CHAPTER 4. SCREENING ANALYSIS

TABLE OF CONTENTS

4.1 INTRODUCTION

........................................................................................................... 4- 1 4.2 TECHNOLOGIES THAT DO NOT AFFECT DAILY ENERGY CONSUMPTION

... 4-2 4.2.1 Higher Efficiency Expansion Valves

................................................................... 4-2 4.2.2 Condenser Fan Motor Controllers

....................................................................... 4-2 4.2.3 Variable Speed Compressors

............................................................................... 4-2 4.2.4 Liquid-Suction Heat Exchangers

......................................................................... 4-3 4.3 SCREENED-OUT TECHNOLOGIES

............................................................................ 4-3 4.3.1 Thermoacoustic Refrigeration

............................................................................. 4-3 4.3.2 Magnetic Refrigeration

........................................................................................ 4-3 4.3.3 Electro-Hydrodynamic Enhan ced Heat Transfer

................................................. 4-4 4.3.4 Copper Rotor Motors

........................................................................................... 4-4 4.4 REMAINING TECHNOLOGIES

................................................................................... 4-4

4-i BVM_FINAL_FR_TSD_Chapter4_08-14-09.docCHAPTER 4. SCREENING ANALYSIS

4.1 INTRODUCTION

This chapter addresses the screening analysis that the U.S. Department of Energy (DOE) conducted in support of the ongoing energy conserva tion standards rulemakings for refrigerated bottled or canned beverage vending machines. These rulemakings are mandated by the Energy Policy Act of 2005 and are effective for equipm ent manufactured 3 year s after the date of publication of this final rule estab lishing energy conser vation standards.

In the market and technology assessment (cha pter 3), DOE presente d an initial list of technologies that can reduce the energy consumpti on of refrigerated beverage vending machines. The goal of the screening analysis is to screen out technologies that will not be considered further in the rulemaking analyses. Some of the technologies considered in chapter 3 can reduce annual energy consumption under real-world conditions, but may not reduce daily energy consumption (DEC), as measured by the Amer ican National Standards Institute/American Society of Heating, Refrigerating and Air-C onditioning Engineers (ANS I/ASHRAE) Standard 32.1–2004, Methods of Testing for Ra ting Vending Machines for Bottled, Canned, and Other Sealed Beverages . DOE removed from consideration thos e technologies that do not reduce DEC. DOE evaluated the remaining technologies using the screening criteria set forth in the Energy Policy and Conservation Act (EPCA). (42 U.S.C. 6311–6317)

Section 325(o) EPCA establishes criteria for prescribing new or amended standards that are designed to achieve the maximum improvement in energy efficiency. Further, EPCA directs the Secretary of Energy to determine whether a standard is technol ogically feasible and economically justified. (42 U.S.C. 6295(o)(2)(A ), as directed by 42 U.S.C. 6316(a)(1)–(3)). EPCA also establishes guidelines for determinin g whether a standard is economically justified. (42 U.S.C. 6295(o)(2)(B)) In view of the EPCA requirements for determining whether a standard is technologically feasib le and economically justified, Appendix A to subpart C of Title 10, Code of Federal Regulations, Part 430 (10 CFR Part 430), “Procedures, Interpretations, and Policies for Consideration of New or Revised Energy Conservation Standards for Consumer Products” (the Process Rule), sets forth procedures to guide DOE in its consideration and promulgation of new or revised efficiency standa rds. These procedures elaborate on the statutory cr iteria provided in 42 U.S.C. 6295(o) and, in part, eliminate probl ematic technologies early in the process of prescribing or amending an energy efficiency standa rd. In particular, secti ons 4(b)(4) and 5(b) of the Process Rule provide guidance to DOE for ma king a determination whether to eliminate from consideration any technology that presents unacc eptable problems with respect to the following criteria:

Technological feasibility. Technologies incorporated in commercial equipment or in working prototypes will be consid ered technologically feasible.

Practicability to manufacture, install, and service. If mass production of a technology in commercial equipment and reliable installa tion and servicing of the technology could be achieved on the scale necessary to serve the relevant market at the time of the effective date of

4-1 BVM_FINAL_FR_TSD_Chapter4_08-14-09.docthe standard, then that technology will be consid ered practicable to manufacture, install, and service.

