# Energy Conservation Program: Test Procedures for Compressors > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2016-10170 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** May 5, 2016 - **Citation:** 81 FR 27220 ## Text DEPARTMENT OF ENERGY 10 CFR Parts 429 and 431 [Docket No. EERE-2014-BT-TP-0054] RIN 1904-AD43 Energy Conservation Program: Test Procedures for Compressors AGENCY: Office of Energy Efficiency and Renewable Energy, Department of Energy. ACTION: Notice of proposed rulemaking and announcement of public meeting. SUMMARY: In this document, the U.S. Department of Energy (DOE) proposes to prescribe new definitions, sampling provisions, and test procedures for compressors in a new subpart of DOE regulations. The proposed test procedure would provide instructions for determining the full-load package isentropic efficiency for certain fixed-speed compressors and the part-load package isentropic efficiency for certain variable-speed compressors based on test methods described in International Organization for Standardization (ISO) Standard 1217:2009, “Displacement compressors—Acceptance tests,” (ISO 1217:2009). This document also proposes certain modifications and additions to ISO 1217:2009 to increase the specificity of certain testing methods and improve the repeatability of tested and measured values. In this notice, DOE also announces a public meeting to discuss and receive comments on issues presented in this notice of proposed rulemaking. DATES: Comments: DOE will accept comments, data, and information regarding this notice of proposed rulemaking (NOPR) before and after the public meeting, but no later than July 5, 2016. See section V, “Public Participation,” for details. Meeting: DOE will hold a public meeting on Monday, June 20, 2016 from 9:30 a.m. to 12:00 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. ADDRESSES: The public meeting will be held at the U.S. Department of Energy, Forrestal Building, Room 8E-089, 1000 Independence Avenue SW., Washington, DC 20585. 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 document. Interested parties are encouraged to submit comments using the Federal eRulemaking Portal at www.regulations.gov. Any comments submitted must identify the NOPR for test procedures for compressors, and provide docket number EERE-2014-BT-TP-0054 and/or regulation identifier number (RIN) 1904-AD43. Comments may be submitted using any of the following methods: • Federal eRulemaking Portal: www.regulations.gov. Follow the instructions for submitting comments. • Email: AirCompressors2014TP0054@ee.doe.gov Include the docket number and/or RIN in the subject line of the message. • Mail: Ms. Brenda Edwards, U.S. Department of Energy, Building Technologies Office, Mailstop EE-5B, 1000 Independence Avenue SW., Washington, DC 20585-0121. If possible, please submit all items on a compact disk (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 of this document (Public Participation). 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 regulations.gov index. However, some documents listed in the index, such as those containing information that is exempt from public disclosure, may not be publicly available. A link to the docket Web page can be found at: https://www1.eere.energy.gov/buildings/appliance_standards/product.aspx/productid/87. This Web page will contain a link to the docket for this proposed rule on the www.regulations.gov site. The www.regulations.gov Web page will contain simple instructions on how to access all documents, including public comments, in the docket. See section V for information about how to submit comments through 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: compressors@ee.doe.gov. Ms. Johanna Jochum, U.S. Department of Energy, Office of the General Counsel, GC-33, 1000 Independence Avenue SW., Washington, DC 20585-0121. Telephone: (202) 287-6307. Email: Johanna.Hariharan@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: DOE proposes to incorporate by reference into part 431 the testing methods contained in certain applicable sections of the following industry standard: International Organization for Standardization (ISO) 1217:2009, “Displacement compressors—Acceptance tests,” sections 2, 3, and 4; subsections 5.2, 5.3, 5.4, 5.6, 5.9, 6.2(g), 6.2(h); and subsections C.1.1, C.2.2, C.2.3, C.2.4, C.4.1, C.4.2.1, C.4.2.3, C.4.3.2, C.4.4 of Annex C. This material is available from the International Organization for Standardization, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland, www.iso.org. +41 22 749 01 11. It is also available for inspection at U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program, Suite 600, 950 L'Enfant Plaza SW., Washington, DC 20024, (202) 586-2945, or go to http://energy.gov/eere/buildings/appliance-and-equipment-standards-program. See section IV.M for additional information on this standard. Table of Contents I. Authority and Background A. Authority B. Background II. Summary of the Notice of Proposed Rulemaking III. Discussion A. Definition of Covered Equipment B. Scope of Applicability of the Test Procedure 1. Summary of Scope of Applicability 2. Equipment System Boundary and Application a. Equipment System Boundary b. Application c. Definition of Air Compressor d. Definition of Air Compressor Components 3. Compression Principle 4. Styles of Drivers a. Electric Motor- and Engine-Driven Compressors b. Styles of Electric Motor 5. Compressor Capacity (Compressor Motor Nominal Horsepower) 6. Output Pressure Range C. Energy-Related Metrics 1. Specific Input Power and Isentropic Efficiency 2. Selected Metric: Package Isentropic Efficiency 3. Load Points and Weighting Factors for Calculating Full-Load and Part-Load Isentropic Efficiency 4. Full-Load Isentropic Efficiency 5. Part-Load Isentropic Efficiency D. Test Method 1. Referenced Industry Test Method 2. Modifications, Additions, and Exclusions to ISO 1217:2009 a. Sections Not Included in DOE's Incorporation by Reference b. Terminology c. Testing Conditions d. Equipment Configuration e. Data Collection and Sampling f. Allowable Deviations From Specified Load Points g. Calculations and Rounding h. Measurement Equipment i. Determination of Maximum Full-Flow Operating Pressure, Full-Load Operating Pressure, and Full-Load Actual Volume Flow Rate E. Definition of Basic Model F. Representations of Energy Use and Energy Efficiency G. Sampling Plans for Tested Data and AEDMs 1. Statistical Sampling Plan 2. Alternative Efficiency Determination Methods a. Background b. Basic Criteria Any AEDM Must Satisfy c. Validation d. Records Retention Requirements e. Additional AEDM Requirements 3. Enforcement Provisions IV. Procedural Issues and Regulatory Review A. Review Under Executive Order 12866 B. Review Under the Regulatory Flexibility Act 1. Small Business Determination a. Methodology for Estimating the Number of Small Entities b. Air Compressor Industry Structure and Nature of Competition 2. Burden of Conducting the Proposed DOE Compressor Test Procedure 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 Public Meeting B. Procedure for Submitting Prepared General Statements for Distribution C. Conduct of Public Meeting D. Submission of Comments E. Issues About Which DOE Seeks Comment VI. Approval of the Office of the Secretary I. Authority and Background Compressors are included in the list of “industrial equipment” that DOE may determine to include as “covered equipment,” and thus establish and amend energy conservation standards and test procedures. (42 U.S.C. 6311(1)(L), 6311(2)(A)-(B), 6312(b)). Specifically, DOE issued a Proposed Determination of Coverage (2012 Proposed Determination) that proposed to establish compressors as covered equipment. 77 FR 76972 (Dec. 31, 2012). However, DOE has not yet exercised this authority and thus no Federal energy conservation standards or test procedures for compressors are currently in place. In this document, DOE proposes to establish test procedures for compressors. The following sections discuss DOE's authority to establish test procedures for compressors and relevant background information regarding DOE's consideration of test procedures for this equipment. A. Authority Title III of the Energy Policy and Conservation Act of 1975, as amended, (42 U.S.C. 6291, et seq.; “EPCA” or, “the Act”) sets forth a variety of provisions designed to improve energy efficiency. 1 1 All references to EPCA in this document refer to the statute as amended through the Energy Efficiency Improvement Act of 2015, Public Law 114-11 (Apr. 30, 2015). Part C of Title III, which for editorial reasons was codified as Part A-1 upon incorporation into the U.S. Code (42 U.S.C. 6311-6317), establishes the Energy Conservation Program for Certain Industrial Equipment. Under EPCA, DOE may include a type of industrial equipment, including compressors, as covered equipment if it determines that to do so is necessary to carry out the purposes of Part A-1. (42 U.S. 6311(1)(L), 6311(2)(B)(i), and 6312(b)). The purpose of Part A-1 is to improve the efficiency of electric motors and pumps and certain other industrial equipment in order to conserve the energy resources of the Nation. (42 U.S.C 6312(a)) In DOE's 2012 Proposed Determination, DOE proposed to determine that because (1) DOE may only prescribe energy conservation standards for covered equipment; and (2) energy conservation standards for compressors would improve the efficiency of such equipment more than would be likely to occur in the absence of standards, including compressors as covered equipment is necessary to carry out the purposes of Part A-1. 77 FR 76972 (Dec. 31, 2012). Pursuant to EPCA, DOE's energy conservation program for covered equipment consists essentially of four parts: (1) Testing; (2) labeling; (3) Federal energy conservation standards; and (4) certification and enforcement procedures. Specifically, subject to certain criteria and conditions, EPCA requires DOE to develop test procedures to measure the energy efficiency, energy use, or estimated annual operating cost of each type of covered equipment. (42 U.S.C. 6316(a)) Manufacturers of covered equipment must use the prescribed DOE test procedure: (1) As the basis for certifying to DOE that their equipment complies with the applicable energy conservation standards adopted under EPCA (42 U.S.C. 6295(s) and 6316(a)) and (2) when making representations to the public regarding the energy use or efficiency of those equipment. (42 U.S.C. 6314(d)) Similarly, DOE must use these test procedures to determine whether the equipment complies with any relevant standards adopted pursuant to EPCA. (42 U.S.C. 6295(s) and 6316(a)) There are currently no DOE test procedures or energy conservation standards for compressors. However, DOE is currently evaluating whether to establish energy conservation standards for certain categories of compressors. (Docket No. EERE-2014-BT-STD-0040) DOE must first establish a test procedure that measures the energy use, energy efficiency, or estimated operating costs of such equipment, prior to establishing energy conservation standards for such equipment. See generally 42 U.S.C. 6295(r) and 6316(a). EPCA sets forth the criteria and procedures DOE is required to follow when prescribing or amending test procedures for covered equipment. (42 U.S.C. 6314) Among other things, EPCA requires that test procedures must be reasonably designed to produce test results which reflect energy efficiency, energy use, and estimated operating costs of a type of industrial equipment (or class thereof) during a representative average use cycle (as determined by the Secretary of Energy), and shall not be unduly burdensome to conduct. (42 U.S.C. 6314(a)(2)) Furthermore, DOE is required to publish the proposed test procedures in the Federal Register , and afford interested persons an opportunity (of not less than 45 days' duration) to present oral and written data, views, and arguments on the proposed test procedures. (42 U.S.C. 6314(b)) Consistent with EPCA requirements, DOE proposes to prescribe a test procedure for certain categories of compressors to be used with its ongoing energy conservation standards rulemaking for this equipment (Docket No. EERE-2013-BT-STD-0040). The test procedure, if adopted, would include the methods necessary to: (1) Measure certain performance parameters of the compressor ( i.e., inlet and discharge pressures, flow rate, and packaged compressor power input); and (2) use the measured results to calculate the package isentropic efficiency 2 of the compressor, inclusive of all compressor-package components. DOE proposes specific test procedures and metrics for fixed-speed versus variable-speed compressors: Full-load efficiency for fixed-speed compressors and a part-load efficiency for variable-speed compressors. DOE also proposes to establish the categories of compressors to which the proposed test method would apply. 2 Package isentropic efficiency is defined as the ratio of power required for an ideal isentropic compression process to the actual packaged compressor power input used at a given load point, as determined in accordance with the methods described in sections III.C.4 and III.C.5. If DOE adopts an applicable test procedure, manufacturers would be required to use the adopted test procedure and performance metrics when making representations regarding the energy consumption of covered equipment beginning 180 days after publication of the test procedure final rule in the Federal Register (42 U.S.C. 6314(d)) (see section III.F). B. Background Consistent with DOE's authority under EPCA, as discussed in section I.A, DOE issued the 2012 Proposed Determination that proposed to establish compressors as covered equipment. 77 FR 76972 (Dec. 31, 2012). Subsequently, in February 2014, DOE published a Notice of Public Meeting and Availability of the Framework Document to initiate an energy conservation standard rulemaking for compressors. 