CHAPTER 3. MARKET AND TECHNOLOGY ASSESSMENT

TABLE OF CONTENTS

3.1 INTRODUCTION

........................................................................................................... 3- 1 3.1.1 Definitions

............................................................................................................ 3 -1 3.1.2 Description of Refrigerated Bo ttled 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 RE GULATORY 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

............................................................................ 3-7 3.3.4 Australia

............................................................................................................... 3-8 3.3.5 Rebate Programs

.................................................................................................. 3-9 3.4 MARKET ASSESSMENT

.............................................................................................. 3-9 3.4.1 Trade Associations

............................................................................................... 3-9 3.4.2 Manufacturers and Market Share

....................................................................... 3-10 3.4.2.1 Small Businesses

.................................................................................... 3-11 3.4.3 Equipment Classes

............................................................................................. 3-11 3.4.4 Typical Refrigeration System

............................................................................ 3-12 3.4.5 Energy Savings Potential

................................................................................... 3-14 3.4.6 Barriers to Efficiency Improvements

................................................................. 3-15 3.4.7 Market Performance Data

.................................................................................. 3-15 3.5 TECHNOLOGY ASSESSMENT

.................................................................................. 3-18 3.5.1 Higher Efficiency Lighting

................................................................................ 3-18 3.5.2 Higher Efficiency Lighting Ballasts

.................................................................. 3-19 3.5.3 Higher Efficiency Evaporator Fan Motors

........................................................ 3-19 3.5.4 Evaporator Fan Controls

.................................................................................... 3-20 3.5.5 Higher Efficiency Evaporator Fan Blades

......................................................... 3-20 3.5.6 Improved Evaporator Design

............................................................................. 3-20 3.5.7 Low Pressure Differential Evaporators

.............................................................. 3-21 3.5.8 Improved or Thicker Insulation

......................................................................... 3-21 3.5.9 Improved Glass Pack (for Class A machines)

................................................... 3-22 3.5.10 Defrost Mechanism

............................................................................................ 3-22 3.5.11 Thermoacoustic Refrigeration

........................................................................... 3-23 3.5.12 Magnetic Refrigeration

...................................................................................... 3-23 3.5.13 Electro-Hydrodynamic Enhan ced Heat Transfer

............................................... 3-23 3.5.14 Copper Rotor Motors

......................................................................................... 3-24 3.5.15 Higher Efficiency Compressors

......................................................................... 3-24 3.5.16 Improved Condenser Design

.............................................................................. 3-24 3.5.17 Higher Efficiency Condenser Fan Motors

......................................................... 3-25 3.5.18 Higher Efficiency Condenser Fan Blades

.......................................................... 3-25 3.5.19 Higher Efficiency Expansion Valves

................................................................. 3-25

3-i BVM_FINAL_FR_TSD_Chapter3_08-14-09.doc3.5.20 Variable-Speed Compressors

............................................................................. 3-26 3.5.21 Liquid Suction Heat Exchangers

....................................................................... 3-26 3.5.22 Condenser Fan Motor Controllers

..................................................................... 3-26 REFERENCES

.................................................................................................................... ...... 3-27

LIST OF TABLES

Table 3.2.1 American Society of Heating Refrigerating and Ai r-Conditioning Engineers Standard 32.1-2004 – Standard Test Conditions

.................................................... 3-5 Table 3.3.1 ENERGY STAR Criteria for Beverage Vending Machines

................................... 3-6 Table 3.3.2 California Energy Commissi on – Performance Standards

..................................... 3-8 Table 3.3.3 Beverage Vending Ma chine Rebate Programs

....................................................... 3-9 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

.......................... 3-11 Table 3.4.3 Energy Use by Component fo r Typical Vending Machines

................................. 3-13 Table 3.4.4 Potential Energy Savings Estimat es for Beverage Vending Machines

................ 3-14

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 Refr igerated Beverage Vending Machine Models

..................................................................................................................... 3-6 Figure 3.4.1 Market Performance Data fo r California Energy Co mmission Qualified Class A Equipment Class

...................................................................................... 3-16 Figure 3.4.2 Market Performance Data fo r California Energy Co mmission Qualified Class A Equipment Class

...................................................................................... 3-16 Figure 3.4.3 Market Performance Data fo r California Energy Co mmission Qualified Class B Equipment Class

...................................................................................... 3-17 Figure 3.4.4 Market Performance Data for EN ERGY STAR Class A E quipment Class

......... 3-17 Figure 3.4.5 Market Performance Data for EN ERGY STAR Class B E quipment Class