Adverse impacts on equipment utility or equipment availability. If DOE determines that a technology has significant adverse impact on the utility of the equipment to significant subgroups of consumers, or result in the unavail ability of any covered equipment type with performance characteristics (including reliability), features, sizes, capacities, and volumes that are substantially the same as equipment generally available in the United States at the time, it will not be considered further.

Adverse impacts on health or safety. If DOE determines that a technology will have significant adverse impacts on health or safety, it will not be considered further.

In sum, if DOE determines that a tec hnology or combination of technologies has unacceptable effects on the policies st ated in section 5(b) of the Process Rule, those technologies will be eliminated from considera tion. If a particular technology fails to meet one or more of the four criteria, it will be screen ed out. Section 4.3 below documents the reasons for eliminating any technology.

4.2 TECHNOLOGIES THAT DO NOT AFFECT DAILY ENERGY CONSUMPTION

As stated above, technologies that do not reduce DEC are not considered beneficial in the context of this rulemaking. Therefore, DOE removed the following technologies from consideration: higher e fficiency expansion valves, condenser fan motor controllers, variable speed compressors, and liquid-suctio n heat exchangers (LSHXs).

4.2.1 Higher Efficiency Expansion Valves

Higher efficiency expansion valves can reduce the annual energy consumption of refrigerated beverage vending machines by adap ting to varying loads and ambient conditions. Because ANSI/ASHRAE Standard 32.1–2004 is a steady- state test (i.e., there are no changes in refrigerated-product loading or ambient conditions), there is no opportunity for higher efficiency expansion valves to reduce DEC.

4.2.2 Condenser Fan Motor Controllers

Condenser fan motor controllers can adapt condenser operation to changing ambient temperatures, and thereby reduce annual ener gy consumption of beverage vending machines. However, because testing under the ANSI/ASHRAE Standard 32.1–2004 test procedure is conducted at a constant temperature, there is no opportunity to account for the effect of a condenser fan motor controller on DEC.

4.2.3 Variable Speed Compressors

Variable speed compressors reduce energy c onsumption under real-world conditions by matching their capacity to the re frigeration load, which can change due to variations in ambient conditions and product loading. This technology therefore eliminates the inefficiencies that occur due to mismatched capacity and load in a sing le-speed compressor during part-load operation.

4-2 BVM_FINAL_FR_TSD_Chapter4_08-14-09.docBecause the ANSI/ASHRAE Standard 32.1–2004 te st procedure prescribes steady-state conditions, a variable speed compressor undergoing th is test would be limited to single-speed operation. The resulting energy efficiency ratio would be no better than a properly sized singlespeed compressor, so there would be no appreciable energy savings. Similarly, under ANSI/ASHRAE Standard 32.1–2004, the performance of a high-efficiency variable-speed compressor would be comparable to a high-efficiency single-speed compressor.

4.2.4 Liquid-Suction Heat Exchangers

An LSHX is an indirect liquid-to-vapor heat transfer device that evaporates any residual liquid refrigerant remaining in an evaporator discharge line, and thereby minimizes the risk of liquid refrigerant carryin g over to the compressor suction. In general, LSHXs are installed in refrigeration systems to ensure proper system operation and increasing system performance. Due to the combination of refrigerant type, opera ting temperature, ambient conditions, and other factors, an LSHX does not consistently re duce DEC, as measured by the ANSI/ASHRAE Standard 32.1–2004 test procedure.

4.3 SCREENED-OUT TECHNOLOGIES

This section addresses the technologies that DOE screened out because they did not meet the requirements of sections 4(a) and 5(b) of the Process Rule. DOE considered the following four factors: (1) technological f easibility; (2) practicabil ity to manufacture, install, and service; (3) adverse impacts on equipment utility to consumers; and (4) adverse impacts on health or safety. Four technologies we re screened out: thermoacous tic refrigeration, magnetic refrigeration, electro-hydrodynamic (EHD) h eat exchangers, and copper rotor motors.

