiler size on performance. Figure 3.2.16. shows the variation of average thermal efficiency on input rating category. The trend show s that average thermal efficiency increased gradually un til the input reache d 10,000

- 11,500 kBtu/h

, a fter which

there is a gradual decline in performance.

Figure 3.2

. 16

. Comparison of Average Thermal Efficiency of Large Gas

- Fired

Natural Draft Steam Commercial Packaged Boilers Sub Category

Based o n Input Rating

3.2.6.7 Small (300k Btu /h

- 2,500k Btu /h) Oil

- Fired Natural Draft Steam Commercial Packaged Boilers

Small oil

- fired natural draft steam commercial packaged boilers constitute 2.2

- percent of the database. These boilers are required to have a minimum thermal ef ficiency

o f 81

- percent . There are 37 qualified boilers within this equipment class listed in the

AHRI Directory of Certified Product Performance . All boiler models of this equipment

class are made from c ast i ron and are non

- modulating and non

- condensing.

M ore than 50

- percent of boilers manufactured in this equipment class have an input rating between 300 and 500 kBtu/h. Figure 3.2

. 17

. below shows this distribution of boilers based on input rating categories. 77 78 79 80 812500 - 40004000 - 55005500 - 70007000 - 85008500 - 1000010000 - 1150011500 - 1300013000 - 1450014500 - 1600016000 - 1750017500 - 19000Average Thermal Efficiency [%]

Input rating category [kBtu/h] Average Thermal Efficiency Based on Input Rating

3

- 29Figure 3.2

. 17

. Distribution of Small Oil

- Fired Natural Draft Steam Boilers Based on Input Ratings



### Manufacturers.

The 37 models listed in the AHRI directory for this equipment class are manufactured by six companies. Out of the 37 models , 25 models are manufactured by Slant/Fin Corporation alone. Other major manufacturing companies along with the boiler input ratings which they man ufactur e are listed in the Table 3.2.15. below

.

Table 3.2

. 15

. List of Companies in the Air

- Conditioning, Heating, and Refrigeration

Institute Directory that Manufacture Small Oil

- Fired Natural Draft Steam Commercial Packaged Boilers

Name of M anufacturer300 kBtu/h-500kBtu/h500kBtu/h-700kBtu/h700kBtu/h-900kBtu/h900kBtu/h-1100kBtu/h1100kBtu/h-1300kBtu/h1300 kBtu/h-1500kBtu/h1500kBtu/h-1700kBtu/h1700kBtu/h-1900kBtu/h1900kBtu/h-2100kBtu/h2100kBtu/h-2300kBtu/h2300kBtu/h-2500kBtu/h

P B Heat, L LC X
Slant/Fin Corporation X X X X X X X X X

Smith Cast Iron Boilers X X X

U.S. Boiler Co., Subsidiary Of Burnham Holdings,Inc X

Weil

- Mclain X



### Characterization of Boilers Based on Efficiency.

The distribution of boilers based on thermal efficiency shows that most CPB s in this equipment class operate at 82

- percent efficiency with the least number of boilers at

81

- percent

. Figure 3.2.18. shows this distribution. 0 2 4 6 8 10 12 14 16 18300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

3

- 30Figure 3.2

. 18

. Distribution of Small Oil

- Fired Natural Draft Steam Commercial Packaged Boilers Based o n Thermal Efficiency



### Variation of Average Efficiency with Input Rating.

The average thermal efficiency for each input rating was calculated to assess impact of boiler size on effici ency. Figure 3.2

. 19 shows the variation of average thermal efficiency with input rating. The trend show s that average thermal efficiency peaks at an input rating of ab out 600

- 700kBtu/h

.

Figure 3.2

. 19

. Comparison of Average Thermal Efficiency of Small Oil

- Fired Natural Draft Steam Commercial Packaged Boilers Sub Category

Based o n Input Rating 0 2 4 6 8 10 12 14 16 18

81 82 83Number of Models

Thermal Efficiency [%] Distribution of Boilers Based on Thermal Efficiency

79.50 80.00 80.50 81.00 81.50 82.00 82.50 83.00300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Average Thermal Efficiency [%]

Input Rating Category [kBtu/h] Average Thermal Efficiency Based on Input Rating

3

- 313.2.6.8 Large (>2,500k Btu /h) Oil

- Fired Natural Draft Steam Commercial Packaged Boilers

There are 95 large oil

- fired natural draft steam CPB models included in AHRI’s Directory of Certified Product Performance of commercial packaged boilers. These

boilers are required to have a minim um thermal efficiency of 81

- percent . All boilers in this equipment class listed in the AHRI directory are non

- condensing and non

modulating

, and have a cast iron heat exchanger

. Figure 3.2

. 20

. below shows the

distribution of boilers by input rating.

Figure 3.2

. 20

. Distribution of Large Oil

- Fired Natural Draft Steam Commercial

Packa ged Boilers Based o n Input Rating

The m aximum number of boilers is in the 2500 kBtu/h to 4000 kBtu/h input rating

range . The number of boilers gradually decrease s with increasing boiler input rating

. DOE also notes that the largest oil

- fired boilers were found in this equipment class.



### Manufacturers.

Smith Cast Iron Boilers is the sole company listed in AHRI database which

manufactures boilers in this equipment class

.



### Characterization of Boilers Based on Efficiency.

Boilers in this class have a thermal efficiency ranging from 81

- percent to 86

- pecent

. Figure 3.2.21. shows the distribution of boilers by thermal efficiency. More than

50

- percent of boiler s are listed with thermal efficiency between 82

- percent and 84

- percent while there are 33 boilers in the range between 81

- percent and 82

- percent. 0 5 10 15 20 252500 - 40004000 - 55005500 - 70007000 - 85008500 - 1000010000 - 1150011500 - 1300013000 - 1450014500 - 1600016000 - 17500Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

3

- 32Figure 3.2

. 21

. Distribution o f Large Oil

- Fired Natural Draft Steam Commercial Packaged Boilers B ased on Thermal Efficiency



### Variation of Average Efficiency with Input Rating.

Figure 3.2.22. below shows the average thermal efficiency as a function of input rating. The values vary moderately between input categor ies . There are no modulating or condensing boilers in this equipment class.

Figure 3.2

. 22

. Comparison of Average Thermal Efficiency of Large Oil

- Fired

Natural Draft Steam Commercial Packaged Boiler s Sub

- Category

Based o n Input Rating

3.2.6.9 Small (300k Btu /h

- 2,500k Btu /h) Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

Small gas

- fired mechanical draft hot water commercial packaged boilers

constitute about 32

- percent of models in the AHRI Directory of 0 5 10 15 20 25 30 35

81 82 83 84 85Number of Models

Thermal Efficiency [%] Distribution of Boilers Based on Thermal Efficiency

81 81.5

82 82.5

83 83.52500 - 40004000 - 55005500 - 70007000 - 85008500 - 1000010000 - 1150011500 - 1300013000 - 1450014500 - 1600016000 - 17500Average Thermal Efficiency [%]

Input Rating Category [kBtu/h] Average Thermal Efficiency Based on Input Rating

3

- 33Certified Product Performance . This equipment class cont ains the highest number of boiler models as compared to all other equipment classes . Boilers in this equipment

class are required to have a minimum thermal efficiency of 80 percent

. Boilers in this equipment class are made from aluminum, cast iron, co pper, stainless steel, or steel

. Figure 3.2

. 23 below shows a pie chart which depicts the constitution of boilers in this equipment class based on materials used to make the primary heat exchanger. Figure

3.2

. 24 depicts classification of condensing boilers based on the type of material used for making the primary heat exchanger

.

In co ndensing boilers, the condensate that is removed from exhaust gases turns
acidic in nature

, due to the presence of carbon dioxide in flue gases. As a result, materials

chosen for the heat exchanger for this purpose are those which have capabilities to resi st
acidic corrosion. Considering this, DOE notes, that the classification of boiler shown in Figure 3.2

. 23 and Figure 3.2

. 24 is based on primary heat exchanger which does not come in contact with the acidic condensate. The secondary or condensing heat exchanger which

does come in contact with the acidic condensate is made from a d ifferent material which is typically corrosion resistant. This observation was verified by DOE through literature review of condensing boiler models.

