3-i

CHAPTER 3: MARKET AND TECHNOLOGY ASSESSMENT

TABLE OF CONTENTS

3.1 INTRODUCTION ........................................................................................................... 3-1

3.2 MARKET ASSESSMENT.............................................................................................. 3-1

3.2.1 Product Definitions.......................................................................................................... 3-1

3.2.2 Product Classes.............................................................................................................. 3-10

3.2.3 Product Test Procedures ................................................................................................ 3-13

3.2.4 Manufacturer Trade Groups........................................................................................... 3-14

3.2.5 Manufacturer Information.............................................................................................. 3-15

3.2.6 Regulatory Programs ..................................................................................................... 3-20

3.2.7 Voluntary Programs....................................................................................................... 3-21

3.2.8 Saturation in U.S. Homes............................................................................................... 3-21

3.2.9 Historical Shipments...................................................................................................... 3-22

3.2.10 Historical Efficiencies.................................................................................................... 3-27

3.2.11 Product Retail Prices...................................................................................................... 3-27

3.2.12 Industry Cost Structure .................................................................................................. 3-35

3.2.13 Inventory Levels and Capacity Utilization .................................................................... 3-38

3.3 TECHNOLOGY ASSESSMENT.................................................................................. 3-41

3.3.1 Product Operation .......................................................................................................... 3-41

3.3.2 Product Operation and Components.............................................................................. 3-44

3.3.3 Technology Options....................................................................................................... 3-50

3.3.4 Energy Efficiency .......................................................................................................... 3-69

REFERENCES ......................................................................................................................... 3-71

LIST OF TABLES

Table 3.2.2: Miscellaneous Refrigeration Product Classes ....................................................... 3-13

Table 3.2.3 Miscellaneous Residential Refrigeration Product Manufacturers.......................... 3-15

Table 3.2.4 CEC Wine Chiller Standards.................................................................................. 3-20

Table 3.2.5 Household Saturation Estimates for Miscellaneous Refrigeration Products.......... 3-22

Table 3.2.6 Estimated Historical Shipments of Miscellaneous Refrigeration Products............ 3-24

Table 3.2.7 Comparison of Estimated Market Shares of Cooled Cabinets by Capacity ........... 3-27

Table 3.2.8: Proportion of Shipments (2008-2011 Average) by Capacity ................................ 3-28

Table 3.2.9: Cooled Cabinet Price Regression Analysis ........................................................... 3-31

Table 3.2.10 Major Appliance Manufacturing Industry Employment and Earnings ................ 3-35

Table 3.2.11 Household Refrigerator and Home Freezer Manufacturing Industry 

Employment and Earnings................................................................................. 3-36

Table 3.2.12 Major Appliance Manufacturing Industry Materials and Wages Cost................. 3-36
3-ii

Table 3.2.13 Household Refrigerator and Home Freezer Manufacturing Industry 

Materials and Wages Cost ................................................................................. 3-37

Table 3.2.14 Industry Cost Structure Using SEC Data, Average 2006-2012............................ 3-38

Table 3.2.15 Household Refrigerator and Home Freezer Manufacturing Industry 

Inventory Levels ................................................................................................ 3-39

Table 3.2.16 Air-Conditioning and Warm Air Heating Equipment Manufacturing 

Industry Inventory Levels.................................................................................. 3-39

Table 3.2.17 Full Production Capacity Utilization Rates, ......................................................... 3-40

Table 3.3.1: Primary Water System Components...................................................................... 3-50

Table 3.3.2: Technology Options............................................................................................... 3-51

Table 3.3.3: Compressor Rating Conditions.............................................................................. 3-52

Table 3.3.4: Maximum Available Compressor Efficiencies for Miscellaneous 

Refrigeration Products....................................................................................... 3-54

Table 3.3.5: Efficiencies of Some of Embraco’s Variable-Speed Compressor Models............ 3-55

Table 3.3.6: Efficiencies of LG’s Current Linear Compressor Models..................................... 3-56

Table 3.3.7: Comparison of Various VIP Core Materials ......................................................... 3-61

Table 3.3.8: Center-of-Panel Thermal Conductivity of VIPs.................................................... 3-62

Table 3.3.9: Comparison of Various Gas-Filled Panel Core Materials..................................... 3-63

Table 3.3.10 Glass Door Resistivity Options............................................................................. 3-65

LIST OF FIGURES

Figure 3.2.1 Typical Wine Chiller............................................................................................... 3-3

Figure 3.2.2 Dual-Zone Wine Chiller.......................................................................................... 3-4

Figure 3.2.3 Typical Non-Compressor Refrigerator.................................................................... 3-6

Figure 3.2.4 Typical Hybrid Refrigeration Product..................................................................... 3-8

Figure 3.2.5 Typical Portable Ice Maker ..................................................................................... 3-9

Figure 3.2.6 Typical Non-Portable Ice Maker............................................................................. 3-9