79 FR 6839 (Feb. 5, 2014). In the Framework Document, DOE requested feedback from interested parties on multiple issues, including the definition of compressor, characteristics of different compressor categories, and how to test compressor efficiency. DOE held a public meeting to discuss the Framework Document on April 1, 2014, hereafter referred to as the “Framework public meeting.” DOE received 15 comments in response to the Framework Document. After the comment period, DOE held interviews with several interested parties to help gather additional information necessary to complete the regulatory analyses that were described in the Framework Document. Those recommendations received from interested parties in both comments on the Framework Document and during the Framework public meeting, as well as feedback provided during the preliminary manufacturer interviews, that are pertinent to the test procedure and performance metric are addressed in this NOPR and reflected in DOE's proposed compressor test procedure. II. Summary of the Notice of Proposed Rulemaking In this test procedure NOPR, DOE proposes to establish a new subpart T to 10 CFR part 431 that would contain, among other things, definitions and a test procedure applicable to compressors. However, DOE proposes to establish test procedures for only a specific subset of compressors. Specifically, this proposed test procedure would apply only to a subset of rotary and reciprocating compressors, as defined in section III.B of this NOPR. DOE intends this proposed test procedure to apply to the same equipment for which DOE is considering adopting energy conservation standards (Docket No. EERE-2014-BT-TP-0054). However, DOE notes that the scope of any energy conservation standards would be established in that rulemaking. This proposed test procedure prescribes methods for measuring and calculating the energy performance of certain rotary and reciprocating compressors, inclusive of all compressor package components. 3 DOE also proposes to describe the energy performance of certain rotary and reciprocating compressors using package isentropic efficiency. The package isentropic efficiency describes the ratio of the ideal isentropic power required for compression to the actual packaged compressor power input used for the same compression process. DOE proposes to use full-load package isentropic efficiency as the metric for rating certain fixed-speed compressors (η isen,FL ) and part-load package isentropic efficiency as the metric for rating certain variable-speed compressors (η isen,PL ). DOE believes these metrics would provide a representative measurement of the energy performance of the rated compressor under an average cycle of use. 3 As discussed further in section III.B.2.c, DOE proposes to define air compressors as a “packaged compressor,” inclusive of a compression element (“bare compressor”), driver(s), and mechanical equipment to drive the compressor element. DOE's proposed test method includes measurements of the inlet and discharge pressures, actual volume flow rate, and packaged compressor power input, as well as calculations of the theoretical power necessary for compression—all of which are required to calculate full- or part-load package isentropic efficiency. For reproducible and uniform measurement of these values, DOE proposes to incorporate by reference the test methods established in certain applicable sections of ISO Standard 1217:2009, “Displacement compressors—Acceptance tests,” sections 2, 3, and 4; subsections 5.2, 5.3, 5.4, 5.6, 5.9, 6.2(g), 6.2(h); and subsections C.1.1, C.2.2, C.2.3, C.2.4, C.4.1, C.4.2.1, C.4.2.3, C.4.3.2, C.4.4 of Annex C; along with certain modifications and additions, as noted in section III.D.2. Members of the compressor industry developed ISO 1217:2009, which contains methods for determining inlet and discharge pressures, actual volume flow rate, and packaged compressor power input for electrically driven packaged displacement compressors. DOE has reviewed the relevant sections of ISO 1217:2009 and has determined that ISO 1217:2009, in conjunction with the additional referenced test methods and calculations proposed in this test procedure (see sections III.D.2 and III.C, respectively), would produce test results that reflect the energy efficiency, energy use, or estimated operating costs of a compressor during a representative average use cycle. (42 U.S.C. 6314(a)(2)) DOE has also reviewed the burdens associated with conducting the proposed test procedure, including ISO 1217:2009 and, based on the results of such analysis, has found that the proposed test procedure would not be unduly burdensome to conduct. ( See 42 U.S.C. 6314(a)(2)) DOE's analysis of the burdens associated with the proposed test procedure is presented in section IV.B. DOE also proposes to establish, in subpart B of part 429 of Title 10 of the Code of Federal Regulations, requirements regarding the sampling plan for testing and allowable representations for certain rotary and reciprocating compressors. The proposed sampling plan requirements are similar to those for several other types of commercial and industrial equipment ( e.g., pumps) and are appropriate for compressors based on the expected range of measurement uncertainty and manufacturing tolerances for this equipment (see section III.G). DOE also proposes provisions regarding the representations of energy consumption, energy efficiency, and other relevant metrics manufacturers may make in their manufacturer literature (see section III.F). Any representations of the energy efficiency or energy use of compressors to which an adopted test procedure applies must be made based on the adopted compressor test procedure beginning 180 days after the publication date of any test procedure final rule establishing such procedures. (42 U.S.C. 6314(d)) III. Discussion In this NOPR, DOE proposes to place a new compressor test procedure and related definitions into a new subpart T of part 431, add new sampling plans for this equipment in a new section 429.61 of 10 CFR part 429, add a new alternative efficiency determination method (AEDM) for this equipment in 10 CFR 429.70, and add new enforcement provisions for compressors in 10 CFR 429.110 and 134. The proposed subpart T would contain definitions, materials incorporated by reference, and the test procedure applicable to certain classes and configurations of compressors established as a result of this rulemaking, as shown in Table III.1. DOE would also incorporate in subpart T any energy conservation standards for compressors resulting from the concurrent energy conservation standard rulemaking. ( See Docket No. EERE-2013-BT-STD-0040) Table III.1—Summary of Proposals in This NOPR, Their Location Within the Code of Federal Regulations, and the Applicable Preamble Discussion Location Proposal Summary of Additions Applicable Preamble Discussion 10 CFR 429.61 Sampling Plan Minimum number of compressors to be tested to rate a compressor basic model Section III.G 10 CFR 429.110 Enforcement Provisions Method for determining compliance of basic models Section III.G.3 10 CFR 431.341 Purpose and Scope Scope of the proposed compressor regulations Section III.B 10 CFR 431.342 Definitions Definitions pertinent to categorizing and testing of compressors Section III.B.2 10 CFR 431.343 Incorporation by Reference Description of industry standards incorporated by reference in the DOE test procedure and related definitions Section III.D 10 CFR 431.344 Test Procedure Instructions for determining the package isentropic efficiency for applicable categories of compressors Sections III.C and III.D * Note: DOE also proposes minor modifications to 10 CFR 429.2 and 429.70; to apply the general definitions to the equipment-specific provisions proposed for compressors at 10 CFR 429.61 and propose AEDM requirements for compressors, respectively. The following sections discuss DOE's proposals regarding establishing new testing and sampling requirements for compressors, including A) definition of covered equipment, B) scope of applicability of the test procedure, C) energy-related metrics, D) test method, E) definition of basic model, F) representations of energy use and energy efficiency, and G) sampling plans for testing and AEDMs. These sections also present any pertinent comments DOE received in response to the February 2014 Framework Document, as well as DOE's responses to those comments. A. Definition of Covered Equipment Although a compressor is listed as a type of industrial equipment in EPCA, the term is not defined. (42 U.S.C. 6311(2)(B)(i)) In the Framework Document, DOE requested feedback on a definition for the term “compressor,” taken from the International Organization for Standardization (ISO) Technical Report 12942:2012, “Compressors—Classification—Complementary information to ISO 5390,” (“ISO/TR 12942:2012”). (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 3). Specifically, ISO Technical Report 12942:2012 defines compressor as a machine or apparatus converting different types of energy into the potential energy of gas pressure for displacement and compression of gaseous media to any higher pressure values above atmospheric pressure with pressure-increase ratios exceeding 1.1. In response to the provided definition, the Edison Electric Institute (EEI) supported the use of the ISO/TR 12942:2012 definition. The National Resources Defense Council (NRDC), the Northwest Energy Efficiency Alliance (NEEA), the California Investor Owned Utilities (CA IOUs), the Southern California Gas Company (SCGC), and a joint comment submitted by the American Council for an Energy-Efficiency Economy (ACEEE), the Appliance Standards Awareness Project (APSP), the Northwest Energy Efficiency Alliance (NEEA), and the Alliance to Save Energy (ASE) (hereafter referred to as the Joint Commenters) recommended establishing the pressure ratio that defines compressors to align with the maximum ratio that will eventually be proposed for the DOE's energy conservation standards rulemaking for fans and blowers (“Fans and Blowers Rule,” Docket No. EERE-2013-BT-STD-0006, EEI, No. 0012 at p. 3; NRDC, No. 0019 at p. 1; NEEA, No. 0040 at p. 23; CA IOUs, No. 0018 at p. 2; SCGC, No. 0018 at p. 2; and Joint Comment, No. 0016 at p. 1) The Compressed Air and Gas Institute (CAGI) commented that the pressure ratio was too low and suggested using a ratio of 2.5. (CAGI, No. 0009 at p. 1; CAGI, No. 0040 at p.2) DOE agrees with the recommendations from interested parties suggesting alignment of the pressure ratio used to define compressors with any maximum pressure ratio adopted for fans and blowers. That is, DOE believes that, in order to ensure comprehensive and equitable coverage of equipment ( i.e., prevent gaps in coverage and double coverage by two rules) it is critical that the maximum pressure ratio applicable to fans and blowers be mutually exclusive with the minimum pressure ratio proposed to define compressors. Although DOE intends to align the maximum pressure ratio for fans and blowers with the minimum pressure ratio for compressors, DOE notes that the Fans and Blowers Rules are currently in progress and that DOE has not issued a notice of proposed rulemaking for either a test procedure or energy conservation standards. As a result, DOE has not yet offered any formal proposals for a limiting maximum pressure ratio for fans and blowers. However, DOE discussed the use of pressure ratio limits in the Framework Document for its Fans and Blowers Rule. Specifically, DOE discussed a definition for the term “blower,” as “an axial or centrifugal fan with a “specific ratio, 4 ” between 1.11 and 1.20” (Docket No. EERE-2013-BT-STD-0006-0001 at p. 9). 4 Specific ratio is defined in ISO 13349:2010 as the total pressure at the outlet of the fan over the total inlet pressure. This term is synonymous to pressure ratio, as discussed in this document. DOE received comments in response to its discussion of specific ratio limits in the Fans and Blowers Rule Framework Document. Specifically, Ingersoll-Rand supported use of an upper limit of 25 kJ/kg for equipment being considered as a part of the Fans and Blowers Rule (Docket No. EERE-2013-BT-STD-0006-0153 at p. 6). DOE notes that ISO 13349:2010 5 also defines fans based on a maximum energy limit of 25 kJ/kg of air and indicates that 25 kJ/kg is equivalent to a specific ratio of 1.3. The CA IOUs, in response to the Fans and Blowers Framework Document, commented that they were aware of the ongoing compressors rulemaking, and that the respective pressure ratio limits of each rule should be aligned in order to prevent gaps in coverage (“Fans and Blowers Rule,” Docket No. EERE-2013-BT-STD-0006-0011 at p. 3). 5 ISO 13349:2010 Fans—Vocabulary and definitions of categories. Additionally, DOE notes that, following the completion of the Framework comment period, an ASRAC Working Group was established to negotiate proposed energy conservation standards for fans and blowers. 80 FR 17359 (Apr. 1, 2015). Ultimately this Working Group concluded its negotiations on September 3, 2015, with a supportive vote on several recommendations (“a term sheet”) for DOE regarding the testing and regulation this equipment. (Docket No. EERE-2013-BT-STD-0006, No. 179) Although the Working Group's term sheet did not explicitly include an upper limit on pressure ratio, the working group did discuss, and come to “general agreement” on a “maximum fan energy limit of 25 kJ/kg” (approximately 1.3 pressure ratio) as the appropriate cutoff to distinguish between fans and compressors. (Docket No. EERE-2013-BT-STD-0006; Public Meeting, No. 84 at p. 11). As discussed previously, DOE agrees with the recommendations from NRDC, NEEA, CA IOUs, SCGC and the Joint Commenters, suggesting alignment of the pressure ratio used to define compressors with any maximum pressure ratio adopted for fans and blowers. Consequently, DOE proposes to incorporate into its definition of a compressor, a pressure ratio limit of greater than 1.3. DOE believes that, based on the most recent Fans and Blowers Rule public information (discussed above), a pressure ratio limit of 1.3 is the most appropriate cutoff to distinguish between fans and compressors, and this cutoff limit meets the intent of definitional alignment between the Fans and Blowers Rule and this rulemaking. DOE notes that it is proposing to limit the definition of a compressor using pressure ratio, rather than fan energy (in kJ/kg), as fan energy is not a commonly used parameter in the compressor industry and DOE is unaware of any compressor industry test standards that specify the calculation of such a parameter. Alternatively, pressure ratio is a commonly used, and well understood, parameter in the compressor industry, and is easily derived from test methods contained in common industry standards, such as ISO 1217:2009. In addition to the lower pressure ratio limit of “greater than 1.3”, DOE proposes to base the remainder of its compressor definition on the ISO 12942:2012 definition of a compressor; which was discussed in the Compressors Framework Document and supported in previously discussed comments submitted by EEI. Ultimately, DOE proposes to define a compressor as a machine or apparatus that converts different types of energy into the potential energy of gas pressure for displacement and compression of gaseous media to any higher pressure values above atmospheric pressure and has a pressure ratio 6 greater than 1.3. 