Figure 3.2

. 23 . Classification of Small Gas Fired Mechan ical Draft Hot Water Commercial Packaged Boilers Based on Material Used in the Primary Heat Exchanger 6%

6%

62% 23% 3% Distribution of Boilers Based on Material of Primary Heat Exchanger

Aluminum

Cast Iron

Copper

Stainless Steel

Steel

Total: 728

3

- 34Figure 3.2

. 24

. Classification of Small Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Condensing Boilers Based on Material Used in

the Primary Heat Exchanger

In this equipment class, out of 7 28 boiler models, 337 models were condensing

boilers and 463 models were modulating

. Figure 3.2

. 25

. below shows the distribution of

boilers based on boiler size. The f igure also shows the number of condensing and modulating boilers in each input rating category.

Figure 3.2

. 25

. Distribution of Small Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Based o n Input Rating

Th is chart indicates that condensing boilers are well spread out over the entire

boiler

- size range. Most boilers within this equipment class have an input rating between

300 and 400 kBtu/h. Between input ratings of 2,100 to 2,500 kBtu/h

, there are very few

boilers

. 13%

2%

29% 50% 6% Distribution of Condensing Boilers Based on Material of Primary Heat Exchanger

Aluminum

Cast Iron

Copper

Stainless Steel

Steel

Total: 337

0 20 40 60 80 100300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

Other Boilers Condensing Boilers Condensing and Modulating Boilers Modulating Boilers

3

- 35

### Manufacturers.

Of the companies listed in the AHRI Directory of Certified Product Performance

, 27 ou t of 33 manufacture small gas

- fired mechanical draft hot water commercial packaged boilers. Raypak , Lochinvar and Camus Hydronics appear to be the major manufacturers in this equipment class based on the number of models offered

. Table

3.2.16. below shows the list of manufacturers and the size of boiler which they produc e

.

Table 3.2

. 16

. List of Companies in the Air

- Conditioning, Heating, and Refrigeration

Institute Directory that Manufacture Small Gas

- Fired Mechanical

Draft Hot Water Commercial Packaged Boilers

Name of M anufacturer300 kBtu/h-500kBtu/h500kBtu/h-700kBtu/h700kBtu/h-900kBtu/h900kBtu/h-1100kBtu/h1100kBtu/h-1300kBtu/h1300 kBtu/h-1500kBtu/h1500kBtu/h-1700kBtu/h1700kBtu/h-1900kBtu/h1900kBtu/h-2100kBtu/h2100kBtu/h-2300kBtu/h2300kBtu/h-2500kBtu/h

A.O. Smith Water Products Co. X X X X X X X X X X

Aerco International, Inc. X X X X X X

Aerco International, Inc. X
Bosch Thermotechnology Corp X X X X X X X X
Bryan Steam, LLC X X X

Burnham Commercial X X X X X X X X X X
Camus Hydronics Ltd. X X X X X X X X X X

Cleaver

- Brooks X X X X X X
Crown Boiler Co,

- Subsidiary Of Burnham Holdings Inc. X X X X X

DDR Americas, Inc. X X X X X X X X X X
Fulton Heating Solutions X X X X X

Harsco Industrial, Patterson

- Kelley X X X X X X X

Heat Transfer Products Inc. X X X Hydrotherm Division o f Mestek,

Inc. X X X X

Laars Heating Systems Company X X X X X X X X X
Lochinvar Corporation X X X X X X X X X X

P B Heat, LLC X X X
Parker Boiler Company X X X X X X
Raypak, Inc. X X X X X X X X X

RBI Water Heaters Division o f Mestek, Inc. X X X X X X X X X X X

Slant/Fin Corporation X

Smith Cast Iron Boilers X X

Thermal Solutions Products LLC

, Subsidiary Of Burnham Holdings

Inc. X X X X X X

Triangle Tube X

3

- 36U.S. Boiler Co., Subsidiary o f Burnham Holdings,Inc X X

Viessmann Manufacturing Company, Inc. X X X X X X X X X

Weil

- Mclain X X X



### Characterization of Boilers Based on Efficiency. Figure 3.2.26. shows the distribution of boiler in this equipment class by thermal efficiency

. The distribution of these boilers is broadly divided based on condensing and

non

- condensing boilers and genera lly concentrated arou n d two peaks: m ost of the non

condensing boilers ha ve a thermal efficiency of 84 to 8 5

- percent and most condensing

boilers have a thermal efficiency of 94 to 95

- percent

.

Figure 3.2

. 26

. Distribution of Small Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Based On Thermal Efficiency



### Variation of Average Efficiency with Input Rating

The presence of condensing boilers across the entire range of input ratings

increases the average efficiency of boilers in this category substantially. All condensing boilers average over 93

- percent . The average thermal efficiencies across all input ratings

were found to be between 84

- percent and 93

- percent . Th e average efficiency in this equipment class is significantly above the current minimum energy conservation standard

of 80

- percent

. Figure 3.2

. 27 below shows the variation of average thermal efficiency with input rating category. 0 30 60 90 120 150 180

80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99Number of Models

Thermal Efficiency [%] Distribution of Boilers Based on Thermal Efficiency

Other Boilers Condensing Boilers Condensing and Modulating Boilers Modulating Boilers

3

- 37Figure 3.2

. 27

. Comparison of Average Thermal Efficiency of Small Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Sub Category Based on Input Rating

3.2.6.10 Large (>2,500kBtu/h) Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

Approximately 5

- percent of the boilers in AHRI’s Directory of Certified Product

Performance are in the large gas

- fired mechanical draft hot water equipment class. These

boilers are required to have a minimum combustion efficiency of 79

- percent . Similar to

the small gas

- fired mechanical draft hot water equipment clas s, boiler models in this equipment class are made from c ast i ron, s teel, a luminum and c opper. DOE analyzed the

number of boilers of each heat exchanger material type. Figure 3.2

. 28 below is a pie chart

that depicts the distribution of boiler models based on the material used in the primary heat exchanger

. Figure 3.2

. 29 is a pie ch art that shows classification s of condensing

boilers based on material used to make the primary heat exchanger

.

Similar to the observations in the small gas

- fired mechanical draft hot water equipment class, DOE notes, that the classification s of boiler s s hown in Figure 3.2

. 28 and Figure 3.2

. 29 are based on primary heat exchanger s that do not come in contact with the

acidic co ndensate. The secondary or condensing heat exchanger that does come in

contact with the acidic condensate is made from a different material that is typically

corrosion resistant. This observation was subsequently validated by DOE through

literature review of condensing boiler models. 76.00 80.00 84.00 88.00 92.00 96.00 100.00300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Average Thermal Efficiency [%]

Input Rating Category [kBtu/h] Average Thermal Efficiency Based on Input Rating

Overall thermal efficiency Condensing Boilers

3

- 38Figure 3.2

. 28 . Classification of Large Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Based on Material Used in the Primary Heat Exchanger

Figure 3.2

. 29 . Classification of Large Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Condensing Boilers Based on Material Used in

the Primary Heat Exchanger

DOE also analyzed t he distribution of boilers with respect to boiler input rating. Figure 3.2

. 30

. below shows this analysis and highlights the type of boiler included in this equipment class ( e.g ., condensing and/or modulating

, etc. ) Out of the 8 3 models considered for the analysis, 6 1 boiler models had capacity ranging from 2,500

- 4,000kBtu/h. No boiler had a capacity higher than 6,200kBtu/h. 1%

46%

33%

18% 2% Distribution of Boilers Based on Material of Primary Heat Exchanger

Aluminum

Cast Iron

Stainless Steel

Steel

Copper

Total: 83

2%

9%

57% 32% Distribution of Condensing Boilers Based on Material of Primary Heat Exchanger

Aluminum

Cast Iron

Stainless Steel

Steel

Total: 47

3

- 39Figure 3.2

. 30

. D istribution of Large Gas

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Based o n Input Rating



### Manufacturers.

A total of 17 manufacturers listed in the AHRI Directory of Certified Product

Performance produced boilers in this equipment class. Bosch Thermotechnology Corp., Camus Hydronics Ltd. and DDR Americas Inc. produced majority of the models. Table

3.2.17. below shows the list of manufacturers and the size of equipment they produced.

