# Energy Conservation Program for Certain Commercial and Industrial Equipment: Test Procedures for Commercial Packaged Boilers > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2016-05138 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** March 17, 2016 - **Citation:** 81 FR 14642 ## Text DEPARTMENT OF ENERGY 10 CFR Parts 429 and 431 [Docket Number EERE-2014-BT-TP-0006] RIN 1904-AD16 Energy Conservation Program for Certain Commercial and Industrial Equipment: Test Procedures for Commercial Packaged Boilers AGENCY: Office of Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Notice of proposed rulemaking and public meeting. SUMMARY: The U.S. Department of Energy (DOE) proposes to amend the test procedure and applicable definitions for commercial packaged boilers, as well as modify the sampling plans for commercial packaged boilers in its regulations pertaining to energy efficiency programs for certain programs for commercial and industrial equipment. This rulemaking will fulfill DOE's statutory obligations to make its test procedure consistent with the applicable industry test procedure and to review its test procedures for covered equipment at least once every seven years. In this notice of proposed rulemaking (NOPR), DOE proposes to incorporate by reference certain sections of the American National Standards Institute (ANSI)/Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Standard 1500, “2015 Standard for Performance Rating of Commercial Space Heating Boilers,” and, in addition, incorporate amendments that clarify the coverage for field-constructed commercial packaged boilers and the applicability of DOE's test procedure and standards for this category of commercial packaged boilers, provide an optional field test for commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h, provide a conversion method to calculate thermal efficiency based on combustion efficiency testing for steam commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h, modify the inlet and outlet water temperatures during tests of hot water commercial packaged boilers, establish limits on the ambient temperature and relative humidity conditions during testing, modify setup and instrumentation requirements to remove ambiguity, and standardize terminology and provisions for “fuel input rate.” This NOPR also announces a public meeting to discuss and invite comments, data, and information about the issues and proposed amendments presented in this test procedure rulemaking for commercial packaged boilers. DATES: Meeting: DOE will hold a public meeting on Monday, April 4, 2016, from 10 a.m. to 3 p.m., in Washington, DC. The meeting will also be broadcast as a webinar. See section V, “Public Participation,” for webinar registration information, participant instructions, and information about the capabilities available to webinar participants. Comments: DOE will accept written comments, data, and information regarding this NOPR before and after the public meeting, but not later than May 31, 2016. See section V, “Public Participation,” for details. ADDRESSES: The public meeting will be held at the U.S. Department of Energy, Forrestal Building, Room 6E-069, 1000 Independence Avenue SW., Washington, DC 20585-0121. Persons may also attend the public meeting via webinar. To attend, please notify Ms. Brenda Edwards at (202) 586-2945. For more information, refer to section V, “Public Participation,” near the end of this notice. Interested parties are encouraged to submit comments using the Federal eRulemaking Portal at www.regulations.gov. Interested parties may submit comments by any of the following methods: • Federal eRulemaking Portal: www.regulations.gov. Follow the instructions for submitting comments. • Email: CommPackagedBoilers2014TP0006@ee.doe.gov. Include docket number EERE-2014-BT-TP-0006 and/or regulation identifier number (RIN) 1904-AD16 in the subject line of the message. Submit electronic comments in WordPerfect, Microsoft Word, PDF, or ASCII file format, and avoid the use of special characters or any form of encryption. • Postal Mail: Ms. Brenda Edwards, U.S. Department of Energy, Building Technologies Office, Mailstop EE-5B, Test Procedure for Commercial and Industrial Packaged Boilers, Docket No. EERE-2014-BT-TP-0006 and/or RIN 1904-AD16, 1000 Independence Avenue SW., Washington, DC 20585-0121. If possible, please submit all items on a compact disc (CD), in which case it is not necessary to include printed copies. • Hand Delivery/Courier: Ms. Brenda Edwards, U.S. Department of Energy, Building Technologies Office, 950 L'Enfant Plaza, SW., Suite 600, Washington, DC 20024. Telephone: (202) 586-2945. If possible, please submit all items on a CD, in which case it is not necessary to include printed copies. No telefacsimiles (faxes) will be accepted. For detailed instructions on submitting comments and additional information on the rulemaking process, see section V, “Public Participation,” of this document. Docket: The docket, which includes Federal Register notices, public meeting attendee lists and transcripts, comments, and other supporting documents/materials, is available for review at www.regulations.gov. All documents in the docket are listed in the www.regulations.gov index. However, not all documents listed in the index may be publicly available, such as those containing information that is exempt from public disclosure. A link to the docket Web page can be found at: http://www.regulations.gov/#!docketDetail;D=EERE-2014-BT-TP-0006. This Web page contains a link to the docket for this NOPR on the www.regulations.gov site. The www.regulations.gov Web page contains simple instructions on how to access all documents, including public comments, in the docket. See section V, “Public Participation,” for information on how to submit comments through www.regulations.gov. FOR FURTHER INFORMATION CONTACT: Mr. James Raba, U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Office, EE-5B, 1000 Independence Avenue SW., Washington, DC 20585-0121. Telephone: (202) 586-8654. Email: commercial_packaged_boilers@ee.doe.gov. Mr. Peter Cochran, U.S. Department of Energy, Office of the General Counsel, GC-33, 1000 Independence Avenue SW., Washington, DC 20585-0121. Telephone: (202) 586-9496. Email: Peter.Cochran@hq.doe.gov. For further information on how to submit a comment, review other public comments and the docket, or participate in the public meeting, contact Ms. Brenda Edwards at (202) 586-2945 or by email: Brenda.Edwards@ee.doe.gov. SUPPLEMENTARY INFORMATION: This proposed rule would incorporate by reference into 10 CFR parts 429 and 431 the testing methods contained in the following commercial standard: AHRI/ANSI Standard 1500-2015, “Performance Rating of Commercial Space Heating Boilers,” Section 3 “Definitions,” Section 5 “Rating Requirements,” Appendix C “Methods of Testing for Rating Commercial Space Heating Boilers—Normative,” excluding Figures C5 and C7, Appendix D “Properties of Saturated Steam—Normative,” and Appendix E “Correction Factors for Heating Values of Fuel Gases—Normative,” ANSI approved November 28, 2014. Copies of AHRI standards may be purchased from the Air-Conditioning, Heating, and Refrigeration Institute, 2111 Wilson Blvd., Suite 500, Arlington, VA 22201, or by visiting http://www.ahrinet.org/site/686/Standards/HVACR-Industry-Standards/Search-Standards. See section IV.M for additional information on this standard. Table of Contents I. Authority and Background II. Synopsis of the Notice of Proposed Rulemaking III. Discussion A. Proposing to Adopt Certain Sections of ANSI/AHRI Standard 1500-2015 B. Scope and Definitions 1. Definition of Commercial Packaged Boiler 2. Field-Constructed Commercial Packaged Boilers C. Testing of Large Commercial Packaged Boilers 1. Field Tests for Commercial Packaged Boilers 2. Method To Convert Combustion Efficiency to Thermal Efficiency for Steam Commercial Packaged Boilers 3. Alternative Efficiency Determination Methods 4. Steam Commercial Packaged Boiler Operating Pressure D. Hot Water Commercial Packaged Boiler Operating Temperatures 1. Existing Requirements 2. Issues With Water Temperature Requirements and Proposed Changes 3. Allowable Uncertainty in Water Temperature Measurement 4. Water Flow Rate During Testing E. Testing Conditions F. Setup and Instrumentation G. Fuel Input Rate H. Clerical Issues I. Other Issues 1. Stack Temperature Adjustment for Using Combustion Efficiency in Steam Mode To Represent Hot Water Mode 2. Testing at Part Load 3. Other Industry Test Procedures IV. Procedural Issues and Regulatory Review A. Review Under Executive Order 12866 B. Review Under the Regulatory Flexibility Act C. Review Under the Paperwork Reduction Act of 1995 D. Review Under the National Environmental Policy Act of 1969 E. Review Under Executive Order 13132 F. Review Under Executive Order 12988 G. Review Under the Unfunded Mandates Reform Act of 1995 H. Review Under the Treasury and General Government Appropriations Act, 1999 I. Review Under Executive Order 12630 J. Review Under Treasury and General Government Appropriations Act, 2001 K. Review Under Executive Order 13211 L. Review Under Section 32 of the Federal Energy Administration Act of 1974 M. Description of Materials Incorporated by Reference V. Public Participation A. Attendance at the Public Meeting B. Procedure for Submitting Prepared General Statements for Distribution C. Conduct of the Public Meeting D. Submission of Comments E. Issues on Which DOE Seeks Comment VI. Approval of the Office of the Secretary I. Authority and Background Title III of the Energy Policy and Conservation Act of 1975 (42 U.S.C. 6311, et seq.; “EPCA” or, “the Act”) sets forth a variety of provisions designed to improve energy efficiency. 1 Part C of Title III establishes the “Energy Conservation Program for Certain Industrial Equipment,” which covers certain industrial equipment (hereafter referred to as “covered equipment”), including commercial packaged boilers. 2 (42 U.S.C. 6311(1)(J)) 1 All references to EPCA in this document refer to the statute as amended through the Energy Efficiency Improvement Act of 2015 (April 30, 2015). 2 For editorial reasons, Part C was codified as Part A-1 in the U.S. Code. Under EPCA, the energy conservation program consists essentially of four parts: (1) Testing, (2) labeling, (3) Federal energy conservation standards, and (4) certification and enforcement procedures. The testing requirements consist of test procedures that manufacturers of covered equipment must use as the basis for (1) certifying to the Department of Energy (DOE) that their equipment complies with applicable energy conservation standards adopted under EPCA, and (2) making representations about the efficiency of the equipment. Similarly, DOE must use these test procedures to determine whether the equipment complies with any relevant standards promulgated under EPCA. With respect to commercial packaged boilers (CPB), EPCA requires DOE to use industry test procedures developed or recognized by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) or the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), as referenced in ASHRAE/IES 3 Standard 90.1, “Energy Standard for Buildings Except Low-Rise Residential Buildings.” (42 U.S.C. 6314(a)(4)(A)) Further, if such an industry test procedure is amended, DOE is required to amend its test procedure to be consistent with the amended industry test procedure, unless it determines, by rule published in the Federal Register and supported by clear and convincing evidence, that the amended test procedure would be unduly burdensome to conduct or would not produce test results that reflect the energy efficiency, energy use, and estimated operating costs of that equipment during a representative average use cycle. (42 U.S.C. 6314(a)(4)(B)) 3 Illuminating Engineering Society. EPCA also requires that, at least once every 7 years, DOE evaluate test procedures for each type of covered equipment, including commercial packaged boilers, to determine whether amended test procedures would more accurately or fully comply with the requirements for the test procedures to not be unduly burdensome to conduct and be reasonably designed to produce test results that reflect energy efficiency, energy use, and estimated operating costs during a representative average use cycle. (42 U.S.C. 6314(a)(1)(A)) DOE last reviewed the test procedures for commercial packaged boilers on July 22, 2009. 74 FR 36312. Therefore, DOE is required to re-evaluate the test procedures no later than July 22, 2016, and this rulemaking satisfies that requirement. As the industry standard for commercial packaged boilers was recently updated, this rulemaking will also fulfill DOE's statutory obligations to make its test procedure consistent with the applicable industry test procedure. On September 3, 2013, DOE initiated a test procedure and energy conservation standards rulemaking for commercial packaged boilers and published a notice of public meeting and availability of the Framework document (September 2013 Framework document). 78 FR 54197. Both in the September 2013 Framework document and during the October 1, 2013 public meeting, DOE solicited public comments, data, and information on all aspects of, and any issues or problems with, the existing DOE test procedure, including whether the test procedure is in need of updates or revisions. More recently, DOE also received comments on the test procedure in response to the notice of availability of the preliminary technical support document (TSD) for the standards rulemaking, which was published in the Federal Register on November 20, 2014 (November 2014 Preliminary Analysis). 79 FR 69066. Additionally, on February 20, 2014, DOE published in the Federal Register a request for information (February 2014 RFI) seeking comments on the existing DOE test procedure for commercial packaged boilers, which incorporates by reference Hydronics Institute (HI)/AHRI Standard BTS-2000 (Rev 06.07), “Method to Determine Efficiency of Commercial Space Heating Boilers” (BTS-2000). 