6 DOE proposes to use terminology consistent with ISO 1217:2009 in describing the ratio of discharge to inlet pressures as “pressure ratio,” as opposed to “pressure-increase ratio,” which is the term used in some other industry documents. However, for the purpose of this document “pressure-increase ratio” and “pressure ratio” are synonymous. DOE notes that proposing a pressure ratio of greater than 1.3, DOE intends to align the minimum pressure ratio for compressors to the maximum ratio proposed in the fans and blowers rule and create a continuous spectrum of coverage between the two equipment types. However, as discussed previously, the fans and blowers rulemaking is still in progress, and the limit of 25 kJ/kg (approximately a 1.3 pressure ratio) discussed during Working Group negotiations has not been proposed by DOE and is subject to change. As such, DOE reiterates that the primary intent of proposing a pressure ratio greater than 1.3 is to align with the fans and blowers rule and creates a continuous spectrum of coverage between the two equipment types. If the fans and blowers rulemaking ultimately proposes and adopts an upper limit other than 25 kJ/kg, DOE may alter the pressure ratio threshold of greater than 1.3 referenced in the compressor definition, in order to achieve the original intent of this proposal, either through this rulemaking, the fan and blowers rulemaking, or other subsequent rulemakings. In order to objectively and unambiguously determine whether equipment meets the definition of compressor, DOE also proposes to define the term “pressure ratio.” DOE proposes to define pressure ratio as the ratio of discharge pressure to inlet pressure, as determined at full-load operating pressure. This definition allows DOE to establish quantitatively which equipment meet the pressure ratio requirement proposed in the definition of compressor. This definition of pressure ratio relies on the terms discharge pressure and inlet pressure. Definitions and methods to calculate the discharge pressure and inlet pressure are established in ISO 1217:2009, certain sections of which DOE proposes to incorporate by reference (see section III.D). DOE also notes that in this NOPR DOE proposes methods to identify full-load operating pressure; such methods are discussed further in section III.D.2.i. DOE requests comment on the proposed definitions for compressor and pressure ratio, as well as the definitions referenced in ISO 1217:2009. DOE requests comment on the proposed lower limit of pressure ratio for compressors of “greater than 1.3.” B. Scope of Applicability of the Test Procedure 1. Summary of Scope of Applicability DOE notes that while the definition of compressor, as proposed in section III.A, is broad, the categories of compressors to which the proposed test procedure applies would be limited to a more narrow range of equipment. Specifically, after consideration of feedback from interested parties, as well as DOE research, DOE proposes to limit the applicability of this test procedure to compressors that meet the following criteria: • Are air compressors, as defined in section III.B.2; • Are rotary or reciprocating compressors, as defined in section III.B.3; • Are driven by a brushless electric motor, as defined in section III.B.4; • Are distributed in commerce with a compressor motor nominal horsepower greater than or equal to 1 and less than or equal to 500 horsepower (hp) as defined in section III.B.5; and • Operate at a full-load operating pressure of greater than or equal to 31 and less than or equal to 225 pounds per square inch gauge (psig), as defined in section III.B.6. In this test procedure NOPR, DOE proposes to limit the applicability of the test procedure to compressor equipment being analyzed in the energy conservation standard. However, DOE notes that the broad definition of compressor provides DOE with flexibility to consider establishing test procedures and energy conservation standards for compressors outside the scope of this test procedure in the future. 2. Equipment System Boundary and Application a. Equipment System Boundary In the Framework Document for the compressor standards rulemaking, DOE considered three options for the equipment system boundary, based on the three different ways in which compressors are distributed in commerce: (1) As a bare compressor; (2) as a bare compressor, inclusive of driver(s) and mechanical equipment to drive the bare compressor; and (3) as a bare compressor, inclusive of driver(s) and mechanical equipment to drive the bare compressor, as well as all secondary equipment, componentry, and air conveyance equipment ( i.e., a compressed air system (CAS)). DOE requested comment regarding the feasibility of covering each boundary level of compressor equipment. In the Framework Document, DOE proposed no formal definitions for these equipment configurations. However, DOE described the term “bare compressor” as a “singular machine responsible for the change in air pressure, which is sometimes referred to as an `air end,' and which is the compression chamber where air is compressed.” DOE specifically noted that this term would be exclusive of any other devices, such as an electric motor. (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 6). With respect to the “a bare compressor, inclusive of driver(s) and mechanical equipment to drive the bare compressor ” option (a compressor package), DOE described a configuration of compressor components that includes “a driver, such as an electric motor, and may include other equipment, such as gears, drains, air treatment (filtering) equipment, onboard controls, etc.” DOE noted that this “configuration is considered the single largest piece of equipment brought to market by an individual manufacturer.” 7 7 Ibid. With respect to the “a bare compressor, inclusive of driver(s) and mechanical equipment to drive the bare compressor, as well as all secondary equipment, componentry, and air conveyance equipment ( i.e., a CAS)” option, DOE described a system “inclusive of all componentry that would be attached and would include components starting from the air intake and including the final `point-of-use.' ” DOE noted that under this option, “the compressor could include the many configuration packages that could be attached such as the distribution (piping) network, air-treatment systems, sequencers, storage tanks, and any end-use equipment ( e.g., pneumatic tools).” (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 7). In the Framework Document, DOE requested comment on the different equipment system boundary options. (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 11). In response, Saylor-Beall commented that “while it might be possible to rate the air compressor package, attention needs to be given to the entire compressed air system of the end user.” (Saylor-Beall, No. 0003 at p. 2) 8 Alternatively, Jenny Compressors (“Jenny”) stated that “covering the entire `CAS' may prove nearly impossible since many systems include components from many different manufacturers, and no two systems are the same.” (Jenny, No. 0005 at p. 2) CAGI and the Joint Commenters agreed that DOE should cover the compressor package as part of this rulemaking. (CAGI, No. 0009 at p. 3; Joint Comment, No. 0016 at p. 2) The Joint Commenters also stated that, if DOE covers the compressor package, DOE would need to ensure companies that assemble packages from purchased components are also subject to proposals in this rulemaking. (Joint Comment, No. 0016 at p. 2-3) 8 A notation in this form provides a reference for information that is in the docket of DOE's rulemaking to develop test procedures for pumps (Docket No. EERE-2013-BT-TP-0055, which is maintained at www.regulations.gov ). This particular notation refers to a comment: (1) Submitted by HI; (2) appearing in document number 8 of the docket; and (3) appearing on page 4 of that document. This final rule also contains comments submitted in response to the pumps ECS rulemaking (Docket No. EERE-2011-BT-STD-0031) and such comments will be identified with that docket number. DOE considered these comments and reviewed the pros and cons of each equipment system boundary option. The following paragraphs discuss DOE's finding and conclusions. DOE considers covering a bare compressor to represent significantly lower energy savings compared to the other two equipment system boundary options. Logically, because a bare compressor is a subset of the compressor package and CAS, any energy savings available in the bare compressor would also be available in the compressor package and CAS options. Additionally, some energy savings opportunities are related to the ability to optimize a bare compressor relative to other components of the compressor package or CAS. Covering the bare compressor only would forgo the opportunity to realize those additional savings opportunities. Furthermore, some of those additional components have a significant impact on the energy consumption of the bare compressor in the field and are required for the bare compressor to function as intended. Consequently, DOE believes that determining the energy performance of the bare compressor alone would not be representative of the energy consumption of the equipment under typical use conditions. For these reasons, DOE does not propose to include bare compressors within the scope of applicability of this test procedure. DOE also understands that, while the CAS represents the largest available energy savings, including the CAS in the scope of applicability of this rulemaking has significant drawbacks: • Often a CAS is unique to a specific installation; • Each CAS may include equipment from several different manufacturers; and • A single CAS can include several different compressors, of different categories, which may all have different full-load operating pressures. Implementing a broader, CAS-based approach to regulating compressor efficiency would require DOE to (1) establish a methodology for measuring losses in any arbitrary air-distribution network; and (2) assess what certification, compliance, and enforcement practices would be required for a potentially unlimited, and extremely variable, number of system designs. For these reasons, DOE does not propose to establish the scope of applicability of this test procedure to include CAS. Based on the considerations stated above, at this time, DOE proposes to establish test procedures only for compressor packages, which contain bare compressors, driver(s), mechanical equipment to drive the bare compressor, and any ancillary equipment. DOE believes that determining the energy performance of compressors as a “compressor package” is the most representative of the energy consumption of the equipment under an average cycle of use. b. Application Broadly, compressors are used to compress a wide variety of gases, including, among others, air, natural gas, and refrigerants. In the Framework Document, DOE requested comment on limiting the scope to only “air compressors” and stated that information gathered to that point indicated that non-air compressing equipment accounted for a relatively small fraction of the overall compressors market, in terms of both shipments and annual energy consumption. (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 4). In response, DOE received conflicting feedback on the topic from interested parties. The Edison Electric Institute (EEI) recommended covering all compressor categories regardless of the gas that is compressed because natural gas compressor energy use is projected to increase, while CAGI stated that DOE should cover only air compressors. (EEI, No. 0012 at p. 1-2; CAGI, No. 0009 at p. 1) The Air-Conditioning, Heating, and Refrigeration Institute (AHRI) requested that compressors used in heating, ventilation, and air-conditioning (HVAC) equipment be specifically excluded. (AHRI No. 0015, at p. 1) After the publication of the Framework Document, DOE announced several new initiatives to modernize the country's natural gas transmission and distribution infrastructure, including one to explore establishing efficiency standards for natural gas compressors. 9 As part of that effort, DOE published a Request for Information (RFI), on August 5, 2014, to help determine both the feasibility of energy conservation standards for natural gas compressors and whether they are similar enough to air compressors to be considered within the scope of this rulemaking. 