Table 3.2

. 17

. List of Companies in the Air

- Conditioning, Heating, and Refrigeration

Institute Directory that Manufacture Large Gas

- Fired Mechanical

Draft Hot Water Commercial Packaged Boilers

Name of M anufacturer 2500

- 4000 [kBtu/h] 4000

- 5500 [kBtu/h] 5500

- 7000 [kBtu/h]

A.O. Smith Water Products Co. X
Aerco International, Inc. X Bosch Thermotechnology Corp X X
Bryan Steam, LLC X

Burnham Commercial X Camus Hydronics Ltd. X X

DDR Americas, Inc. X X X Fulton Heating Solutions X X
Harsco Industrial, Patterson

- Kelley X Hydrotherm Division Of Mestek, Inc. X Lochinvar Corporation X
P B Heat, L LC X Parker Boiler Company X X

RBI Water Heaters Division Of Mestek, Inc. X

Smith Cast Iron Boilers X 0 10 20 30 40 50 60 70

2500 - 4000 4000 - 5500 5500 - 7000Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

Other Boilers Condensing Boilers Condensing and Modulating Boilers Modulating Boilers

3

- 40Thermal Solutions Products L LC

, Subsidiary Of Burnham Holdings Inc. X

Viessmann Manufacturing Company, Inc. X X



### Characterization of Boilers Based on Efficiency.

Similar to most equipment classes which have condensing boilers, the distribution of boiler combustion efficiency shows a concentration of equipment in two ranges

– the

non

- condensing range (generally less than 86

- percent ) and the condensing range (generally over 92

- percent ) . This is because condensing boiler s typically achieve

efficiencies which are substantially higher than non

- condensing boilers. T here are only

three boilers in the range between condensi ng and non

- condensing (roughly 88

- to 91

- percent ) . A large number of non

- condensing boilers were found to have a combustion efficiency of 85

- percent , while the condensing boiler s typically had combustion

efficiencies around 94

- to 95

- percent

.

Figure 3.2.31. below shows the distribution of boilers over different combustion efficiency levels.

Figure 3.2

. 31

. Distribution of Large Gas

- Fired Mechanica l Draft Hot Water Commercial Packaged Boilers Based On Combustion Efficiency



### Variation of Average Efficiency with Input Rating

Average combustion efficiencies for this equipment class are between 89

- and 90

- percent . These efficiency levels in each input category are raised significantly due to presence of high efficiency condensing boilers. The Figure 3.2.32. bel ow shows average combustion efficiency levels of boilers in each input rating category. 0 5 10 15 20 25

84 85 86 87 88 89 90 91 92 93 94 95 96 97Number of Models

Combustion Efficiency [%] Distribution of Boilers Based on Combustion Efficiency

Other Boilers Condensing Boilers Condensing and Modulating Boilers Modulating Boilers

3

- 41Figure 3.2

. 32

. Comparison of Average Combustion Efficiency of Large Gas

- Fired

Mechanical Draft Hot Water Commercial Packaged Boiler s Sub Category Based o n Input Rating

3.2.6.11 Small (300k Btu /h

‒ 2,500k Btu /h) Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

Small oil

- fired mechanical draft hot water CP B s are required to have a minimum thermal efficiency of 82

- p ercent . There are 48 commercial packaged boiler models in this equipment class, of which eight are condensing boilers. All condensing boilers of this equipment class listed in the database are made from steel

. Figure 3.2

. 33

. below shows the distribution of boiler models for each boiler input category.

Figure 3.2

. 33

. Distribution of Small Oil

- Fired Mechanical Draft Hot Water Commercial Packaged B oilers Based on Input Rating



### Manufacturers. 84 86 88 90 92 94 96

2500 - 4000 4000 - 5500 5500 - 7000Average Combustion Efficiency[%]

Input Rating Category [kBtu/h] Average Combustion Efficiency Based on Input Rating

All Boilers Condensing Boilers

0 1 2 3 4 5300 - 400400 - 500500 - 600600 - 700700 -800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

Other Boilers Condensing Boilers

3

- 42There are six companies listed in the AHRI Directory of Certified Product

Performance that manufacture boilers in this equipment class. Table 3.2.18. below shows the names of the companies and the size of boilers they manufactured.

Table 3.2

. 18

. List of Companies in the Air

- Condition ing, Heating, and Refrigeration

Institute Directory that Manufacture Small Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

Name of M anufacturer300 kBtu/h-500kBtu/h500kBtu/h-700kBtu/h700kBtu/h-900kBtu/h900kBtu/h-1100kBtu/h1100kBtu/h-1300kBtu/h1300 kBtu/h-1500kBtu/h1500kBtu/h-1700kBtu/h1700kBtu/h-1900kBtu/h1900kBtu/h-2100kBtu/h2100kBtu/h-2300kBtu/h2300kBtu/h-2500kBtu/h

Bosch Thermotechnology Corp X X X X X X

Burnham Commercial X X X X X X X X X

Crown Boiler Co

. Subsidiary

Of Burnham Holdings Inc. X X X X X

Fulton Heating Solutions X

Slant/Fin Corporation X

Smith Cast Iron Boilers X X X X X X X X X X Viessmann Manufacturing Company, Inc. X X X X X X X X X X



### Characterization of Boilers Based on Efficiency

Non

- condensing boilers, for this equipment class were spread over from 82

- percent to 88

- percent with the most models at 87

- percent and 88

- percent efficiency

levels

. Condensing boilers were fairly evenly distr ibuted between 92

- percent and 98

- percent thermal efficiency. Figure 3.2.34. below shows distribution of boilers based on thermal efficiency class.

Figure 3.2

. 34

. Distribution of Small Oil

- Fired Mechanical Draft Hot W ater Commercial Packaged boilers Based o n Thermal Efficiency 0 2 4 6 8 10 12 14 16

82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98Number of Modelss

Thermal Efficiency [%] Distribution of Boilers Based on Thermal Efficiency

Other Boilers Condensing Boilers

3

- 43

### Variation of Average Efficiency with Input Rating

The average thermal efficiency of models as a function of input rating was analyzed for this equipment class. The analysis shows an even distribution of thermal efficiency irrespective of input rating. Figure 3.2.35 below shows the variation of average

therma l efficiency with input rating. Condensing boilers are also plotted in the same chart. This helped in understanding the sizes of condensing boiler s in this equipment

class

.

Figure 3.2

. 35

. Comparison of Ave rage Thermal Efficiency of Small Oil

- Fired

Mechanical Draft Hot Water Commercial Packaged Boilers Sub Category Based o n Input Rating

3.2.6.12 Large ( >2,500k Btu /h) Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers

Large oil

- fired mechanical draft boilers comprise only 1 percent of AHRI’s Directory of Certified Product Performance . These boilers are require d

, under subpart E of 10 CFR Part 431, to have a minimum combustion efficiency of 84

- percent . Out of 24

boiler models in t his segment, six models are condensing and these condensing models

each have a heat exchanger made from steel. All non

- condensing boilers in this equipment class have a heat exchanger made from cast iron. Figure 3.2

. 36 below shows distribution of boilers of both types with respect to input size. 76 80 84 88 92 96 100300 - 400400 - 500500 - 600600 - 700700 -800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Average Thermal Efficiency [%]

Input Rating Category [kBtu/h] Average Thermal Efficiency Based on Input Rating

Other Boilers Condensing Boilers

3

- 44Figure 3.2

. 36

. Distribution of Large Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Based On Input Rating



### Manufacturers. There are four companies listed in the AHRI Directory of Certified Product

Performance that manufacture boilers in this equipment class. Table 3.2.19. below describes the different boilers manufactured by different companies for each input rating

.

