3-i CHAPTER 3. MA R KET AND TECHNOLOGY ASSESSMENT

TABLE OF CONTENTS 3.1 INTRODUCTION ........................................................................................................... 3-1 3.1.1 Definitions............................................................................................................ 3-1 3.1.2 Description of Refrigerated Bottled or Canned Beverage Vending Machines.............................................................................................................. 3-2 3.2 TEST PROCEDURES..................................................................................................... 3-4 3.2.1 Department of Energy.......................................................................................... 3-4 3.3 DOMESTIC AND INTERNATIONAL REGULATORY AND NON-REGULATORY ACTIVITIES.................................................................................................................... 3-5 3.3.1 ENERGY STAR .................................................................................................. 3-5 3.3.2 Canadian Standards Association.......................................................................... 3-7 3.3.3 California Energy Commission............................................................................ 3-8 3.3.4 Australia............................................................................................................... 3-9 3.3.5 Rebate Programs .................................................................................................. 3-9 3.4 MARKET ASSESSMENT ............................................................................................ 3-10 3.4.1 Trade Associations............................................................................................. 3-10 3.4.2 Manufacturers and Market Share....................................................................... 3-11 3.4.2.1 Small Businesses.................................................................................... 3-12 3.4.3 Equipment Classes............................................................................................. 3-12 3.4.4 Typical Refrigeration System ............................................................................ 3-13 3.4.5 Energy Savings Potential ................................................................................... 3-15 3.4.6 Barriers to Efficiency Improvements................................................................. 3-16 3.4.7 Market Performance Data.................................................................................. 3-16 3.5 TECHNOLOGY ASSESSMENT.................................................................................. 3-19 3.5.1 Higher Efficiency Lighting................................................................................ 3-19 3.5.2 Higher Efficiency Lighting Ballasts .................................................................. 3-20 3.5.3 Higher Efficiency Evaporator Fan Motors ........................................................ 3-20 3.5.4 Evaporator Fan Controls.................................................................................... 3-21 3.5.5 Higher Efficiency Evaporator Fan Blades ......................................................... 3-21 3.5.6 Improved Evaporator Design............................................................................. 3-22 3.5.7 Low Pressure Differential Evaporators.............................................................. 3-22 3.5.8 Improved or Thicker Insulation ......................................................................... 3-23 3.5.9 Improved Glass Pack (for Class A machines) ................................................... 3-23 3.5.10 Defrost Mechanism............................................................................................ 3-23 3.5.11 Thermoacoustic Refrigeration ........................................................................... 3-24 3.5.12 Magnetic Refrigeration ...................................................................................... 3-24 3.5.13 Electro-hydrodynamic Enhanced Heat Transfer................................................ 3-24 3.5.14 Copper Rotor Motors ......................................................................................... 3-25 3.5.15 Higher Efficiency Compressors......................................................................... 3-25 3.5.16 Improved Condenser Design.............................................................................. 3-25 3.5.17 Higher Efficiency Condenser Fan Motors ......................................................... 3-26 3.5.18 Higher Efficiency Condenser Fan Blades.......................................................... 3-26 3.5.19 Higher Efficiency Expansion Valves................................................................. 3-263-ii

3.5.20 Variable-Speed Compressors............................................................................. 3-27 3.5 .2 1 Liquid Suction Heat Exchangers ....................................................................... 3-27 3.5.22 Condenser Fan Motor Controllers ..................................................................... 3-28 REFERENCES .......................................................................................................................... 3-29

LIST OF TABLES
Table 3.2.1 American Society of Heating, Refrigerating, and Air-Conditioning Engineers

Standard 32.1-2004 – Test Conditions.................................................................... 3-5 Table 3.3.1 ENERGY STAR Criteria for Beverage Vending Machines.................................... 3-6 Table 3.3.2 California Energy Commission – Performance Standards ...................................... 3-8 Table 3.3.3 Beverage Vending Machine Rebate Programs ...................................................... 3-10 Table 3.4.1 Beverage Vending Machine Census and Energy Use Data................................... 3-11 Table 3.4.2 Small Business Manufacturers of Beverage Vending Machines........................... 3-12 Table 3.4.3 Energy Use by Component for Typical Vending Machines.................................. 3-14 Table 3.4.4 Potential Energy Savings Estimates for Beverage Vending Machines ................. 3-15

LIST OF FIGURES
Figure 3.1.1 A typical glass-front beverage vending machine.................................................... 3-3 Figure 3.1.2 A typical solid-door beverage vending machine .................................................... 3-4 Figure 3.3.1 ENERGY STAR Qualified Refrigerated Beverage Vending Machine

Models..................................................................................................................... 3-7 Figure 3.4.1 Market Performance Data for California Energy Commission Qualified

Class A Equipment Class...................................................................................... 3-17 Figure 3.4.2 Market Performance Data for California Energy Commission Qualified

Class A Equipment Class...................................................................................... 3-17 Figure 3.4.3 Market Performance Data for California Energy Commission Qualified

Class B Equipment Class...................................................................................... 3-18 Figure 3.4.4 Market Performance Data for ENERGY STAR Class A Equipment Class......... 3-18 Figure 3.4.5 Market Performance Data for ENERGY STAR Class B Equipment Class......... 3-193-1 CHAPTER 3. MARKET AND TECHNOLOGY ASSESSMENT

3.1 I N TRODUCTION
This chapter details the market and technology assessment that the U.S. Department of Energy (DOE) has carried out in support of the energy conservation standards rulemaking for beverage vending machines (BVMs). This rulemaking is mandated by the Energy Policy Act of 2005 (EPACT 2005) and is effective for equipment manufactured on or after August 8, 2012. The beverage vending machines have never before been the subject of energy conservation regulations at the federal level.
This chapter consists of two sections: the market assessment and the technology assessment. The goal of the market assessment is to develop a qualitative and quantitative characterization of the BVM industry and market structure, based on publicly available information as well as data and information submitted by manufacturers and other stakeholders. Issues that are addressed include manufacturer characteristics and market shares, existing regulatory and non-regulatory efficiency improvement initiatives, equipment classes, and trends in equipment markets and characteristics. The goal of the technology assessment is to develop a preliminary list of technologies that could be used to improve the efficiency of beverage vending machines.
Refrigerated beverage vending machines are used to cool and dispense bottled and canned beverages upon payment. This equipment is primarily used in manufacturing facilities, office buildings, retail sites, schools, colleges and other institutional buildings. The current installed base of beverage vending machines operating in the United States consumes more than 12 billion kilowatt hours (kWh) of electricity annually. 1

3.1 .1 D efinitions
Section 135(c)(4) of EPACT 2005 amended section 325 of the Energy Policy and Conservation Act (EPCA) to include new subsections 325(v)(2), (3) and (4) (42 U.S.C. 6295(v)(2)-(4)), which mandates that DOE issue by rule, no later than August 8, 2009, energy conservation standards for refrigerated bottled or canned beverage vending machines manufactured three years after the date of publication of the final rule establishing the energy conservation standards.
Section 135(a)(3) of EPACT 2005 amended section 321 of EPCA by adding, in part, new subsection 321(40), 42 U.S.C. 6291(40), which establishes the following definitions:

• The term “refrigerated bottled or canned beverage vending machine” means a commercial refrigerator (defined below) that cools bottled or canned beverages and dispenses the bottled or canned beverages on payment.
In addition, section 136(a)(3) of EPACT 2005 amended section 340 of EPCA by replacing subsection 340(9), 42 U.S.C 6311(9), with, in part, definitions for the following terms relating to commercial refrigeration equipment that are relevant to beverage vending machines:3-2

(9) (A) The term “commercial refrigerator, freezer, and refrigerator-freezer”

me a ns refrigeration equipment that—
(i) is not a consumer product (as defined in section 321);
(ii) is not designed and marketed exclusively for medical, scientific, or research purposes;
(iii) operates at a chilled, frozen, combination chilled and frozen, or variable temperature;
(iv) displays or stores merchandise and other perishable materials horizontally, semivertically, or vertically;
(v) has transparent or solid doors, sliding or hinged doors, a combination of hinged, sliding, transparent, or solid doors, or no doors;
(vi) is designed for pull-down temperature applications or holding temperature applications; and
(vii) is connected to a self-contained condensing unit or to a remote condensing unit.