......... 3-18

3-ii BVM_FINAL_FR_TSD_Chapter3_08-14-09.docCHAPTER 3. MARKET AND TECHNOLOGY ASSESSMENT

3.1 INTRODUCTION

This chapter details the market and technology assessment that the U.S. Department of Energy (DOE) has carried out in support of the energy conservation standards rulemaking for beverage vending machines. This rulemaking is mandated by the Energy Policy Act of 2005 (EPACT 2005) and is effective for equipm ent manufactured on or after August 8, 2012. The beverage vending machines have never before been the subject of energy conservation regulations at th e 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 bevera ge vending machine industry an d market structure, based on publicly available information as well as data and information submitted by manufacturers and other stakeholders. Issues that are addressed include manufactur er characteristics and market shares, existing regulatory and non-regulatory e fficiency improvement initiatives, equipment classes, and trends in equi pment markets and characteristi cs. The goal of the technology assessment is to develop a preliminary list of t echnologies that could be used to improve the efficiency of beverage vending machines.

Refrigerated beverage vending machines are used to cool and di spense 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 oper ating in the United States consumes more than 12 billion kilowatt hours (kWh ) of electricity annually. 1

3.1.1 Definitions

Section 135(c)(4) of EPACT 2005 amended section 325 of the Energy Policy and Conservation Act (EPCA) to include new s ubsections 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 publi cation of the final rule establishing the energy conservation standards.

Section 135(a)(3) of EPACT 2005 amended sec tion 321 of EPCA by adding, in part, new subsection 321(40), 42 U.S.C. 6291(40), whic h establishes the following definitions:

 The term “refrigerated bottled or can ned beverage vending machine” means a commercial refrigerator (defined below) th at cools bottled or canned beverages and dispenses the bottled or ca nned beverages on payment.

In addition, section 136(a)(3) of EPAC T 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 th at are relevant to beverage vending machines:

3-1 BVM_FINAL_FR_TSD_Chapter3_08-14-09.doc(9) (A) The term “commercial refrigerat or, freezer, and refrigerator-freezer” means refrigeration equipment that—

(i) is not a consumer product (as defined in section 321);

(ii) is not designed and marketed ex clusively for medical, scientific, or research purposes;

(iii) operates at a chil led, frozen, combination chilled and frozen, or variable temperature;

(iv) displays or stores merchandi se and other perishable materials horizontally, semivertic ally, or vertically;

(v) has transparent or solid door s, sliding or hinged doors, a combination of hinged, sliding, tran sparent, or solid doors, or no doors;

(vi) is designed for pull-down te mperature applications or holding temperature applications; and

(vii) is connected to a self-contain ed condensing unit or to a remote condensing unit.

As presented 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 Na tional Standards Institute (ANSI)/American Society of Heating, Refrigerating, and Air-C onditioning 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 paperboa rd or a combination of both in which a beverage is sealed.

A bottle or can in this context refers to “a se aled container for beverages,” so a bottled or canned beverage is “a beverage in a sealed cont ainer.” DOE expects that such broad definitions for “bottled beverage” and “canne d 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 vendi ng machines can be divided into categories by either machine use designation (indoor use only or indoor/outdoor use) or by door type (glassfront or solid-door). The classification of beverage vending machines by machine use designation of indoor use only and indoor/outdoor use is ex plained in detail below.

3-2 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docFigure 3.1.1 A Typical Glass-Front Beverage Vending Machine

The beverage vending machines intended fo r indoor use only are dominated by glassfront models (Figure 3.1.1) that have a transpar ent 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 because the glass fronts make them vulnerable to vanda lism 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 Underwrite rs Laboratories (UL) Standard 541–2003. 3 The glass-front vending machines are also known as “multi-packag e” vending machines. This design allows the consumer to see the merchandise inside th e machine—commonly displayed on shelves—with some models displaying as many as 45 different varieties of drinks. Product packaging is not limited to cans and bottles, and may also include cartons, juice packs, and non-standard bottle and can shapes. Upon dispensation, many machines have a mechanism to move the merchandise to the door gently rather than dropping the beve rage from the upper shelve s. With the increasing market for non-carbonated soft drinks, such as en ergy 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 refe rred in the industry as “s helf-style” or “fullycooled” machines, because the entire refrigerated volume needs to be cooled, not just the next-tobe-vended product.

The most common beverage vending machine that is intended for both indoor and outdoor use is the solid-door m achine (or closed-front machine; Figure 3.1.2) Closed-front machines house cans or bottles inside a complete ly opaque insulated compartment. With soliddoor 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 varietie s of beverages. A small fracti on of solid-door vending machines are classified as having a “live di splay” 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.