79 FR 45377 (Aug. 5, 2014). Additionally, DOE announced the availability of a preliminary, high-level description of the market and available technology for natural gas compressors. (Docket No. EERE-2014-BT-STD-0051, No. 5). DOE held a public meeting on December 17, 2014, to present and seek comment on the content of that data. Based upon the feedback DOE received in response to the RFI and the NODA, DOE has determined that natural gas compressors are a unique style of compressors that serve different applications and market utility, which would necessitate unique test procedures and standards. As such, DOE opted to consider natural gas compressors separately from air compressors. (Docket No. EERE-2014-BT-STD-0051) 9 See: http://energy.gov/articles/department-energy-announces-steps-help-modernize-natural-gas-infrastructure Regarding refrigerant compressors, DOE considers refrigerant compressors to have the same basic function as air compressors in that they both compress a working fluid to a higher pressure, but with the working fluid of refrigerant compressors being refrigerant instead of air. Refrigerant compressors are typically used in heating, ventilation, air-conditioning and refrigeration (HVACR) equipment. Similar to natural gas compressors, DOE has determined that refrigerant compressors serve a specific and unique application and also necessitate unique test procedures and standards. As such, DOE has opted not to consider refrigerant compressors in this rulemaking. Furthermore, DOE's research found no large market segments or applications for compressor equipment used with gases other than air, natural gas, and refrigerant. Information gathered during confidential manufacturer interviews also indicated that non-air and non-natural gas compressing equipment represented relatively low sales volume and annual energy consumption. Accordingly, for the forgoing reasons, DOE proposes to establish test procedures only for air compressors in this rulemaking. c. Definition of Air Compressor DOE proposes to define the term “air compressor” as a compressor designed to compress air that has an inlet open to the atmosphere or other source of air, and is made up of a compression element (bare compressor), driver(s), mechanical equipment to drive the compressor element, and any ancillary equipment. The first clause of this definition the application of the compressor. The portion of the definition that states, “. . . a compressor designed to compress air that has an inlet open to the atmosphere or other source of air,” describes what is commonly known as an air compressor and establishes that this definition includes air compressors only. DOE includes language regarding the compressor inlet as a secondary identifier of air compressors that focuses on features, so that the definition is not entirely reliant on assessment of design objectives. DOE notes that if this definition were to be adopted, DOE would refer to manufacturer literature, including operation and installation manuals, and any other representations made by the manufacturer when determining design intent. The second clause of this definition discusses the equipment system boundary. Specifically, the portion of the definition which states, “. . . made up of a compression element (bare compressor), driver(s), mechanical equipment to drive the compressor element, and any ancillary equipment.” This clause describes the components that must be to be a regulated air compressor and subject to the proposed test procedure. These specific components are discussed and defined in section III.B.2.d. DOE also notes that the proposed definition of air compressor is similar to the European Union's (EU's) Ecodesign Lot 31 Draft Standard of “basic package compressor,” the ISO 1217:2009 definition of “packaged compressor,” and DOE's own “compressor package” definition from the Framework Document, each of which is presented in the following paragraphs. (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 6). EU Lot 31 Definition of “Basic Package Compressor” Basic package compressor means a compressor made up of compression element (`air end'), electric motor(s) and transmission or coupling to drive the compression element, and which is fully piped and wired internally, including ancillary and auxiliary items of equipment that is considered essential for safe operation and required for functioning as intended; (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 3). ISO 1217:2009 Definition of “Packaged Compressor” Packaged compressor means a compressor with prime mover, transmission, fully piped and wired internally, including ancillary and auxiliary items of equipment and being stationary or mobile (portable unit) where these are within the scope of supply. Framework Document Definition of “Compressor Package” Compressor package refers to the bare compressor plus a driver, such as an electric motor, and may include ancillary equipment such as gears, drains, air-treatment (filtering) equipment, onboard controls, etc. A compressor package is considered the single largest piece of equipment brought to market by an individual manufacturer. (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 6). d. Definition of Air Compressor Components In order to explicitly establish the applicable components included in an air compressor, as defined, DOE must also define the terms “bare compressor,” “driver,” and “mechanical equipment.” The following sections discuss DOE's proposed definitions for those terms. Definition of “Bare Compressor” In the Framework Document, DOE described a “bare compressor” as “[a] singular machine responsible for the change in air pressure and is sometimes referred to as an “air end,” which is the compression chamber where air is compressed.” In this test procedure NOPR, DOE proposes a similar definition for “bare compressor.” However, DOE's proposed definition expands upon and clarifies the discussion presented in the Framework Document to reference several specific design characteristics of bare compressors. Specifically, DOE proposes to include specific language from the definition for mechanical compressor included in ISO/TR 12942:2012 10 to define the term bare compressor. DOE's proposed definition of “bare compressor” reads as follows: 10 The definition of “mechanical compressor” in ISO 12942:2012 includes “compressor machine constituting essentially one or several working members movable in compression chambers and common built-in mechanism for conversion of external energy supply motion of the driver to the required working member motion, and being operable by supply of external mechanical energy from the power output shaft, or motion rod or piston of the driver or speed-adjusting driving gear. NOTE 1 The mechanical compressor contains necessary auxiliary devices for performing the gas compression process in the working chambers: applicable gas inlet and outlet valves, gas flow paths, seals, lubrication system, capacity control means, measuring instruments etc., but it does not contain driver, speed-adjusting gear, gas processing apparatuses and piping or compressor equipment packaging and mounting facilities and enclosures.” Bare compressor 11 means the compression element and auxiliary devices ( e.g., inlet and outlet valves, seals, lubrication system, and gas flow paths) required for performing the gas compression process, but does not include the driver; speed-adjusting gear(s); gas processing apparatuses and piping; or compressor equipment packaging and mounting facilities and enclosures. 11 The compressors industry frequently uses the term “airend” or “air end” to refer to the bare compressor. DOE uses “bare compressor” in the regulatory text of this proposed rule but notes that, for the purposes of this rulemaking, it considers the terms to be synonymous. Definition of Driver As discussed previously, another fundamental element of an air compressor is the driver, which provides mechanical power to drive a bare compressor. Examples include an electric motor, internal combustion engine, or gas turbine. In the Framework Document, DOE described and used the term driver, but did not offer a specific definition. In the recent pumps test procedure final rule, DOE defined the term, as it applies to pumps. 81 FR 4086 (Jan. 25, 2016). Specifically, the pumps test procedure final rule defines driver as “the machine providing mechanical input to drive a bare pump directly or through the use of mechanical equipment. Examples include, but are not limited to, an electric motor, internal combustion engine, or gas/steam turbine.” Id. Due to the similarities between the equipment categories ( i.e., equipment typically driven by electric motors and sometimes accompanied with variable frequency drives), in this NOPR, DOE proposes a definition for “driver” that is similar the one proposed in the pumps test procedure NOPR. DOE proposes a definition for the term “driver” to mean the machine providing mechanical input to drive a bare compressor directly or through the use of mechanical equipment. Definition of Mechanical Equipment An air compressor, as defined, may include mechanical equipment that serves to transfer energy from a driver to the bare compressor. In DOE's pumps test procedure final rule, DOE adopted a definition for mechanical equipment as “any component of a pump that transfers energy from a driver to a bare pump.” 81 FR 4086 (Jan. 25, 2016). Again, due to the similarities between the equipment categories ( i.e., equipment typically driven by electric motors and sometimes accompanied with variable frequency drives), DOE believes such a definition is also applicable to compressors and, as a result, in this NOPR, DOE proposes a definition for the term mechanical equipment as follows: Mechanical equipment means any component of an air compressor that transfers energy from the driver to the bare compressor. Definition of Ancillary Equipment DOE believes that the energy consumption of all components distributed in commerce with an air compressor should be considered when evaluating the energy performance of the air compressor. Consequently, DOE proposes to define ancillary equipment as any equipment distributed in commerce with an air compressor that is not a bare compressor, driver, or mechanical equipment. DOE notes that ancillary equipment would be considered to be part of a given air compressor model, regardless of whether the ancillary equipment is physically attached to the bare compressor, driver, or mechanical equipment at the time when the air compressor is distributed in commerce. DOE requests comment on its proposed definition of air compressor and its use in limiting the scope of applicability of this test procedure. DOE requests comment on the proposed definitions for bare compressor, driver, and mechanical equipment. DOE requests comment on the proposed definition of ancillary equipment, and whether a comprehensive list of potential ancillary equipment is more appropriate. If a comprehensive list of potential ancillary equipment is preferred, DOE requests information on what equipment should be on that list. DOE requests comment on its position that all ancillary equipment distributed in commerce with an air compressor be installed when testing to evaluate the energy performance of the air compressor. DOE requests comment on a potential alternative approach, in which DOE could generate a list of specific ancillary equipment that must be installed to ensure that the test result is representative of compressor performance; equipment on this list would not be optional, regardless of how that compressor model is distributed in commerce. If the alternative approach is preferred, DOE requests comments on what ancillary equipment be required to be installed to representatively measure compressor energy performance and how to evaluate compressor performance if an air compressor is distributed in commerce without certain items on the list. 3. Compression Principle Compressor equipment can use a variety of different compression mechanisms in order to increase the pressure of the gas. The three main compressor categories each rely on a different compression principle and include rotary compressors, reciprocating compressors, and dynamic compressors. In the Framework Document, DOE offered definitions for each of these compressor equipment categories as follows: Dynamic compressor means a compressor in which the increase in gas pressure is achieved continuously by increasing the kinetic energy of the working fluid in the flow path of the equipment due to acceleration to high velocities by mechanical action of blades placed on a rapid rotating wheel and further transformation of the kinetic energy into potential energy by successive deceleration of the working fluid flow rate and associated pressure increase. Rotary compressor means a positive displacement compressor in which gas admission and diminution of its successive volumes or its forced discharge are performed cyclically by rotation of one or several rotors in a compressor casing. Reciprocating compressor means a positive displacement compressor in which gas admission and diminution of its successive volumes are performed cyclically by straight-line alternating movements of a moving member(s) in a compression chamber(s). In the Framework Document, DOE requested comment on which compression categories should be considered for inclusion in the scope of DOE's rulemaking efforts. In response, several interested parties agreed that DOE should cover all three compressor categories. (Joint Comment, No. 0016 at p. 2; CAGI, No. 0009 at p. 1) Scales commented that DOE should focus on centrifugal and rotary screw compressors above 350 hp. (W. Scales, No. 0020 at p. 1) DOE also received annual shipments data, differentiated by these compressor categories, in industry stakeholder submittals. In response to the submitted comments, DOE researched the characteristics, typical usage and applications, and available test methods for the different compressor categories. DOE research indicated that dynamic compressors are typically larger in horsepower than positive displacement compressors, and commonly engineered specifically for a unique customer or application. In addition, DOE found that the standard international test procedure for dynamic compressors, ISO 5389, is considered too complicated and not widely used by industry. As a result of the specialization of dynamic compressor equipment and the complexity of the industry test procedure, very little application and performance data are publicly available, which makes it difficult for DOE to assess the feasibility or representativeness of ISO 5389 or other test procedures for this equipment. In addition, due to the unique industry test procedure and applications of dynamic compressors, DOE believes it is most appropriate to apply a unique test procedure to such equipment. Conversely, ISO 1217:2009 is applicable to both rotary and reciprocating compressors and is currently widely used by the industry for testing and verifying equipment performance. For further details on ISO 1217:2009 see section III.D. Based on the shipments data submitted by interested parties in response to the Framework Document, DOE also estimated the overall size of the air compressors market for each configuration. The shipments data for 2013 provided to DOE suggest that rotary and reciprocating compressors account for the majority of the air compressors market by units shipped. By contrast, dynamic compressors account for fewer than 300 total units shipped, or roughly one percent of the total market. Because rotary and reciprocating compressors can be tested in the same manner and represent the majority of the market, DOE is electing to consider a test procedure that is applicable only to rotary and reciprocating compressors. DOE may create test procedures for dynamic compressors in the future and notes that, due to the differences from rotary and reciprocating compressors, it would be most appropriate to address the test procedure for dynamic compressors as part of a separate rulemaking. To establish the applicability of the test procedure proposed in this NOPR, DOE proposes the following definitions for rotary and reciprocating compressors, which are consistent with those discussed in the Framework Document: Rotary compressor means a positive displacement compressor in which gas admission and diminution of its successive volumes or its forced discharge are performed cyclically by rotation of one or several rotors in a compressor casing. This definition for rotary compressor is consistent with the definition included in ISO/TR 12942:2012 and is currently used within the compressor industry. Reciprocating compressor means a positive displacement compressor in which gas admission and diminution of its successive volumes are performed cyclically by straight-line alternating movements of a moving member(s) in a compression chamber(s). This definition for reciprocating compressor is consistent with the definition included in ISO/TR 12942:2012 and is currently used within the compressor industry. To support the previous definitions, DOE also proposes to define the term positive displacement compressor as a compressor in which the admission and diminution of successive volumes of the gaseous medium are performed periodically by forced expansion and diminution of a closed space(s) in a working chamber(s) by means of displacement of a moving member(s) or by displacement and forced discharge of the gaseous medium into the high-pressure area. This definition for positive displacement compressor is consistent with the definition included in ISO/TR 12942:2012 and is currently used within the compressor industry. DOE requests comment on its proposed definitions of rotary compressor, reciprocating compressor, and positive displacement compressor and their use in defining the scope of applicability of this test procedure. 