Table 3.2

. 19

. List of Companies in the A Air

- Conditioning, Heating, and Refrigeration Institute Directory that Manufacture Large Oil

- Fired

Mechanical Draft Hot Water Commercial Packaged Boilers

Name of M anufacturer 2500

- 4000 [kBtu/h] 4000

- 5500 [kBtu/h] 5500

- 7000 [kBtu/h]

Bosch Thermotechnology Corp X X

Burnham Commercial X
Fulton Heating Solutions X X X Viessmann Manufacturing Company, Inc. X X



### Characterization of Boilers Based on Efficiency.

As mentioned previously, there are six condensing boilers listed as part of this equipment class. As with other equipment classes with condensing boilers, the efficiencies are divided into two ranges: condensing and non

- condensing. The minimum efficiency o f a condensing boiler in this class is about 94

- percent

. Figure 3.2.37 below

shows distribution of equipment for different combustion efficiencies. 0 5 10 15 20

2500 - 4000 4000 - 5500 5500 - 7000Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

Non Condensing Condensing Boilers Condensing and Modulating Boilers

3

- 45Figure 3.2

. 37

. Distribution of Large Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Based On Combustion Efficiency



### Variation of Average Efficiency with Input Rating

The variation of combustion efficiency with input rating is shown in Figure 3.2.38

below.

Figure 3.2

. 38

. Comparison of Average Combustion Efficiency of Small Oil

- Fired Mechanical Draft Hot Water Commercial Packaged Boilers Sub Category Based on Input Rating

3.2.6.13 Small (300k Btu /h

‒ 2,500k Btu /h) Gas

- Fired Mechanical

- Draft Steam Commercial Packaged Boilers

Small gas fired mechanical draft steam commercial packaged boilers are required

to have a minimum thermal efficiency of 79

- percent

. T here are 98 boilers in this 0 2 4 6 8 10

87 88 89 90 91 92 93 94 95 96 97Number of Models

Combustion Efficiency [%] Distribution of Boilers Based on Combustion Efficiency

Other Boilers Condensing Boilers Condensing and Modulating Boilers

80 82 84 86 88 90 92 94 96 98

2500 -4000 4000 -5500 5500 -7000Average Combustion Efficiency[%]

Input Rating Category [kBtu/h] Average Combustion Efficiency Based on Input Rating

Other Boilers Condensing Boilers

3

- 46equipment class listed in AHRI’s Directory of Certified Product Performance . All boilers

of thi s class are non

- condensing, non

- modulating and are made from cast iron. Figure

3.2

. 39

. below shows distribution of equipment based on boiler input rating.

Figure 3.2

. 39

. Distribution of Small Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based o n Input Rating



### Manufacturers.

The AHRI Directory of Certified Product Performance lists boiler models produced by five companies. Table 3.2.20. below shows the list of companies and the input ratings manufactured by each company

.

Table 3.2

. 20

. List of Companies in the Air

- Conditioning, H eating, and Refrigeration

Institute Directory that Manufacture Small Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers

Name of M anufacturer300 kBtu/h-500kBtu/h500kBtu/h-700kBtu/h700kBtu/h-900kBtu/h900kBtu/h-1100kBtu/h1100kBtu/h-1300kBtu/h1300 kBtu/h-1500kBtu/h1500kBtu/h-1700kBtu/h1700kBtu/h-1900kBtu/h1900kBtu/h-2100kBtu/h2100kBtu/h-2300kBtu/h2300kBtu/h-2500kBtu/h

Burnham Commercial X X X X X X X X X X X

Crown Boiler Co. Subsidiary

Of Burnham Holdings Inc. X X X X X X X X X X

P B Heat, L LC X X X X X X X X X X X

Smith Cast Iron Boilers X X X X X X X X X X X

Weil

- Mclain X X X X X X X X X X



### Characterization of Boilers Based on Efficiency.

The distribution of boilers over different efficiency levels is shown in the Figure

3.2.40. below. Most of the boilers in this equipment class have the rmal efficiencies

between 80

- and 81

- percent

. 0 1 2 3 4 5 6 7 8300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

3

- 47Figure 3.2

. 40

. Distribution of Small Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based on Thermal Efficiency



### Variation of Average Efficiency with Input Rating

The average thermal efficiencies for each boiler input rating varies from 80

- to
8 2

- percent

. Figure 3.2.41. below shows average thermal efficiency levels for each input rating category.

Figure 3.2

. 41

. Comparison of Average Thermal Efficiency of Small Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Sub Category

Based on Input Rating 0 5 10 15 20 25 30 35 40

79 80 81 82 83Number of Models

Thermal Efficiency [%] Distribution of Boilers Based on Thermal Efficiency

78 79 80 81 82300 - 400400 - 500500 - 600600 - 700700 - 800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Average Thermal Efficiency [%]

Input Rating Category [kBtu/h] Average Thermal Efficiency Based on Input Rating

3

- 483.2.6.14 Large (>2,500kBtu/h) Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers

Large gas

- fired mechanical draft steam C PBs are re quired , under subpart E of 10 CFR Part 431, to achieve a minimum thermal efficiency of 79

- percent . According to

AHRI’s Directory of Certified Product Performance , 106 boiler models can be classified into this equipment class. All the listed model s are made from cast iron and are non

condensing and non

- modulating type. Figure 3.2

. 42

. below shows distribution of boiler models based on capacity. Most commercial boilers in this equipment class have an input rating between 2,500 and 5,500 kBtu/h.

Figure 3.2

. 42

. Distribution of Large Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based on Input Rating



### Manufacturers.

The AHRI Directory of Certified Product Performance list s f our companies that

manufacture boilers i f this equipment class. Table 3.2.21. below shows the size of boiler (input rating) manufactured by all four companies.

Table 3.2

. 21

. List of Companies in the Air

- Conditioning, Heati ng, and Refrigeration

Institute Directory that Manufacture Large Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers

Name of

Manufacturer 2500

- 4000 [kBtu/h] 4000

- 5500 [kBtu/h] 5500

- 7000 [kBtu/h] 7000

- 8500 [kBtu/h] 8500

- 10000 [kBtu/h]

Burnham Commercial X X X

P B Heat, L LC X X X

Smith Cast Iron

Boilers X X X

Weil

- Mclain X X X X X

0 5 10 15 20 25 30 35 40 45 50

2500 - 4000 4000 - 5500 5500 - 7000 7000 - 8500 8500 - 10000Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

3

- 49

### Characterization of Boilers Based on Efficiency.

Th e th ermal efficiency of boiler models in this equipment class var ies from 79

- percent to 83

- percent

. Figure 3.2.43. below shows distribution of boiler models for different efficiency levels.

Figure 3.2

. 43

. Distribution of Large Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based on Thermal Efficiency



### Variation of Average Efficiency with Input Rating

T o assess the performance of boilers for different input ratings, DOE calculated average thermal efficienc y at different input ratings

. Results indicated that average thermal efficiency decrease d with i ncrease d boiler size for this equipment class . Boilers in the 2,500

‒ 5,500kBtu/h exhibited highest average thermal efficiency. Figure 3.2.44. below shows the variation of average thermal efficiency with input rating. 0 5 10 15 20 25 30 35

79 80 81 82 83Number of Models

Thermal Efficiency [%] Distribution of Boilers Based on Thermal Efficiency

3

- 50Figure 3.2

. 44

. Comparison of Average Thermal Efficiency of Large Gas

- Fired Mechanical Draft Steam Commercial Packaged Boilers Sub Category Based on Input Rating

3.2.6.15 Small (300k Btu /h

‒ 2,500k Btu /h) Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers

S mall oil

- fired mechanical draft steam boilers account for about 4

- percent of commercial packaged boilers in the AHRI Directory of Certified Product Performance

. Subpart E of 10 CFR Part 431 requ ires such comm ercial packaged boilers to have a

minimum thermal efficiency of 81

- percent . All boiler models listed in this equipment

class are made from cast iron and are non

- condensing and non

- modulating. Figure 3.2

. 45

. below shows distribution all qualified boiler models based on their size.

Figure 3.2

. 45

. Distribution of Small Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based On Input Rating



### Manufacturers. 80.2 80.3 80.4 80.5 80.6 80.7 80.8 80.9

81

2500 - 4000 4000 - 5500 5500 - 7000 7000 - 8500 8500 - 10000Average Thermal Efficiency [%]

Input Rating Category [kBtu/h] Average Thermal Efficiency Based on Input Rating

0 1 2 3 4 5 6 7 8 9300 - 400400 - 500500 - 600600 - 700700 -800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Number of Models

Input Rating Category[kBtu/h] Distribution of Boilers Based on Input Ratings

3

- 51Table 3.2.22. below shows a list of companies in the AHRI Directory of Certified

Product Performance which manufacture boilers of this equipment class.