3-3 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docFigure 3.1.2 A Typical Solid-Door Beverage Vending Machine

These machines are typically designed so th ey 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 Loca tions” in accordance with UL Standard 541-2003. 3
These solid-door machines are referred to in the industry as “stack-style” or “zone-cooled” machines, because cold air is directed only at the fraction (or zone) of the refrigerated volume that contains the next-t o-be-vended product.

3.2 TEST PROCEDURES

3.2.1 Department of Energy

Section 135(b) of EPACT 2005 amends sect ion 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 Vendi ng Machines for Bottled, Canned or Other Sealed Beverages. 4 DOE therefore published a final rule on December 8, 2006, incorporating 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 consumpti on and determination of capacity of this equipment. The first modification DOE ma de in adopting ANSI/ASHRAE Standard 32.1–2004 was to specify in the final rule that in secti on 6.2, “Voltage and Freque ncy,” equipment with dual nameplate voltages should be tested at th e lower of the two vo ltages 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 accordan ce with the methodology specified in section 5.2, “Total Refrigerated Volume,” (excl uding subsections 5.2.2.2 through 5.2.2.4) of the ANSI/Association of Home Appliance Ma nufacturers (AHAM) HRF Standard 1–2004, ‘‘Energy, Performance and Capacity of Househol d Refrigerators, Refrigerator-Freezers and Freezers.” 5

3-4 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docThe current version of ANS I/ASHRAE Standard 32.1–2004:

 Defines standard bottled, canned, or ot her sealed beverage storage capacity,

 Establishes uniform methods of testing for determining laboratory performance of vending machines for bottled, canne d, 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 ar e vended at a rate of two per minute, 3 hours after a half-full machine is refilled.

○ Recovery Test is designed to determine the product temperatur e recovery time of a vending machine when loaded with pr oduct at a specified temperature.

Table 3.2.1 American Society of Heating Refr igerating and Air-Conditioning Engineers Standard 32.1-2004 – Standard Test Conditions

Test and Pretest Conditions Energy Consum ption Tests Vend Test Recovery Test Ambient Temperature Perfor m 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 NON

REGULATORY ACTIVITIES

Both Canada and the State of California have efficiency standards in place for refrigerated beverage vending machines. Australi a 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 U.S. 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 st andard 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 Tier I standard was set to qualify the top 25 percent most efficient machines. With Tier 2 now implemented, some manufacturers are alread y producing even more efficient machines.

3-5 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docENERGY STAR performance criteria for qualification are dependent on vendible capacity. Vendible capacity is defined in ASHRAE Standard 32.1-2004 as “the maximum quantity of standard product that can 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) can s 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 pr oduct.” 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 fo r Beverage Vending Machines Equipment Type ENERGY STAR Definiti on Energy Consumption Under Test Conditions

Beverage vending machines A self-contained system designed to accept consumer payments and dispense bottled, canned, and other sealed beverages at appropriate temper atures without on-site labor intervention. Tier 1 (effective April 1, 2004) Tier 2 (effective July 1, 2007) Y = 0.55  [8.66 + (0.009  C)] * Y = 0.45  [8.66 + (0.009  C)] *

* Y=24-hour consumption (kWh/day) after the machine has stabilized; C=vendible capacity (number of cans).

Figure 3.3.1 shows the energy consumption of manufactured units that qualify for ENERGY STAR Tier II, as of May 1, 2009. 6

3-6 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docFigure 3.3.1 ENERGY STAR Qualified Refriger ated Beverage Vending Machine Models

3.3.2 Canadian Standards Association

The Canadian Standards Association (CSA) te st 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 a nnual energy consumption that vary with the category of vending machine. The standard also c ontains the test procedure. The standard is voluntary in all jurisdicti ons 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 pr oducts manufactured, sold, or leased after August 31, 2004.

In Canada, beverage vending machines ar e regulated to the CSA standard and not covered under a voluntary labeling program. Th e maximum daily energy consumption allowed under the CSA standard is described by the following:

Y = 8.66 + (0.009 x C) Eq. 3.1

Where:

Y = 24-hour consumption (kWh/day) after th e machine has reached a stable operating condition, and C = vendible capacity.

3-7 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docThe ENERGY STAR performance levels are 45–55 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 ve nding 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 beca use the market data available to the CSA indicate that regulating to the CSA standard would have litt le 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 mini mum energy performance of equipment sold in California. The Amendments to A ppliance Efficiency Regulations, Regulations 7 propose both an energy efficiency standard and a design vending machines, as of January 1, 2006 (

Table 3.3.2).