4. Styles of Drivers a. Electric Motor- and Engine-Driven Compressors Compressors can be powered using several different kinds of drivers, commonly including electric motors and internal combustion engines. Electric motor-driven equipment may use either single-phase or three-phase electric motors. Engine-driven 12 compressors can be powered by using different kinds of fuels, commonly including diesel, gasoline, and natural gas. In the Framework Document, DOE considered covering all compressors regardless of driver design and requested comments from interested parties. 12 For the purposes of this document, the term “engine” means “combustion engine,” equipment which can convert chemical energy into mechanical energy by combusting fuel in the presence of air. DOE received varying comments regarding the inclusion of engine-driven compressors. Jenny, the Association of Equipment Manufacturers (AEM), and Sullair recommended excluding engine-driven compressors due to the burden imposed by current emissions regulations and overall low energy consumption by these products. (Jenny, No. 0005 at p. 2; AEM, No. 0011 at p. 1-2; Sullair, No. 0013 at p. 2) EEI and the CA IOUs urged DOE to include engine-driven compressors to avoid creating a market trend towards engine-driven compressors. (EEI, No. 0012 at p. 2-3; CA IOUs, No. 0018 at p. 2) The joint Commenters recommended that DOE examine engine-driven compressors to evaluate possible energy savings but noted that generally they are used in low-duty cycle applications. (Joint Comment, No. 0016 at p. 2) In response to comments submitted by interested parties, DOE investigated engine-driven air compressors and found that they are generally portable and designed to be used in environments where access to electricity is limited or non-existent, particularly at the current or voltage levels required by comparable electric motor-driven compressors. Engine-driven air compressors are also typically used as on-demand units, with a low duty cycle and annual energy consumption. Additionally, engine-driven air compressors, by nature of their portability, are difficult to optimize for a specific set of operating conditions, which may affect their efficiency relative to a stationary unit that is designed or selected with a specific load profile in mind. Consequently, engine-driven and electric motor-driven air compressors do not serve the same applications or utility in the marketplace and are not mutual substitutes. DOE is aware that engine-driven air compressors are currently covered by the Environmental Protection Agency's Tier 4 emissions regulations (40 CFR 1039). DOE understands that these Tier 4 regulations have resulted in market-wide redesigns for the engines typically used in these compressors, which has required compressor manufacturers to redesign some aspects of the bare compressor as well. DOE recognizes that any regulations established for engine-driven compressors may result in incrementally more burdensome testing requirements for such equipment and potential design changes that conflict with those required for compliance with Tier 4 regulations. Additionally, the industry standard test method proposed for incorporation into this test procedure, Annex C of ISO 1217:2009, is the most widely-used test method for determining performance of electric motor-driven compressors. However, Annex C of ISO 1217:2009 does not apply to engine-driven compressors. DOE notes that Annex D of ISO 1217:2009, which is not proposed for incorporation into this test procedure, is intended to address engine-driven compressors. However, unlike Annex C of ISO 1217:2009, DOE currently lacks testing and performance data related to Annex D of ISO 1217:2009. Consequently, DOE is unable to verify the repeatability and applicability of Annex D of ISO 1217:2009 at this time. Due to the lack of testing and performance data from Annex D of ISO 1217:2009, as well as the difference in market, application, and applicable industry test procedure; DOE proposes to exclude engine-driven air compressors from the scope of applicability of the test procedure proposed in this rulemaking. However, DOE may consider a test procedure for engine-driven compressors as part of a future rulemaking. b. Styles of Electric Motor Motors used in compressors broadly fall into two categories: brushed and brushless. Brushed motors perform “commutation”—changing the direction of the electric field as the motor's rotor turns—using a sliding electrical contact, or “brush.” Brushless motor technologies may vary widely in how they accomplish commutation, but have in common the absence of brushes. DOE is aware that some small compressors intended for very low duty cycle applications may be manufactured with motors which use brushes. Although brushes are simple to control and inexpensive to construct, they are rarely used in applications with significant operating hours for several reasons. First, brushes generally are less efficient than brushless technology, and are therefore suitable only for applications with low duty cycles. Second, brushes wear and require replacement at regular intervals, which may result in costly downtime in an industrial process. Third, brushes may create electrical arcing, rendering them unsuitable for certain industrial environments where combustible or explosive gases or dusts may exist. Finally, brushes may create more noise than brushless technology, and quieter equipment is often viewed as an important and attractive attribute by an end-user. All of these factors limit the applications suitable for compressors manufactured with brushed motors. However, DOE recognizes there is a unique market segment in which brushed motors are appropriate, such as specific applications in which operating life and durability are not important criteria. As a result, DOE believes that any test procedure designed for compressors sold with brushed electric motors would require a unique load profile in order to accurately reflect a representative average use cycle, as required by EPCA. (42 U.S.C. 6314(a)(2)) DOE also notes that, because compressors sold with brushed motors play a specialized and minor role in the compressors market, they are not associated with significant energy consumption. Consequently, DOE proposes to limit the scope of the test procedure to only those compressors that are driven by brushless motors. DOE may consider separate test procedures or energy conservation standards for compressors sold with brushed electric motors as part of a separate rulemaking. For the purposes of establishing the applicability of this test procedure rulemaking, DOE proposes to define a brushless electric motor as a machine that converts electrical power into rotational mechanical power without use of sliding electrical contacts. DOE considers brushless motors to include, but not be limited to, what are commonly known as induction, brushless DC, permanent magnet, electrically commutated, and reluctance motors. The term brushless motors would not include what are commonly known as brushed DC and universal motors. DOE requests comment on its proposal to establish test procedures for only brushless electric motor-driven equipment and on its proposed definition of brushless electric motor. 5. Compressor Capacity (Compressor Motor Nominal Horsepower) Compressors are sold in a very wide range of capacities. Compressor capacity refers to the overall rate at which a compressor can perform work. Although the ultimate end-user requirement is a specific output volume flow rate of air at a certain pressure, industry typically describes compressor capacity in terms of the “nominal” horsepower of the motor. As a result, in this rulemaking, DOE proposes to consider compressor capacity in terms of the “nominal” horsepower of the motor with which the compressor is distributed in commerce. DOE recognizes that although the term nominal motor horsepower is commonly used within the compressor industry, it is not explicitly defined in ISO 1217:2009. To alleviate any ambiguity associated with these terms, DOE proposes to define the term “compressor motor nominal horsepower” to mean the motor horsepower of the electric motor, as determined in accordance with the applicable procedures in subpart B and subpart X of part 431, with which the rated air compressor is distributed in commerce. In the Framework Document, DOE discussed limiting the scope of applicability based on compressor capacity as measured in horsepower (hp) to units with capacities of between 1 to 500 hp in order to align the scope of compressor standards with the scope of DOE's electric motors standards. See 10 CFR 431.25. Commenters generally recommended expanding the scope to cover compressors larger than 500 hp, in order to capture the maximum possible energy savings that may result from the combined impacts of this test procedure rulemaking and the associated energy conservation standard rulemaking. (EEI, No. 0012 at p. 3; Joint Comment, No. 0016 at p. 2; Natural Resource Defense Council (NRDC), No. 0019 at p. 1; CA IOUs, No. 0018 at p. 2) Jenny and the Joint Commenters also recommended that the lower hp limit should be increased due to the low annual energy usage of compressors under 10 hp. (Jenny, No. 0005 at p. 3; Joint Comment, No. 0016 at p. 2) DOE considered the comments of interested parties regarding the range of equipment capacities considered in this test procedure rulemaking. Shipment data, broken down by rated capacity and compressor style ( i.e. , rotary, reciprocating, and dynamic) indicate that units above 400 hp represent less than 1 percent of the rotary market and virtually none of the reciprocating market. Although it is possible to build positive displacement compressors above 500 hp, shipments are very low and the equipment is typically custom-ordered. DOE notes that, above 500 hp, dynamic compressors are the dominant choice for industrial compressed air service. However, as discussed previously in section III.B.3, the proposed test procedure would not apply to dynamic compressors. Additionally, less performance data is available on units with capacities greater than 500 hp and therefore it is difficult to determine the suitability of the proposed test procedure provisions to such large equipment. Further, testing such large capacity equipment may require more specialized equipment that is less commonly available and would increase the burden associated with conducting the test procedure. Regarding the lower end of the capacity range ( i.e. , 1 hp), DOE notes that available shipment data indicates that compressors 10 hp and below, while consuming less power on a per-unit basis, account for more than a quarter of fixed-speed, rotary units shipped. DOE believes the proposed test procedures are suitable for measuring the performance of such units, and would not preclude the possibility of cost effective energy savings without performing analysis. As a result, DOE proposes limiting the scope of this test procedure to air compressors with a compressor motor nominal horsepower of greater than or equal to 1 and less than or equal to 500 hp. Based on available shipment data, DOE's proposal is expected to cover nearly the entirety of the rotary and reciprocating compressor market. DOE requests comment on its proposed definition of compressor motor nominal horsepower. Additionally, DOE seeks comment on whether motors not currently subject to the test procedure requirements in subpart B and subpart X of part 431 are incorporated into air compressors within the scope of this proposed test procedure. If so, DOE requests comment on how prevalent these motors are, and whether the test methods described in subpart B and subpart X of part 431 would be applicable to determine the compressor motor nominal horsepower of such motors. If the test methods described in subpart B and subpart X of 10 CFR part 431 are not applicable to motors not subject to DOE's current Federal test procedures for small electric or electric motors, DOE requests comment on what test methods could be used to determine their compressor motor nominal horsepower. DOE requests comment on the proposal to include only compressors with a compressor motor nominal horsepower of greater than or equal to 1 and less than or equal to 500 within the scope of this test procedure. 