79 FR 9643. BTS-2000 provides test procedures for measuring steady-state combustion and thermal efficiency of a gas-fired or oil-fired commercial packaged boiler capable of producing hot water and/or steam and operating at full load only. In the February 2014 RFI, DOE requested comments, information, and data about a number of issues, including (1) part-load testing and part-load efficiency rating, (2) typical inlet and outlet water temperatures for hot water commercial packaged boilers, (3) the steam pressure for steam commercial packaged boilers operating at full load, and (4) design characteristics of commercial packaged boilers that are difficult to test under the existing DOE test procedure. Subsequently, on April 29, 2015, AHRI, together with the American National Standards Institute (ANSI), published the “2015 Standard for Performance Rating of Commercial Space Heating Boilers” (ANSI/AHRI Standard 1500-2015). ANSI/AHRI Standard 1500-2015 states “this standard supersedes AHRI Hydronics Institute Standard BTS-2000 Rev. 06.07” in the front matter of the document. DOE believes that ANSI/AHRI Standard 1500-2015 is consistent with the existing metrics and approach incorporated in BTS-2000 but also incorporates provisions that improve the accuracy and repeatability of the test procedure over the BTS-2000 standard. ANSI/AHRI Standard 1500-2015 also adopts several changes that were suggested in public comments submitted by interested parties in response to DOE's September 2013 Framework document, November 2014 Preliminary Analysis, and February 2014 RFI. 4 Therefore, as required by 42 U.S.C. 6314(a)(4)(B), DOE is replacing BTS-2000 with the updated industry standard, ANSI/AHRI Standard 1500-2015, as the basis for the DOE test procedure. Section III.A contains a more detailed discussion of the basis for transitioning to the commercial packaged boiler test procedures outlined in ANSI/AHRI Standard 1500-2015. 4 Comments received as part of the February 2014 RFI about test procedures for commercial packaged boilers are in Docket Number EERE-2014-BT-TP-0006. In some cases, earlier comments that address or are relevant to test procedures for commercial packaged boilers are in the energy conservation standards docket, Docket Number EERE-2013-BT-STD-0030. These comments in response to the September 2013 Framework Document relevant to the test procedure are also placed in the test procedure rulemaking docket, Docket Number EERE-2014-BT-TP-0006 II. Synopsis of the Notice of Proposed Rulemaking In this notice of proposed rulemaking (NOPR), DOE proposes to amend its existing test procedures for commercial packaged boilers at 10 CFR 431.86. DOE proposes to incorporate by reference certain sections of ANSI/AHRI Standard 1500-2015 as a direct replacement for BTS-2000 since, as discussed in section I, ANSI/AHRI Standard 1500-2015 supersedes BTS -2000 and DOE has found ANSI/AHRI Standard 1500-2015 to be more accurate compared to BTS-2000 and not unduly burdensome to conduct for the purposes of testing commercial packaged boilers. To obtain information and data regarding its current test procedures for commercial packaged boilers, DOE sought public comment in the September 2013 Framework document, February 2014 RFI, and November 2014 Preliminary Analysis. In response to the September 2013 Framework document, DOE received comments from the American Boiler Manufacturers Association (ABMA), AHRI, Burnham Holdings (Burnham), Cleaver-Brooks, HTP Incorporated (HTP), and a joint submission 5 from the American Council for an Energy-Efficient Economy (ACEEE), the Appliance Standards Awareness Project (ASAP), and the National Resources Defense Council (NRDC). In response to the February 2014 RFI, DOE received comments from ACEEE, AHRI, Burnham, HTP, the National Propane Gas Association (NPGA), and Sidel Systems (Sidel) (three submittals). Sidel submitted two comments prior to the publication of the February 2014 RFI that also pertain to commercial packaged boilers. In response to the November 2014 Preliminary Analysis, DOE received comments from ABMA, AHRI, Lochinvar LLC (Lochinvar), Raypak, and joint submissions 6 from Pacific Gas and Electric (PGE) and Southern California Edison (SCE), and ACEEE, ASAP, and NRDC. 5 The joint submission by ACEEE, ASAP, and NRDC is referred to as the “Joint Advocates” comment in references to the documents submitted to the docket. 6 The joint submission by PGE and SCE is referred to as the “Joint Utilities” comment in references to the documents submitted to the docket. The comments received from stakeholders typically concern BTS-2000 since ANSI/AHRI Standard 1500-2015 had not yet been published at the time DOE solicited comments. Some of the comments received from stakeholders that concerned BTS-2000 apply equally to ANSI/AHRI Standard 1500-2015, whereas other comments are not applicable to ANSI/AHRI Standard 1500-2015. ANSI/AHRI Standard 1500-2015 updates several provisions from BTS-2000 to: (1) Improve repeatability of testing; (2) further clarify the test procedure; and (3) increase the allowable operating steam pressure during steam commercial packaged boiler testing. ANSI/AHRI Standard 1500-2015 also incorporates provisions that accommodate the testing of large commercial packaged boilers that have difficulty meeting the requirements in the existing DOE test procedure. In addition to adopting ANSI/AHRI Standard 1500-2015 as a replacement for BTS-2000 in the DOE test procedure, DOE further proposes several modifications to its test procedure that are not captured in ANSI/AHRI Standard 1500-2015. The additional proposed amendments include the following: • Clarifying the coverage of field constructed commercial packaged boilers under DOE's regulations; • incorporating an optional field test for commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h; • incorporating an optional conversion method to calculate thermal efficiency based on combustion efficiency test for steam commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h; • modifying the inlet and outlet water temperatures required during tests of hot water commercial packaged boilers to be more representative of field conditions; • requiring additional limits on the room ambient temperature and relative humidity during testing; • modifying setup and instrumentation requirements to remove ambiguity; and • standardizing terminology and provisions in regulatory text related to “fuel input rate.” These proposed amendments are intended to improve the repeatability of the test and to accommodate some commercial packaged boilers for which testing has previously been difficult or burdensome. DOE reviewed these additional proposed amendments as well as the proposal to incorporate by reference ANSI/AHRI Standard 1500-2015 under 42 U.S.C. 6314(a)(4)(C) and, in aggregate, DOE has tentatively concluded that there would not be an overall effect on efficiency ratings. Accordingly, DOE proposes that the amended test procedure would be effective 30 days after publication of any final rule in the Federal Register and would be required for any representations made with regard to the energy efficiency of commercial packaged boilers 360 days following publication of any final rule in the Federal Register. (42 U.S.C. 6314(d)) DOE's rationale regarding the impact of the proposed test procedure amendments on measured energy efficiency of commercial packaged boilers is discussed in the subsequent sections. III. Discussion Based on DOE's review of the existing test procedure for commercial packaged boilers and comments submitted by interested parties, DOE has determined that certain amendments and clarifications are necessary in order to improve the repeatability of the DOE test procedure, accommodate certain commercial packaged boilers for which manufacturers have expressed difficulty testing under the provisions of the existing test procedure, and clarify the applicability of DOE's test procedure and energy conservation standards to field-constructed equipment. The following sections address comments received and propose specific improvements for DOE's test procedures for commercial packaged boilers. A. Proposing To Adopt Certain Sections of ANSI/AHRI Standard 1500-2015 The existing DOE test procedure for commercial packaged boilers incorporates by reference BTS-2000 to determine the steady-state efficiency of steam or hot water commercial packaged boilers while operating at full load. As described in section I, on April 29, 2015, AHRI published a new ANSI/AHRI Standard 1500-2015 (ANSI approved November 28, 2014), which supersedes BTS-2000. On May 29, 2015, AHRI submitted a request directly to DOE to update the incorporation by reference in the DOE test procedure to reference the new ANSI/AHRI Standard 1500-2015. (Docket EERE-2014-BT-TP-0006, AHRI, No. 29 at p. 1) 7 DOE reviewed both documents and DOE believes that the recently published ANSI/AHRI Standard 1500-2015 standard is not unduly burdensome to conduct and represents an improvement over BTS-2000 while retaining the general testing methodology and metrics ( i.e., thermal and combustion efficiency) of the existing test procedure. 8 7 A notation in this form provides a reference for information that is in Docket No. EERE-2014-BT-TP-0006. This particular notation refers to a comment from AHRI on p. 1 of document number 29 in the docket. 8 Thermal efficiency is measured for all commercial packaged boilers except for oil-fired and gas-fired commercial packaged boilers that provide hot water and have greater than 2,500,000 Btu/h in fuel input rate, for which combustion efficiency is used. See 10 CFR 431.87(b). Specifically, ANSI/AHRI Standard 1500-2015 contains the following key substantive changes as compared to BTS-2000: • Improvements in instrumentation accuracy specifications, including removing outdated instrumentation; use of more appropriate measurement units; and revising gas chemistry instrumentation accuracy requirements to reflect those of commonly used devices; • more specific instructions for establishing test procedure configuration, particularly for water piping and positioning of temperature measurement devices in fluid stream; • establishment of criteria that indicate when a steady-state condition is met; 9 9 BTS 2000 noted in section 9.1.1.1.6 that “a state of equilibrium shall have been reached when consistent readings are obtained during a 30 minute period,” but did not explicitly define what “consistent” meant. ANSI/AHRI Standard 1500-2015 incorporates specific thresholds for steam pressure and percent CO 2 or O 2 in the flue gas to specify the maximum allowable fluctuations that may occur during “steady-state” operation. • allowance of steam operating pressure up to 15 psig; and • instructions addressing how to conduct testing when manufacturers do not provide sufficient information within their installation materials shipped with the commercial packaged boiler. DOE notes that several of the changes incorporated into ANSI/AHRI Standard 1500-2015 were also suggested by interested parties in public comments responding to DOE's September 2013 Framework document, November 2014 Preliminary Analysis, and February 2014 RFI. DOE seeks comment on its proposal to replace BTS-2000 with ANSI/AHRI Standard 1500-2015 in its test procedure for commercial packaged boilers. This is identified as Issue 1 in section V.E. B. Scope and Definitions DOE proposes to incorporate several new definitions that help clarify the scope and applicability of DOE's commercial packaged boiler test procedure. DOE notes that any changes or amendments to DOE's definitions at 10 CFR 431.82, if adopted, would also apply to DOE's energy conservation standards for commercial packaged boilers. 1. Definition of Commercial Packaged Boiler While EPCA authorizes DOE to establish, subject to certain criteria, test procedures and energy conservation standards for packaged boilers, to date, DOE has only established test procedures and standards for commercial packaged boilers, a subset of packaged boilers. In 2004, DOE published a final rule (October 2004 final rule) establishing definitions, test procedures, and energy conservation standards for commercial packaged boilers. 69 FR 61949 (Oct. 21, 2004). In the October 2004 final rule, DOE defined “commercial packaged boiler” as a type of packaged low pressure boiler that is industrial equipment with a capacity (fuel input rate) of 300,000 Btu per hour (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 “hot water supply boiler.” DOE also defined “packaged low pressure boiler” as a packaged boiler that is: (1) A steam boiler designed to operate at or below a steam pressure of 15 psig; or (2) a hot water commercial packaged boiler designed 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 definition. 69 FR 61960. DOE notes that, because commercial packaged boilers are currently defined as a subset of packaged low pressure boilers, all commercial packaged boilers have to meet the pressure and temperature criteria established in the definition of a “packaged low pressure boiler.” Consequently, DOE is proposing to modify DOE's definition of “commercial packaged boiler” to explicitly include the pressure and temperature criteria established by the “packaged low pressure boiler” definition. DOE believes such a modification will clarify the characteristics of the equipment to which DOE's test procedure and energy conservation standards apply. As a result, DOE proposes to remove its definition for packaged low pressure boiler, as it is no longer necessary. DOE notes that the term “packaged high pressure boiler” also is no longer used in the commercial packaged boiler subpart, and therefore proposes to remove its definition. DOE seeks comment on these proposals. This is identified as Issue 2 in section V.E. 2. Field-Constructed Commercial Packaged Boilers EPCA establishes the statutory authority by which DOE may regulate “packaged boilers” and 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)) In adopting the EPCA definition for a “packaged boiler,” DOE amended the definition to: (1) Include language to address the various ways in which packaged boilers are distributed in commerce; and (2) explicitly exclude custom-designed, field-constructed boilers. 69 FR 61949, 61952. “Custom-designed, field-constructed” boilers were excluded because DOE believed the statutory standards for “packaged boilers” were not intended to apply to these boiler systems, which generally require alteration, cutting, drilling, threading, welding or similar tasks by the installer. As a result, DOE defined 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 and does not include a boiler that is custom designed and field constructed. 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 shipped at different times and from more than one location. 