Table 3.3.2 California Energy Commiss ion – Performance Standards

Product CEC Definition Maximum Daily Energy Consumption kWh Design Standard

January 1, 2006 January 1, 2007 Beverage Vending Machine Refrigerated canned and bottled beverage vending machines when tested at 90°F ambient temperatureexcept multipackage units. 0.55  (8.66 + (0.009  C) 0.55  (8.66 + (0.009  C) Refrigerated canned and bottled beverage vending machines shall be equipped with hard wired controls and/or software capable of automatically placing th e machine into a lowpower mode during periods of extended inactivity while still connected to its power source. The machine sh all 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. Refrigerated 0.55  (8.66 + 0.55  (8.66 + multi-package canned and bottled beverage vending machines when (0.009  C) (0.009  C) (B) Refrigeration low power state – the average beverage temperature is allowed to rise above 40 degrees Fahrenheit (°F) for an extended period of time.

tested at 75°F (C) Whole machine low power state – the lights ambient are off and the refrigerat ion operates in its low temperature. power state.

3-8 BVM_FINAL_FR_TSD_Chapter3_08-14-09.doc(D) The machine shall be capable of 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 En ergy Efficiency Committee (NAEEEC) has 15 minimum energy performance standards (MEPS) for a variety of technologies. Report No: 2008/10, Refrigerated Beverage Vending Machines , released in September 2008. 8 Its standards are based on the North American work of the Canadian Standards Association, the California Energy Commission, and the U.S. ENERGY STAR program.

NAEEEC has introduced effi ciency 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 final MEPS levels shall be equivalent to the ENERGY STAR criteria, as amended December 2004.

 A category of products shall be established as “high effici ency” products th at shall be equivalent to the higher efficiency tier in ENERGY STAR requirements.

3.3.5 Rebate Programs

Several rebate programs for beverage vendi ng machines are offered by local utilities, including Austin Energy, Avista Utilities, Conne cticut 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 organiza tions 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 th e lighting and compressor in refrigerated vending machines and the entire snack machine when th e machines are not being used, particularly overnight. These controllers are “s mart” and operate to ensure that the beverage is cold, yet can save 20–50 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 av ailable for beverage vending machines.

3-9 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docTable 3.3.3 Beverage Vending Machine Rebate Programs Utility Condition 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 commut ated motors (ECMs) 20/motor

3.4 MARKET ASSESSMENT

The following market assessment identifies th e manufacturer trade association, domestic manufacturers of beverage ve nding machines, manufacturer mark et 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 Associa tion (NAMA) is the trade association for manufacturers of refrigerated beverage ve nding machines, and the American Beverage Association (ABA) is the trade a ssociation for the bottlers and sy rup 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 technical department of NAMA was found ed in 1957 to ensure the vending industry serve public health by dispensing safe and wholesome food. To this end, NAMA provides various technical servic es to group members:

 Establishment of voluntary “Standard for San itary Design and Construction of Food and Beverage Vending Machines”

 Inspection of vending machines for complia nce with Food and Drug Administration and NAMA requirements;

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

 Training for technicians on effectiv e vending machine maintenance; and

 Industry Publications on technical services, health, and safety.

3-10 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docABA is the trade association for America’s non-alcoholic refreshment beverage industry. It is closely linked with the re frigerated beverage vending machin e industry in so far as ABA’s members (e.g., Pepsi-Cola Co., Coca-Cola Co.) are the largest purchaser s of beverage vending machines. The association provides a forum fo r the members to discuss common issues and serves as an industry liaison to the government and public. It offers t echnical 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 Manufacturers 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 bevera ge 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 ba se, annual shipments, equipment lifetime, unit energy consumption, and national aggregate energy consumption.

3-11 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docTable 3.4.1 Beverage Vending Machine Census and Energy Use Data Census and Energy Use Data Source 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 s t Annual Report (2003 values) Unit Energy Consumption: 3,000 kWh/year 3,644 kWh/year ADL (1996) 11 E-SOURCE (1996) 1 Primary Annual Energy Consumption: 0.121 quad ADL (1996) 11

3.4.2.1 Small Businesses

DOE considered the possibility that small businesses would be particularly impacted by the promulgation of energy conservation standa rds for beverage vending machines. The Small Business Administration (SBA) defines small bus iness manufacturing enterprises for automatic vending machine manufacturing as t hose having 500 employees or fewer. 12 SBA lists small 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 expre ssed in terms of the aver age annual receipts or the average employment of a firm. For beverage vending machines, the size standard is matched to NAICS code 333311, Automatic Vending Mach ine Manufacturing, and is 500 employees.