6. Output Pressure Range DOE also proposes in this NOPR to limit the applicability of the test procedure based on the full-load operating pressure of the equipment. Specifically, DOE proposes that the test procedure only be applicable to compressors with full-load operating pressures greater than or equal to 31 psig and less than or equal to 225 psig. DOE believes this range represents the majority of the reciprocating and rotary compressor market. In the Framework Document, DOE discussed limiting the scope of this initial compressor test procedure based on the full-load operating pressure of the compressors. (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 8). However, in the Framework Document, DOE used the comparable terms “absolute discharge pressure” and “absolute gauge output pressure.” (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 19). DOE also notes that the full-load operating pressure is related to the pressure ratio, discussed previously in section III.A, but describes the absolute increase in pressure, whereas the pressure ratio represents the pressure increase expressed as a multiple of the inlet pressure of the compressor. In response to the Framework Document, CAGI noted that industry generally considers compressors to have a pressure ratio of greater than 2.5. (CAGI, No. 0009 at p. 1) In a separate submission, CAGI provided the following more detailed breakdown of the rotary compressors market: • Approximately 4.4 to 30 pounds per square inch gauge (psig) (pressure ratio greater than 1.3 and less than or equal to 3.0): The compressors industry generally refers to these products as blowers—a term DOE is considering defining as part of its fans and blowers rulemaking (Docket No. EERE-2013-BT-STD-0006). The majority of these units are typically distributed in commerce as bare compressors and do not include a driver, mechanical equipment, or controls. • 31 to 79 psig (pressure ratio greater than 3.1 and less than or equal to 6.4): There are relatively few compressed air applications in this pressure range, contributing to both low product shipment volume and low annual energy consumption. • 80 to 139 psig (pressure ratio greater than 6.4 and less than or equal to 10.5): This range represents the majority of general compressed air applications, shipments, and annual energy use. • 140 to 215 psig (pressure ratio greater than 10.5 and less than or equal to 15.6): This range represents certain specialized applications, relatively lower sales volumes and annual energy consumption when compared to the 80 to 139 psig rotary compressor segment. • Greater than 215 psig (pressure ratio greater than 15.6): This range represents even more specialized applications, which require highly engineered rotary compressors that vary based on each application. (CAGI, No. 0030 at p. 4) DOE did not receive any additional information that separated the market of reciprocating compressors by pressure. According to the Lot 31 preparatory study final report, 13 single- and two-stage reciprocating compressors typically operate from 0.8 to 12 bar (12 to 174 psig; pressure ratio 1.8 to 13), and multi-stage reciprocating compressors typically operate from 12 to 700 bar (174 to 10,152 psig; pressure ratio 13 to 701). However, based on market research and discussions with various compressor manufacturers, DOE believes that pressure ranges for reciprocating compressors are similar to rotary compressors. 13 For copies of the EU Lot 31 draft regulation: www.regulations.gov/conentStreamer?document=EERE-2013-BT-STD-0040-0031&disposition=attachment&contentType=pdf. Based on DOE's research and information from commenters, DOE proposes to apply the test procedure to compressors with full-load operating pressures of between 31 and 225 psig (pressure ratios greater than ~3.1 and less than or equal to 16.3). DOE notes that while some commenters suggested an upper limit of 215 psig, full-load operating pressure values may be generated differently by each manufacturer and it is not clear that they are completely comparable between manufacturers. 14 For example, a product listed at 215 psig from one manufacturer may compete with a product listed at 217 psig from another, which may compete with one listed at 212 psig from a third. Although DOE's proposed test procedure seeks to eliminate this issue ( see specifically , section III.D.2.i), DOE must still account for the current lack of consistent pressure rating methodology in the compressor industry. As a result, DOE proposes to adopt an upper limit of 225 psig to include the majority of non-special purpose equipment DOE could identify on the market. Compressor equipment with full-load operating pressures below 31 psig and above 225 psig generally serve applications that do not often overlap with the 31-225 psig compressor market and do not represent a significant volume of sales. DOE notes that equipment with full-load operating pressures below 31 psig and above 225 psig may still meet the proposed definition of air compressor. DOE may consider extending test procedure applicability to these compressors in a future rulemaking. 14 DOE notes that there is no universally accepted procedure for establishing full-load operating pressure and, thus, no assurances that values are comparable. DOE requests comment on its characterization of the rotary compressor market by pressure ranges, and whether the reciprocating compressor market is similarly characterized. As the full-load operating pressure would be used to determine the applicability of the proposed test procedure, it is important that the full-load operating pressure be established consistently amongst compressor models. To that end, DOE proposes to establish a specific definition and procedure for determining full-load operating pressure for applicable compressors, which is based on the maximum full-flow operating pressure. Specifically, DOE proposes to define the term full-load operating pressure as follows: Full-load operating pressure means the represented value of discharge pressure, which must be greater than or equal to 90 percent and less than or equal to 100 percent of the maximum full-flow operating pressure. The term full-load operating pressure is commonly used in the compressors industry to characterize compressor output air pressure and appears as a listed parameter on CAGI's voluntary performance verification data sheets. Additionally, the EU Lot 31 draft standard 15 characterizes compressor output pressure using a nearly identical term, “full load outlet pressure.” DOE proposes this definition of full-load operating pressure in order to characterize compressor output pressure in a manner consistent with both the U.S. industry and the European standard, and to ensure reproducible and comparable representations among the different manufacturers and models. Specifically, DOE understands the full-load operating pressure to be a nominal term at which manufacturers elect to produce ratings. For example, the CAGI datasheets define the term as “the operating pressure at which the capacity and electrical consumption were measured for this data sheet.” 16 Therefore, DOE is defining the term “full-load operating pressure” to be a nominal, self-declared value that is within a certain range of the actual, measured maximum full-flow operating pressure. 15 http://www.regulations.gov/contentStreamer?documentId=EERE-2013-BT-STD-0040-0031&disposition=attachment&contentType=pdf . 16 See, for example, http://www.cagi.org/pdfs/Fixed%20Speed%20Datasheet%2010-11%20rev8.pdf. While DOE understands the need to provide manufacturers some discretion with regard to the selection of the full-load operating pressure, specifying that the selected nominal value is within 10 percent of the actual, tested maximum full-flow operating pressure ensures that the self-declared value is in fact representative of the equipment's capacity and provides better consistency and comparability among ratings. As the proposed definition of full-load operating pressure references the maximum full-flow operating pressure, DOE also proposes a definition and test method (discussed in section III.D.2.i) for maximum full-flow operating pressure. Specifically, the maximum full-flow operating pressure is defined as the maximum discharge pressure at which the compressor is capable of operating as determined in accordance with the methods described in the applicable section of the compressor test procedure. 17 This is the actual maximum operating pressure of the equipment, consistent with the CAGI definition of the term, which describes the maximum full-flow operating pressure as maximum pressure attainable at full flow, usually the unload pressure setting for load/no load control or the maximum pressure attainable before capacity control begins. In the case of the term full-load operating pressure, there is a corresponding flow term, full-load actual volume flow rate, which DOE proposes to define as the actual volume flow rate of the compressor at the full-load operating pressure. The full-load actual volume flow rate is a dependent value and is determined through measurement at the full-load operating pressure, as determined in section III.D.2.i. 17 In the definition proposed in section 10 CFR 431.344, this language refers to the appropriate section number of the regulatory text as it would appear in the Code of Federal Regulations. The proposed definition of full-load actual volume flow rate mentions the actual volume flow rate of the equipment; therefore, DOE must also define the term actual volume flow rate. ISO 1217:2009 defines a similar term, actual volume flow rate of a compressor, as the actual volume flow rate of gas, compressed and delivered at the standard discharge point, referred to conditions of total temperature, total pressure and composition prevailing at the standard inlet point. 18 Assuming, as proposed, this test procedure applies only to air compressors, DOE's proposes the following, similar definition: 18 This language also describes the parameter called “corrected volume flow rate,” which works out to be equivalent to “actual volume flow rate” and is addressed in this section. Actual volume flow rate means the volume flow rate of air, compressed and delivered at the standard discharge point, referred to conditions of total temperature, total pressure and composition prevailing at the standard inlet point. DOE notes that the terms standard discharge point, total temperature, total pressure, and [gas] composition are explicitly defined in ISO 1217:2009, and DOE proposes to incorporate these definitions by reference. DOE also notes that the term “referred to,” which is common compressor industry parlance, is synonymous with the term “normalized to.” In both cases, the objective is to characterize measured values with respect to a common reference point so that they may be more easily compared. In this case, the reference point is the measured atmospheric conditions at the compressor inlet point. The compressor industry describes this practice as “referring” the values to inlet conditions. In the interest of harmonization with the definition supplied in ISO 1217:2009, DOE proposes to keep the term “referred to” in its definition of actual volume flow rate. DOE also proposes that actual volume flow rate be measured in accordance with section C.4.2.1 of annex C of ISO 1217:2009. DOE notes that section C.4.2.1 of annex C of ISO 1217:2009 refers to a parameter called “corrected volume flow rate;” for the purposes of this test procedure, DOE proposes that the terms corrected volume flow rate and actual volume flow rate be deemed equivalent and synonymous. Section C.4.2.1 of annex C of ISO 1217:2009 also includes a correction factor for shaft speed, which is clarified in section C.4.2.2 of annex C of ISO 1217:2009 as “only required when the electric motor drive is not supplied.” As described in section III.B.2, DOE is proposing to establish test procedures only for compressor packages, which always include a driver ( i.e., electric motor). Therefore, DOE proposes to specify that the correction factor for shaft speed in section C.4.2.1 of annex C of ISO 1217:2009 is not to be used. DOE requests comment on the proposed definitions of full-load operating pressure, maximum full-flow operating pressure, and full-load actual volume flow rate, and actual volume flow rate. DOE requests comment on the proposal to include only compressors with a full-load operating pressure greater than or equal to 31 psig and less than or equal to 225 psig within the scope of this test procedure. C. Energy-Related Metrics 1. Specific Input Power and Isentropic Efficiency In the Framework Document, DOE discussed the two most common metrics used in the compressor industry today to describe the performance of air compressors: package specific power and package isentropic efficiency. (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 10-11). Package specific power is the compressor power input at a given load point, divided by the actual volume flow rate at the same load point, as determined in accordance with the methods described in section III.C.1. Further discussion of the relevant portions of ISO 1217:2009 and DOE's proposal to incorporate it by reference is found in section III.D of this document. DOE notes that section C.4.4 of annex C of ISO 1217:2009 refers to “specific energy consumption.” For the purposes of this test procedure, the terms specific energy consumption and package specific power are interchangeable. Package isentropic efficiency is the ratio of power required for an ideal isentropic compression process at a given load point 19 to the actual packaged compressor power input used at the same load point, as determined in accordance with the methods described in section III.C.4 and III.C.5. 19 Or a weighted average of several, specified load points. The two metrics under consideration provide similar but different information. Package specific power provides users with a way to directly calculate the power required to deliver a particular flow rate of air; this metric is currently used by the CAGI Voluntary Performance Verification Program to characterize compressor performance. 20 However, package specific power calculations are only valid at the output pressure at which a unit is tested and cannot be used to compare units operating at different pressures. 20 http://cagi.org/performance-verification/overview.aspx. Package isentropic efficiency measures how efficiently a compressor package delivers a given flow rate of air. Package isentropic efficiency is relative to an ideal isentropic process and therefore can be used to compare units across a wide range of pressures. DOE notes that the EU has adopted package isentropic efficiency as the regulatory metric in their draft air compressor regulation. 