Table 3.2

. 22

. List of Companies in the Air

- Conditioning, Heating, and Refrigeration

Institute Directory that Manufacture Small Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers

**Name of** M **anufacturer**300 kBtu/h-500kBtu/h500kBtu/h-700kBtu/h700kBtu/h-900kBtu/h900kBtu/h-1100kBtu/h1100kBtu/h-1300kBtu/h1300kBtu/h-1500kBtu/h1500kBtu/h-1700kBtu/h1700kBtu/h-1900kBtu/h1900kBtu/h-2100kBtu/h2100kBtu/h-2300kBtu/h2300kBtu/h-2500kBtu/h

Burnham Commercial X X X X X X X X X X

Crown Boiler Co. Subsidiary Of Burnham Holdings Inc. X X X X X X X X X

P B Heat, LLC X X X X X X X X X X X

Smith Cast Iron Boilers X X X X X X X X X X X

Weil

- Mclain X X X X X X X X X



### Characterization of Boilers Based on Efficiency

Figure 3.2.46. below shows number of models by thermal efficiency. The majority (a lmost 80

- percent ) of models are with in the 82

- to 84

- percent efficiency range.

Figure 3.2

. 46

. Distribution of small oil

- fired mechanical draft steam commercial packaged boilers based on thermal efficiency



### Variation of Average Efficiency with Input Rating

The average thermal efficiency for each input rating categ ory was calculated and

the result is shown below in Figure 3.2.47. The chart shows a reasonably even distribution of average thermal efficiencies with the minimum average thermal efficiency across the entire input range at 82

- percent and the maximum at 8 4

- pe rcent

. 0 5 10 15 20 25 30 35 40

81 82 83 84 85 86Number of Models

Thermal Efficiency [%] Distribution of Boilers Based on Thermal Efficiency

3

- 52Figure 3.2

. 47

. Comparison of Average Thermal Efficiency of Small Oil

- Fired Mechanical Draft Steam Commercial Packaged Boiler Sub Category

Based o n Input Rating

3.2.6.16 Large ( >2,500k Btu /h) Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers

Subpart E of 10 CFR Part 431 requires l arge oil

- fired mechanical draft steam

CPBs to achieve a minimum thermal efficiency of 81

- percent . All boilers listed in this equipment class use a cast iro n heat exchanger

. T here are no condensing or modulating

boilers in this equipment class. Figure 3.2

. 48

. below shows that the majority of boilers under this equipment class have input ratings from 2,500kBtu/h to 5,500kBtu/h.

Figure 3.2

. 48

. Dist ribution of Large Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based On Input Rating 81.5 82.0 82.5 83.0 83.5 84.0300 - 400400 - 500500 - 600600 - 700700 -800800 - 900900 - 10001000 - 11001100 - 12001200 - 13001300 - 14001400 - 15001500 - 16001600 - 17001700 - 18001800 - 19001900 - 20002000 - 21002100 - 22002200 - 23002300 - 24002400 - 2500Average Thermal Efficiency [%]

Input Rating Category [kBtu/h] Average Thermal Efficiency Based on Input Rating

0 10 20 30 40 50 60

2500 - 4000 4000 - 5500 5500 - 7000 7000 - 8500Number of Models

Input Rating Category [kBtu/h] Distribution of Boilers Based on Input Ratings

3

- 53

### Manufacturers.

There are four manufacturers listed in the AHRI Directory of Certified Product

Performance which produce boilers in this equipment class. Weil

- McLain also produces

more than 50

- percent of the total boiler model s in this equipment class. Table 3.2.23.

below shows the manufacturers and the boiler size (input rating) that each company is currently producing.

Table 3.2

. 23

. List of Companies in the Air

- Conditioning, Heating, and Refrigeration

Institute Directory that Manufacture Large Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers

Manufacturer Name 2500

- 4000 [kBtu/h] 4000

- 5500 [kBtu/h] 5500

- 7000 [kBtu/h] 7000

- 8500 [kBtu/h]

Burnham Commercial X X X

P B Heat, LLC X X X

Smith Cast Iron Boilers X X X

Weil

- Mclain X X X X



### Characterization of Boilers Based on Efficiency.

The efficiency of boilers in this equipment class varies from 81

- percent to 86

- percent

. Figure 3.2

. 49

. shows the distribution of thermal efficiency ratings for this equipment class.

Figure 3.2

. 49

. Distribution of Large Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers Based On Thermal Efficiency



### Variation of Average Efficiency with Input Rating

Average thermal efficiency does not vary substantially with input size. The

average thermal efficiency was between 82

- percent and 83

- percent for all input ratings 0 5 10 15 20 25 30 35

81 82 83 84 85 86Number of Models

Thermal Efficiency [%] Distribution of Boilers Based on Thermal Efficiency

3

- 54analyzed

. Figure 3.2.50. below shows the variation of average thermal efficiency with

i nput rating

.

Figure 3.2

. 50

. Comparison of Average Thermal Efficiency of Large Oil

- Fired Mechanical Draft Steam Commercial Packaged Boilers Sub Category

Based on Input Rating

3.3 TECHNOLOGY ASSESSMEN T

The technology assessment focus e s on understanding how commercial packaged

boilers use energy and on identifying potential technology changes that would improve the efficiency of this equipment

. Measures that improve the rated equipment efficiency are called technology options, and they are based on existing technologies

, as well as working prototypes. In consultation with interested parties, DOE create d a list of technology options for consideration in this rulemaking. After research ing this list of technology options, DOE conside r ed each option in light of the four screening criteria

discussed in chapter 4

. Those technology options that pass the screening criteria will be

considered suitable options for improv ing the efficiency of the equipment in the engineering analysis, and wi ll assist DOE in determining the efficiency levels from the baseline through the max

- tech design.

3.3.1 Boiler Equipment

Commercial packaged boilers are pressure vessels designed to transfer heat via

combustion to water or steam

, used for space heating , and in some applications domestic

hot water as well

. Commercial packaged boilers can be condensing or noncondensing in design. Condensing design boilers recover additional heat by condensing part of the water vapor produced by the burning fuel

. h A boiler consist s of : (1) a tank/shell ( or other form of pressure vessel to hold the water or steam ); (2) a burner ; (3) a combustion

h This require s that the water returning to the boiler system be cold enough to sufficiently carry out the condensation process of the water vapor in the exhaust. 82 82.5

83 83.5

2500 - 4000 4000 - 5500 5500 - 7000 7000 - 8500Average Thermal Efficiency [%]

Input Rating Category [kBtu/h] Average Thermal Efficiency Based on Input Rating

3

- 55chamber (also sometimes referred to as a firebox); (4) a heat exchanger ; (5) automatic

controls ; and (6) mechanical draft equipment ( e.g ., forced or induced draft blower) if applicable ( i.e. If the boiler is not of natural draft )

. The following provides further details regarding the components used in commercial packaged boilers.

Construction Materials

N on

- condensing boilers are often made of cast iron, steel, copper, or copper

- clad steel, and are usually designed to prevent corrosion and thermal shock. Condensing boilers are usually made of stainless steel or aluminum construction , because the acidic

conde nsate w ould corrode copper, cast iron, or carbon steel. Condensing boilers may

include s econdary heat exchangers which, due to exposure to corrosive condensate formation in the heat exchanger

, must also be constructed of corrosion

- resistant

materials.

Ta nk/Pressure Vessel

Boiler tanks ( also called the pressure vessel or boiler shell ) are frequently cylindrical in shape, but can also be of rectangular or other construction styles

. The inside walls of the tank opposite combustion regions are sometimes line d with insulating

materials to maintain sufficient flame temperature for clean combustion. The outside surfaces of the tank are usually covered with insulation to reduce heat losses through the boiler jacket.

Burner

Burners combine the fuel and air and then ignite the mixture to start the combustion process. The boiler fuel type dictates the type of burner tha t is used.