DOE studied the potential impacts on these small businesses in detail and presented the results in the manufacturer impact analysis (MIA; chapter 12 of this TSD). 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. Seaga Manufacturing, In c. Automatic Merchand ising Systems, Inc. Multi-Max Vending Wittern Group Edina Technical Products

3.4.3 Equipment Classes

Beverage vending machines can be divided in to different equipment classes categorized by physical characteristics that affect the efficiency of th e equipment. Most of these characteristics affect the merchandise that the equipment cools and vends, and how that merchandise is accessed by the cu stomer. Key physical characteri stics are the door type (glassfront or solid-front) and the vendible capacity (o r the refrigerated volume) of the machine. The energy consumption of the refrigerated bevera ge 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)

3-12 BVM_FINAL_FR_TSD_Chapter3_08-14-09.doc(b) Class B Machine (any beverage vending machine)

Beverage vending machines for indoor/outdoor use: (a) Class 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 Cl ass A machines installe d outdoors (because of safety and vandalism reasons) and hardly any Cla ss 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 m achine not considered to be Class A)

DOE has reduced the number of equipment cl asses 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 mach ines manufactured today typi cally utilize a transparent (glass or transparent polymer) front and generally use “she lf-style” vending mechanisms. Because the next-to-be-vended product is visi ble to the consumer and any product can be selected by the consumer off of the shelf, a ll bottled or canned beve rage 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 vende d bottled or canned beverage is not generally visibl e 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 refriger ation systems consisting of a compressor, evaporator, condenser, and e xpansion 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 typical ly located in the bottom portion of the unit, between the ground and the refrigerated cabinet . Refrigerant is pipe d 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 re sults 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 65–75 percent of th e total energy consumed (Table 3.4.3). 13 Oversized single-speed compressors are commonly used to provide excess cooli ng 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

3-13 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docevaporator fan runs continuously to distribute air through the refr igerated cabinet and consumes about 8 percent of total machin e energy. Lighting systems usually remain on the entire time a vending machine is plugged in. Di fferent lighting systems are us ed, depending on the machine, but usually consume 5–20 percent of the to tal energy. Dispensing mechanisms operate intermittently, whenever a product is purchased, and therefore do not use a significant amount of energy (1–3 percent) compared to other components.

Table 3.4.3 Energy Use by Component for Typical Vending Machines Component Class A Machine % Class B Machine % Compressor Condenser Fan Evaporator Fan Lighting Money-Handling Mechanism 76 9 8 4 3 65 7 8 19

1
Heat enters the refrigerated section of the cabinet by the following methods:

 Released by the evaporator fan motor

 Released by the lighting (g lass-front units only)

 Conduction through the insulated envelope

 Infiltration through imperfections in constructio n such as cracks in the box or improperly sealed delivery doors

 Radiation through the glass fr ont (glass-front units only)

 Product restocking (warm product placed into th e 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 eff ect 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 an d minimize the amount of heat absorbed by the refrigerant. Exposure to sunlight greatly increases heat gain in to 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-intensit y lighting fixtures can have a similar (but smaller) effect.

Condenser coils are usually located in the bot tom of the machine, with air intakes at ground level. Because coils often ge t dirty and clogged, condensers of ten 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 mach ine. Trapped heat increases the inlet air temperature at the condenser, causing operations at higher c ondensing temperatures.

3-14 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docThe site owner can improve vending machine efficiency by keeping machines in cool/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 savings potential in 2010–2035 ranges fr om 0.48–1.11 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 Estima tes for Beverage Vending Machines Technology/Standard Level Energy 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 Po tential Estimates, DOE (October 2005).
The technologies shown in the above table are described below.

 Combination of technologies: This is a theo retical “combination” of two technologies presented in the ADL 1996 report—a high effici ency compressor and a brushless directcurrent (DC) evaporator fan motor. Both th e compressor and the evaporator fan motor are relatively simple to change and could be de ployed 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 2-year payback technologies: The 1996 ADL report details beverage vending machine designs including energy efficient techno logies that individu ally have either a less than 2-year or a less th an 5-year PBP. A combination of high efficiency compressor, electronic lighting ballast and an ECM eva porator fan motor was shown to have a payback of less than 2 years. These energy e fficient technologies gave an energy savings potential of 32 percent.

3-15 BVM_FINAL_FR_TSD_Chapter3_08-14-09.doc Less than 5-year payback technologies: A co mbination of variable-speed compressor, electronic lighting ballast, an ECM evaporat or fan motor and improved insulation was shown to have a payback of less than 5 y ears, giving a 42 percent total energy savings potential.