10 CFR 431.82. In this NOPR, DOE wishes to further clarify the differentiation between field-constructed commercial packaged boilers, which are excluded from DOE's commercial packaged boiler regulations, and field-assembled commercial packaged boilers, which are subject to DOE's regulations. A field-constructed commercial packaged boiler is a custom-designed commercial packaged boiler that requires welding of structural components in the field during installation. Specifically, DOE considers structural components to include heat exchanger sections, flue tube bundles and internal heat exchanger surfaces, external piping to one or more heat exchanger sections or locations, and the mechanical supporting structure the heat exchanger rests upon in the case where a support structure is not provided with the commercial packaged boiler. For the purposes of this clarification, welding does not include attachment using mechanical fasteners or brazing; and any jackets, shrouds, venting, burner, or burner mounting hardware are not structural components. Conversely, a field-assembled commercial packaged boiler can be assembled in the field without the welding of the structural components that were previously listed. DOE reiterates that field-assembled equipment is covered, is required to be tested using the DOE test procedure, and is required to comply with the applicable energy conservation standards and certification requirements. In this NOPR, DOE also proposes to clarify that the field-constructed exemption pertains to commercial packaged boilers specifically, not the broader definition of packaged boiler. Therefore, DOE proposes to remove this exclusionary language from its definition for “packaged boiler” and to incorporate the exclusion for field-constructed equipment into its definition for commercial packaged boiler. DOE seeks comment on its proposed definition for “field-constructed” and this is identified as Issue 3 in section V.E. C. Testing of Large Commercial Packaged Boilers In response to the energy conservation standards September 2013 Framework document, Cleaver-Brooks, Burnham, and ABMA stated that for practical reasons, testing requirements should be limited to boilers with rated maximum input capacities less than 2,500,000 Btu/h. These commenters raised concerns regarding the time and expense of testing larger boilers, and the ability of some independent testing laboratories and manufacturers to test larger boilers due to heat sink requirements for the hot water generated. (Docket EERE-2013-BT-STD-0030, Cleaver-Brooks, No. 12 at p. 1; Docket EERE-2013-BT-STD-0030, Burnham, No. 15 at p. 2; Docket EERE-2013-BT-STD-0030, ABMA, No. 14 at p. 3) ABMA reiterated these concerns in response to the November 2014 Preliminary Analysis. (Docket EERE-2013-BT-STD-0030, ABMA, No. 33 at pp. 1-2) Lochinvar, in response to the November 2014 Preliminary Analysis, stated that alternative efficiency determination method (AEDM) rules mitigated test burden concerns for large boilers. (Docket EERE-2013-BT-STD-0030, Lochinvar, No. 34 at p. 1) In response, DOE notes that neither the statutory definition for “packaged boiler” at 42 U.S.C. 6311(11)(B) nor the definition for “commercial packaged boiler” at 10 CFR 431.82 set an upper limit on the maximum fuel input rate of covered equipment. The energy conservation standards for commercial packaged boilers at 10 CFR 431.87 also do not establish any limitations based on the fuel input rate of equipment. Consequently, commercial packaged boiler models with high fuel input rates are subject to DOE's existing standards for commercial packaged boilers, and to establish such a fuel input rate limit for covered equipment with existing standards would violate the anti-backsliding provisions of EPCA found at 42 U.S.C. 6313(a)(6)(B)(iii)(I) for those equipment larger than the limit. Additionally, both BTS-2000 (incorporated by reference in the existing DOE test procedure) and ANSI/AHRI Standard 1500-2015 (proposed to be incorporated by reference) include any commercial packaged boiler with fuel input rate of 300,000 Btu/h or greater. DOE recognizes the commenters' concerns that it may be difficult to test thermal efficiency for large commercial packaged boilers and notes that EPCA requires that test procedures shall not be unduly burdensome to conduct. (42 U.S.C. 6314(a)(2)) Specifically, DOE recognizes that large commercial packaged boilers may not be fully assembled until they are installed at the field site, which may preclude them from being tested in a laboratory setting. DOE also recognizes that, as the size of the equipment increases, testing costs incurred to condition the incoming water and air to the test procedure rating conditions, as well as management of the hot water generated during testing, also increases. In this NOPR, DOE proposes several amendments to the DOE test procedure in order to provide greater flexibility for testing certain large commercial packaged boilers and field-assembled commercial packaged boilers. Specifically, DOE proposes the following provisions: • A field test of combustion efficiency for commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h; • a calculation method to convert combustion efficiency to thermal efficiency for steam commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h; and • an increase in allowable steam pressure to 15 psi (by incorporating by reference AHRI Standard 1500-2015). DOE notes that the continued allowance for the use of an AEDM also facilitates the ability to ascertain the efficiency of large commercial packaged boilers. These proposed amendments for providing greater flexibility in the testing of large commercial packaged boilers are discussed in the following subsections. 1. Field Tests for Commercial Packaged Boilers DOE proposes to adopt an optional test method for commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h which would allow for: (1) Measuring a steam or hot water commercial packaged boiler's combustion efficiency in the field; and (2) converting the measured combustion efficiency to thermal efficiency via a calculation method for steam commercial packaged boilers (discussed in section III.C.2). DOE understands “field test” to mean a combustion efficiency test that is conducted at the location in which a given commercial packaged boiler is or will be installed and commissioned for use. DOE understands that the combustion efficiency test is less burdensome to conduct on large commercial packaged boilers than the thermal efficiency test and is more feasible to conduct in the field than the thermal efficiency test. Specifically, the test setup required for obtaining the combustion efficiency according to ANSI/AHRI Standard 1500-2015 is less involved and requires less instrumentation in the working fluid stream (flow meters are not required) than the thermal efficiency test, and involves calculations using primarily the flue gas temperature and constituents. The combustion efficiency test also requires less time to run than the thermal efficiency test and therefore requires less fuel and water, which must be managed and disposed of as part of the test. DOE believes that allowance for testing commercial packaged boilers with fuel input rates greater than 5,000,000 Btu/h in the field would reduce the burden associated with testing this equipment and would mitigate the concerns of interested parties regarding laboratory limitations. However, DOE notes that changes to the test procedure are necessary to account for the following issues associated with testing in the field: • Ambient conditions in the field may be difficult to control (see section III.E of this NOPR). • Setup requirements of thermal efficiency test (both ANSI/AHRI Standard 1500-2015 and proposed DOE test procedure amendments) may not be possible to achieve in field (see section III.F of this NOPR). • Maintaining inlet and outlet water temperatures or steam quality (as applicable) may not be possible in the field (see section III.D of this NOPR). Consequently, DOE proposes that the aforementioned requirements for ambient conditions, certain setup requirements, steam quality, and inlet and outlet water temperatures not apply for field tests. While DOE believes such flexibility is necessary to limit burden when testing large commercial packaged boilers in the field, DOE recognizes that eliminating these requirements regarding testing conditions may decrease the accuracy and repeatability of the test. As such, DOE is proposing that the optional field test only be available for commercial packaged boilers with fuel input rates greater than 5,000,000 Btu/h, for which testing in a laboratory setting is difficult, expensive, or impractical. To help improve the consistency and repeatability of field tests, DOE also proposes that manufacturers measure these values (inlet water temperature, outlet water temperature, ambient relative humidity, and ambient temperature) and maintain the records of these measurements as part of the test data underlying the manufacturer's compliance certification in accordance with the requirements in 10 CFR 429.71. If a manufacturer elects to use the field test option in the test procedure, the manufacturer would also be required to report that the rated efficiency is based on a field test. Since DOE proposes this optional methodology primarily to accommodate commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h, DOE proposes to allow certification based on a sample size of one for manufacturers utilizing the field test and conversion methodology. DOE has never intended that a manufacturer build more than one unit solely for the purposes of testing and clarified this during the Commercial Certification Working Group meetings (Docket No. EERE-2013-BT-NOC-0023). Additionally, 10 CFR 429.12(a) requires that certification of equipment occur before distribution in commerce. With respect to commercial packaged boilers that are not field assembled, distribution in commerce would be determined, similar to other covered equipment, using the factors specified in the certification, compliance, and enforcement final rule published on March 7, 2011. 76 FR 12422, 12426-12427. Any field tested basic model of a commercial packaged boiler that has not been previously certified through testing or an AEDM would be required to be certified by the manufacturer to DOE within 15 days of commissioning. (Note: by “commissioning,” DOE means adapting the boiler operating conditions and parameters to those required for the building space heating load.) DOE proposes to adopt this exception in recognition of the high test burden and practical limitations of testing these boilers prior to distributing them in commerce; however, DOE notes that, if the field test demonstrates that the unit does not meet the applicable standard, then the manufacturer would have to decommission the unit until it can be modified and retested to demonstrate compliance with the standard. Failure to decommission the unit immediately ( i.e., allowing the unit to be used during any time period while the unit is being redesigned, parts are being built or ordered, etc. to make the unit compliant) would constitute a violation of the standards and the certification requirements. DOE also notes that, when a single unit is tested, there is no tolerance on the performance; the tested unit must meet the standard. Since commercial packaged boilers with fuel input rates greater than 5,000,000 Btu/h would not be easily transported between manufacturer, laboratory, and consumer facilities, DOE also proposes that, at its discretion, assessment and enforcement testing of commissioned units could also be conducted as field tests. The location at which the enforcement field test is performed may or may not be the same location at which the manufacturer conducted its field test. DOE recognizes that a field test could not meet the existing laboratory accreditation requirements found at 10 CFR 429.110(a)(3) and there proposes an exception in this section specifically for field tests of commercial packaged boilers. DOE seeks comments on the following issues, and these are also listed in section V.E: • The feasibility of conducting a combustion efficiency test in the field for steam and hot water commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h (Issue 4). • Whether the thermal efficiency test can be conducted for steam commercial packaged boilers with fuel input rate greater than 2,500,000 Btu/h and less than or equal to 5,000,000 Btu/h (Issue 5). • The specific limitations, if any, that preclude combustion efficiency testing in a laboratory setting for steam commercial packaged boilers with fuel input rate greater than 2,500,000 Btu/h and less than or equal to 5,000,000 Btu/h (Issue 6). • The specific additional equipment or facilities and their associated cost that would be required to accommodate testing commercial packaged boilers with fuel input rate greater than 2,500,000 Btu/h and less than or equal to 5,000,000 Btu/h in a laboratory setting (Issue 7). • Whether the 5,000,000 Btu/h fuel input rate is an adequate threshold for the allowance of the field combustion test and conversion methodology, and if not, what threshold should be used (Issue 8). • Whether certification should be permitted for field tested units after distribution in commerce and after commissioning, in particular the impact of this approach on building inspectors (Issue 9). 2. Method To Convert Combustion Efficiency to Thermal Efficiency for Steam Commercial Packaged Boilers DOE also proposes a method for converting the combustion efficiency of a steam commercial packaged boiler to thermal efficiency. Such a conversion would be necessary for steam commercial packaged boilers because the efficiency metric for this equipment at 10 CFR 431.86 is thermal efficiency. DOE proposes this conversion method only for those steam commercial packaged boilers with a fuel input rate greater than 5,000,000 Btu/h based on the concerns presented in section III.C. This conversion methodology would be available to manufacturers or laboratories to perform a combustion efficiency test in a laboratory setting or as a field test as described in III.C.1. The proposed conversion method calculates thermal efficiency by subtracting a constant value from the combustion efficiency, which must be measured in accordance with ANSI/AHRI Standard 1500-2015. Thermal efficiency includes heat exchanger effectiveness and jacket losses which are not captured in the combustion efficiency. The constant value subtracted from the tested combustion efficiency value represents those additional losses. In order to determine such a value, DOE analyzed the AHRI directory (as of January 2015). 10 DOE looked at the difference between rated combustion and thermal efficiency for all steam commercial packaged boilers with rated input larger than 5,000,000 Btu/h. DOE found 52 basic models of steam commercial packaged boilers with a rated input larger than 5,000,000 Btu/h and the difference between rated combustion and thermal efficiency ranged between 0.5 percent and 2.0 percent. Based on these values, DOE proposes subtracting 2.0 percent from the measured combustion efficiency of steam commercial packaged boilers with fuel input rating 5,000,000 Btu/h or greater in order to calculate a rated thermal efficiency. DOE believes that subtracting 2.0 percent from the measured combustion efficiency determined during the field test would result in conservative thermal efficiency ratings of models, thereby encouraging manufacturers to conduct thermal efficiency tests. 