• Atmospheric burners typically use natural gas or propane in natural draft applications

. An atmospheric burner uses the pressure

- induce d velocity of gas exiting an orifice to mix such gas with primary combustion air. An atmospheric burner then uses natural draft to mix secondary air into the flame during

combustion.

• A gas

- power burner is a type of burner that uses a blower to supply com bustion

air into th e combustion zone. This may be an external ly mounted gun

- type burner

similar to an oil

- pressure atomizing burner, or an incorporated fan and gas delivery system within the boiler.

• An oil

- power burner may be a pressure atomizing burner or an air atomizing

burner. A pressure atomization oil burner uses oil pumped through a nozzle to create a fine mist that is then mixed with the combustion air and ignited at the

front of the burner. An air a tomizing burner uses compressed air to atomize the oil into a fine mist before being delivered and ignited in the combustion chamber.

Heat Exchanger s

3

- 56A heat exchanger is a device used to transfer heat from one medium to another. All boilers come equipped w ith air

- to

- water heat exchangers. The primary boiler heat exchanger designs include: (1) water tube; (2) fire tube; (3) cast iron; and (4) tubeless. i

For water tube boilers, combustion gases circulate around water or steam

- filled

tubes

. Heat transfer is a chieved by radiation from the flames as well as by convection from the hot combustion gases. There may be up to several thousand water tubes in a boiler, depending on the size of the unit. j The water tubes are often welded together to

form the walls of t he combustion chamber , called a “waterwall.” Water

- tube designs are

often used in steam boilers. Finned copper water tube boilers are designed with rows of horizontal finned tubes located above the combustion chamber. Finned copper water

tube boilers are general ly hot water boilers. The water

- tube design can enable more rapid

start

- up due to lower thermal mass and can enhance thermal shock resistance due to greater structural flexibility relating to thermal expansion and contraction.

For fire tube boiler s, the boiler tank is filled with water and heat is transferred as hot combustion gases pass through one to several metal tubes or other passageways in the heat exchanger. k Fire tube boilers are often characterized by their number of passes ( i.e.

, number of times combustion gases flow the length of the boiler). The combustion gas flows through the length of a bundle of tubes and then is turned around and passes back through an additional bundle of tubes. l Fire tube boiler combustion chambers may be dry

- b ase, wet

- base, or wet

- leg. Dry

- base chambers are refractory

- lined chamber s that

direct the combustion gases from the firebox to the heat transfer tube s ; the chamber is usually located beneath the fluid

- backed sections. Wet

- base chambers often utilize a

w ater

- c ooled turn

- around chamber to direct the flue gases from the combustion chamber

to the tube banks , although dry

- backed turn

- around chambers are also sometimes used.

A wet

- backed turn

- around chamber is fully surrounded by fluid

- backed sections except for the necessary openings

– thereby eliminating the need for the refractory lining. Wet

leg combustion chambers have fluid

- backed sections on the top and sides of the chamber.

Cast iron boilers are made up of cast pressure sections bolted together or

con nected by push nipples to form a block assembly. m T he water is contained inside cast

i ASHRAE 2008 HVAC Systems and Equipment Handbook (Available at: https://www.ashrae.org/resources

-- publications/handbook ).
j Characterization Industrial Commercial Boiler Population (2005) (Available at: https://www1.eere.energy.gov/manufacturing/distributedenergy/pdfs/characterization_industrial_commeric al_boiler_population.pdf ).

k The heat is transferred in the fir st pass of fire tube boiler by radiation and convection then by convection on the remaining passes of the boiler.

l DOE's Improving Steam System Performance : A S ourcebook for I ndustry (2012) (Available at: http://www1.eere.energy.gov/manufacturing/tech_assistance/pdfs/steamsourcebook.pdf ).

m Heselton, Kenneth E. Marcel Dekker

, Boiler operator's handbook ( 2005 ).

3

- 57iron sections

, and combustion gases flow through designated passages outside the

sections

. n Cast iron boilers may be of dry

- base, wet

- leg, or wet

- base design.

T ubeless b oilers use the outside of its shell as part of the heat exchanger surface.

The re is a central flue surrounded by water which serves the first pass of the combustion

gases. o The combustion gases then exit the central flue through a nozzle that connects it

to the hollow shell wall which has internal steel fins that run the length of the boiler tank.

T hen the combustion gases make several passes through the shell wall before exiting the

stack. p

Controls

A b oiler must be capable of providing immediate response to load demand

variations w hile maintain ing its efficiency and safety features. Thus, boilers come equipped with a variety of controls.

• The main operating control (pressure

- actuated for steam boilers and
temperature

- actuated for hot water boilers ) controls the firing rate of the fuel by monitoring hot water temperature or steam pressure. q Operating controls could provide on/off, high/low/off, and modulating functions. r

• The low

- water cutoff switch stops fuel flow to the burner if minimum

water lev els are not detected. s

• The pressure gauge / regulator monitors boiler pressure and shuts off the fuel supply to the boiler if allowable boiler pressure is exceeded. Additionally, the temperature/pressure relief valve releases steam if the

pressure gage/regulator fails and pressure builds dangerously high. t

• The flame safeguard control monitors the burner for proper operation and

shut s off the fuel supply if a flame is not detected in the burner

. u

Draft

n BetterBricks “Boilers Introduction How Boilers Work” (Available at: http://www.betterbricks.com/sites/default/files/operations/om_of_boilers_final.pdf ).

o S ee http://www.spthermal.com/hurst.html

. p Heselton, Kenneth E. Marcel Dekker

, Boiler operator's handbook ( 2005 ).

q BetterBricks “Boilers Introduction How Boilers Work” (Available at: http://www.betterbricks.com/sites/default/files/operations/om_of_boilers_final.pdf ).

r ASHRAE 2008 HVAC Systems and Equipment Handbook (Available at: https://www.ashrae.org/resources

-- publications/handbook ).

s ASHRAE 2008 HVAC Systems and Equipment Handbook (Available at: https://www.ashr ae.org/resources

-- publications/handbook ).

t See http://homerepair.about.com/od/heatingcoolingrepair/ss/Residential

- Steam

- Boiler

- Controls.htm

.

u Se e https://www.osha.gov/dte/grant.../fy07/sh.../mod_7_boiler_safety2.pptx

.

3

- 58Draft types include natural and mechanical draf t, as well as a unique type periodic

or intermittent forced draft achieved by pulse combustion. A natural draft boiler is designed to work with a negative pressure in the firebox and flue connection, where the pressure difference is developed by the buoya ncy of hot gases in the chimney. A

mechanical draft boiler has either a forced draft or induced draft blower. A forced draft boiler uses a blower upstream of the combustion chamber, and the fan is located at the

inlet of the b urner and pushes air through the burner, thereby ensuring that adequate air is delivered to the combustion process. v The blower pulls air from the boiler room or may be connected to a duct system which pulls in outside air, then delivers air to the combustion chamber at a positive p ressure above atmospheric pressure

. An induced draft

boiler uses a blower located at the outlet side of the boiler heat exchanger to pull flue gases out of the boiler due to a negative pressure in the combustion chamber , thereby causing air flow into the inlet of the boiler

.

3.3.2 Technology Options that Improve Combustion Efficiency and/or Thermal Efficiency

DOE identified technology options by reviewing commercial packaged boiler manufacturer specification sheets and equipment literature , recent trade publicat ions, technical journals, and patent filings. DOE also consult ed with manufacturer s during interviews about these technology options. At this time, DOE is aware of a set of technology options (discussed in further detail below) that could be used to impr ove commercial packaged boiler thermal efficiency and/or combustion efficiency. Technology options that are applicable only to equipment subject to a thermal efficiency standard are noted. The following list includes technologies that would improve the rated efficiency:

1. Jacket i nsulation optimization ( t hermal e fficiency o nly)

2. Heat exchanger improvements (including condensing heat exchanger, external and internal tube surface enhancement)

3. Burner derating

4. Improved burner technology

5. Combustion air preheaters

6. Economizers

7. Blowdown waste heat recovery

8. Integrated, high

- efficiency steam bo ilers

Jacket Insulation Optimization (Thermal Efficiency Only)

O utside surfaces of boiler tank/pressure vessel are usually covered with insulation

to reduce heat los ses through the boiler jacket. At many times however, thermal insulation may either be under applied or over applied. Both cases lead to increased

v DOE's Improving Steam System Performance : A S ourcebook for I ndustry (Available at: http://www1.eere.energy.gov/manufacturing/tech_assistance/pdfs/steamsourcebook.pdf ).