As p resented above, section 135(a)(3) of EPACT 2005 defines a “refrigerated bottled or canned beverage vending machine,” in part, as equipment that cools bottled or canned beverages and dispenses them on payment. In the Framework document, DOE considered the definitions for “bottle” and “can” established in American National Standards Institute (ANSI)/American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Standard 32.1– 2004, which are:

bottle: a glass or plastic container in which a beverage is sealed.

can: a container made of metal or paperboard or a combination of both in which a beverage is sealed.
DOE expects that such broad definitions for “bottled beverage” and “canned beverage” would allow for more comprehensive coverage of existing beverage vending machine equipment, and particularly of certain types of equipment that are currently experiencing market growth.

3.1.2 Description of Refrigerated Bottled or Canned Beverage Vending Machines
Refrigerated bottled or canned beverage vending machines can be divided into categoriesby either machine use designation (indoor use only or indoor/outdoor use) or by door type (glass3-3

front or solid-door). The classification of beverage vending machines by machine use de s ignation of indoor use only and indoor/outdoor use is explained in detail below.

Figure 3.1.1 A typical glass-front beverage vending machine
The beverage vending machines intended for indoor use only are dominated by glassfront models (shown in Figure 3.1.1) that have a transparent panel which enables a purchaser to see the merchandise as it is vended. In this type of machine, the merchandise itself is illuminated and used to attract the purchaser’s attention. 2 These machines are found primarily indoors bec ause the glass fronts make them vulnerable to vandalism in addition to introducing the problem of solar gain and heat loss through the glass front. These machines are marked “For Indoor Use Only” in accordance with Underwriters Laboratories (UL) Standard 541– 2003. 3 The gla ss-front vending machines are also known as “multi-package” vending machines. This design allows the consumer to see the merchandise inside the machine – commonly displayed on shelves − with some models displaying as many as 45 different varieties of drinks. Productpackaging is not limited to cans and bottles, and may also include cartons, juice packs, and nonstandard bottle and can shapes. Dispensed mechanically, many machines have a mechanism to move the merchandise to the door gently rather than dropping the beverage from the upper shelves. With the increasing market for non-carbonated soft drinks, such as energy drinks, fruit juices and water (which come in a variety of packaging types and sizes), these machines provide a much wider choice for the consumer. These glass-front machines are also referred in the industry as “shelf-style” or “fully-cooled” machines, because the entire machine needs to be cooled, not just the next-to-be-vended product.
The most common beverage vending machine that is intended for both indoor and outdoor use is the solid-door machine (or closed-front machine) (shown in Figure 3.1.2) that houses cans or bottles inside a completely opaque insulated compartment. With solid-door machines, the vended product cannot be seen and the machine either has signage or a backlit panel on the front advertising the contents. The unlit machine (signage only) is typical of machines placed in external locations. Depending on the model, these machines can contain up to 800 cans and up to 12 varieties of beverages. A small fraction of solid-door vending machines are classified as having a “live display” door type, where a sample of product offerings is visible to the consumer. Some of these machines show a non-vendible version of the product in a small glass window, although the front door is predominantly solid.3-4 Figure 3.1.2 A typical solid-door beverage vending machine
These machines are typically designed so they can be placed outdoors and can withstand weather effects. The machines intended for both indoor and outdoor use are marked “Suitable for Outdoor Use” or “Suitable for Protected Locations” in accordance with UL Standard 541- 2003. 3 These solid-door machines are referred to in the industry as “stack-style” or “zonecoo led” machines, because only the fraction (or zone) of the machine volume that contains the next-to-be-vended product is directly cooled.

3.2 TEST PROCEDURES

3.2.1 Department of Energy
Section 135(b) of EPACT 2005 amends section 323 of EPCA by adding, in part, new subsection 323(b(15), 42 U.S.C. 6293(b)(15), which requires that the test procedure for refrigerated bottled or canned beverage vending machines be based on ANSI/ASHRAE) Standard 32.1–-2004, Methods of Testing for Rating Vending Machines for Bottled, Canned or Other Sealed Beverages. 4 DOE therefore published a final rule on December 8, 2006, in c orporating the ANSI/ASHRAE Standard 32.1-2004 with two modifications by reference into section 431.294 of subpart Q to Title 10, Code of Federal Regulations Part 431 (10 CFR Part 431) for the measurement of energy consumption and determination of capacity of this equipment. The first modification DOE made in adopting ANSI/ASHRAE Standard 32.1–2004 was to specify in the final rule that in section 6.2, “Voltage and Frequency,” equipment with dual nameplate voltages should be tested at the lower of the two voltages only. The second modification DOE made was to specify that the measurement of “vendible capacity” of refrigerated bottled or canned beverage vending machines should be in accordance with the second paragraph of section 5, “Vending Machine Capacity,” of ANSI/ASHRAE Standard 32.1– 2004, and that the measurement of “refrigerated volume” of refrigerated bottled or canned beverage vending machines should be in accordance with the methodology specified in section 5.2, “Total Refrigerated Volume,” (excluding subsections 5.2.2.2 through 5.2.2.4) of the ANSI/Association of Home Appliance Manufacturers (AHAM) HRF Standard 1–2004, ‘‘Energy, Performance and Capacity of Household Refrigerators, Refrigerator-Freezers and Freezers.” 5

The current version of ANSI/ASHRAE Standard 32.1–2004:3-5

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc • Defines standard bottled, canned, or other sealed beverage storage capacity,

• Es t ablishes uniform methods of testing for determining laboratory performance of vending machines for bottled, canned, or other sealed beverages

• Defines the following tests and test conditions as shown in Table 3.2.1 below:

○ Energy Consumption Test is designed to determine the stabilized daily and unit energy consumption of the vending machine over a 24-hour period.

○ Vend Test is designed to determine how much cold product a machine will deliver, at the required temperature, when products are vended at a rate of two per minute, three hours after a half-full machine is refilled.

○ Recovery Test is designed to determine the product temperature recovery time of a vending machine when loaded with product at a specified temperature.
Table 3.2.1 American Society of Heating Refrigerating and Air-Conditioning Engineers Standard 32.1-2004 – Standard Test Conditions

Test and Pretest Conditions En e rgy Consumption Tests Vend Test Recovery Test
Ambient Temperature Perform twice: At 90±2°F (32.2±1°C) and at 75°F±2°F (23.9±1°C) 90±2°F (32.2±1°C) 90±2°F (32.2±1°C)

Relative Humidity 65±5% for 90±2°F test and 45±5% for 75±2°F test 65±5% 65±5%

Reloaded Product Temperature __ 90±1°F (32.2±0.5°C) 90±1°F (32.2±0.5°C) Average Beverage Temperature (for test) 36±1°F (2.2±0.5°C) Throughout Test 40°F or less (4.4°C or less) Final Temperature 33-40°F

(0.6-4.4°C) Final Temperature Average Beverage Temperature (for pretest conditions) Not Applicable 36±1°F (2.2±0.6°C) Pretest Conditions 36±1°F (2.2±0.6°C)

Pretest Conditions

3.3 DOMESTIC AND INTERNATIONAL REGULATORY AND NONREGULATORY ACTIVITIES
Both Canada and the State of California have efficiency standards in place for refrigerated beverage vending machines. Australia has several efficiency standards in place for beverage vending machines. In addition, the voluntary ENERGY STAR labeling program has been in place since 2004.