10 Available at: https://www.ahridirectory.org/ahridirectory/pages/home.aspx. Manufacturers must use the certified rating for any representation of efficiency no matter which methodology is used. That is, for equipment certified under the calculation procedure, any representations of the energy efficiency must be made based on the calculated value and any equipment certified using the tested value of thermal efficiency must be made based on the results of that testing. DOE seeks comments on the following issues, which are also listed in section V.E: • The proposed conversion method for calculating thermal efficiency based on measured combustion efficiency for steam commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h (Issue 10); • The proposed value for the difference between the combustion efficiency and thermal efficiency in the conversion method (proposed value of 2.0 percent of the combustion efficiency), whether the value would result in conservative ratings, and what number DOE should use instead if the proposed value is not adequate (Issue 11); • Whether the 5,000,000 Btu/h fuel input rate is an adequate threshold for the allowance of the field test (for combustion efficiency) and/or conversion methodology, and if not, what threshold should be used (Issue 12); and • If the field test (for hot water and steam commercial packaged boilers) and conversion methodologies (for steam commercial packaged boilers) do not adequately accommodate commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h, what procedure should DOE implement in order to do so (Issue 13). 3. Alternative Efficiency Determination Methods The provisions under 10 CFR 429.70 provide for alternative methods for determining energy efficiency and energy use of certain equipment, including commercial packaged boilers. An AEDM must first be validated for a particular validation class in accordance with the requirements of 10 CFR 429.70(c) using the applicable test procedure ( e.g., the test procedure under 10 CFR 431.86 for commercial packaged boilers). For each validation class of commercial packaged boilers, at least two (2) distinct basic models must be tested in order to validate the AEDM before using the AEDM to predict the fuel input rate or efficiency of a commercial packaged boiler. 10 CFR 429.70(c)(2)(iv). Such a test may be performed on any individual models in a validation class that meet or exceed the current applicable Federal energy conservation standard, regardless of size. As noted by Lochinvar in response to the November 2014 Preliminary Analysis, the AEDM process mitigates test burden concerns for large commercial packaged boilers. (Docket EERE-2013-BT-STD-0030, Lochinvar, No. 34 at p. 1) However, in light of DOE's proposal to allow field tests for commercial packaged boilers with fuel input rates than 5,000,000 Btu/h (described in section III.C.1), DOE proposes to limit the cases in which field tests may be used for AEDM validation pursuant to 10 CFR 429.70(c)(2). Specifically, DOE proposes that AEDMs validated using data derived from field tests may only be used to rate commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h. As discussed in section III.C.1, DOE proposes a field test option for commercial packaged boilers with fuel input rates greater than 5,000,000 Btu/h that disregards certain testing requirements, measures combustion efficiency, and applies a calculation method to convert combustion efficiency to thermal efficiency (for steam commercial packaged boilers). While this field test option reduces testing burden, it also leads to more variability and uncertainty in the test results. As such, DOE believes that the proposed allowances for field tests of commercial packaged boilers with fuel input rate greater than 5,000,000 Btu/h would not provide sufficient validation of an AEDM for use on smaller units that must undergo laboratory tests. Therefore, DOE proposes that AEDMs validated based on field test data may only be used for commercial packaged boilers with fuel input rates greater than 5,000,000 Btu/h. Laboratory tests of commercial packaged boilers of any size ( i.e., not field tested) can continue to be used to validate an AEDM that is used to rate commercial packaged boilers of any size, including those with fuel input rate greater than 5,000,000 Btu/h. 4. Steam Commercial Packaged Boiler Operating Pressure Section 8.6.1 of BTS-2000 provides that tests may be made at atmospheric pressure or at pressure not exceeding 2 psi gauge, and section 8.6.3 of BTS-2000 requires that the moisture in steam not exceed 2 percent of the water fed to the commercial packaged boiler during the test. These provisions are incorporated by reference in the existing DOE test procedure for commercial packaged boilers. DOE solicited public comments on test pressure and steam moisture content in the September 2013 Framework document; during the October 1, 2013 energy conservation standards Framework document public meeting; and in the February 2014 RFI. In particular, DOE requested comments about (1) the appropriate steam pressure for steam commercial packaged boilers operating at full load, (2) the effect of different steam pressures on steady-state efficiency (thermal or combustion), and (3) the impacts of the steam pressure testing requirements on the amount of water carryover and the system operation. ABMA expressed concern that the steam pressure requirements in BTS-2000 may be suitable for certain boilers but not for some larger-capacity models. For example, ABMA indicated that a fire-tube boiler cannot operate successfully at 2 psig steam pressure. Instead, ABMA argued that a fire-tube boiler should be operated at 10 to 12 psig steam pressure to achieve acceptable steam quality. (Docket EERE-2013-BT-STD-0030, ABMA, No. 13 at p. 31) ABMA also commented that while steam pressure not greater than 0-2 psig has been adequate for the majority of boilers, the 0-2 psig test pressure is unrealistic for larger-capacity steam boilers, as it causes high steam velocity at the steam/water interface and the steam outlet nozzle, which results in excessive water entrainment and carryover ( i.e., poor steam quality). (Docket EERE-2013-BT-STD-0030, ABMA, No. 14 at p. 2) Cleaver-Brooks commented that it cannot test its steam boilers at such low operating pressures because its boilers are designed to operate near or at 10 psig. (Docket EERE-2013-BT-STD-0030, Cleaver-Brooks, No. 12 at p. 1) Burnham encouraged DOE to raise the limit of the required steam test pressure to give manufacturers flexibility for equipment designed to operate at pressures above 2 psig. (Docket EERE-2014-BT-TP-0006, Burnham, No. 4 at p. 2) AHRI opined that an alternative steam pressure requirement may have an effect on the steady-state measurement, but that such change would be minimal. (Docket EERE-2014-BT-TP-0006, AHRI, No. 6 at p. 2) DOE notes that it has also received several requests for test procedure waivers, citing the inability to simultaneously meet the maximum steam pressure requirement (of between 0 and 2 psig) and the steam moisture requirement (of less than or equal to 2 percent moisture). Based on the public comments and the waiver requests DOE has received to date, DOE understands that larger commercial packaged boilers are designed for operating pressures greater than 2 psig and have difficulty being tested in accordance with the DOE existing test procedure for commercial packaged boilers; that is, at a pressure not exceeding 2 psig and also not exceeding 2 percent moisture in the produced steam. DOE notes that, to accommodate testing of these commercial packaged boilers, section 5.3.6 of ANSI/AHRI Standard 1500-2015 requires that tests shall be made at atmospheric pressure or at the pressure required to comply with Section 5.3.7 [of ANSI/AHRI Standard 1500-2015], not exceeding 15 psi gauge. Therefore, DOE recognizes that amending 10 CFR 431.86 to replace BTS-2000 with ANSI/AHRI Standard 1500-2015 would permit steam operating pressures up to but not exceeding 15 psig and therefore resolve the issues associated with testing large commercial packaged boilers designed to operate at higher pressures. DOE does not anticipate this change would have an effect on measured efficiency ratings because it is being made to accommodate only certain large commercial packaged boilers that manufacturers have claimed cannot be tested under the existing DOE test procedure and for which manufacturers submitted waiver requests under 10 CFR 431.401. DOE also notes that ANSI/AHRI Standard 1500-2015 allows for any steam pressure from 0-15 psig to be used for testing. However, DOE believes that it is important to maintain consistency and repeatability within the CPB test procedure and subsequent ratings. Therefore, DOE proposes that only those commercial packaged boilers that cannot operate at a steam pressure below 2 psig would be able to apply such a provision in order to also meet the steam quality requirement. However, DOE recognizes that, theoretically, variation in steam pressure would result in changes in both thermal and combustion efficiency. Therefore, to ensure commercial packaged boilers that cannot be tested at the prescribed 0-2 psig steam pressure are tested in a consistent manner, DOE proposes that such equipment be tested at the steam pressure closest to 2 psig that it can maintain while also maintaining the requirement of less than 2 percent moisture in the steam, not exceeding 15 psig. DOE notes that a manufacturer may need to incrementally increase steam test pressure above atmospheric pressure or the 2 psig requirement to meet the moisture requirement, thereby maintaining steam quality. DOE is not aware of any commercial packaged boilers that would require higher operating pressures than 15 psig to maintain the steam quality requirements. DOE seeks comments, data, and information about pressures recommended by manufacturers and relevance to actual operating conditions in buildings. This is identified as Issue 14 in section V.E. DOE also seeks comment on whether DOE should require testing to be performed at the lowest possible steam pressure where steam quality requirements can be met. This is identified as Issue 15 in section V.E. DOE also requests comment on if there are any commercial packaged boilers that require steam pressures greater than 15 psig to maintain 2 percent moisture in the produced steam. This is identified as Issue 16 in section V.E. D. Hot Water Commercial Packaged Boiler Operating Temperatures In the energy conservation standards September 2013 Framework document, the February 2014 RFI, and the November 2014 Preliminary Analysis DOE requested comments, data, and information about the appropriate inlet and outlet water temperatures for part-load and full-load testing conditions of hot water commercial packaged boilers, and information about how these equipment are currently tested. Issues pertaining to the inlet water temperature and the temperature rise required by the test procedure were also raised during the public meeting regarding the energy conservation standards September 2013 Framework document. In addition to the comments solicited in response to the September 2013 Framework document, February 2014 RFI, and the November 2014 Preliminary Analysis; DOE conducted confidential manufacturer interviews as part of the energy conservation standards rulemaking process for commercial packaged boilers (manufacturer interviews), during which manufacturers also discussed issues regarding the commercial packaged boiler test procedure. In the subsequent sections, DOE discusses the existing requirements regarding hot water temperatures, issues identified by interested parties, proposed changes to the hot water temperature requirements, and potential impacts of those proposed changes. 1. Existing Requirements The existing DOE test procedure for commercial packaged boilers incorporates by reference BTS-2000 which includes test requirements for inlet and outlet water temperatures for non-condensing and condensing commercial packaged boilers. For a non-condensing commercial packaged boiler, section 8.5.1.1 of BTS-2000 requires inlet water temperature to be between 35 °F and 80 °F (at Point A in Figure III.1), and outlet water temperature to be 180 °F ± 2 °F (at Point C in Figure III.1). For a condensing commercial packaged boiler, section 8.5.1.2 of BTS-2000 requires inlet water temperature to be 80 °F ± 5 °F (at Point A in Figure III.1 and outlet water temperature to be 180 °F ± 2 °F (at Point C in Figure III.1). These temperature requirements are consistent with those in ANSI/AHRI Standard 1500-2015. Specifically, Figure III.1 (taken from Figure C9 in ANSI/AHRI Standard 1500-2015) identifies the location of the measurement of the inlet water temperature (Point A: T IN ) and the outlet water temperature (Point C: T OUT ). EP17MR16.001 The difference between the inlet and outlet water temperatures describes the temperature rise across the commercial packaged boiler. BTS-2000 also includes an allowance in section 8.5.1.1.1 for tubular commercial packaged boilers to use a recirculating loop, which reduces the temperature rise across the commercial packaged boiler itself (Point B to Point C), while maintaining the inlet water temperature requirements specified in the DOE test procedure as measured at Point A. That is, in cases where a recirculating loop is used, BTS-2000 requires that the temperature requirements described previously must still be met at Point A in Figure III.1 prior to mixing with the warmer recirculating loop water. BTS-2000 (and ANSI/AHRI Standard 1500-2015 at section 5.3.5.3) also limits the temperature rise between Point B and Point C to not less than 20 °F for commercial packaged boilers tested using a recirculating loop. ANSI/AHRI Standard 1500-2015 expands the allowable use of a recirculating loop to all commercial packaged boilers in section 5.3.5.3, where previously it was allowed for commercial packaged boilers with tubular heat exchangers only. The measurements of inlet and outlet water temperature at Points A and C are used in Equation 1 to calculate the amount of energy transferred into the heated water, as described by item C7.2.11.3 in ANSI/AHRI Standard 1500-2015 (also in 11.1.11.3 of BTS-2000). This equation is given by EP17MR16.002 where Q S is the rate of heat transferred in Btu/h, W is the weight of heated water in pounds (lb) measured during the test, C P,H2O is the specific heat of water in Btu/lb/°F, T OUT is the outlet water temperature at Point C (°F), T IN is the inlet water temperature at Point A (°F), and t T is the test duration in hours. In general, the efficiency of a commercial packaged boiler is proportional to the amount of water heated and the amount of heat energy added to this amount of water. As shown in Equation 1, the amount of heat energy transferred is proportional to the product of the weight of the water fed (W) and the temperature rise across the commercial packaged boiler (T OUT −T IN ). The efficiency is therefore dependent on the inlet water temperature, whereby lower inlet temperatures result in greater amounts of heat energy transferred and therefore higher thermal efficiencies. As the energy from the flue gases is only transferred to the hot water in the heat exchanger, the first law of thermodynamics establishes a lower limit on the temperature the flue gas can achieve, which is the lowest water temperature within the commercial packaged boiler. Therefore as the inlet water temperature is reduced, more energy may be extracted from the combustion gases, resulting in potentially higher efficiency. These conditions hold true for both non-condensing and condensing commercial packaged boilers. 