ENERGY STAR and CEC do not specify a specific technology but require manufacturers 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 manufacturer s but do not pay the util ity 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 beverage vending machines. In general, the bottlers or distributors place the machines at the enduser’s site for free in exchange for the exclusiv e right to service the m achine and/or to split the coin-box revenues with the end user. In almost all cases, the end us er, not the bottler or distributor, pays the electric bi ll. Consequently, most bottling companies and distributors are concerned primarily with first costs and have litt le interest in energy efficiency because they do not pay the utility bills. Accord ingly, 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 technolog ies include a focus by equipment purchaser on first costs, lack of awar eness of the availability of energy efficiency improvements, and a lack of in centive since the equipment purchas er 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 the CEC and ENERGY STAR websites. 16,17 From these data sheets, equipment data such as capacity and daily energy consumption (DEC), according to the test procedure in ANSI/ASHRAE St andard 32.1–2004, are known. Figure 3.4.1, Figure 3.4.3, Figure 3.4.4 and Figure 3.4.5 show DEC values as a function of vendible capacity, while Figure 3.4.2 shows DEC values as a function of refrigerated volume (in cubic feet).

3-16 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docFigure 3.4.1 Market Performance Data for California Energy Commission Qualified Class A Equipment Class

Figure 3.4.2 Market Performance Data for California Energy Commission Qualified Class A Equipment Class

3-17 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docFigure 3.4.3 Market Performance Data for California Energy Commission Qualified Class B Equipment Class

Figure 3.4.4 Market Performance Data for ENERGY STAR Class A Equipment Class

3-18 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docFigure 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 preliminar y 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 inte rior lighting to illuminate the merchandise on display, while Class B machines ha ve an illuminated sign on the exterior. Higher efficiency lighting leads to energy savings in tw o ways: less energy is used directly for lighting and, in those units with lighting internal to the refrigerated space, less he at 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.

An even more recent trend is the use of light emitting diode (LED) technology. Although LEDs 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 Resour ce Center indicates that lighti ng display cases using LEDs were

3-19 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docfound desirable by consumers. LEDs are predicted to steadily increase in efficacy and decrease in cost as technology improves. 18 These predicted trends have been proven true since the ANOPR. See chapter 5 of the TSD for a detailed de scription of the changes made to LED prices and specifications for the final rule.

3.5.2 Higher Efficiency Lighting Ballasts

Most illuminated beverage vending machin es use fluorescent lighting with magnetic ballasts, which use inductance to modulate power flow to fluorescent lamps. Magnetic ballasts have significant electrical resistance losses. El ectronic ballasts use solid state electronics to modulate power provided to fluorescent lamps. El ectronic ballasts, which convert power at high frequency, have lower electrical resistance losses compared to ma gnetic ballasts which operate at line frequency. In addition, fluorescent lamps ope rate more efficiently at the higher frequency provided by electronic ballasts. In addition to the direct redu ctions in electrical power consumption, heat generated by the lighting and th e lighting ballast contri bute to the heat load. By increasing ballast efficiency, th e compressor load is also reduced.

3.5.3 Higher Efficiency Evaporator Fan Motors

Evaporator fan motors move air across the ev aporator coil and typica lly run at one speed. Manufacturers match the motor size and blade to th e evaporator coil to meet the expected load under most conditions. Higher efficiency evapor ator fan motors reduce energy consumption by requiring less electrical power to generate motor shaft output power.

Electric motors operate based on the inter action 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 re versed 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 electromagne t is therefore not sufficient to start such a motor. One of the most significant differences be tween different types of single-phase motors is the way in which they handl e this start-up problem.

Nearly all inexpensive fan motors are of e ither the shaded-pole or the permanent split capacitor (PSC) variety, and the same is most likely true for sta ndard beverage vending machine fan motors (fan motors not marketed as “hi gh efficiency”). In both cases, the electromagnet consists of windings of electrical wire through wh ich current is driven. In a shaded-pole motor, a portion of these windings is “shaded” by a coppe r 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 betw een the shaded and un-shaded portions of the magnet remains throughout operation. As a result, shaded-pole motors are inefficient, with typical motor efficiencies less than 20 percent. 19 Shaded-pole motors are, however, electrically simple and inexpensive.

In a PSC motor, a smaller, start-up winding is present in addition to the main winding. The start-up winding is electricall y connected in parallel with the main winding and in series

3-20 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docwith 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 moto r reaches steady state. Because of this, PSC motors are more energy efficient than their shaded-pole counterparts, with motor efficiencies ranging from 50–70 per cent. Like shaded-pole motors , PSC motors are produced in large quantities and are relatively inexpensive. 20 Beverage vending machine equipment fan energy efficiency can be substantially improved by replacing shaded-pole motors, in the models that use them, with PSC motors.

A third type of electric motor, the electr onically 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, whic h are sold in high volumes, are three-phase electric motors with efficiencies even great er 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 contro ls are programmed such that th e evaporator fan runs at a 100 percent duty cycle to circulat e cold air at all times and to prevent frost build up on the evaporator fan coil. However, refrigerated beve rage vending machine utility can be maintained with a lower duty cycle. This could be accomp lished 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 cons umption savings by reducing the required fan shaft power. The evaporator fans typically used in beverage vend ing 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 pre ssure drops, for which sheet metal fans are not well suited. Required fan shaft power could be reduc ed if the fan blades were optimized for each given application.