3.3.1 ENERGY STAR
The Environmental Protection Agency (EPA) has developed voluntary performance standards for beverage vending machines as part of the ENERGY STAR labeling program. ENERGY STAR is a two-tiered standard with the first tier effective since April 1, 2004, for new machines and April 31, 2006, for rebuilt machines. Tier 2 went into effect on July 1, 2007, for new machines. Originally, the standard was set for the top 25 percent of machines to qualify for3-6

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc Tier 1. But with Tier 2 now implemented, some manufacturers are already producing even more ef f icient machines.
ENERGY STAR performance criteria vary according to the vending machine’s vendible capacity. a In order to qualify, models must meet the requirements for energy use shown in Table 3.3.1

. Table 3.3.1 ENERGY STAR Criteria for Beverage Vending Machines
Equipment Ty p e ENERGY STAR Definition Energy Consumption Under Test Conditions

Tier 1 (effective April 1, 2004) Tier 2 (effective July 1, 2007) Beverage vending machines A self-contained system

designed to accept consumer payments and dispense bottled, canned, and other sealed beverages at appropriate temperatures without on-site labor intervention. Y = 0.55 x [8.66 + (0.009 x C)] Y = 0.45 x [8.66 + (0.009 x C)]

Where Y = 24-hour consumption (kWh/day) after the machine has stabilized, and C = vendible capacity (number of cans). Figure 3.3.1 shows the energy consumption of manufactured units that qualify for ENERGY STAR Tier 1, as of May 25, 2007. 6 As can be seen, a few models even exceed the Tier 2 level that went into effect on July 1, 2007.

a Vendible capacity is defined in ASHRAE Standard 32.1-2004 as “the maximum quantity of standard product that

ca n be dispensed from one full loading of the vending machine without further reload operations when used as recommended by the manufacturer. The standard product shall be 12-oz. (355 ml) cans for machines that are capable of dispensing 12-oz. (355 ml) cans. For all other machines, the standard product shall be the product specified by the manufacturer as the standard product.”3-7

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc Fi g ure 3.3.1 ENERGY STAR Qualified Refrigerated Beverage Vending Machine Models

3.3.2 Canadian Standards Association
The Canadian Standards Association (CSA) test standard for beverage vending machines is CAN/CSA Standard C804–96, Energy Performance of Vending Machines . The CSA standard sets out minimum performance criteria for annual energy consumption that vary with the category of vending machine. The standard also contains the test procedure. The standard is voluntary in all jurisdictions in Canada, except in:

• Ontario, where these criteria are regulated by the Province of Ontario's Energy Efficiency Act (Ontario Regulation 82/95, amended to O. Reg 18/02) and apply to products manufactured, sold or leased after April 1, 2003, and

• New Brunswick, where these criteria are regulated in Regulation 95-70 of the New Brunswick Energy Efficiency Act (O.C. 95-555), and apply to products manufactured, sold, or leased after August 31, 2004.
In Canada, beverage vending machines are regulated to the CSA standard and not covered under a voluntary labeling program. The maximum daily energy consumption allowed under the CSA standard is described by the following: -1.00 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00

0 100 200 300 400 500 600 700 800 900

Vendible Capacity (Number of Cans)Daily Energy Consumption (kWh/day)

Tier 1 Tier 2 Indoor Indoor/Outdoor Daily Energy Consumption for ENERGY STAR Beverage Vending Machines

(ANSI/ASHRAE Standard 32.1

- 2004)3-8

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc Y = 8 .66 + (0.009 x C) Eq. 3.1

where Y = 24-hour consumption (kWh/day) after the machine has reached a stable operating condition, and C = vendible capacity.
The ENERGY STAR performance levels are 45 to 55 percent more efficient than those specified in the CSA standard. In 2004, CSA proposed to regulate the energy efficiency levels of bottled and canned beverage vending machines to the ENERGY STAR Tier 1 levels – thereby harmonizing with the California Energy Commission (CEC). The California levels were chosen rather than those of CSA Standard C804–96 because the market data available to the CSA indicate that regulating to the CSA standard would have little effect on the market, since the major manufacturers are already working toward the more stringent California standard. The only major difference is that the CSA proposes to move to the ENERGY STAR Tier 2 levels effective January 1, 2008.

3.3.3 California Energy Commission
CEC’s tiered specification regulates the minimum energy performance of equipment sold in California. The Amendments to Appliance Efficiency Regulations, California Code of Regulations 7 propose both an energy efficiency standard and a design standard for beverage

ve n ding machines, as of January 1, 2006. (See Table 3.3.2.)

Table 3.3.2 California Energy Commission – Performance Standards Maximum Daily Energy Co n sumption (kWh) Product CEC Definition January 1, 2006 January 1,

2007 Design Standard

Refrigerated canned and bottled beverage vending machines when tested at 90°F ambient temperatureexcept multipackage units. 0.55 x (8.66 +

(0.009 x C) 0.55 x (8.66 +

(0.009 x C) Beverage Vending Machine

Refrigerated

multi-package canned and bottled beverage vending machines when tested at 75°F ambient temperature. 0.55 x (8.66 +

(0.009 x C) 0.55 x (8.66 +

(0.009 x C) Refrigerated canned and bottled beverage

vending machines shall be equipped with hard wired controls and/or software capable ofautomatically placing the machine into a lowpower mode during periods of extended inactivity while still connected to its power source. The machine shall be capable of operating in each of the low power mode states described below: (A) Lighting low power state – lights off for an extended period. (B) Refrigeration low power state – the average beverage temperature is allowed to rise above 40 degrees Fahrenheit (°F) for an extended period of time. (C) Whole machine low power state – the lights are off and the refrigeration operates in its low power state. (D) The machine shall be capable of3-9

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc automatically returning itself back to its normal operating conditions at the conclusion of the inactivity period. The low power mode related controls/software shall be capable of on-site adjustments by the vending operator or machine owner.

3.3.4 Australia
The National Appliance and Equipment Energy Efficiency Committee (NAEEEC) has 15 minimum energy performance standards (MEPS) for a variety of technologies. Report No: 2004/11, Refrigerated Beverage Vending Machines , released in April 2005. 8 Its standards are ba s ed on the North American work of the Canadian Standards Association, the California Energy Commission, and the U.S. ENERGY STAR program.
NAEEEC has introduced efficiency regulations by:

• MEPS should be implemented based on daily energy consumption. Units will also be required to automatically access low power modes and be shipped with those modes enabled.

• A specific test should be developed by the Standards Australia Working Group under ME-008, based on ANSI/ASHRAE Standard 32.1–2004.

• The proposed MEPS levels shall be equivalent to the ENERGY STAR criteria, as amended December 2004.

• A category of products shall be established as “high efficiency” products that shall be equivalent to the higher efficiency tier in ENERGY STAR requirements.

3.3.5 Rebate Programs
Several rebate programs for beverage vending machines are offered by local utilities, including Austin Energy, Avista Utilities, Connecticut Light and Power, Efficiency Vermont, Puget Sound Electricity, San Diego Gas and Electric, Seattle City Light, and Southern California Edison.
The majority of rebate programs offered by the previous organizations involve a cash incentive for installing an energy-saving machine sensor control system. This device uses a motion detector and a time clock to shut off the lighting and compressor in refrigerated vending machines and the entire snack machine when the machines are not being used, particularly overnight. These controllers are “smart” and operate to ensure that the beverage is cold, yet can save 20 percent to 50 percent on the electricity used by these machines. The most widely used device is the VendingMiser, created by USA Technologies.