3

- 59thermal losses in form of convection and radiation. To mitigate this problem, t hermal

insulation optimization techniques can be utiliz ed to improve insulation performance.

Unnecessarily thick insulation leads to increase in surface area which would subsequently lead to increased losses. Too thin an insulation reduces overall thermal resistance which also leads to significant radiation and con vection losses . The optimum

insulation thickness for a simple cylinder depends on the outside heat transfer coefficient and the thermal conductivity of the insulation material. The outside heat transfer

coefficient for natural convection can be calculated using empirical equations available in literature. Using such simple techniques, overall performance of boilers may be improved significantly.

Heat Exchanger Improvements (Including Condensing Heat Exchan g er)

At most operating temperatures, condensing co mmercial packaged boilers operate at higher efficiencies than non

- condensing commercial packaged boiler s by capturing latent heat resulting from the phase change of water vapor in combustion gases. The level of efficiency gain by condensing boilers, compared to non

- condensing designs, is usually greater at low distribution system operating temperatures, when non

- condensing boilers sometimes use supply/return water mixing valves to maintain boiler temperatures that are high enough to prevent condensati on and possible related corrosion.

Improvements to the heat exchanger can be achieved by modifying baseline designs of standard boilers . A number of design modifications can be implemented which may increase thermal and/or combustion efficiencies. Some of these are listed below:

1. I ncrease heat exchanger surface area

2. M odify or add heat exchanger surface features

3. M odify or add heat exchange r baffles and turbulators;

4. I ncrease the corrosion resistance of the primary heat exchanger or use a

corrosion

- resistant secondary heat exchanger to withstand flue gas

condensation.

DOE notes that increasing the heat exchanger surface area may bring about insignificant improvements in thermal efficiency. Through manufacturer interviews,

DOE estimates that a 10

- percent incre ase in surface area would result in a 1 to 2

- percent
increase in thermal efficiency.

An alternat ive way to increase heat transfer surface area is to add surface features

, such as fins. Many commercial boilers made from copper

, use compact fin

- tube heat

e xchangers. Cast Iron boilers also have pin fins on the water and/or air side of the heat exchanger. Though these features considerably improve performance, there may still be a possibility for improvement with regards to fin geometry and design

.

Many s tudies have been carried out for different fin designs for fin tube heat exchangers. One such study compared the air side performance of plate (straight), wavy

and louvered fin s on a fin tube heat exchanger. Results indicate that for a fixed fan power

3

- 60and capacity, 40

- percent lower surface area would be required while using a louvered fin heat exchanger as compared to a plate fin

- tube heat exchanger

. 11 The study also compared heat transfer coefficient for heat exchangers having same fin density for all three types of fins and r esults show superior performance of louvered fin over wavy and plate fins

. 11 Similar studies prove that there exists an opportunity to impr ove conventional heat exchanger design by using wavy fins and louvered fins over straight

fins. 12 Figure 3.3

. 1 shows a type of louvered fin used in cross

- flow heat exchangers.

Figure 3.3

. 1

. Fin

- tube heat exchanger with louvered fin s 12

Another method to improve heat exchanger performance is the use of turbulators

to increase convective heat transfer. Turbulators are used to impart turbulence in the flow of flue gases or water. Turbulent heat transfer generally delivers higher thermal transport as compared to laminar flow heat transfer. This is because turbulent flow causes shearing of thermal boundary layers which are formed when a fluid transfers heat with a surface.

In these boundary l ayer s , viscous forces dominate leading to conductive heat transfer and high thermal resist a nce. With introduction of turbulence, these layers get disturb ed and

heat tra nsfer becomes dominated by convective forces. This allows greater amount of

heat to be transferred.

This effect also occurs when hot flue gases flow through a fire tube boi ler. By introducing turbulators flue gases can easily be converted into turbulent regime. Interviews with manufacturers suggest that almost 1 to 2

- percent incremental efficiency can be obtained by adding turbulators inside fire tubes. So me typical turbulators which can be used include twisted tape, c onical rings

, wire coils , swirl flow generators etc. 13

Internal ribs may also provide improvement in heat transfer by allowing the gases to remain in turbulent flow throughout the tube

. 14

For water tube boilers alternative tube designs

, such as corrugated tubes with or

without internal r ifling

, show considerable promise. One extensive study suggests

considerable heat transfer enhancement for different geometries of spira l ly corrugated tubes as compared to smooth circular tubes. 15 In addition

, considerable advancement in tube design has occ urred over the past few years. A new addition which has come about

wi t h advancement of manufacturing techniques is the evolution of micro

- fin surface tubes for boiling and condensation. 16 Depending on wetting capabilities, microfin tubes

allow formation of a thin film on the surface of the tubes and therefore provide a substantial increase in heat transfer coefficient.

3

- 61Internal rifling of water tubes corrugation is another approach which can be used to improve convective heat transfer. 15

, 16 Similar to turbulators, rifling allows the fluid to approach turbulent regime by providing a circumferential velocity component t o the flow

. V iscous layers near the surface also get disturbed due to this centrifugal motion and this

increases heat transfer near the surface.

In addition to all of the above , switching from natural draft systems to m echanical draft systems can also be implemented . In natural draft systems, movement of air through the boiler is driven by buoyancy of flue gases. Mechanical draft systems allow forced convection dominated heat transfer where a pressure differential is maintained

across the boiler (by a blower or fan) in order to allow flow of flue gases. The velocity of flue gases passing through fire tubes or over the heat exchanging surface determines the

heat transfer coefficient.

Improving th e heat exchanger for a boiler can improve the effectiveness of heat transfer from the hot combustion gases to the water that is distributed to the heated space. The improve d effectiveness of the heat exchanger can increase combustion and thermal

efficienc y

. High pressure

- drop heat exchangers can also serve to reduce off

- cycle draft losses by restricting the flow of air through the heat exchanger, and subsequent loss of heat, when the burner is not operating

.

Burner Derating
Burner derating is the operatio n of a boiler at a reduced firing rate. Reducing burner firing rate for gas and oil boilers while keep ing heat exchanger geometry, the

surface area , and the fuel

- to

- air ratio the same

, will increase the ratio of heat transfer surface area to energy input, thereby increasing the efficiency of the boiler

. However, depending on the degree of reduction, a lower energy input means that less heat will be produced , and

, thus

, lower utility may be provided than with conventional burner firing

rates.

Improved Burner Technology

Pulse Combustion

Pulse combustion burners operate on self

- sustaining

, resonating pressure waves that alternately depressurize the combustion chamber (drawing a fresh fuel

- air mixture into the chamber) and pressurize it ( through heating an d expansion of the fuel/air mixture during combustion ). Pulse combustion systems feature high heat transfer rates, and can achieve higher efficiency levels than conventional boiler designs.

Premix Burners

P remix ing fuel gas and combustion air prior to ar rival at the flame results in more complete combustion using lower levels of excess air. The lower levels of excess air not only reduce the amount of fuel required to heat the combustion air but also raise the temperature of the gases entering the heat ex changer

, which enhances heat exchange and

3

- 62improves efficiency. Lower levels of excess air also raise the water vapor d ew point

, which facilitates condensation and the recovery of latent heat and improves efficiency when the unit is operating in condensing mode.

Low

- Pressure, Air

- Atomized Oil Burner

F uel input rate is controlled by the size of the nozzle orifice. Pressure

- atomizing nozzles that are designed for low firing rates suffer rapid fouling of the small internal passages, leading to inadequate sp ray patterns and poor combustion performance. To overcome the low input limitations of conventional oil burners, Brookhaven National Laboratory developed a low

- pressure, air

- atomized oil burner. w In addition, it can operate with low levels of excess comb ustion air for lean

- burning, ultra

- clean

combustion. A lower level of excess air generally imp roves combustion efficiency.