2. Issues With Water Temperature Requirements and Proposed Changes Through the October 2013 Framework document, February 2014 RFI, the November 2014 Preliminary Analysis, manufacturer interviews, and a review of the existing DOE test procedure, DOE identified the following concerns regarding its existing water temperature requirements for commercial packaged boilers: • The current temperature rise is unrepresentative of actual operating conditions. • The current temperature rise may induce excessive stresses on some commercial packaged boilers. • The presence of recirculating loops during testing leads to significant variability in the actual temperature rise across the commercial packaged boiler (Point B to Point C in Figure III.1). These issues are discussed in detail in this section. During the manufacturer interviews, a number of manufacturers indicated that the 100 °F temperature rise in BTS-2000 (for both condensing or non-condensing commercial packaged boilers) was unrepresentative of real-world conditions, and instead indicated that commercial packaged boilers are typically designed for a 20 °F to 40 °F temperature rise. These manufacturers suggested that testing with a 20 °F to 40 °F temperature rise would better reflect conditions found in typical building applications. DOE understands this to mean the actual temperature rise across the commercial packaged boiler itself ( i.e., between Point B and Point C in Figure III.1). During the public meeting regarding the September 2013 energy conservation standards Framework document, ACEEE asserted that a 100 °F temperature rise is an inadequate way to characterize modern boilers, does not provide sufficient information about performance of a boiler with a 20 °F temperature rise between inlet and outlet water temperature at part-load conditions, and is essentially irrelevant for comparing efficiencies among a range of boiler sizes. (Docket EERE-2013-BT-STD-0030, ACEEE, No. 13 at pp. 20, 36) In later comments, ACEEE recommended a 20 °F temperature rise, arguing that it is within the range of the most common temperature rise and provides the most conservative value for full-load, steady-state efficiency. ACEEE also commented that a manufacturer should be able to publish “application ratings” (informational ratings obtained at different operating conditions) for different temperature rise values. In addition, whether for a fixed capacity or modulating boiler, ACEEE observed that the lower inlet water temperatures result in higher efficiencies, and ACEEE stated its understanding that almost all the efficiency gain is due to the release of latent energy at inlet water temperatures less than 140 °F. ACEEE then suggested that a commercial packaged boiler should be rated at the lowest inlet water temperature that remains under the manufacturer's warranty for continuous service, whether for a fixed capacity or modulating boiler. (Docket EERE-2014-BT-TP-0006, ACEEE, No. 2 at p. 2.) A joint comment from ACEEE, ASAP, and NRDC suggested that the existing DOE test procedure for commercial packaged boilers is obsolete because it obscures the annual energy savings potential of condensing boilers in commercial building applications. BTS-2000 measures efficiency at peak load, using a minimum 100 °F temperature rise between inlet and outlet (note: BTS-2000 defines inlet temperature at a location preceding the reentry of any recirculating loop water), and requires 180 °F outlet temperature. (This continues to be the case in ANSI/AHRI Standard 1500-2015.) However, the commenters argued that the existing test procedure does not consider condensing boilers that can operate at part load with greater efficiency if the system design allows for inlet water at condensing temperatures (<140 °F). (Docket EERE-2013-BT-STD-0030, Joint Advocates, No. 16 at p. 2) In response to the November 2014 Preliminary Analysis, Raypak suggested that the wide range in allowable inlet water temperatures in BTS-2000 is to accommodate the wide range of ground water temperatures throughout the year. (Docket EERE-2013-BT-STD-0030, Raypak, No. 35 at p. 3) ABMA expressed concerns on behalf of its members that (1) water temperatures required by BTS-2000 are obsolete or do not represent installed boilers; (2) the temperature rise resulting from the required inlet and outlet water temperatures set forth in BTS-2000 can place excessive stress on the boiler pressure vessel, thereby leading to shorter boiler life; and (3) the considerable cost of testing larger boilers could approach $1 million. ABMA added that test pressures and temperatures should be more realistic in terms of normal system operating conditions and that an appropriate inlet temperature would be 140 °F or the manufacturer's recommended minimum. (Docket EERE-2013-BT-STD-0030, ABMA, No. 14 at p. 1-3) DOE notes that these concerns continue to apply to ANSI/AHRI Standard 1500-2015 since these temperatures are the same as those found in BTS-2000. Cleaver-Brooks stated that BTS-2000 specifies an outlet temperature of 180 °F and an inlet water temperature of 38 °F [sic] to 80 °F for non-condensing boilers. (Note: BTS-2000 prescribes an inlet water temperature of 35 °F.) Instead, for much of its equipment, Cleaver-Brooks stated that it specifies a minimum inlet water temperature of 140 °F to reduce damage from thermally induced stresses. Cleaver-Brooks asserted that neither the required steam nor the hot water test conditions set forth in the existing DOE test procedure for commercial packaged boilers reflect actual conditions in buildings, and that test conditions overestimate boiler efficiency compared to what an end-user would be expected to experience in actual applications. The commenter suggested modifying the test procedure to require an outlet water temperature of 180 °F and an inlet water temperature of 140 °F or, at a minimum, to allow such test conditions as an alternative. (Docket EERE-2013-BT-STD-0030, Cleaver-Brooks, No. 12 at p. 1) Again, DOE notes that these concerns also apply to ANSI/AHRI Standard 1500-2015, as the standard maintains the same inlet and outlet water temperature requirements as BTS-2000. DOE also believes that the inlet water temperatures described by Cleaver-Brooks and ABMA are intended to mean the inlet water temperature in the absence of a recirculating loop. As noted earlier, the existing DOE test procedure (section 8.5.1.1.1 of BTS-2000) allows for the use of a recirculating loop for tubular commercial packaged boilers, thereby increasing the inlet water temperature seen by the commercial packaged boiler (shown as Point B in Figure III.1) and reducing the actual temperature rise across the commercial packaged boiler. Similarly, Lochinvar stated in response to the November 2014 Preliminary Analysis that the allowance in BTS-2000 for a recirculation loop in some instances would result in higher water temperature going into the commercial packaged boiler. Lochinvar noted that efficiency curves that present the efficiency of a commercial packaged boiler as a function of return (inlet) water temperature (and are sometimes provided in marketing literature) are not based on the methodology of BTS-2000. Lochinvar further recommended that DOE not attempt to correct the efficiency of commercial packaged boilers for inlet water temperature. (Docket EERE-2013-BT-STD-0030, No. 34 at p. 3) In order to address the issues presented in section III.D.2, DOE proposes amendments to the inlet and outlet water temperatures for both condensing and non-condensing commercial packaged boilers. Upon consideration of the above comments about inlet and outlet water temperatures; review of commercial packaged boiler manufacturer literature; and consideration of results of testing of commercial packaged boilers at temperatures that, according to commercial packaged boiler manufacturers, would reflect normal system operating conditions; DOE agrees with interested parties that a 100 °F to 145 °F nominal temperature rise does not necessarily reflect conditions typically associated with installed non-condensing or condensing commercial packaged boilers. Further, DOE acknowledges that the presence of recirculating loops in testing obscures the actual inlet water temperature entering the commercial packaged boiler at Point B in Figure III.1 (and therefore the actual temperature rise experienced by the commercial packaged boiler) because the inlet water temperature is measured and maintained at Point A only, under the existing procedure. Specifically, DOE observed that, based on the permissible inlet and outlet temperatures, the tolerances on those temperatures, and the use of recirculating loops, the temperature rises between Point B and Point C in Figure III.1 allowable by both BTS-2000 and ANSI/AHRI Standard 1500-2015 can range from 20 °F to 147 °F for non-condensing commercial packaged boilers (section 8.5.1.1 of BTS 2000 and section 5.3.5.1 of ANSI/AHRI Standard 1500-2015) and 20 °F to 107 °F for condensing commercial packaged boilers (section 8.5.1.2 of BTS 2000 and section 5.3.5.2 of ANSI/AHRI Standard 1500-2015). (Note: the minimum temperature rise of 20 °F across the commercial packaged boiler assumes that recirculating loops are currently being used for these tests.) DOE notes that such variability has the potential to yield variability in tested combustion efficiency and thermal efficiency ratings. Accordingly, to improve the consistency and repeatability of the DOE test procedure, DOE proposes to revise the hot water temperature requirements to require the inlet water temperature to be 140 °F ±1 °F for non-condensing equipment, as determined at Point B (see Figure III.1). For non-condensing equipment, DOE is maintaining the outlet temperature of 180 °F but is specifying a new tolerance for this measurement, which is discussed further in section III.D.3). Similarly, DOE proposes to require an outlet water temperature of 120 °F ±1 °F for condensing equipment, as determined at Point C (see Figure III.1). For condensing equipment, DOE is proposing an inlet water temperature specification of 80 °F as measured at Point B in Figure III.1 and updating the measurement tolerance to ±1 °F, as discussed section III.D.3. DOE believes these test temperatures will more accurately represent the energy efficiency of commercial packaged boilers and are more consistent with the conditions typically observed in field installations. DOE also notes that the proposed temperature requirements result in equivalent temperature rises across the commercial packaged boiler for condensing and non-condensing equipment in order to maintain comparability. The proposed temperature requirements also incorporate inlet water temperatures that more accurately represent the efficiencies of non-condensing and condensing commercial packaged boilers. DOE does not believe that maintaining the same outlet water temperature for non-condensing and condensing commercial packaged boilers is important for maintaining comparability of ratings. DOE is proposing to modify the location at which the inlet water temperature is maintained from Point A to Point B, which is immediately preceding the commercial packaged boiler, downstream of the recirculation loop (see Figure III.1). DOE believes that the comments of interested parties refer to the temperature rise experienced across the commercial packaged boiler itself (Point B to Point C) and that, therefore, DOE's proposal is consistent with the input of interested parties. In addition, DOE notes that specifying the inlet water temperature at Point B, immediately prior to entering the commercial packaged boiler would remove ambiguity and improve the consistency and repeatability of the DOE test procedure. This temperature is more directly related to the measured thermal or combustion efficiency than the temperature rise determined with the inlet water upstream of the recirculation loop (between Point C and Point A of Figure III.1). DOE recognizes that these inlet temperatures would typically be produced through the use of a recirculating loop to temper incoming feedwater to the appropriate inlet temperature. In proposing to adopt ANSI/AHRI Standard 1500-2015, DOE is proposing to allow recirculation loops to be used on all commercial packaged boilers and, as such, DOE clarifies that recirculation loops could be used to meet the new proposed inlet water requirements. However, DOE proposes that the efficiency calculations in section C7.2.11.3 in ANSI/AHRI Standard 1500-2015 would continue to use the water temperature and flow rate measured upstream of the recirculating loop, if present (Point A in Figure III.1). DOE acknowledges that this would require measurements of water temperature at both Point A and Point B for equipment tested with recirculating loops. However, DOE notes that by continuing to use the temperature at Point A in the calculation of thermal efficiency, the precision of the resulting thermal efficiency will not be impacted as compared to the current methodology. While DOE believes that the proposed inlet and outlet temperature requirements are applicable and representative for the majority of commercial packaged boilers available on the market, DOE is aware that some commercial packaged boilers are unable to operate at a temperature rise across the commercial packaged boiler of 40 °F. Specifically, DOE is aware that some commercial packaged boilers are only capable of operating with lower temperature differentials, such as 20 °F. As such, DOE is proposing to adopt provisions for commercial packaged boilers that cannot operate with a temperature rise of 40 °F across the boiler (Point B to Point C), as indicated in the manufacturer literature. For