Table 3.3.3 summarizes some of the rebates available for BVMs:3-10

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc Table 3.3.3 Beverage Vending Machine Rebate Programs

Utility Co n dition Rebate/Incentive Austin Energy Installation of VendingMiser Free VendingMiser (listed as $200 value) Avista Utilities Installation of Machine Sensor Control System $90/unit Connecticut Light and Power Installation of Machine Sensor Control System $75/unit Efficiency Vermont Installation of Machine Sensor Control System $45/unit Puget Sound Electricity Installation of VendingMiser $80/unit San Diego Gas and Electric Installation of Machine Sensor Control System $90-125/unit Seattle City Light Installation of VendingMiser $80/unit Southern California Edison Installation of Machine Sensor Control System $90/unit Installation upgrade of shaded-pole evaporator fan motor to either permanent split capacitor (PSC) motors or electronically commutated motors (ECMs) $20/motor

3.4 MARKET ASSESSMENT
The following market assessment identifies the manufacturer trade association, domestic manufacturers of beverage vending machines, manufacturer market share; defines equipment classes; provides energy savings potential data; presents barriers to efficiency improvements; and summarizes market performance data.

3.4.1 Trade Associations
The National Automatic Merchandising Association (NAMA) is the trade association for manufacturers of refrigerated beverage vending machines, and the American Beverage Association (ABA) is the trade association for the bottlers and syrup companies in the beverage industry.

NAMA was founded in 1933 and serves all food and refreshment vending, coffee service, and food management industries. Members of the organization include service companies, equipment manufacturers, and suppliers. 9

The t echnical department of NAMA was founded in 1957 to ensure the vending industry serve public health by dispensing safe and wholesome food. To this end, NAMA provides various technical services to group members:

• Establishment of voluntary “Standard for Sanitary Design and Construction of Food and Beverage Vending Machines”

• Inspection of vending machines for compliance with Food and Drug Administration and NAMA requirements;

• Certification of companies and individual vending machines as “NAMA” approved, which may be advertised as a service mark;

• Training for technicians on effective vending machine maintenance; and

• Industry Publications on technical services, health, and safety.3-11

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc ABA is the trade association for America’s non-alcoholic refreshment beverage industry. It is c losely linked with the refrigerated beverage vending machine industry in so far as ABA’s members (e.g., Pepsi-Cola Co., Coca-Cola Co.) are the largest purchasers of BVMs. The association provides a forum for the members to discuss common issues and serves as an industry liaison to the government and public. It offers technical and non-technical services to its members. In addition, ABA projects a unified voice for the non-alcoholic refreshment beverage industry in legislative and regulatory matters. 10

3.4.2 M anufacturers and Market Share
The three manufacturers that hold a majority of domestic market share for beverage vending machines are listed below.

• Crane Merchandising/Dixie-Narco, Inc.

• Royal Vendors, Inc.

• Sanden-Vendo America
Other manufacturers of refrigerated beverage vending machines are listed below.

• Seaga Manufacturing

• Automatic Merchandising Systems

• Multi-Max Distributed Vending System

• Distributed Vending Company

• Edina Technical Products

• Jofemar USA

• Wittern Group
Table 3.4.1 summarizes relevant market and performance data for beverage vending machines. Values are presented for installed base, annual shipments, equipment lifetime, unit energy consumption, and national aggregate energy consumption.
Table 3.4.1 Beverage Vending Machine Census and Energy Use Data

Census and Energy Use Data So u rce of the Data

Installed Base (units):

• Cans 2,400,000

• Bottles 1,125,000

• Other 186,000

Total 3,711,000 Arthur D. Little, Inc. (ADL) (1996) 11

Annual Shipments (units): 342,000 Appliance Magazine 51 st Annual Report (2003 values)

Unit Energy Consumption: 3,000 kWh/year ADL (1996) 113-12

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc 3,644 kWh/year E-SOURCE (1996) 1

Primary Annual Energy Consumption: 0.121 Quad ADL (1996) 11

3.4.2.1 Small Businesses

DOE is considering the possibility that small businesses would be particularly impacted by the promulgation of energy conservation standards for beverage vending machines. The Small Business Administration (SBA) defines small business manufacturing enterprises for automatic vending machine manufacturing as those having 500 employees or fewer. 12 SBA lists

sm a ll business size standards for industries as they are described in the North American Industry Classification System (NAICS). The size standard for an industry is the largest that a for-profit concern can be in that industry and still qualify as a small business for Federal Government programs. These size standards are generally expressed in terms of the average annual receipts or the average employment of a firm. For beverage vending machines, the size standard is matched to NAICS code 333311, Automatic Vending Machine Manufacturing, and is 500 employees.
DOE will study in detail the potential impacts on these small businesses during the manufacturer impact analysis, which will be conducted as a part of the notice of proposed rulemaking analysis. Table 3.4.2 lists the small business beverage vending machine manufacturers that DOE has identified.
Table 3.4.2 Small Business Manufacturers of Beverage Vending Machines Royal Vendors, Inc. Se a ga Manufacturing, Inc. Automatic Merchandising Systems, Inc. Jofemar USA Wittern Group Edina Technical Products

3.4.3 Equipment Classes
Beverage vending machines can be divided into different equipment classes categorized by physical characteristics that affect the efficiency of the equipment. Most of these characteristics affect the merchandise that the equipment cools and vends, and how thatmerchandise is accessed by the customer. Key physical characteristics are the door type (glassfront or solid-front) and the vendible capacity (or the refrigerated volume) of the machine. The energy consumption of the refrigerated beverage vending machine also depends on where the machine is placed (indoors or outdoors) and the ambient conditions (temperature and relative humidity) to which it is exposed. DOE proposed the following four equipment classes in its Framework document, defined according to equipment use designation and physical characteristics such as door type:
Beverage vending machines for indoor use only: (a) Class A Machine (glass front or fully cooled) (b) Class B Machine (any beverage vending machine)3-13

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc Beverage vending machines for indoor/outdoor use: (a ) C lass A Machine (glass-front or fully-cooled) (b) Class B Machine (closed-front or zone-cooled)
However, based on comments made by the stakeholders at the Framework public meeting, and data showing that there are few Class A machines installed outdoors (because of safety and vandalism reasons) and hardly any Class B machines that are certified for indoor use only, DOE has decided to use the following two equipment classes of beverage vending machines:
(a) Class A Machine (glass front or fully cooled) (b) Class B Machine (any beverage vending machine not considered to be Class A)

DOE is reducing the number of equipment classes from four to two. Energy usage has been proven to be unaffected by machine location. Research has also proven there are not any locations in the U.S. whose annual temperature gradient would warrant a separate equipment class to differentiate indoor and outdoor machines. Therefore, DOE is using the following two equipment class descriptions:

• Class A beverage vending machines manufactured today typically utilize a transparent (glass or transparent polymer) front and generally use “shelf-style” vending mechanisms. Because the next-to-be-vended product is visible to the consumer and any product can be selected by the consumer off of the shelf, all bottled or canned beverage containers are necessarily enclosed within the refrigerated volume.

• Class B beverage vending machines in use today generally have an opaque front and utilize a “stack-style” vending mechanism. The next-to-be vended bottled or canned beverage is not generally visible to the consumer and is located at the bottom of a vertical stack of beverage containers. Any products visible to a consumer in this class of machines are for display purposes only.