Tangential fans also provide an opportunity to decrease equipment energy consumption. 21 Tangential fans utilize a vortex builder to genera te a uniform airflow over a large surface. This makes them better suited to eva porator and condenser fans, which need to distribute airflow over a large coil surface area. A single long tangentia l fan can meet the airflow requirements for an entire refrigerated cabinet, while requiri ng a single high efficiency fan motor.

3.5.6 Improved Evaporator Design

The evaporator is a refrigerant-to-air heat exchanger composed of metals with high thermal conductivity such as aluminum and coppe r. It is responsible for evaporating and superheating the entering refriger ant liquid-vapor mixture while ex tracting heat from the air in the refrigerated space. The internal heat-excha nging surfaces in contact with refrigerant are commonly referred to as “refri gerant-side” while the external heat-exchanging surfaces in contact with the air are re ferred to as “air-side.”

3-21 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docDepending 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 diffe rence is necessary to dr ive 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 di rectly related to the total refrigeration load and the thermal characteristics of the evaporator as shown in Eq. 3.2:

( CAT

 DAT ) Q   T LM  Eq. 3.2  CAT

 SET  UA ln 

   DAT

 SET

Where:

Q = the total refrigeration load in Br itish thermal units per hour (Btu/h), U

= the heat transfer coefficient of the evaporator in Btu/  F/square foot (ft 2 ), A = the area of the evaporator in ft 2

, CAT = the case air temperature, and Δ T LM = the log mean temperature difference of the coil in  F.

Increasing the area of the coil decreases the necessary Δ T LM and therefore decreases the SET. This results in an increased compre ssor energy efficiency ratio (EER) and lower compressor energy consumption.

Enhancements to the refrigerant-side surface area of the evaporat or 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 numb ers 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 t ube passes. Large spaces between fins and tubes also reduce frost “bridging,” wh ich can completely block airflow through portions of the coil.

3.5.8 Improved or Thicker Insulation

Either increasing the insulation thickness or reducing insulation thermal conductivity will reduce the energy consumption of beverage vend ing machines. Typical insulation thickness for refrigerated beverage vending machines ranges from 1.5–2 inches. Blow-in polyurethane foam is used for most machines. The impact of an incr ease in insulation thickness and insulation quality

3-22 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docis limited for glass-front machines by the fact that a large portion of the cooling load is due to infiltration.

Improved-technology polyurethane foam in sulation has a reduced conductivity, which reduces the heat load. The improvement is due main ly 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 suggest s that technologies that allow reduction in insulation thickness while maintaining thermal re sistivity (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 elimin ate a conduction path. They are generally filled with supporting powder that prevents collapse of th e 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 be tween 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 re duce 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 sw itching from an aluminum frame to a vinyl frame.

3.5.10 Defrost Mechanism

As the air in the refrigerated space is cool ed, water vapor condenses on the surface of the evaporator coil. In refrigerators and freezers, wher e the evaporator coil is below 32 °F, this water freezes as it collects, forming a gr owing layer of frost. The fros t reduces cooling performance by increasing the thermal resistance to heat transf er 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 co il, and where defrost must occur quickly to prevent any significant rise in product temperat ure. Electric defrost involves melting frost by briefly turning on an electric resi stance heater, which is in contact with or near the evaporator coil.

3-23 BVM_FINAL_FR_TSD_Chapter3_08-14-09.doc3.5.11 Thermoacoustic Refrigeration

Thermoacoustic refrigeration is a technology that uses high-amplitude sound waves in a pressurized gas to pump heat from one place to a nother. 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 refrigerat or, 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 alternat ing 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 th at of the nearby stack wa ll, heat is transferred from the gas to the stack wall. If the local temp erature of the gas drops below that of the stack wall, heat is transferred from the wall to the gas.

Prototypes of thermoacoustic re frigerators have been demo nstrated for refrigeration applications. A prototype thermo acoustic refrigeration unit designe d for an ice-cream freezer has been measured to be as efficient as the vapor compression unit it replac es. This technology is expected to improve in efficiency with furt her 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 pr oportional control, wher e the cooling capacity can be continuously controlled so that the output can be adjusted accura tely for varying load conditions. Although this technol ogy currently does not impr ove upon the efficiencies of conventional refrigeration tec hnology, thermoacoustic refriger ation 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 ma gnetic fields and combined with heat exchangers to transfer heat, they can be used to remove heat from a refrigerated space a nd reject heat to the surroundings.