non-condensing commercial packaged boilers, DOE is proposing that, if the commercial packaged boiler cannot operate with an inlet temperature of 140 °F ± 1 °F at Point B in Figure III.1 when the outlet temperature is 180 °F ± 1 °F, DOE is proposing that the inlet temperature be maintained as close to 140 °F ± 1 °F as possible, consistent with manufacturer's instructions provided in the literature for that basic model and that the average inlet water temperature measured at Point B in Figure III.1 be reported as part of the certification report for the basic model. Similarly, for condensing commercial packaged boilers that cannot operate with a temperature rise of 40 °F across the commercial packaged boiler, DOE is proposing that the inlet temperature at Point B in Figure III.1 be maintained as close to 80 °F ± 1 °F as possible, consistent with manufacturer's instructions provided in the literature for that basic model, while the outlet temperature is maintained at 120 °F ± 1 °F, consistent with the DOE test procedure. Again, the average inlet water temperature measured at Point B in Figure III.1 would be reported as part of the certification report for the basic model DOE seeks comments, data, and information about whether the proposed testing conditions related to water temperatures are appropriate both for a non-condensing commercial packaged boiler and a condensing commercial packaged boiler. This is identified as Issue 17 in Section V.E. DOE also requests comment on the proposed test provisions to accommodate commercial packaged boilers that cannot be tested with a temperature rise of 40 °F across the commercial packaged boiler (Point B to Point C). This is identified as Issue 18 in Section V.E. Under EPCA, DOE is required to determine what impacts, if any, its amendments to a test procedure will have on ratings. (42 U.S.C. 6293(e); 42 U.S.C. 6314(a)(4)(C)) DOE proposes using the temperature rise across the commercial packaged boiler itself as described in order to improve the repeatability of the tests. Whereas the existing test procedure (using BTS-2000, incorporated by reference) allows for a wide range of temperature rises across the commercial packaged boiler due to the allowance of recirculating loops and a measurement location upstream of the recirculation loop, which obscures the actual temperature rise across the commercial packaged boiler, DOE's proposed amendments would remove ambiguity by standardizing this temperature rise across all commercial packaged boilers where possible. DOE notes that the effect on any individual commercial packaged boiler could be to slightly increase or slightly decrease measured efficiency, depending on how the test was previously performed. Further, based on discussions with manufacturers, DOE believes that testing is already performed using a recirculating loop for equipment that does not utilize a tubular heat exchanger in order to prevent damaging the equipment and provide the boiler with inlet water temperatures more representative of typical field conditions. Therefore, in combination with the other proposed amendments to the test procedure, DOE has tentatively determined that the proposed amendments, in aggregate, would not result in an overall measurable impact on ratings. 3. Allowable Uncertainty in Water Temperature Measurement HTP initially expressed concern about several operating conditions being either unspecified or unrealistic, and suggested updated test parameters for commercial packaged boilers that would be more reasonable. (Docket EERE-2013-BT-STD-0030, HTP, No. 18 at p.4) However, in later comments and after further analysis, HTP concluded that the test conditions should not be amended because manufacturers cannot be confident that the DOE test method would maintain an acceptable level of uncertainty if different test points or temperature rises were to be used. Instead, HTP commented that an acceptable test method uncertainty analysis should be completed to verify the Appliance Standards and Rulemaking Federal Advisory Committee (ASRAC) agreed-upon 5-percent allowable tolerance on ratings in order to account for variations in manufacturing and testing. (Docket EERE-2014-BT-TP-0006, HTP, No. 5 at p. 4) In response to HTP's concerns regarding the uncertainty of the test, DOE proposes to reduce the tolerances for inlet and outlet water temperatures during the test period to ±1 °F for both non-condensing and condensing commercial packaged boilers so that testing uncertainties are not increased. DOE notes that the required minimum accuracy of the inlet and outlet water temperature measurement instrumentation is ±0.2 °F (Table C1 of ANSI/AHRI Standard 1500-2015 and Table 1 of BTS-2000). Therefore, the instrumentation required by the test procedure is sufficiently precise to accommodate this tolerance. Investigative testing performed by DOE showed that reducing the temperature rise did not substantially increase the variability in thermal efficiency between repeated tests compared to the expected variability of the currently allowable temperature rises. Furthermore, a review of the data obtained during investigative testing showed little variation over time in the temperatures themselves, typically less than ±1 °F over the course of the test. DOE seeks additional comments, data, and analysis concerning thermal efficiency test measurement uncertainty. This is identified as Issue 19 in section V.E. 4. Water Flow Rate During Testing Burnham and AHRI observed that a change in the specified water temperatures would potentially change the water flow rate and the calculated efficiency resulting from the test procedure. Higher flow rates and a resulting higher total volume of water are necessary to achieve smaller temperature rises. According to the commenters, decreasing the temperature rise would require a higher water flow rate and may exceed the water handling, cooling, processing, and disposal capabilities of many laboratories currently testing using the existing DOE test procedure ( i.e., BTS-2000). Further, the commenters argued that reducing the temperature rise by lowering the outlet temperature may result in increased measured thermal efficiency. In view of these concerns, both AHRI and Burnham recommended that the current operating temperatures should be retained. (Docket EERE-2014-BT-TP-0006, Burnham, No. 4 at p. 2; Docket EERE-2014-BT-TP-0006, AHRI, No. 6 at p. 2) DOE is aware that the water temperature rise across the commercial packaged boiler is inversely related to the flow rate of the working fluid (water or steam) at a given burner fuel input rate, and that increasing water flow rates to achieve lower temperature rises may reduce the commercial packaged boiler size that laboratories are capable of testing. However, as stated previously, DOE also acknowledges that, under the proposed test procedure, recirculating loops, which reduce the temperature rise across the commercial packaged boiler with modest flow rates of incoming feedwater and outgoing water for disposal, would be allowed for all commercial packaged boilers, not just commercial packaged boilers with tubular heat exchangers as is currently allowed in section 8.5.1.1.1 of BTS-2000. This is supported by Lochinvar's assertion that recirculating loops are used in testing and increase the inlet water temperature to the commercial packaged boiler. (Docket EERE-2013-BT-STD-0030, No. 34 at p. 3) In addition, DOE notes that the 100 °F temperature rise required by both BTS-2000 and ANSI/AHRI Standard 1500-2015 is not directly comparable to DOE's proposed temperature rise of 40 °F due to the difference in where the inlet temperature requirement is measured. DOE believes that requiring the temperature to be measured and maintained at the location downstream of the recirculation loop and just prior to the commercial packaged boiler inlet would allow manufacturers and laboratories to continue using incoming water at much lower temperatures (at or near the current 35 °F to 80 °F of BTS-2000 and ANSI/AHRI Standard 1500-2015). That is, under these proposed inlet and outlet temperature conditions (when utilizing a recirculation loop), the same temperatures and test conditions could be established under the existing and new test procedures (due to the different measurement locations). DOE therefore believes that the concerns regarding an increase in water flow rate (and therefore reduction in laboratory capacity) may be overstated in view of the proposed change in location of where the inlet water temperature would be measured under the proposed test procedure. DOE seeks comment regarding the prevalence of using recirculating loops in testing; specifically, DOE requests comment about the kinds of commercial packaged boilers utilizing recirculation loops during testing and the conditions at which these commercial packaged boilers and recirculating loops operate. This is identified as Issue 20 in section V.E. DOE estimates the impact on manufacturers of requiring higher water flow rates in section IV.B. DOE seeks further comments, data, and information concerning the capabilities of test laboratories, particularly in light of the specific proposed conditions contained in this NOPR. This is identified as Issue 21 in section V.E. E. Testing Conditions For non-condensing commercial packaged boilers, the existing DOE test procedure does not prescribe test room requirements for ambient temperature or humidity. For combustion efficiency tests of condensing commercial packaged boilers, the existing DOE test procedure requires that the “humidity of the room shall at no time exceed 80 percent.” 10 CFR 431.86(c)(2)(ii). Additionally, BTS-2000 requires that test air temperature, as measured at the burner inlet, be within ±5 °F of the ambient temperature, where ambient temperature is measured within 6 feet of the front of the unit at mid-height. ANSI/AHRI Standard 1500-2015 prescribes an allowable ambient temperature during the test between 30 °F and 100 °F (section 5.3.8) with the relative humidity not exceeding 80 percent in the test room or chamber (section 5.3.9). Section C3.6 of ANSI/AHRI Standard 1500-2015 also requires that test air temperature, as measured at the burner inlet, be within ±5 °F of the ambient temperature (which is measured within 6 feet of the commercial packaged boiler at mid-height; see section C3.7 of ANSI/AHRI Standard 1500-2015). DOE understands that ambient temperature and humidity, including test air temperature, can have a measurable effect on the tested efficiency of commercial packaged boilers, particularly condensing commercial packaged boilers. 11 High humidity or any increase in humidity over a baseline would enable a commercial packaged boiler to capture more latent heat from combustion gases, thereby resulting in a higher measured efficiency. DOE recognizes that this effect would be noticeable both in tests for combustion efficiency and thermal efficiency. Therefore, DOE proposes to amend 10 CFR 431.86 so as to minimize this effect. 11 Test air temperature is defined in ANSI/AHRI Standard 1500-2015 as the temperature of the air being supplied to the burner from the room. As noted previously, the existing DOE test procedure requires a maximum of 80-percent ambient relative humidity in the test room or chamber when testing a condensing commercial packaged boiler for combustion efficiency only. DOE proposes to require that ambient relative humidity at all times be 60 percent ± 5 percent during thermal and combustion efficiency testing of commercial packaged boilers. 12 While DOE acknowledges that the effect of ambient humidity on the efficiency of non-condensing commercial packaged boilers is less than that for condensing commercial packaged boilers, DOE nevertheless proposes the same ambient humidity requirements for all commercial packaged boilers in order to maintain consistency and comparability between ratings. Also, DOE proposes that the ambient relative humidity be measured and recorded at each 30-second interval during the entire test. DOE seeks comments, data, and information about room ambient relative humidity, whether the proposed constraints are appropriate, and if not, what are appropriate constraints on room ambient relative humidity when testing commercial packaged boilers. This is identified as Issue 22 in section V.E. 12 Humidity is the amount of water vapor in the air. Absolute humidity is the water content of air. Relative humidity, expressed as a percent, measures the current absolute humidity relative to the maximum for that temperature. Specific humidity is a ratio of the water vapor content of the mixture to the total air content on a mass basis. In addition to proposed limits to ambient relative humidity when testing commercial packaged boilers, DOE proposes an ambient room temperature of 75 °F ± 5 °F during testing of commercial packaged boilers. The ambient temperature would be measured and recorded at each 30-second interval during the entire test. Additionally, DOE proposes that the ambient room temperature cannot differ by more than ± 2 °F from the average ambient room temperature during the “Test Period” (as described in section C4 of Appendix C of ANSI/AHRI Standard 1500-2015; proposed for incorporation by reference) at any reading. DOE believes that limiting ambient room temperature and relative humidity during testing will improve repeatability and provide for test conditions that more closely reflect the ambient conditions that commercial packaged boilers experience in normal operation. For non-condensing hot water and steam commercial packaged boilers, DOE anticipates negligible changes in the rated efficiency for a particular commercial packaged boiler due to the proposed changes to room ambient temperature and relative humidity requirements. Nevertheless, DOE proposes limits to ambient conditions for non-condensing commercial packaged boilers to prevent testing from occurring at extreme ambient temperature or relative humidity, which would be outside the expected range of conditions that commercial packaged boilers experience in normal operation. In comparison, ambient room temperature and relative humidity would have some effect on the test results for condensing commercial packaged boilers. However, Because DOE expects that current efficiency ratings generally have been determined at typical ambient room temperatures and relative humidity levels, DOE also expects that reported rating values will not change as a result of the proposed limits on ambient room temperature and relative humidity, which fall within the typical ambient room temperatures and relative humidity levels. DOE seeks comments, data, and information about the aforementioned proposed room ambient temperatures, whether the proposed constraints are