3.4.4 Typical Refrigeration System
Vending machines use self-contained refrigeration systems consisting of a compressor, evaporator, condenser, and expansion device. In Class A machines, the compressor and condenser are typically located in a compartment to one side of the refrigerated cabinet. In Class B machines, the compressor and condenser are typically located in the bottom portion of the unit, between the ground and the refrigerated cabinet. Refrigerant is piped through the expansion device to an evaporator inside the refrigerated cabinet. The compressor consumes by far the most energy in the vending machine. Laboratory test results of a single Class A and a Class B machine for a 24-hour test with ambient conditions at 90°F and 65 percent relative humidity indicate the compressor accounts for 65 to 75 percent of the total energy consumed (see Table 3.4.3). 13 Oversized single-speed compressors are commonly used to provide excess

co o ling capacity to pull down product temperatures quickly after the machine is restocked. A condenser fan operates concurrently with compressor cycling and uses less than 10 percent of the total energy. The evaporator fan runs continuously to distribute air through the refrigerated3-14

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc cabinet and consumes about 8 percent of total machine energy. Lighting systems usually remain

on t he entire time a vending machine is plugged in. Different lighting systems are used, depending on the machine, but usually consume 5 to 20 percent of the total energy. Dispensing mechanisms operate intermittently, whenever a product is purchased, and therefore do not use a significant amount of energy (1 to 3 percent) compared to other components.
Table 3.4.3 Energy Use by Component for Typical Vending Machines

Component Cla s s A Machine [%] Class B Machine [%] Compressor 76 65 Condenser Fan 9 7 Evaporator Fan 8 8 Lighting 4 19 Money-Handling Mechanism 3 1 Heat enters the refrigerated section of the cabinet by the following methods:

• Released by the evaporator fan motor

• Released by the lighting (glass-front units only)

• Conduction through the insulated envelope

• Infiltration through imperfections in construction such as cracks in the box or improperly sealed delivery doors

• Radiation through the glass front (glass-front units only)

• Product restocking (warm product placed into the machine must be cooled to acceptable temperature).
A vending machine’s refrigeration system is highly vulnerable to changes in its surroundings. Cooling load can be increased by high ambient temperatures, which raise head pressure, resulting in loss of refrigeration effect and increased compression ratio. High ambient temperatures also increase conduction, radiation, and sensible infiltration loads. High humidity increases latent infiltration load, and can cause extreme ice build-up on the evaporator coil. This may severely restrict airflow through the unit and minimize the amount of heat absorbed by the refrigerant. Exposure to sunlight greatly increases heat gain into the refrigerated space through direct solar radiation (especially in glass-front machines) raises the sol-air temperature of the cabinet exterior, and increases conduction load. Exposure to high-intensity lighting fixtures can have a similar (but smaller) effect.
Condenser coils are usually located in the bottom of the machine, with air intakes at ground level. Because coils often get dirty and clogged, condensers often lose their heat rejection effectiveness, which reduces refrigeration capacity and increases compressor power use. Steel security cages are often placed around machines, especially when they are outdoors. These cages trap heat rejected by the condenser as it exits the rear of the machine. Trapped heat increases the inlet air temperature at the condenser, causing operations at higher condensing temperatures.3-15

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc The site owner can improve vending machine efficiency by: keeping machines in

co o l/shaded locations to minimize sun exposure, keeping condenser coils clean, and installing a controller that will shift the unit to low power mode based on low traffic or low sales rate.

3.4.5 Energy Savings Potential
In the Priority Setting Document (October 2005), 14 DOE estimated that the cumulative energy

sav ings potential in the years 2010–2035 ranges from 0.48 to 1.11 quads for beverage vending machines, depending on the energy efficiency technologies implemented, as shown in Table 3.4.4.
Table 3.4.4 Potential Energy Savings Estimates for Beverage Vending Machines

Technology/Standard Level En e rgy Savings Potential (%) Annual

Energy Savings Potential (quads) Energy Saving

Potential (2010- 2035), (quads) Source

Combination (high efficiency compressor and brushless DC evaporator fan motor) 28 0.034 0.71 ADL (1996)
<2 Years Payback (ECM for evaporator fans and high efficiency compressor) 32 0.039 0.85 ADL (1996)
<5 Years Payback (add high efficiency condenser fan motor) 42 0.051 1.11 ADL (1996)
ENERGY STAR Tier 1 18 0.022 0.48 ENERGY STAR website ENERGY STAR Tier 2 33 0.040 0.87 ENERGY STAR website CEC January 1, 2006 18 0.022 0.48 CEC Appliance Efficiency Regulations CEC January 1, 2007 18 0.022 0.48 CEC Appliance Efficiency Regulations Source: “FY2006 Appliance Standards Program Priority-Setting Summary Report and Actions Proposed,” Beverage Vending Machines – Energy Saving Potential Estimates, DOE (October 2005). The technologies shown in the above table are described below.

• Com bination of technologies: This is a theoretical “combination” of two technologiespresented in the ADL 1996 report—a high efficiency compressor and a brushless directcurrent (DC) evaporator fan motor. Both the compressor and the evaporator fan motor are relatively simple to change and could be deployed on a retrofit basis. The energy savings potential for vending machines was shown at 28 percent of annual energy consumption, with simple payback periods of about 1 year for the high efficiency compressor and about two years for the brushless DC evaporator fan motor.

• Less than two-year payback technologies: The 1996 ADL report details beverage vending machine designs including energy efficient technologies that individually have either a less than two-year or a less than five-year payback period. A combination of high efficiency compressor, electronic lighting ballast and an ECM evaporator fan motor was shown to have a payback of less than two years. These energy efficient technologies gave an energy savings potential of 32 percent.3-16

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc • Less than five-year payback technologies: A combination of variable-speed compressor,

e l ectronic lighting ballast, an ECM evaporator fan motor and improved insulation was shown to have a payback of less than five years, giving a 42 percent total energy savings potential.

ENERGY STAR and CEC do not specify a specific technology but require

man ufacturers to design equipment to meet performance specification levels.

3.4.6 Barriers to Efficiency Improvements
A split-incentive system is where bottling companies or distributors purchase nearly all vending machines from the equipment manufacturers but do not pay the utility bills associated with their operation. The split-incentive system, described in a 2002 report by the American Council for an Energy Efficient Economy 15 is the largest barrier to improved efficiency for be v erage vending machines. In general, the bottlers or distributors place the machines at the end-user’s site for free in exchange for the exclusive right to service the machine and/or to split the coin-box revenues with the end user. In almost all cases, the end user, not the bottler or distributor, pays the electric bill. Consequently, most bottling companies and distributors are concerned primarily with first costs and have little interest in energy efficiency because they do not pay the utility bills. Accordingly, manufacturers do not include efficiency measures in their designs if the measures increase initial cost, despite the short payback periods.
In short, barriers to adoption of energy efficiency technologies include a focus by equipment purchaser on first costs, lack of awareness of the availability of energy efficiency improvements, and a lack of incentive since the equipment purchaser generally does not pay the utility bills.