21 21 Available at: http://www.regulations.gov/contentStreamer?documentId=EERE-2013-BT-STD-0040-0031&disposition=attachment&contentType=pdf. In the Framework Document, DOE requested feedback regarding both metrics and which would be more appropriate for any potential compressors energy conservation standard. (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 11). The Joint Commenters and NRDC commented that both package specific power and package isentropic efficiency should be considered to provide end users with the most information possible when making purchasing decisions. (Joint Comment, No. 0016 at p. 3; NRDC, No. 0019 at p.1; and NRDC, No. 0019 at p. 2) The CA IOUs recommended that a part-load test metric be used to assist in the design optimization of compressor systems with multiple compressors. (CA IOUs, No. 0018 at p. 3) The following section discusses DOE's selected metric and DOE's rationale for selecting it. 2. Selected Metric: Package Isentropic Efficiency After careful consideration of Framework Document comments and additional feedback received during interviews with manufacturers, DOE proposes to adopt package isentropic efficiency as the representative metric for describing the energy performance of certain compressors. However, DOE notes that package isentropic efficiency, as introduced in section III.C.1, is a generic metric applicable to all load points. Therefore, DOE must define a load point (or load points) for the purpose of determining a reproducible and comparable efficiency rating for each compressor model. Kaeser corroborated this idea in its comment, and stated that ISO 1217:2009 provides instructions for how to perform testing but does not specify at what points to perform said tests. (Kaeser Compressors, No. 0040 at p. 94) In relation to load points and the proposed metric, NEEA requested that the test procedure account for variable-speed compressors, while the CA IOUs recommended that DOE include a part-load efficiency metric. (NEEA, No. 0040 at p. 92; and CA IOUs, No. 0018 at p. 3). DOE agrees that part-load performance may be valuable for users of variable-speed compressors. However, DOE believes that a part-load performance metric would not be applicable to all fixed-speed compressors, as many of these compressors are not designed to operate at part-load. Consequently, DOE proposes to establish two versions of package isentropic efficiency: full-load package isentropic efficiency and part-load package isentropic efficiency. Full-load package isentropic efficiency would apply only to fixed-speed compressors, whereas part-load package isentropic efficiency would apply only to variable-speed compressors. Full-load isentropic efficiency is evaluated at a single load point, while part-load isentropic efficiency is a weighted composite of performance at multiple load points (or rating points). This structure follows the structure of the draft EU compressors regulation and is consistent with the previously discussed interested party comments. DOE believes these metrics and load points provide the best representation of energy consumption for fixed- and variable-speed equipment, respectively. Equations 1 and 2 describe the full- and part-load package isentropic efficiency. Further details on the calculation of these metrics are contained in sections III.C.4 and III.C.5. Further details on load points and weighting are discussed in section III.C.3. EP05MY16.000 Where: η isen,FL = package isentropic efficiency at full-load operating pressure, P isen,100 % = isentropic power required for compression at full-load operating pressure, and P real,100 % = packaged compressor power input at full-load operating pressure. EP05MY16.001 Where: η isen,PL = part-load package isentropic efficiency, ω i = weighting factor for rating point i, P isen,i = isentropic power required for compression at rating point i, P real,i = packaged compressor power input at rating point i, and i = selected rating points. In order to clearly separate the two groups of compressors, DOE proposes the following definitions for fixed-speed and variable-speed compressors. Fixed-speed compressor means an air compressor that is not capable of adjusting the speed of the driver continuously over the driver operating speed range in response to incremental changes in the required compressor flow rate. Variable-speed compressor means an air compressor that is capable of adjusting the speed of the driver continuously over the driver operating speed range in response to incremental changes in the required compressor actual volume flow rate. The proposed definition for fixed-speed compressor encompasses compressors that use single speed and multi-speed drivers. Both definitions are based on the definitions for non-continuous control and continuous control, respectively, as adopted in DOE's pumps test procedure final rule, due to the similarities between compressors and pumps. 81 FR 4086 (Jan. 25, 2016). The following section discusses load points for both full-load and part-load package isentropic efficiency. 3. Load Points and Weighting Factors for Calculating Full-Load and Part-Load Isentropic Efficiency DOE reviewed the load points and weighting factors used by current industry programs. For fixed-speed compressors, the CAGI Performance Verification Program specifies testing at two load points: (1) flow rate at full-load operating pressure and (2) zero flow rate. In contrast, the European Union's draft air compressors regulation 22 specifies testing fixed-speed compressors only at full-load. 22 Available at: http://www.regulations.gov/contentStreamer?documentId=EERE-2013-BT-STD-0040-0031&disposition=attachment&contentType=pdf. For variable-speed compressors, the CAGI Performance Verification Program references Annex E of ISO 1217:2009 and specifies testing at a minimum of six load points: • maximum volume flow rate, • three or more volume flow rates evenly spaced between the minimum and maximum volume flow rate, • minimum volume flow rate, and • no-load power. In contrast, the European Union's draft air compressors regulation 23 specifies testing variable-speed compressors at only three designated load points; 40, 70, and 100 percent of the flow rate measured at full-load operating pressure (or maximum flow rate). 23 Available at: http://www.regulations.gov/contentStreamer?documentId=EERE-2013-BT-STD-0040-0031&disposition=attachment&contentType=pdf. DOE believes that the EU's draft approach of requiring testing at only three load points would reduce the burden of testing while still providing an accurate representation of the unit's part-load performance. Further, by stipulating specific load points for testing rather than evenly spaced load points, the EU method ensures that all variable-speed compressors are tested at the same load points, resulting in simple and accurate comparisons across equipment models. Consequently, DOE proposes to adopt the same load profiles for fixed-speed and variable-speed compressors as those published in the draft EU air compressors regulation. These load points are summarized in Table III.2. Table III.2—Load Profiles Based on Compressor Configuration Compressor configuration Load profile Load points Fixed-speed compressors Full-Load Maximum flow rate. Variable-speed compressors Part-Load 40, 70, and 100 percent of maximum flow rate. As first discussed in section III.C.2, and shown in equation 2, the part-load package isentropic efficiency metric requires a weighting factor for each load point in order to calculate the final part-load package isentropic efficiency. These weighting factors are meant to represent the percentage of operating time the compressor is operating at each load point. The draft EU air compressors regulation, after which DOE modeled its proposed part-load efficiency calculation, specifies weights of 25, 50, and 25 percent; at load points of 40, 70, and 100 percent of maximum flow, respectively. DOE notes that the CAGI Performance Verification Program does not use a weighted average part-load metric, and thus does not provide weighting factors. DOE found no other weighting factors currently in use within the compressor industry. Additionally, DOE was unable to find real-world, representative load profile data for equipment in the field. In the absence of representative load profile data, DOE proposes adopting the EU load weighting factors, which would allow for direct and equitable comparisons between equipment, since the weighting factors would be applicable to all variable-speed equipment. In addition, DOE believes these weighting factors adequately represent the operating range of variable-speed compressors and would not be unduly burdensome to conduct, since compressor manufacturers may already perform such testing in support of compliance with the EU regulations. Table III.3 summarizes DOE's proposal for weighting factors for the part-load package isentropic efficiency metric. Table III.3—Weight Values for Specified Part-Speed Compressor Load Profile Load point (percent of maximum flow rate) Weighting factors (ω i as specified in equation 6) 40 0.25 70 0.50 100 0.25 DOE requests comment on the proposed load points and weighting factors for package isentropic efficiency for both fixed-speed and variable-speed compressors. 4. Full-Load Isentropic Efficiency As discussed in section III.C.2, DOE proposes to rate fixed-speed compressors with the full-load isentropic efficiency metric. This section discusses, in detail, the formulas needed to calculate full-load isentropic efficiency for fixed-speed compressors. DOE notes that certain inputs to these formulas are measured or calculated using ISO 1217:2009, certain sections of which DOE proposes to incorporate by reference (see section III.D). For these inputs, DOE has referenced the specific locations within ISO 1217:2009 where those values or procedures may be found. Complete details on ISO 1217:2009, and DOE's justification for its use in this test procedure, are discussed in section III.D. As discussed in section III.C.3, full-load package isentropic efficiency is calculated at one load point: full-load operating pressure. The equation for full-load package isentropic efficiency is as follows: EP05MY16.002 Where: η isen,FL = η isen,100 % = package isentropic efficiency at full-load operating pressure and 100 percent of full-load actual volume flow rate, P real,100 % = packaged compressor power input at full-load operating pressure and 100 percent of full-load actual volume flow rate, as determined from equation 4, 24 and 24 The correction factor for the shaft speed (K 4 ) in section C.4.3.1 of annex C in ISO 1217:2009 is not applicable to this test procedure because the electric motor drive is included in the package, and it is therefore omitted from this equation. P isen,100 % = isentropic power required for compression at full-load operating pressure and 100 percent of full-load actual volume flow rate, as determined from equation 5. As referenced in equation 3, the packaged compressor power input at full-load operating pressure and 100 percent of full-load actual volume flow rate is determined in accordance with equation 4: EP05MY16.003 Where: K 5 = correction factor for inlet pressure and pressure ratio, as determined in section C.4.3.2 of annex C to ISO 1217:2009 at a contractual inlet pressure of 100 kPa, 25 and 25 The correction factor for inlet pressure uses contractual values for inlet pressure. Since a contractual value is not applicable to this test procedure, DOE proposes to use a value of 100 kPa from annex F in ISO 1217:2009. P PR,100 % = packaged compressor power input reading at full-load operating pressure and 100 percent of full-load actual volume flow rate, as determined in section C.2.4 of annex C to ISO 1217:2009 (watts). The isentropic power required for compression at full-load operating pressure and 100 percent of full-load actual volume flow rate (P isen,100 % ), shown in equation 5, is evaluated using measurements taken while the unit is operating at full-load operating pressure: EP05MY16.004 Where: V 1_ m3/s = corrected volume flow rate at full-load operating pressure and 100 percent of full-load actual volume flow rate, as determined in section C.4.2.1 of annex C of ISO 1217:2009 (cubic meters per second) with no corrections made for shaft speed, p 1 = Atmospheric pressure, as determined in section 5.2.2 of ISO 1217:2009 (Pa), p 2 = discharge pressure at full-load operating pressure and 100 percent of full-load actual volume flow rate, determined in accordance with section 5.2 of ISO 1217:2009 (Pa), and κ = isentropic exponent (ratio of specific heats) of air, which, for the purposes of this test procedure, is 1.400. 26 26 The isentropic exponent of air has some limited variability with atmospheric conditions. DOE chose a fixed value of 1.400 to align with the EU Lot 31 proposed metric calculations. DOE requests comment on its proposed definition for full-load package isentropic efficiency, and its use as the metric for fixed-speed compressors. 5. Part-Load Isentropic Efficiency As discussed in section III.C.2, DOE proposes to rate variable-speed compressors with the part-load package isentropic efficiency metric. This section discusses, in detail, the formulas needed to calculate part-load isentropic efficiency for fixed-speed compressors. DOE notes that certain inputs to these formulas are measured or calculated using ISO 1217:2009, certain sections of which DOE proposes to incorporate by reference. For these inputs, DOE has referenced the specific location within ISO 1217:2009 where that value or calculation procedure is found. However, complete details on ISO 1217:2009, and DOE's justification for its use in this test procedure, are discussed in section III.D. As discussed in section III.C.3, part-load package isentropic efficiency is calculated using a weighted average of three load points: 40, 70, and 100 percent of maximum flow rate. The equation for part-load package isentropic efficiency is as follows: EP05MY16.005 Where: η isen,PL = part-load package isentropic efficiency for a variable-speed compressor, η isen, 100 % = package isentropic efficiency at full-load operating pressure, as determined in equation 3, η isen,70 % = package isentropic efficiency at 70 percent of full-load actual volume flow rate, as determined in equation 7, η isen,40 % = package isentropic efficiency at 40 percent of full-load actual volume flow rate, as determined in equation 9, ω 40 % = weighting at 40 percent of full-load actual volume flow rate (0.25), as described in section III.C.3, ω 70 % = weighting at 70 percent of full-load actual volume flow rate (0.5), as described in section III.C.3, and ω 100 % = weighting at 100 percent of full-load actual volume flow rate (0.25), as described in section III.C.3. The equation for full-load package isentropic efficiency is the same as noted in III.C.4, above (equation 3 through equation 5). Package isentropic efficiency at 40 and 70 percent of full-load actual volume flow rate are defined as follows: EP05MY16.006 Where: η isen,70 % = package isentropic efficiency at 70 percent of maximum flow rate, P isen,70 % = isentropic power required for compression at 70 percent of full-load actual volume flow rate, as determined in equation 11, and P real,70 % = packaged compressor power input at 70 percent of full-load actual volume flow rate, as determined from equation 8. 