appropriate, and if not, what are appropriate constraints on room ambient temperature. This is identified as Issue 23 in section V.E. F. Setup and Instrumentation In DOE's review of the existing test procedure, DOE identified several setup instructions and instrumentation requirements for which clarifications are expected to improve the accuracy and repeatability of test results. These include: (1) Additional specifications regarding the steam riser/header geometry, (2) additional requirements regarding the use of steam condensate return piping, and (3) additional insulation requirements for the steam and water piping. First, in section C2.3, “Steam Piping,” of ANSI/AHRI Standard 1500-2015 (section 7.3 of BTS-2000), the description of the steam riser/header geometry may lead to different interpretations which can impact the amount of entrained water reaching the steam separator and result in variability in the measured thermal efficiency of commercial packaged boilers. Specifically, variations in the nominal pipe diameter or size of the pipe of the steam riser and the height of the steam riser above the water line may impact the amount of entrained water in the steam and may result in exceeding the DOE test procedure's 2 percent limit for moisture content in the steam. In order to reduce the amount of entrained water in the steam to satisfy this steam moisture requirement, the water level within the commercial packaged boiler is typically lowered during testing (within the allowable tolerance for the water level pursuant to manufacturer literature or ANSI/AHRI Standard 1500-2015 section C4.1.1.1.3, as applicable). However, lowering the water level inside the heat exchanger decreases the thermal efficiency of the commercial packaged boiler because as the water level is lowered, less heat exchanger surface area is in contact with water. Therefore, variations in the steam riser and header geometry can affect the amount of moisture in the steam and require changes in the water level to meet the 2 percent moisture content requirement, which can then result in decreased thermal efficiency measurements for the same commercial packaged boiler model. To decrease the variability and increase the repeatability and precision of the DOE test procedure, DOE therefore proposes to clarify the description of the steam riser and header geometry in its test procedure. Specifically, DOE proposes to adopt section C2.3 of ANSI/AHRI Standard 1500-2015 with additional provisions regarding the description of the steam riser and header geometries. The proposed additional specifications and the reason for inclusion are as follows: • No reduction in diameter shall be made in any horizontal header piping, as a reduction in pipe diameter in the horizontal header prevents entrained water from draining properly and typically leads to non-steady-state operation. In the case of commercial packaged boilers with multiple steam risers, the cross-sectional area of the header must be no less than 80 percent of the summed total cross-sectional area of the risers, and the header pipe must be constant in diameter along its entire length. • The diameter of the vertical portion of the steam condensate return pipe that is above the manufacturer's recommended water level may be reduced to no less than one half of the header pipe diameter to ensure adequate operation of the return loop and draining of entrained water back into the commercial packaged boiler. DOE notes that section C2.3 of ANSI/AHRI Standard 1500-2015 specifies that the steam riser shall be connected in accordance with the manufacturer's instructions. However, in the event the manufacturer's literature does not specify necessary height and dimension characteristics for steam risers, headers, and return piping, DOE proposes the following requirements to ensure consistent and repeatable testing: • The header pipe diameter must be the same size as the commercial packaged boiler's steam riser (steam take-off) pipe diameter. In the case of commercial packaged boilers with multiple steam risers, the cross-sectional area of the header must be no less than 80 percent of the summed total cross-sectional area of the risers, and the header pipe must be constant in diameter along its entire length. • The height measured from the top of the header to the manufacturer's recommended water level must be no less than the larger of 24 inches or 6 times the header pipe diameter. • The distance between the vertical steam riser (steam take-off) leading to the water separator and the elbow leading to the condensate return loop must be a minimum of three (3) header pipe diameters to prevent entrained water from entering the separator piping. • If a water separator is used, piping must pitch downward to the separator at a rate of at least 1/4 inch per foot of pipe length in order to assure proper collection of moisture content and steady-state operation during testing. • A vented water seal is required in steam moisture collection plumbing to prevent steam from escaping through the moisture collection plumbing. DOE notes that header diameters that are larger than the diameter of the steam outlet can result in atypically low steam flow rate in the header, affecting carryover of entrained water, while smaller diameter headers may reduce the measured steam quality, possibly requiring tests to be conducted at lower water levels, which may result in lower efficiencies. Undersized headers with pipe diameters that are smaller than the diameter of the steam outlet on the commercial packaged boiler can also impede or prevent adequate draining of entrained water. Second, Figure C5, “Suggested Piping Arrangement for Steam Boilers, Condensate Measurement,” and Figure C7, “Suggested Piping Arrangement for Steam Boilers, Feedwater Measurement,” in ANSI/AHRI Standard 1500-2015 both allow a steam commercial packaged boiler to be tested without a steam condensate return pipe. DOE proposes that all steam commercial packaged boiler test setups be required to include a steam condensate return pipe to minimize variation in tests. DOE also proposes to prohibit use of the “suggested” piping arrangements in Figures C5 and C7 for steam commercial packaged boiler testing setups. DOE believes these changes would ensure that commercial packaged boilers that typically require a steam condensate return pipe for adequate operation have one installed during testing. DOE believes that requiring a steam condensate return pipe, with the criteria specified in this section, would ensure consistent and repeatable test results. DOE further believes that such requirement would not have a significant impact upon thermal efficiency or steam moisture content for a steam commercial packaged boiler that may operate without a steam condensate return pipe. Third, Sections C2.3 and C2.4 in ANSI/AHRI Standard 1500-2015 provide only minimal guidance about insulation requirements for steam and water piping components that are used in the thermal efficiency test. To provide for repeatability and minimize heat losses in the piping, DOE proposes to adopt the minimum pipe insulation thickness and conductivity requirements in ASHRAE/IES Standard 90.1-2013, Table 6.8.3-1. DOE also believes these requirements would be more representative of insulation requirements for outlet piping used in most commercial applications. In view of all the above, DOE seeks comment about its proposed changes to the steam riser, header, and return water loop testing requirements. This is identified as Issue 24 in section V.E. DOE recognizes that for oil-fired commercial packaged boilers, burners are not always included when shipped from the manufacturer. In such cases, DOE proposes that the unit be tested with the particular make and model of burner certified by the manufacturer. Since each basic model distributed in commerce must be certified, DOE expects that using a manufacturer's certification will provide the most complete list of all burners for use with a particular boiler. Furthermore, DOE expects all burners specified in the installation and operation manual would be certified to the Department as part of the commercial packaged boiler basic model. If multiple burners are specified in the installation and operation manualor in one or more certification reports, then DOE proposes that any of the listed burners may be used for testing and all must be certified to the Department. DOE believes these provisions provide manufacturers with ample opportunity to specify burners that should be used with their commercial packaged boilers for testing, and will reduce ambiguity concerning what burner a commercial packaged boiler can be tested with. DOE believes these changes represent a clarification in how burners are specified and therefore does not anticipate any changes in ratings for commercial packaged boilers. DOE seeks comment regarding the specification of burners for oil-fired commercial packaged boilers and this is identified as Issue 25 in section V.E. With respect to outdoor commercial packaged boilers, units with multiple outdoor venting arrangements provided by the manufacturer are required by ANSI/AHRI Standard 1500-2015 section C2.2.5 to be tested using the arrangement having the least draft loss. However, draft loss is not defined nor are provisions provided in ANSI/AHRI Standard 1500-2015 for determining which arrangement has the least draft loss. DOE proposes language in its test procedure to clarify how this is determined, specifically by adding the straight lengths of venting for each arrangement supplied with the equipment and using the one with the shortest total length. DOE believes this is a clarification only and does not believe ratings for commercial packaged boilers would be affected by this clarification. In addition to these proposed clarifications regarding the setup and configuration of commercial packaged boilers for testing, DOE proposes clarifications and provisions regarding the test instrumentation and calibration. Specifically, regarding section 7.6, “Application of Additional Instruments (Steam),” of BTS-2000 (now section C2.6 of ANSI/AHRI Standard 1500-2015), ABMA commented that references to mercury and use of a mercury manometer should be removed, suggesting that mercury is no longer an industry-acceptable pressure measuring fluid for testing steam boilers. 13 (Docket EERE-2013-BT-STD-0030, ABMA, No. 14 at p. 3-4) DOE has concluded that the mercury-based instrumentation is outdated and recognizes that the ANSI/AHRI Standard 1500-2015 does not require or reference the use of mercury manometers. As such, DOE notes that by incorporating by reference ANSI/AHRI Standard 1500-2015 as proposed in this NOPR, the DOE test procedure would no longer specify or reference use of mercury manometers (or other mercury-based instrumentation). 13 A “manometer” is an instrument that uses a column of liquid, such as mercury or water, contained in a glass or plastic tube and is used to measure the pressure of gases. Additionally, ABMA suggested that some other required instrumentation prescribed in BTS-2000 is outdated and that some calculation methods contained therein are laborious. In particular, ABMA inquired whether an oxygen (O 2 ) combustion analyzer may be used to determine combustion efficiency rather than the existing calculation procedures if it can be shown that its results are equivalent. (Docket EERE-2013-BT-STD-0030, ABMA, No. 14 at pp. 3-4) ANSI/AHRI Standard 1500-2015 includes a methodology for using an O 2 combustion analyzer for measurements of combustion efficiency, and DOE's proposal to incorporate by reference this industry standard would adopt this methodology. DOE recognizes ABMA's concern on this topic and seeks additional comments, and particularly data, about whether the oxygen combustion analyzer produces equivalent combustion efficiencies to the carbon monoxide (CO) and carbon dioxide (CO 2 ) calculations provided by ANSI/AHRI Standard 1500-2015 and BTS-2000. This is identified as Issue 26 in section V.E. DOE acknowledges that section C.1.1, “Calibration,” of ANSI/AHRI Standard 1500-2015 requires instruments to be calibrated to a recognized standard at regular intervals. DOE believes that such a requirement is sufficient for ensuring appropriate calibration procedures for applicable test equipment. However, in order to ensure accurate and repeatable test measurements, DOE is proposing a provision that would require all instrumentation to be calibrated at least once per year. For combustion measurement equipment (instruments listed in the “Gas Chemistry” row of Table C1 in ANSI/AHRI Standard 1500-2015), DOE proposes to require calibration using standard gases with purities of greater than 99.9995 percent for all constituents analyzed. DOE acknowledges that manufacturers and laboratories may have existing calibration and documentation protocols in place that already meet these requirements. Finally, DOE proposes to require that data obtained digitally be sampled and recorded at 30-second intervals or less, and data related to rates, flows, or flux be integrated over the 15-minute intervals required throughout ANSI/AHRI Standard 1500-2015. Data not related to rates, flows, or fluxes shall be averaged over the 15-minute interval. DOE proposes this requirement as a means of confirming that ambient condition requirements and water temperatures are maintained for the duration of the test. This requirement would apply to digital flow meters for measuring water flow. However, DOE proposes that this requirement would not apply to the use of a scale for measuring the weight of feedwater collected, which would continue to be recorded in 15-minute intervals as provided in ANSI/AHRI Standard 1500-2015. DOE seeks comment on its proposal to require digital data acquisition, and this is identified as Issue 27 in section V.E. DOE seeks general comment as to the proposed clarifications to test procedure setup and instrumentation. This is identified as Issue 28 in section V.E. G. Fuel Input Rate In DOE's existing regulations, equipment classes and the standards that apply to them are determined partly on the basis of the size of the commercial packaged boiler. However, several terms are used interchangeably in BTS 2000, ANSI/AHRI Standard 1500-2015, and in the existing DOE test procedure and energy conservation standards to describe the size of the commercial packaged boiler, each of which is derived from the maximum rated fuel input rate to the commercial packaged boiler. For example, the existing DOE test procedure for commercial packaged boilers at 10 CFR 431.86 uses the term “rated input capacity” and “fuel input” while the energy conservation standards for commercial packaged boilers at 10 CFR 431.87 use “capacity,” “rated maximum input,” “maximum