3.4.7 Market Performance Data
DOE conducted a survey of existing beverage vending machines and compiled a performance database. The primary source of information for the database was equipment data sheets that were publicly available on CEC and ENERGY STAR websites. 16,17 From these data sh e ets, equipment data such as capacity and calculated daily energy consumption (CDEC), according to the test procedure in ANSI/ASHRAE Standard 32.1–2004, are known. Figure 3.4.1, Figure 3.4.3, Figure 3.4.4 and Figure 3.4.5 show CDEC values as a function of vendible capacity, while Figure 3.4.2 shows CDEC values as a function of refrigerated volume (in cubic feet).3-17

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc

CEC Qualified Type A BVM

0 1 2 3 4 5 6 7 8 9 10

0 100 200 300 400 500 600 700 800 900 Vendible Capacity [cans]CDEC [kWh/day]

Figure 3.4.1 Market Performance Data for California Energy Commission Qualified Class

A Equipment Class

CEC Qualified Type A BVM

0 1 2 3 4 5 6 7 8

0 5 10 15 20 25 30 35 40 Refrigerated Volume [ft 3 ]CDEC [kWh/day]

Figure 3.4.2 Market Performance Data for California Energy Commission Qualified Class

A Equipment Class3-18

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc

CEC Qualified Type B BVM

0 1 2 3 4 5 6 7 8

0 5 0 100 150 200 250 300 350 400 450 Vendible Capacity [cans]CDEC [kWh/day]

Figure 3.4.3 Market Performance Data for California Energy Commission Qualified Class

B Equipment Class

ENERGY STAR Qualified Type A BVM

0 1 2 3 4 5 6 7 8

0 100 200 300 400 500 600 Vendible Capacity [cans]CDEC [kWh/day]

Figure 3.4.4 Market Performance Data for ENERGY STAR Class A Equipment Class3-19

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc

ENERGY STAR Qualified Type B BVM

0 1 2 3 4 5 6 7 8 9 10

0 100 200 300 400 500 600 700 800 900 Vendible Capacity [cans]CDEC [kWh/day]

Figure 3.4.5 Market Performance Data for ENERGY STAR Class B Equipment Class

3.5 TECHNOLOGY ASSESSMENT
The purpose of the technology assessment is to develop a preliminary list of technologies that could potentially be used to improve the efficiency of beverage vending machines.

3.5.1 Higher Efficiency Lighting
Refrigerated beverage vending machines often include lighting to illuminate the contents, an exterior sign, or both. Class A machines typically include interior lighting to illuminate the merchandise on display, while Class B machines have an illuminated sign on the exterior. Higher efficiency lighting leads to energy savings in two ways: less energy is used directly for lighting and, in those units with lighting internal to the refrigerated space, less heat energy is dissipated into the refrigerated volume by the lamp and ballast.
Efficiency in lighting is commonly measured as efficacy (lumens/watt), or the quantity of light output (measured in lumens) per electrical energy input (measured in watts). Recently, the vending machine industry has been moving toward the use of T-8 fluorescent lighting in all cases, which is substantially more efficacious than T-12 lighting, and is predominantly used with electronic ballasts, which are more efficient than magnetic ballasts commonly used in T-12 lighting.3-20

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc An even more recent trend is the use of light emitting diode (LED) technology. Although LED s are currently less efficacious than fluorescent technology, they are more directional than linear fluorescent bulbs, allowing for comparable illumination with less total wattage. There have been recent advancements in LED efficacy as well as the adoption of LED technology by Seaga Manufacturing in their new Premium Collection of refrigerated beverage vending machines. Research by the Lighting Resource Center indicates that lighting display cases using LEDs were found desirable by consumers. LEDs are predicted to steadily increase in efficacy and decrease in cost as technology improves. 18

3.5 .2 H igher Efficiency Lighting Ballasts
Most illuminated beverage vending machines use fluorescent lighting with magnetic ballasts, which use inductance to modulate power flow to fluorescent lamps. Magnetic ballasts have significant electrical resistance losses. Electronic ballasts use solid state electronics to modulate power provided to fluorescent lamps. Electronic ballasts, which convert power at high frequency, have lower electrical resistance losses compared to magnetic ballasts which operate at line frequency. In addition, fluorescent lamps operate more efficiently at the higher frequency provided by electronic ballasts. In addition to the direct reductions in electrical power consumption, heat generated by the lighting and the lighting ballast contribute to the heat load. By increasing ballast efficiency, the compressor load is also reduced.

3.5.3 Higher Efficiency Evaporator Fan Motors
Evaporator fan motors move air across the evaporator coil and typically run at one speed. Manufacturers match the motor size and blade to the evaporator coil to meet the expected load under most conditions. Higher efficiency evaporator fan motors reduce energy consumption by requiring less electrical power to generate motor shaft output power.
Electric motors operate based on the interaction between a field magnet and a magnetic rotor. In a brushed motor, the field magnets are permanent magnets and the rotor is an electromagnet; the situation is reversed in a brushless motor. The electromagnetic interactions between these two magnets cause the rotor to rotate.
The simplest type of electric motor—the single-phase electric motor—suffers from a serious shortcoming. Single-phase motors only produce a rotating magnetic field when the rotor is rotating, and simply powering the electromagnet is therefore not sufficient to start such a motor. One of the most significant differences between different types of single-phase motors is the way in which they handle this start-up problem.
Nearly all inexpensive fan motors are of either the shaded-pole or the permanent split capacitor (PSC) variety, and the same is most likely true for standard BVM fan motors (fan motors not marketed as “high efficiency”). In both cases, the electromagnet consists of windings of electrical wire through which current is driven. In a shaded-pole motor, a portion of these windings is “shaded” by a copper loop. The interactions between the magnetic field generated by the shaded portion and that generated by the un-shaded portion induce rotation when the motor is powered. The imbalance between the shaded and un-shaded portions of the magnet remains throughout operation. As a result, shaded-pole motors are inefficient, with typical motor3-21

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc efficiencies less than 20 percent. 19 Shaded-pole motors are, however, electrically simple and in e xpensive.
In a PSC motor, a smaller, start-up winding is present in addition to the main winding. The start-up winding is electrically connected in parallel with the main winding and in series with a capacitor. At start-up, the interactions between the magnetic field generated by the start up winding and that generated by the main winding induce rotation. Because of the capacitor, however, the current to the start-up winding is cut off as the motor reaches steady state. Because of this, PSC motors are more energy efficient than their shaded-pole counterparts, with motor efficiencies ranging from 50 to 70 percent. Like shaded-pole motors, PSC motors are produced in large quantities and are relatively inexpensive. 20 BVM equipment fan energy efficiency can be s ubstantially improved by replacing shaded-pole motors, in the models that use them, with PSC motors.
A third type of electric motor, the electronically commutated permanent magnet (ECM) motor (also known as a brushless permanent magnet motor), is more energy-efficient than either shaded-pole or PSC motors. ECM motors, which are sold in high volumes, are three-phase electric motors with efficiencies even greater than PSC motors. However, ECM motors can weigh about twice as much and are more expensive than equivalent PSC motors.

3.5.4 Evaporator Fan Controls
Typically, evaporator fan controls are programmed such that the evaporator fan runs at a 100 percent duty cycle to circulate cold air at all times and to prevent frost build up on the evaporator fan coil. However, refrigerated beverage vending machine utility can be maintained with a lower duty cycle. This could be accomplished through software reprogramming and the addition of relays and switches.