This refrigeration technology could be used in any possible applic ation where cooling, heating or power generation is used today. Becau se 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 tran sfer is the result of applying a highvoltage electrostatic potential fiel d across a heat transfer fluid, such as a refrigerant or refrigerant mixture. The applied field destabilizes the thermal boundary layer, thereby producing better mixing of the bulk fluid flow and increasing the net heat transfer coefficient. This procedure appears to be more effective when applie d to phase-change processes (e.g., boiling and condensation).

3-24 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docThis phenomenon is typically used to electr onically control the capacity of a heat exchanger by raising the applied voltage to increa se the heat transfer. This can lead to improved efficiencies by using smaller capacity equipmen t, 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. Howe ver, 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 po wer (voltage x current) and the associated energy penalty low.

3.5.14 Copper Rotor Motors

Making the critical components of an induc tion motor’s rotor (e.g., conductor bars and end rings) out of copper instead of aluminum, which is the curre nt practice, improves the energy efficiency of the motor. The greater electrical conductivity of copper results in lower resistance heating losses in the rotor and t hus lower losses in the motor. Fu rther improvements in the design and fabrication of copper motors, such as optim ization 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 th e efficiency of beverage vending machine compressors. High efficiency reciprocating and scroll compressors, sometimes incorporating variable-speed motors, all have higher efficienci es than the traditional reciprocating compressors commonly used in beverage vending machines.

Scroll compressors compress gas in a fundame ntally different manner from traditional compressors—between two spirals, one fixed and one rotating. High efficiency reciprocating compressors are as efficient, or more effici ent, 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 condens er 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 refrige rant vapor while rejecting heat from the refrigerant to the ambient air.

Depending on the requirements of the equipmen t, 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 Δ T LM of the coil and therefore decrease the SC T, resulting in increased compressor efficiency (increased EER).

Enhancements to the refrigerant-side surf ace area of the condenser typically include rifled or diamond-pattern tubing an d increased number of tube pa sses. Enhancements to the airside surface area include increa sed fin pitch (decreased fin sp acing), fin patterns (wavy or zigzag), and increased nu mbers of tube passes.

3-25 BVM_FINAL_FR_TSD_Chapter3_08-14-09.docIncreasing 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 resu lt 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. Th e manufacturer will match th e 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 di scussion 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 cons umption 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 buil der 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 requiri ng one high efficiency fan motor.

3.5.19 Higher Efficiency Expansion Valves

Expansion valves are refrigerant metering de vices 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 expansi on 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 opera ting conditions. They are often oversized for worst-case conditions, and ther efore may operate at reduced efficiency during normal operation. However, using an alternate technology such as a thermostatic expansion valve (i.e., TXV) or an electronic expansion va lve (i.e., EEV) will likely not provide significant energy savings over a properly sized capil lary tube under steady-state conditions.

3-26 BVM_FINAL_FR_TSD_Chapter3_08-14-09.doc3.5.20 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 typically increase efficiency over a broad operating range but do not inherently increase maximum efficiency at the compressor rating point. Variable-speed compressors reduce energy consumption in three ways:

1. When refrigerant flow is reduced duri ng part-load operation, the condenser and evaporator (designed for full flow conditions) ar e more effective and thus more efficient. Temperature drops decrease, resulting in re duced pressure rise across the compressor, which also improves efficiency.

2. Close matching of load eliminates the cycli ng that occurs with single-stage compressors. Maintaining a constant pressure is more effi cient 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 evapor ator rather than the condenser. Essentially, some of the heat rejection lo ad is rejected to the evapor ator during this time, reducing overall system performance. Variable-speed operation would elim inate or significantly reduce compressor off-time and the related inefficiencies.

3.5.21 Liquid Suction Heat Exchangers

The purpose of a liquid suction heat exchange r is to further cool the flow of liquid refrigerant entering the expansion valve using the flow of gaseous re frigerant leaving the evaporator, thus providing addi tional sub-cooling for the ente ring liquid by super-heating the exiting suction vapor. Hotter suction vapor is desira ble because it is less susceptible to heat gains in the return piping to the comp ressor, provides an additional margin of safety as superheated vapor for compressor operation (since any liqui d entering the compressor may cause damage). Additional sub-cooling of the li quid 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 enthal py. In addition, the possibility of compressor overheating brought on by the combination of incr eased 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 depe nd on several factors, including evaporator temperature, type of refrigeran t used, and system pressures.

3.5.22 Condenser Fan Motor Controllers

Condenser fan motor controllers allow fan mo tors to run at variable speed, to match changing conditions in the vending machine. Matc hing 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 c ondenser fan motor controllers.

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