Combustion Air Preheaters

Combustion air preheaters (also known as recuperators) are air

- to

- air heat exchangers that transfer energy from the flue gases back into the system. However, instead of transferring the energy into the feed water as is done with an economizer, the energy is transferred to increase the temperature of the incoming combustion air, thereby potentially resulting i n improved efficiency.

The gas

- gas heat transfer for such systems can be achieved using a fin tube

– cross flow heat exchanger. Modifications such as improved fin

- tube designs and fin configuration would provide additional benefit.

E conomizers

Economizer s may allow for an increase in boiler thermal efficiency x by transferring excess flue gas heat into incoming feed water

. y Economizers are usually air

to

- water heat exchangers. There are noncondensing and condensing economizers available on the market. Condensing economizers are designed to allow condensation of

the exhaust gas.

Blowdown Waste Heat Recovery
In large steam commercial boilers, salt and sediment residue gets left ou t in the water stored in the boiler. These dissolved solids also known as TDS ( t otal dissolved solids) are removed from the boiler in a process known as b lowdown. Depending on size of boiler, blowdown can either be a continuous

, periodic or maintenance tim e process. In either case, stored heat energy in blowdown water which would otherwise be wasted away in a drain, can be utilized to preheat incoming water. This blowdown process may require a separator (available on the market) which separates water from s team. By

w See : http://www.osti.gov/bridge/servlets/purl/248539

- wWbYod/webviewable/248539.pdf

.

x Note that economizers would only show an increase in thermal efficiency if they are an integral component of the boiler.

y See https://www1.eere.energy.gov/manufacturing/tech_deployment/pdfs/steamsourcebook.pdf

.

3

- 63integrating this technology, there is potential to reduce fuel requirement to achieve desired water temperature. This technique may also marginally increase efficiency levels as the stored heat derived from combustion gases is utilized to a great er extent.

Integrated, High

- Efficiency Steam Boilers
Certain manufacturers have developed integrated, high

- efficiency steam boilers that combine multiple design features to increase fuel

- to

- steam efficiency. Such features

can include enhanced heat transf er surfaces ( e.g. , spiral fire tubes), as well as feed water economizers and high

- turndown modulating burners capable of maintaining low levels of

excess combustion air. Cleaver

- Brooks, in partnership with DOE and the Gas Technology Institute (GTI)

, devel oped the first i ntegrated, h igh

- e fficiency s team b oilers

called a " Super Boiler ." z

DOE notes that the integrated high

- efficiency steam boiler concept described above is essentially a combination of several different technology options integrated into

a com mercial boiler equipment. It does not refer to any particular technology option that can be applied to CPBs to improve efficiency. As a result, DOE has decided not to consider the concept as a potential technology option. DOE has presented the concept

here purely for information purposes.

3.3.3 Technology Options to Reduce Seasonal Boiler Energy Consumption

DOE is aware of a number of boiler technologies exist that reduce overall fuel consumption by improving the average seasonal efficiency , including the following technologies:

1. Modulating burners

2. Electronic ignition

3. Dampers

4. T emperature reset contro ls

5. Thermal post

- purge controls

6. Delayed

- action oil pump solenoid valve

Modulating Burners

Two

- stage and modulating burners can decrease losses caused by burner cycling
at part ial loads. However, m odulating burners may not accomplish net energy efficiency gains if excess combustion air levels must be increased at low firing rates (in order to maintain combustion performance) or if electrical power requirem ents for the burner do

not decrease in linear proportion to the firing rate

. In condensing boiler applications, an increase in excess combustion air ratio can result in reduced latent heat recovery due to decreased flue gas dew point temperatures. This c an result in an energy loss that outweighs the benefit of reduced burner cycling.

z See http://www1.eere.energy.gov/manufacturing/tech_assistance/pdfs/how_superboiler_works.pdf for

further information.

3

- 64Electronic Ignition

Boilers can be equipped with electronic ignition systems, which ignite burners on demand using electrical component s

.

There are different types of elect ronic ignition systems including:

(1) Intermittent Pilot Ignition : This is a device that lights a pilot light by generating a spark. The pilot light in turn lights the main burner.

(2) Direct Spark Ignition (DSI): DSI ignites the main burner directly by generatin g a spark.

(3) Interrupted Duty Ignition Systems : All modern oil burners have a type of electronic ignition called an interrupted duty ignition. A step

- up transformer supplies power to two electrodes, which causes a spark to jump. The interrupted duty igniti on system for an oil burner activates the spark until either a steady flame is established or the end of the trial

- for

ignition (TFI) period. aa

(4) Hot Surface Ignition : The igniter in this system is an electrically heated resistance element that thermally ignites the main burner directly without the use of a pilot light.

Unlike standing pilot ignition systems that consume fuel continuously, electronic

devices and their control modules operate only during the active mode , which improves efficiency

. Solid

- state electronic ignition components can also achieve electricity savings compared to older, iron

- core transformer technologies.

Dampers

Off

- cycle (which refers to the burner off

- cycle) dampers restrict the intake a nd exhaust air flow through the venting system during standby mode by closing when the burner is not operating, thereby trapping residual heat in the heat exchanger. During the

burner off

- cycle, the boiler loses heat by natural convection and conduction t hrough the combustion air inlet and flue. Installing a damper at these points improves efficiency by preventing heat from escaping and minimizing off

- cycle heat losses.

Temperature Reset Controls

Temperature reset controls monitor outside air temperature o r burner operating hours (BOH) to estimate the required heating load , which can vary as a function of outdoor temperature , solar and wind conditions, internal heat gain, or thermostat

aa “Trial for ignition” is the period du ring which the burner is attempting to ignite the fuel it is delivering to

the nozzle.

3

- 65setback/recovery. The hydronic water supply temperature is then modulat ed up or down to enable the thermal distribution capacity to match the actual heating demand. bb

Thermal Post

- Purge Controls

Thermal post

- purge controls allow the hydronic circulating pump to continue operation after the termination of a thermostat demand for heat. The circulation pump continues to operate after the shutdown of the burner until the boiler temperature drops down to a programmed level that depends on type of boiler and fuel. The thermal post

purge concept functions most effectively when the control anticipates the end of the heating demand and shuts off the burner early enough so that the residual heat transferred during the post

- purge cycle just satisfies the temperature requirement of the building. Substantial benefits are achieved by red uced boiler temperature during standby mode/off mode through reduced jacket and draft heat losses.

Delayed

- Action Oil Pump Solenoid Valve

A delayed

- action oil pump solenoid valve is installed between the oil pump and the burner nozzle to supplement the fue l pump regulator . It does so by delaying the fuel release by three to six seconds after the igniter and burner blower start until the oil pressure reaches the level required to fully discharge the oil into the combustion chamber without dripping. This en sures that the oil burns more completely , which improves efficiency since heat exchangers will suffer less fouling

.

bb 2008 ASHRAE Handbook

– HVAC Systems and Equipment (Available at: https://www.ashrae.org/resources

-- publications/handbook ).

3

- 66REFERENCES

1 . Air Conditioning, Heating and Refrigeration Institute’s certified directory o f

commercial boilers. URL: https://www.ahridirectory.org/ahridirectory/pages/home.aspx

2 . Canadian Energy Conservation Standards proposed by National Resources Canada,

updated as of November 2011. URL: http://www.nrcan.gc.ca/e nergy/regulations

- codes

standards/bulletins/7145#Commercial_Packaged_Gas

3 . U.S. Department of Energy

- Office of Energy Efficiency and Renewable Energy.

Federal Energy Management Program. How to Buy an Energy

- Efficient Commercial

Boiler. June 8, 2010. (L ast Accessed March 11, 2014). http://www.nwfpa.org/nwfpa.info/component/content/article/301

- how

- to

- buy

- an

energy

- efficient

- commer cial

- boiler

4 . Boiler Heating Systems and Components Rebates, Minnesota Energy Resources, URL:

http://www.minnesotaenergyresources.com/business/boiler_rebates.aspx

5 . B oilers and Water Heating Rebate Catalog, Energy

- efficiency rebates for your

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