3.5.5 Higher Efficiency Evaporator Fan Blades
High efficiency evaporator fan blades, or tangential evaporator fans, move air more efficiently, yielding energy consumption savings by reducing the required fan shaft power. The evaporator fans typically used in beverage vending machines have sheet metal blades. The blades are typically supplied by a fan blade manufacturer and mounted to the motor by the equipment manufacturer. These fan blades are not optimized for refrigerated beverage vending machines. Evaporator fans may have lower efficiencies due to the higher required pressure drops, for which sheet metal fans are not well suited. Required fan shaft power could be reduced if the fan blades were optimized for each given application.
Tangential fans also provide an opportunity to decrease equipment energy consumption. 21 Tan g ential fans utilize a vortex builder to generate a uniform airflow over a large surface. This makes them better suited to evaporator and condenser fans, which need to distribute airflow over a large coil surface area. A single long tangential fan can meet the airflow requirements for an entire refrigerated cabinet, while requiring a single high efficiency fan motor.3-22

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc 3.5.6 Improved Evaporator Design

Th e evaporator is a refrigerant-to-air heat exchanger composed of metals with high thermal conductivity such as aluminum and copper. It is responsible for evaporating and superheating the entering refrigerant liquid-vapor mixture while extracting heat from the air in the refrigerated space. The internal heat-exchanging surfaces in contact with refrigerant are commonly referred to as “refrigerant-side” while the external heat-exchanging surfaces in contact with the air are referred to as “air-side.”
Depending on the requirements of the equipment, the evaporator will have a discharge air temperature (DAT) that can be up to 10 ° F colder than the desired temperature of the product in the refrigerated space. Because a temperature difference is necessary to drive heat from the air into the refrigerant, the saturated evaporator temperature (SET) must be considerably colder than the DAT. The magnitude of this driving force is directly related to the total refrigeration load and the thermal characteristics of the evaporator as shown in Equation 3.2:
( )

ln CAT DAT CAT SET DAT SET T Q

UA LM −

−

−    

  = =∆ Eq. 3.2

where Q is the total refrigeration load in British thermal units per hour (Btu/h), U is the heat transfer coefficient of the evaporator in Btu/ ° F/square foot (ft 2)

, A is the area of the evaporator in ft 2

, CAT is the case air temperature, and ∆T LM is the log mean temperature difference of the coil in ° F.

I n creasing the area of the coil decreases the necessary ∆T LM and therefore decreases the SET. Thi s results in an increased compressor energy efficiency ratio (EER) and lower compressor energy consumption.
Enhancements to the refrigerant-side surface area of the evaporator typically include rifled or diamond-pattern tubing and increased number of tube passes. Enhancements to the air-side surface area include increased fin pitch (decreased fin spacing), fin patterns (wavy or zig-zag), and increased numbers of tube passes.
Increasing the overall size of the coil in one or more dimensions without changing other aspects of the coil is another way to increase the area. However, most applications limit the amount of coil size increase. Most approaches to increasing the evaporator surface area also result in an increase in required fan motor power and an increase in refrigerant pressure drop.

3.5.7 Low Pressure Differential Evaporators
Decreasing the air-side pressure drop of an evaporator coil allows for the use of lowerpower evaporator fan motors. This requires reducing restrictions to the flow of air across the coil such as high fin pitch, and high numbers of tube passes. Large spaces between fins and tubes also reduce frost “bridging,” which can completely block airflow through portions of the coil.3-23

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc 3.5.8 Improved or Thicker Insulation

Ei t her increasing the insulation thickness or reducing insulation thermal conductivity will reduce the energy consumption of beverage vending machines. Typical insulation thickness for refrigerated beverage vending machines ranges from 1.5 to 2 inches. Blow-in polyurethane foam is used for most machines. The impact of an increase in insulation thickness and insulation quality is limited for glass-front machines by the fact that a large portion of the cooling load is due to infiltration.
Improved-technology polyurethane foam insulation has a reduced conductivity, which reduces the heat load. The improvement is due mainly to the formation of smaller air cells within the foam insulation structure and better cell-size consistency. Use of better foam reduces the heat load, assuming no wall thickness change.
The importance of refrigerated volume suggests that technologies that allow reduction in insulation thickness while maintaining thermal resistivity (R-value) would be of interest. Vacuum panels could provide such performance. Vacuum panels are airtight panels sealed with glass or plastic, which are evacuated to eliminate a conduction path. They are generally filled with supporting powder that prevents collapse of the external seal. Much work needs to be done to demonstrate the reliability of vacuum panels to show that they will perform for many years without leaking and losing their insulating value. In addition, current-technology vacuum panels do not provide the necessary structural rigidity between sheet metal panels that is possible with foamed-in-place polyurethane insulation.

3.5.9 Improved Glass Pack (for Class A machines)
For Class A machines, the glass front allows consumers to view the merchandise they can purchase. However, the glass front (referred to as a glass pack) allows heat transfer due to radiation and glass packs typically are not good insulators of heat compared to solid walls. Thus any improvements made to the glass pack to reduce radiation and conduction heat loads will also reduce compressor power. Glass pack improvements can be accomplished in several ways: addition of spectrally selective coatings (referred to as low-E coatings), adding panes of glass, using argon instead of air as a filler gas, and switching from an aluminum frame to a vinyl frame.

3.5.10 Defrost Mechanism

A s the air in the refrigerated space is cooled, water vapor condenses on the surface of the evaporator coil. In refrigerators and freezers, where the evaporator coil is below 32 °F, this water freezes as it collects, forming a growing layer of frost. The frost reduces cooling performance by increasing the thermal resistance to heat transfer from the coil to the air, and by obstructing airflow. Both the method in which defrost is performed and control of the defrost cycle can lead to increased energy savings.
There are two methods available for defrosting the evaporator coil in this case: off-cycle defrost and electric defrost. Off-cycle defrost involves shutting off refrigerant flow to the coil while leaving the evaporator fan running. This method is used where cabinet air is above the freezing point of water and can be used to melt the frost. Electric defrost is used where the air temperature is not high enough to defrost the coil, and where defrost must occur quickly to3-24

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc prevent any significant rise in product temperature. Electric defrost involves melting frost by br i efly turning on an electric resistance heater, which is in contact with or near the evaporator coil.

3.5.11 Thermoacoustic Refrigeration
Thermoacoustic refrigeration is a technology that uses high-amplitude sound waves in a pressurized gas to pump heat from one place to another. A device consisting of a series of small parallel channels, referred to as a “stack,” is fixed in place at a set location inside a resonator tube. In the case of a thermoacoustic refrigerator, external work is supplied by the standing sound wave in the resonator.
The longitudinal standing sound wave causes the gas particles to oscillate back and forth parallel to the walls of the stack. The alternating compression and rarefaction of the gas causes the local temperature of the gas to oscillate due to the adiabatic nature of sound waves. If the local temperature of the gas becomes higher than that of the nearby stack wall, heat is transferred from the gas to the stack wall. If the local temperature of the gas drops below that of the stack wall, heat is transferred from the wall to the gas.
Prototypes of thermoacoustic refrigerators have been demonstrated for refrigeration applications. A prototype thermoacoustic refrigeration unit designed for an ice-cream freezer has been measured to be as efficient as the vapor compression unit it replaces. This technology is expected to improve in efficiency with further development of heat exchangers and other subsystems. It is also likely that efficiency in many applications could improve because thermoacoustic refrigerators are well suited to proportional control, where the cooling capacity can be continuously controlled so that the output can be adjusted accurately for varying load conditions. Although, this technology currently does not improve upon the efficiencies of conventional refrigeration technology, thermoacoustic refrigeration has the environmental benefit of being refrigerant-free.

3.5.12 Magnetic Refrigeration
Magnetic refrigeration utilizes the magneto-caloric effect where magneto-caloric materials like gadolinium absorb heat from their surroundings when entering a magnetic field, then reject heat to their surroundings when exiting a magnetic field. When magneto-caloric materials are circulated through magnetic fields and combined with heat exchangers to transfer heat, they can be used to remove heat from a refrigerated space and reject heat to the surroundings.
This refrigeration technology could be used in any possible application where cooling, heating or power generation is used today. Because of the early stage of development, many technical issues need to be addressed for this technology to be commercially viable.