27 27 The correction factor for the shaft speed (K 4 ) in section C.4.3.1 of annex C in ISO 1217:2009 is not applicable to this test procedure because the electric motor drive is included in the package, and it is therefore omitted from this equation. EP05MY16.007 Where: K 5 = correction factor for inlet pressure and pressure ratio, as determined in section C.4.3.2 of annex C to ISO 1217:2009 at a contractual inlet pressure of 100 kPa, 28 and 28 The correction factor for inlet pressure uses contractual values for inlet pressure. Since a contractual value is not applicable to this test procedure, a value of 100 kPa from annex F in ISO 1217:2009 is used. P PR, 70 % = packaged compressor power input reading at full-load operating pressure and 70 percent of full-load actual volume flow rate, as determined in section C.2.4 of annex C to ISO 1217:2009 (watts). EP05MY16.008 Where: η isen,40 % = package isentropic efficiency at 40 percent of full-load actual volume flow rate, P isen,40 % = isentropic power required for compression at 40 percent of full-load actual volume flow rate, as determined in equation 12, and P real,40 % = packaged compressor power input at 40 percent of full-load actual volume flow rate, as determined from equation 10. 29 29 The correction factor for the shaft speed (K 4 ) in section C.4.3.1 of annex C in ISO 1217:2009 is not applicable to this test procedure because the electric motor drive is included in the package, and it is therefore omitted from this equation. EP05MY16.009 Where: K 5 = correction factor for inlet pressure and pressure ratio, as determined in section C.4.3.2 of annex C to ISO 1217:2009 at a contractual inlet pressure of 100 kPa, 30 and 30 The correction factor for inlet pressure uses contractual values for inlet pressure. Since a contractual value is not applicable to this test procedure, a value of 100 kPa from annex F in ISO 1217:2009 is used. P PR, 40 % = packaged compressor power input reading at full-load operating pressure and 40 percent of full-load actual volume flow rate, as determined in section C.2.4 of annex C to ISO 1217:2009 (watts). Finally, P isen,70 % , and P isen,40 % would then be calculated using values measured at each of the designated rating points, as shown in equations 11 and 12 respectively: EP05MY16.010 Where: V 1_m3/s = corrected volume flow rate at 70 percent of full-load actual volume flow rate, as determined in section C.4.2.1 of annex C of ISO 1217:2009 (cubic meters per second) with no corrections made for shaft speed, p 1 = Atmospheric pressure, as determined in section 5.2.2 of ISO 1217:2009 (Pa), p 2 = discharge pressure at 70 percent of full-load actual volume flow rate, determined in accordance with section 5.2 of ISO 1217:2009 (Pa), and κ = isentropic exponent (ratio of specific heats) of air, which for the purposes of this test procedure is 1.400. 31 31 The isentropic exponent of air has some limited variability with atmospheric conditions. DOE chose a fixed value of 1.400 to align with the EU Lot 31 proposed metric calculations. EP05MY16.011 Where: V 1_m3/s = corrected volume flow rate at 40 percent of full-load actual volume flow rate, as determined in section C.4.2.1 of annex C of ISO 1217:2009 (cubic meters per second) with no corrections made for shaft speed, p 1 = Atmospheric pressure, as determined in section 5.2.2 of ISO 1217:2009 (Pa), p 2 = discharge pressure at 40 percent of full-load actual volume flow rate, determined in accordance with section 5.2 of ISO 1217:2009 (Pa), and κ = isentropic exponent (ratio of specific heats) of air, which for the purposes of this test procedure is 1.400. 32 32 The isentropic exponent of air has some limited variability with atmospheric conditions. DOE chose a fixed value of 1.400 to align with the EU Lot 31 proposed metric calculations. DOE requests comment on its proposed definition for part-load package isentropic efficiency, and its use as the metric for variable-speed compressors. D. Test Method This section discusses DOE's proposal for a test method to measure, in a standardized and reproducible manner, all quantities needed to determine package isentropic efficiency. These quantities are: Inlet and discharge pressures, flow rate, and packaged compressor power input at given load point(s). Specifically, DOE proposes to incorporate by reference the test methods contained in certain, applicable sections of ISO 1217:2009 as the basis for the compressors test procedure. However, DOE notes that several modifications and additions to ISO 1217:2009 are required to determine the package isentropic efficiency of applicable compressors and improve the repeatability of ratings. These proposals are discussed in sections III.D.1 and III.D.2. 1. Referenced Industry Test Method In the Framework Document, DOE noted the need to establish a test method capable of reliably measuring compressor performance for determining compliance with energy conservation standards. DOE stated that it was considering two industry standards (ISO 1217:2009 and ISO 5389:2005) as the basis for DOE's compressor test procedure. DOE requested comments from interested parties on the potential use of several test procedures, including ISO 1217:2009, as a basis for the development of a DOE test procedure. (Docket No. EERE-2013-BT-STD-0040, No. 1 at p. 12). In response to the Framework Document, The Joint Commenters, CAGI, and the CA IOUs all recommended using ISO 1217:2009 for compressor package testing. (CAGI, No. 0009 at p. 3; Joint Comment, No. 0016 at p. 3; and CA IOUs, No. 0018 at p. 3) CAGI further commented during the Framework Public Meeting that it would evaluate ISO 1217:2009 to determine if additional changes were necessary. (CAGI, No. 0040 at p. 92) Ingersoll-Rand cautioned that ISO 1217:2009 may require changes in order to measure package isentropic efficiency but provided no specific recommendations regarding these changes. (Ingersoll-Rand, No. 0040 at p. 90) DOE agrees with Ingersoll-Rand, and DOE has proposed specific methods for calculating package isentropic efficiency, as discussed in sections III.C.4 and III.C.5. DOE's proposal uses the methods and results of ISO 1217:2009 as a basis for their proposed test procedure, but provides additional calculations and provisions that are necessary for determining package isentropic efficiency. In response to the comments regarding the use of ISO 1217:2009, DOE reviewed ISO 1217:2009 and ultimately determined that it (1) is the most widely used test standard in the compressor industry for evaluating positive displacement compressor performance; and (2) it attempts to define uniform methods for conducting laboratory tests to determine the inlet and discharge pressures, flow rate, and packaged compressor power input at a given load point—all of which are required to calculate part- and full-load package isentropic efficiency (as defined sections III.C.4 and III.C.5). ISO 1217:2009 also contains certain specifications regarding test equipment, instrument accuracy, and test tolerances. However, as discussed previously, DOE notes that several modifications and additions to ISO 1217:2009 are required to determine the package isentropic efficiency of applicable compressors and improve the repeatability and reproducibility of ratings. Generally, in DOE's view, ISO 1217:2009 is an appropriate industry testing standard for evaluating performance of applicable compressors. However, DOE notes that ISO 1217:2009 is written as a customer acceptance test. As such, DOE believes that several modifications and additions to ISO 1217:2009 are required in order to provide the specificity and repeatability required by DOE. These proposed modifications are discussed in detail in section III.D.2. Furthermore, DOE notes that ISO 1217:2009 provides both “complete” and “simplified” test methods for a variety of compressor categories, only some of which are within the scope of applicability of DOE's proposed test procedure. As such, DOE proposes to incorporate by reference only the sections of ISO 1217:2009 that are relevant to the equipment within the scope of applicability of DOE's proposed test procedure. The specific sections proposed for incorporation, and well as the specific proposed modifications, are discussed further in III.D.2. Ultimately, by incorporating by reference much of ISO 1217:2009 into the proposed DOE test procedure, DOE believes that the resulting DOE test procedure will remain closely aligned with existing and widely used industry procedures and limit testing burden on manufacturers. 2. Modifications, Additions, and Exclusions to ISO 1217:2009 As discussed previously, DOE believes that certain modifications, additions, and exclusions are necessary to ensure repeatable and reproducible test results and provide measurement methods and testing equipment specifications for the entire scope of compressors that DOE would address as part of this proposal. These specific modifications, additions and exceptions are discussed in the following sections III.D.2.a through III.D.2.i. a. Sections Not Included in DOE's Incorporation by Reference While DOE proposes to incorporate by reference certain, applicable sections of ISO 1217:2009 as the basis for its compressor test procedure, DOE notes that the following sections, subsections, and annexes of the standard are not applicable to DOE's regulatory framework: • Sections 1, 7, 8 and 9, in their entirety; • Section 6, in its entirety (except subsections 6.2(g), and 6.2(h), which would be incorporated by reference); • Subsections 5.1, 5.5, 5.7, and 5.8; • Annexes A, B, D, E, F, and G in their entirety; and • Sections C.1.2, C.2.1, C.3, C.4.2.2, C.4.3.1 and C.4.5 of Annex C. Specifically, section 1 of ISO 1217:2009, titled “Scope,” discusses the scope of applicability of ISO 1217:2009. However, the scope discussed in section 1 of ISO 1217:2009 does not align with the specific proposed scope of applicability for DOE's test procedure, as established in section III.B of this notice. Section 7 of ISO 1217:2009 is titled “Uncertainty of measurement” and simply refers the reader to Annex G for information on uncertainty of measurement. Section 7 of ISO 1217:2009 is not called upon by any other sections of ISO 1217:2009 relevant to the testing of compressors within the scope of this rulemaking. Section 8 of ISO 1217:2009 is titled “Comparison of test results with specified values” and discusses how to compare test results with contractually guaranteed performance values. Such methods would not be required for testing and rating compressors in accordance with DOE's proposed test procedure. Furthermore, in section III.G, DOE proposes its own sampling and enforcement criteria for compressors included in the scope of applicability of this proposed test procedure. Section 9, titled “Test report,” contains requirements regarding the generation of a test report. These requirements are not relevant to the testing and rating of compressors in accordance with DOE's proposed procedure. Accordingly, DOE is not proposing to incorporate these sections of ISO 1217:2009 by reference. Section 6 of ISO 1217:2009 is titled “Test procedures” and discusses procedures for a compressor acceptance test. However, DOE proposes to incorporate by reference much of Annex C to ISO 1217:2009, titled “Simplified acceptance test for electrically driven packaged displacement compressors.” Both Section 6 and Annex C of ISO 1217:2009 provide methods to calculate discharge pressure, inlet pressure, flow rate, and packaged compressor power input at a given load point. However, the methods contained in Annex C are more specifically optimized for the categories of compressors within the scope of applicability of this rulemaking, and are more widely used in the compressor industry. As a result, DOE proposes to incorporate by reference the methods prescribed in Annex C to ISO 1217:2009, and not to incorporate by reference section 6 of ISO 1217:2009, with the following exceptions: • DOE proposes to incorporate by reference sections 6.2(g), and 6.2(h) of ISO 1217:2009, as they contain important testing configuration information that is not supplied in Annex C to ISO 1217:2009. • DOE proposes not to incorporate by reference sections C.1.2, C.2.1, C.3, C.4.2.2, C.4.3.1 and C.4.5 of Annex C to ISO 1217:2009, as these subsection provide instructions that are not relevant to the testing and rating of compressors in accordance with DOE's proposed procedure. Subsection 5.1 of ISO 1217:2009 contains general statements related to measuring equipment, methods and accuracy; however, DOE finds most of the statements and instructions in this subsection to be general and ambiguous in nature. To avoid any confusion, DOE proposes not to incorporate by reference subsection 5.1 of ISO 1217:2009. Subsections 5.5 and 5.8 to ISO 1217:2009 provide instructions for how to measure quantities not relevant to DOE proposed test procedures. As a result, DOE proposes not to incorporate by reference subsections 5.5 and 5.8 of ISO 1217:2009. Subsection 5.7 provides instruction for how to measure power and energy; however, this information is also provided in Annex C to ISO 1217:2009. As discussed previously, DOE proposes to use the methods established in Annex C rather than Section 5. Consequently, DOE proposes not to incorporate by reference subsection 5.7 of ISO 1217:2009. Annex A to ISO 1217:2009, “Acceptance test for liquid-ring compressors;” annex B to ISO 1217:2009, “Simplified acceptance test for bare compressors;” and annex D to ISO 1217:2009, “Simplified acceptance test for internal combustion engine-driven packaged displacement compressors;” are not required for, or applicable to, testing compressors within the proposed scope of this rulemaking. As such, DOE proposes to not incorporate annexes A, B, and D to ISO 1217:2009 by reference. Annex E to ISO 1217:2009, titled “Acceptance test for electrically driven packaged displacement variable speed drive compressors,” is currently used by CAGI to evaluate variable-speed compressors for their performance verification program. This annex stipulates a specific set of load points and states that a variable-speed compressor should be tested at each load point using the methods established in annex C of ISO 1217:2009. However, the load points identified in annex E are not the same as the variable-speed load points proposed by DOE in section III.C.3. Consequently, it is not necessary for DOE to include annex E within this proposed test procedure, and DOE is not proposing to incorporate annex E to ISO 1217:2009 by reference. Annex F to ISO 1217:2009 is titled “Reference conditions” and provides info [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%3A2016-10170. Public record. Not legal advice.