rated capacity,” and “size category (input),” all of which are intended to mean the same thing. BTS-2000, which is incorporated by reference in the existing DOE test procedure for commercial packaged boiler, uses the terms “input,” “input rating,” and “manufacturer's nameplate input.” ANSI/AHRI Standard 1500-2015 defines “input rating” as the maximum Btu/h or gph [gallons per hour] input located on the Boiler rating plate. Furthermore, neither the existing DOE regulatory text nor BTS-2000 specify how to determine this “rated” or “nameplate” maximum fuel input rate for a commercial packaged boiler. However, BTS-2000 and ANSI/AHRI Standard 1500-2015 require that the input be within ±2 percent of the “manufacturer's nameplate input” (BTS-2000) or “Input Rating” (ANSI/AHRI Standard 1500-2015). To clarify how to determine the appropriate equipment class for commercial packaged boilers, DOE proposes to adopt a definition for the term “fuel input rate.” DOE believes this is necessary to reduce ambiguity and standardize terminology throughout its commercial packaged boiler regulations. The proposed definition for “fuel input rate” states that it is determined using test procedures prescribed under 10 CFR 431.86 and represents the maximum rate, or “high fire rate,” at which the commercial packaged boiler uses energy. DOE proposes to use this term in the division of equipment classes and applicable testing provisions to determine the fuel input rate. Manufacturers would be required to measure the fuel input rate during certification testing and use the mean of the measured values, after applying the applicable rounding provisions, 14 in certification reports pursuant to 10 CFR 429.60(b)(2). DOE also notes that, for commercial packaged boilers certified using an AEDM, that AEDM would be used to determine the fuel input rate and the same rounding provisions would apply. DOE believes it is critical to clarify how the fuel input rate is to be determined because the applicable standards for a commercial packaged boiler are based in part on the fuel input rate of the commercial packaged boiler. These proposed additions would clarify for manufacturers what energy conservation standard applies to a given basic model. 14 The proposed calculations for the fuel input rate include a rounding requirement to the nearest 1,000 Btu/h; this is discussed in this section III.G. DOE also proposes clarifications in its regulatory text that specify precisely how the fuel input rate is to be determined when using the DOE test procedure. DOE notes sections C4.1.1.2.3 and C4.1.2.2.3 of ANSI/AHRI Standard 1500-2015 require the total measured fuel input during the test to be within 2 percent of the “boiler Input Rating” and sections C4.1.1.1.4 and C4.1.2.1.5 require the measured fuel input rate, measured at 15-minute intervals to confirm steady-state, to be within 2 percent of the fuel input rate listed on the commercial packaged boiler nameplate. However, ANSI/AHRI Standard 1500-2015 does not specify the quantities and calculation procedure to be used in determining this value. DOE's clarifications specify the amount of oil or gas, as applicable, needed to ensure the fuel input rate is at steady-state (which is evaluated at 15-minute intervals). Moreover, DOE also proposes that steady-state is confirmed when the measured fuel input rate does not vary by more than ± 2 percent between 15 minute interval readings rather than in comparison to the commercial packaged boiler nameplate. Section 5.2.2 of ANSI/AHRI Standard 1500-2015 specifies rounding gross output (as defined in section 3.20 of ANSI/AHRI Standard 1500-2015) to the nearest 1,000 Btu/h. DOE does not propose to adopt this section of ANSI/AHRI Standard 1500-2015 because DOE regulations are not based on gross output. Instead, DOE proposes adding a requirement to the DOE test procedure that values of fuel input rate for each unit tested be rounded to the nearest 1,000 Btu/h. Also, the representative value of fuel input rate for a model would be rounded to the nearest 1,000 Btu/h for representation purposes (including certification). Additionally, DOE proposes that, for its enforcement testing, this rate would be measured pursuant to 10 CFR 431.86 and compared against the fuel input rate certified by the manufacturer. If the measured fuel input rate is within 2 percent of the certified value, then DOE will use the certified value when determining equipment class and calculating combustion and/or thermal efficiency for the model. If the measured fuel input rate is not within ±2 percent of the certified value, then DOE will follow these steps to bring the fuel input rate to within ±2 percent of the certified value. First, DOE will attempt to adjust the gas pressure in order to increase or decrease the fuel input rate as necessary. If the fuel input rate is still not within ±2 percent of the certified value, DOE will then attempt to modify the gas inlet orifice ( e.g., drill) accordingly. Finally, if these measures do not bring the fuel input rate to within ±2 percent of the certified value, DOE will use the measured fuel input rate when determining equipment class and the associated combustion and/or thermal efficiency standard level for the basic model. DOE proposes a fuel input rate tolerance of ±2 percent based on the steady-state criteria already present in ANSI/AHRI Standard 1500-2015 sections C4.1.1.1.4 and C4.1.2.1.5, and believes that such a requirement would not impose additional testing burden or affect ratings. DOE proposes this verification process to provide manufacturers with additional information about how DOE will evaluate compliance. DOE also notes that modification of the orifice to meet these conditions would not be considered a field constructed modification. DOE considers these provisions to be clarifications to its test procedure, and this is supported by the existing requirement in BTS-2000 that the measured fuel input rate during testing must be within ±2 percent of the fuel input rate listed on commercial packaged boiler nameplates. DOE seeks comment regarding its proposed definition and methodology for measuring and verifying fuel input rate and steady-state, identified as Issue 29 in section V.E. H. Clerical Issues DOE proposes an amendment to the regulatory text to clarify those places in AHRI/ANSI Standard 1500-2015 that refer to manufacturer's “specifications or recommendations,” to mean as specified or recommended in the installation and operation manual shipped with the commercial packaged boiler or in supplemental instructions provided by the manufacturer pursuant to 10 CFR 429.60(b)(4). Furthermore, DOE proposes amendments to the regulatory text that clarify the order in which these manufacturer instructions must be used should a conflict arise between them. For parameters or considerations not specified by the DOE test procedure, the manual shipped with the commercial packaged boiler must first be consulted and used. Should the manual shipped with the commercial packaged boiler not provide the necessary information, the supplemental instructions must be consulted and used. The supplemental instructions provided pursuant to 10 CFR 429.60(b)(4) do not replace or alter any requirements in the DOE test procedure and are not meant to override the manual shipped with the commercial packaged boiler. In cases where these supplemental instructions conflict with any instructions or provisions provided in the manual shipped with the commercial packaged boiler, the manual shipped with the commercial packaged boiler must be used. DOE also proposes to clarify that unless otherwise noted, in all incorporated sections of ANSI/AHRI Standard 1500-2015 the term “boiler” means “commercial packaged boiler” as defined in 10 CFR 431.82. DOE found two clerical issues in its review of ANSI/AHRI Standard 1500-2015. First, DOE notes that while section C2.3 of ANSI/AHRI Standard 1500-2015 anticipates that steam could be superheated and therefore temperature measurement of the steam would be required, it does not provide sufficient steam property tables or provisions for using the superheated steam temperature for calculating the thermal efficiency. DOE therefore proposes provisions for using this temperature and includes expanded steam property tables. Second, DOE notes that section C4.1.1.1.2 of ANSI/ AHRI Standard 1500-2015 states that tests shall be conducted at atmospheric pressure or at the minimum steam pressure required to comply with Section 5.3.5. However, Section 5.3.5 describes the hot water rating conditions for ANSI/AHRI Standard 1500-2015. DOE believes that this was intended to refer instead to Section 5.3.6, and therefore proposes language in order to correct this. Upon review of its definitions at 10 CFR 431.82 concerning commercial packaged boilers, DOE determined that additional description of the term “combustion efficiency” was warranted and is therefore proposing to modify that definition. Specifically, the existing definition for “combustion efficiency” does not describe what the metric represents and so DOE is proposing additional language to indicate that the combustion efficiency measures how much of the fuel input energy is converted to useful heat in combustion. DOE proposes rounding requirements for thermal efficiency and combustion efficiency values. DOE notes that while section 5.2.1 of ANSI/AHRI Standard 1500-2015 includes rounding requirements to the nearest tenth of a percent for thermal and combustion efficiency, DOE proposes to clarify in its regulations that values used for purposes of DOE compliance certification (representative values) must be values rounded to the nearest tenth of a percent. With respect to the requirements for testing and certifying commercial packaged boiler models capable of supplying either steam or hot water, DOE notes that commercial packaged boilers that are capable of producing steam and commercial packaged boilers that are capable of producing hot water are subject to different energy conservation standards. However, DOE is also aware that some commercial packaged boiler models are capable of supplying both steam and hot water. DOE notes that such commercial packaged boiler models span two equipment classes (both the steam and hot water variations of the applicable fuel type and fuel input rate category combination) and therefore are subject to the energy conservation standards and testing requirements for both equipment classes. Models capable of producing both steam and hot water must be certified as two basic models. DOE also proposes to move the requirements related to representative values of efficiency for such commercial packaged boilers. For commercial packaged boiler models capable of supplying either steam or hot water and with fuel input rate less than or equal to 2,500,000 Btu/h, under the existing test procedure (10 CFR 431.86(c)(2)(iii)) manufacturers must: • Determine the representative value of the thermal efficiency in steam mode based on thermal efficiency in steam mode determined in accordance with the test procedure in § 431.86 or determined with an AEDM; and • Determine the representative value of the thermal efficiency in hot water mode based on either: ○ The thermal efficiency in hot water mode determined in accordance with the test procedure in § 431.86 or determined with an AEDM; or ○ The thermal efficiency in steam mode determined in accordance with the test procedure in § 431.86 or determined with an AEDM. For commercial packaged boiler models capable of supplying either steam or hot water and with fuel input rate greater than 2,500,000 Btu/h, under the existing test procedure (10 CFR 431.86(c)(2)(iii)) manufacturers must: • Determine the representative value of the thermal efficiency in steam mode based on thermal efficiency in steam mode determined in accordance with the test procedure in § 431.86 or determined with an AEDM; and • Determine the representative value of the combustion efficiency in hot water mode based on either: ○ The combustion efficiency in hot water mode determined in accordance with the test procedure in § 431.86 or determined with an AEDM; or ○ The combustion efficiency in steam mode determined in accordance with the test procedure in § 431.86 or determined with an AEDM. DOE notes that these are existing provisions for such boilers at 10 CFR 431.86(c)(2)(iii) that establish the testing and rating requirements for commercial packaged boiler models capable of supplying either steam or hot water. Because provisions related to representations are typically in 10 CFR part 429, DOE is moving and rephrasing these requirements. Therefore, DOE notes that these regulations do not alter testing or rating options compared to the existing test procedure. DOE seeks comment on its proposed clerical corrections and clarifications, identified as Issue 30 in section V.E. I. Other Issues In response to the September 2013 Framework document and February 2014 RFI, DOE received several comments about other issues, not discussed previously in this notice, concerning the test procedure for determining the energy efficiency of a commercial packaged boiler. These issues and comments are addressed in the following subsections. 1. Stack Temperature Adjustment for Using Combustion Efficiency in Steam Mode To Represent Hot Water Mode DOE's existing test procedure allows commercial packaged boilers with fuel input rate greater than 2,500,000 Btu/h capable of producing steam and hot water to use the combustion efficiency as measured in steam mode to represent the combustion efficiency in hot water mode. 10 CFR 431.86(c)(2)(iii)(B). DOE has received multiple waiver requests that asked to use an adjustment to the stack temperature for using this rating method in order to more accurately reflect the combustion efficiency of a commercial packaged boiler operating in hot water mode. The adjustment is given by Equation 2: EP17MR16.003 where T F,SS,adjusted is the adjusted steady-state flue temperature used for subsequent calculations of combustion efficiency, T F,SS is the measured steady-state flue temperature during combustion efficiency testing in steam mode, T sat is the saturated steam temperature that corresponds to the measured steam pressure, and 180 is the hot water outlet temperature. The proposed adjustment equation is derived by assuming that the heat transfer properties of the heat exchanger operating in hot water mode are roughly the same as the heat transfer properties of the heat exchanger operating in steam mode. This assumption is already implicit in the DOE allowance for using combustion efficiency ratings in steam mode to represent those in hot water mode, and, thus, this m [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2016-05138. Public record. Not legal advice.