3.5.13 Electro-hydrodynamic Enhanced Heat Transfer
Electro-hydrodynamic (EHD) enhanced heat transfer is the result of applying a highvoltage electrostatic potential field across a heat transfer fluid, such as a refrigerant or refrigerant mixture. The applied field destabilizes the thermal boundary layer, thereby producing better3-25

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc mixing of the bulk fluid flow and increasing the net heat transfer coefficient. This procedure ap p ears to be more effective when applied to phase-change processes (e.g., boiling and condensation).
This phenomenon is typically used to electronically control the capacity of a heat exchanger by raising the applied voltage to increase the heat transfer. This can lead to improved efficiencies by using smaller capacity equipment, most of the time without EHD, and then utilizing the EHD effect during peak loads. EHD can replace, or work in conjunction with, enhanced surface heat exchangers. To use EHD, an electrical voltage (from a few volts to thousands of volts) is applied to the heat transfer device. However, because the heat transfer fluids are typically dielectric (of low electrical conductivity), even high voltages produce very little current. This low current helps keep the power (voltage x current) and the associated energy penalty low.

3.5.14 Copper Rotor Motors
Making the critical components of an induction motor’s rotor (e.g., conductor bars and end rings) out of copper instead of aluminum, which is the current practice, improves the energy efficiency of the motor. The greater electrical conductivity of copper results in lower resistance heating losses in the rotor and thus lower losses in the motor. Further improvements in the design and fabrication of copper motors, such as optimization of the steel laminations, could further increase the efficiency of copper motors over aluminum motors.

3.5.15 Higher Efficiency Compressors
Several technologies exist to increase the efficiency of beverage vending machine compressors. High efficiency reciprocating and scroll compressors, sometimes incorporating variable-speed motors, all have higher efficiencies than the traditional reciprocating compressors commonly used in beverage vending machines.
Scroll compressors compress gas in a fundamentally different manner from traditional compressors—between two spirals, one fixed and one rotating. High efficiency reciprocating compressors are as efficient, or more efficient, than scroll compressors. However, some drawbacks exist including noise, cost and reliability, compared to scroll compressors.

3.5.16 Improved Condenser Design
Like the evaporator, the condenser is a refrigerant-to-air heat exchanger composed of metals with high thermal conductivity such as aluminum and copper. It is responsible for condensing and sub-cooling the entering refrigerant vapor while rejecting heat from the refrigerant to the ambient air.
Depending on the requirements of the equipment, the condenser will have a saturated condenser temperature (SCT) that is about 10 °F warmer than the ambient air. As with evaporator coils, increasing the area of the condenser coil will decrease the necessary ∆T LM of the

co i l and therefore decrease the SCT, resulting in increased compressor efficiency (increased EER).3-26

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc Enhancements to the refrigerant-side surface area of the condenser typically include ri fled or diamond-pattern tubing and increased number of tube passes. Enhancements to the airside surface area include increased fin pitch (decreased fin spacing), fin patterns (wavy or zigzag), and increased numbers of tube passes.
Increasing the overall size of the coil in one or more dimensions without changing other aspects of the coil is another way to increase the area. However, most applications limit the amount of coil size increase in order to maintain overall equipment dimensions. Most approaches to increasing the condenser surface area also result in an increase in required fan motor power and an increase in refrigerant pressure drop.

3.5.17 Higher Efficiency Condenser Fan Motors
Condenser fan motors are responsible for moving air across the condenser coil and typically run at one speed. The manufacturer will match the motor size and blade to the evaporator coil to meet the expected load on the case under most conditions. Higher efficiency condenser fan motors reduce energy consumption by requiring less electrical power to generate motor shaft output power. Condenser fan motors are generally of the same size and type as evaporator fan motors. See section 3.5.3 for a discussion of higher efficiency evaporator fan motor technology.

3.5.18 Higher Efficiency Condenser Fan Blades
High efficiency condenser fan blades, or tangential condenser fans, move air more efficiently, yielding energy consumption savings by reducing the required fan shaft power. The condenser fans typically used in refrigeration equipment have sheet metal blades. The blades are typically supplied by a fan blade manufacturer and mounted to the motor by the equipment manufacturer. These fan blades are not optimized for beverage vending machines. Required fan shaft power could be reduced if the fan blades were optimized for each given application.
Tangential fan also provide an opportunity to decrease refrigeration equipment energy consumption. Tangential fans utilize a vortex builder to generate a uniform airflow over a large surface. This makes them ideal for evaporator and condenser fans that need to distribute airflow over a large surface area. A single long tangential fan can meet the airflow requirements for an entire condenser, while only requiring one high efficiency fan motor.

3.5.19 Higher Efficiency Expansion Valves
Expansion valves are refrigerant metering devices whose purpose is to control the amount of refrigerant flowing to the evaporator coil. In doing so, they simultaneously decrease the temperature and pressure of the refrigerant, creating a cold liquid-vapor mixture. The low temperature of the refrigerant leaving the expansion valve creates the driving force to move heat out of the refrigerated space and into the evaporator.
The most basic type of expansion device is a capillary tube, which is used in beverage vending machines. The capillary tube is a long, thin piece of pipe that creates a pressure drop in the refrigerant through frictional losses. Capillary tubes must be sized to the particular application and cannot adjust for variations in load or ambient operating conditions. They are3-27

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc often oversized for worst-case conditions, and therefore may operate at reduced efficiency during

no r mal operation. However, using an alternate technology such as a thermostatic expansion valve (i.e., TXV) or an electronic expansion valve (i.e., EEV) will likely not provide significant energy savings over a properly sized capillary tube under steady-state conditions.

3.5.20 Variable-Speed Compressors
Variable-speed compressors are implemented through the use of an electronic control on the compressor motor, which allows the motor to operate at different speeds. Variable-speed compressors reduce energy consumption in three ways b :

1. W hen refrigerant flow is reduced during part-load operation, the condenser and evaporator (designed for full flow conditions) are more effective and thus more efficient. Temperature drops decrease, resulting in reduced pressure rise across the compressor, which also improves efficiency.

2. Close matching of load eliminates the cycling that occurs with single-stage compressors. Maintaining a constant pressure is more efficient because losses at higher pressure rise are greater than gains at lower pressure rise.

3. During the off-cycle, the pressure in the system equilibrates. At the intermediate pressure, refrigerant vapor condenses in the cold evaporator rather than the condenser. Essentially, some of the heat rejection load is rejected to the evaporator during this time, reducing overall system performance. Variable-speed operation would eliminate or significantly reduce compressor off-time and the related inefficiencies.

3.5.21 Liquid Suction Heat Exchangers
The purpose of a liquid suction heat exchanger is to further cool the flow of liquid refrigerant entering the expansion valve using the flow of gaseous refrigerant leaving the evaporator, thus providing additional sub-cooling for the entering liquid by super-heating the exiting suction vapor. Hotter suction vapor is desirable because it is less susceptible to heat gains in the return piping to the compressor, provides an additional margin of safety as superheated vapor for compressor operation (since any liquid entering the compressor may cause damage). Additional sub-cooling of the liquid entering the expansion valve is desirable because it provides additional cooling capacity in the evaporator. However, the compressor work is increased because the suction vapor has greater enthalpy. In addition, the possibility of compressor overheating brought on by the combination of increased compressor work and hotter vapor limits the use of this method in some situations. The possibility for these problems and the potential gains of liquid suction heat exchangers depend on several factors, including evaporator temperature, type of refrigerant used, and system pressures.

b Variable-speed compressors typically increase efficiency over a broad operating range but do not inherently incr ease maximum efficiency at the compressor rating point.3-28

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc 3.5.22 Condenser Fan Motor Controllers

C o ndenser fan motor controllers allow fan motors to run at variable speed, to match changing conditions in the vending machine. Matching the fan speed to all conditions improves coil performance. This allows the refrigeration system to run more efficiently at different ambient humidity and temperature levels. However, under steady-state conditions, there is no energy savings benefit with condenser fan motor controllers.3-29

BVM_ANOPR_TSD_Ch3_MTA_2008-06-10.doc REFERENCES

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