4.3.1 Thermoacoustic Refrigeration

Thermoacoustic refrigeration uses high-amp litude sound waves in a pressurized gas to pump heat from one place to another. Because th is technology is in the research stage, DOE believes that it would not be practicable to ma nufacture, install, and service this technology on the scale necessary to serve the relevant market at the time of the effective date of the standard. Because this technology is in the research stage, DOE also cannot assess whether thermoacoustic refrigeration will have any adverse impacts on ut ility to significant subgroups of customers, result in the unavailability of a ny type of refrigerated beverage vending machines, or present any significant adverse impacts on health or safety.

4.3.2 Magnetic Refrigeration

Magnetic refrigeration is a cooling technology th at is based on the ma gnetocaloric effect, in which a reversible change in temperature of a suitable material is caused by exposing the material to a changing magnetic fi eld. Magnetic refrigeration can be used to attain extremely low temperatures and can be adapted to the cooli ng temperatures used in common refrigerated beverage vending machines. However, DOE understa nds that magnetic refr igeration is in the research stage and, therefore, believes that it wo uld not be practicable to manufacture, install, and service this technology on the scale and in the timeframe necessary to serve the relevant market at the time of the effectiv e date of the standar d. Because this technology is in the research

4-3 BVM_FINAL_FR_TSD_Chapter4_08-14-09.docstage, DOE also cannot assess whether it will have any adverse impacts on utility to significant subgroups of customers, result in the unavailability of any type of refrigerated beverage vending machines, or present any significant a dverse impacts on health or safety.

4.3.3 Electro-Hydrodynamic Enhanced Heat Transfer

EHD enhancement of heat transfer is the re sult of applying a high- voltage electrostatic potential field across a heat transfer fluid, such as a refrigerant or re frigerant mixture. The applied field destabilizes the thermal boundary la yer, thereby producing better mixing of the bulk fluid flow and increasing the net heat transfer coefficient. This procedure appears to be more effective when applied to phase-change pro cesses (e.g., boiling and condensation). Because EHD-enhanced heat transfer is in the research stage and is not being used in commercially produced or sold refrigerated beverage vending machines, DOE believes that it would not be practicable to manufacture, instal l, and service this technology on the scale necessary to serve the relevant market at the time of the effective date of the standard. Because this technology is in the research stage, DOE also cannot assess whether it will have any adverse impacts on utility to significant subgroups of customers, result in the unavailability of any type of beverage vending machines, or present any adverse impacts on health or safety.

4.3.4 Copper Rotor Motors

Motor manufacturers have long known that subs tituting copper for die-cast aluminum in rotors would significantly reduce motor losses and improve electrical energy efficiency. However, manufacturing die-cast copper rotors requires specialized equipment, significant investment, and proprietary know-how that are no t yet suitable for production of the millions of motors produced annually. DOE recognizes the adva ntages of this significant advance in motor technology, but believes that it w ould not be practicable to manuf acture, install, and service copper rotor motors on the scale necessary to se rve the relevant market at the time of the effective date of the standard. Further, DOE cannot assess whether the manufacture and use of copper rotor motors would have any adverse imp acts on the utility of re frigerated beverage vending machines to significant subgroups of custom ers, result in the unavailability of any type of refrigerated beverage vending machines, or present any significant adverse impacts on health or safety.

4.4 REMAINING TECHNOLOGIES

After eliminating those technologies that do not reduce DEC and do not meet the requirements of sections 4(a) and 5(b) of the Process Rule, DOE is considering the following technologies:

 higher efficiency lighting

 higher efficiency lighting ballasts

 higher efficiency evaporator fan motors

 evaporator fan motor controllers

 higher efficiency evaporator fan blades

 improved evaporator design

4-4 BVM_FINAL_FR_TSD_Chapter4_08-14-09.doc low-pressure differential evaporators

 improved or thicker insulation

 defrost mechanism

 higher efficiency compressors

 improved condenser design

 higher efficiency condenser fan motors

 higher efficiency condenser fan blades

 improved glass pack design (for Class A machines)

4-5 BVM_FINAL_FR_TSD_Chapter4_08-14-09.doc