Figure 3.2.7 Market Shares for the Domestic Cooled Cabinet Product Market........................ 3-18

Figure 3.2.8 Historical Market Shares of Cooled Cabinet Shipments by Year and 

Capacity from NPD Group ................................................................................ 3-26

Figure 3.2.9 Average Retail Prices (2009 – 2011) For All Cooled Cabinet Categories............ 3-28

Figure 3.2.10 Vapor-Compression Cooled Cabinet Retail Price as a Function of % of 

CEC Baseline Annual Energy Use .................................................................... 3-29

Figure 3.2.11 Average Price Distributions for 1-11 Bottle Cooled Cabinets. Note: WC1 

indicates survey data.......................................................................................... 3-32

Figure 3.2.12 Average Price Distributions for 12-19 Bottle Cooled Cabinets. Note: WC1 

indicates survey data.......................................................................................... 3-32

Figure 3.2.13 Average Price Distributions for 20-29 Bottle Cooled Cabinets. Note: WC1 

indicates survey data.......................................................................................... 3-33

Figure 3.2.14 Average Price Distributions Across Cooled Cabinet Capacities. Note: WC1 

indicates survey data.......................................................................................... 3-33

Figure 3.2.15 Purchase Prices of Ice Makers............................................................................. 3-34

Figure 3.3.1 Typical Vapor-Compression Refrigeration Circuit............................................... 3-42

Figure 3.3.2 Batch Icemaking Process....................................................................................... 3-43
3-iii

Figure 3.3.3 Components of a Vapor-Compression Refrigerator-Freezer ................................ 3-45

Figure 3.3.4 All Low-Back-Pressure R-134a Compressors <700 Btu/hr, Excluding 

Variable-Speed................................................................................................... 3-53

Figure 3.3.5 Cooled Cabinet Energy Consumption as a Function of Interior Volume ............. 3-70
3-1

CHAPTER 3. MARKET AND TECHNOLOGY ASSESSMENT 

3.1 INTRODUCTION

This chapter provides a profile of the miscellaneous refrigeration products in the United 

States. The U.S. Department of Energy (DOE) developed the preliminary market and technology 

assessment presented in this chapter primarily from publicly available information. This 

assessment is helpful in identifying the major manufacturers and their product characteristics, 

which form the basis for the engineering and life-cycle cost (LCC) analyses. Present and past 

industry structure and industry financial information help DOE in the process of conducting the 

manufacturing impact analysis.

3.2 MARKET ASSESSMENT

3.2.1 Product Definitions

The miscellaneous refrigeration products addressed in this rulemaking are consumer 

refrigeration products that are not currently covered by DOE energy conservation standards. 

These consumer products include hybrid refrigerators, refrigerator-freezers, and freezers (i.e.,

products that include warm compartments such as wine storage compartments as at least half of 

the refrigerated volume in products that otherwise perform the functions of refrigerators, 

refrigerator-freezers, or freezers), cooled cabinets (including wine chillers), refrigeration 

products that do not use vapor-compression technology (i.e., products that do not include 

compressor and condenser units as integral parts of the cabinet assembly), and ice makers. 

The Rulemaking Framework Document for Wine Chillers and Miscellaneous 

Refrigeration Products (hereafter referred to as the Framework Document) initially discussed 

extending the scope of this rulemaking to address all of the above products.1

Before the publication of the Framework Document, DOE published a coverage 

determination proposal (hereafter referred to as the November 2011 Coverage Proposal). 76 FR 

69147 (Nov. 8, 2011). In this document, DOE preliminarily determined that consumer 

refrigeration products that do not incorporate compressors qualify as covered products as defined 

by the Energy Policy and Conservation Act of 1975 (42 U.S.C. 6291, et seq.; “EPCA” or, “the 

Act”).

After the publication of the Framework Document, DOE published another coverage 

determination proposal (hereafter referred to as the October 2013 Coverage Proposal). 78 FR 

65223 (Oct. 31, 2013). In this document, which expands the scope of the November 2011 

Coverage Proposal, DOE proposed to add hybrid (or combination) refrigerators, refrigeratorfreezers, and freezers (i.e., products that include warm compartments such as wine storage 
3-2

compartments in products that otherwise perform the functions of refrigerators, refrigeratorfreezers, or freezers); cooled cabinets (i.e., products including wine chillers that are composed 

entirely of warm compartments); refrigeration products that do not use vapor-compression 

refrigeration systems (i.e., products that do not use a compressor and condenser as the 

refrigeration source); and ice makers as covered products as defined by EPCA. This proposal 

would add all of these products under a single new aggregate product coverage category, referred 

to as “miscellaneous refrigeration products,” which would be distinct from existing categories 

covering consumer refrigerators, refrigerator-freezers, and freezers. It therefore overrides the 

November 2011 Coverage Proposal, which had proposed to cover all products that do not use 

vapor-compression refrigeration systems in a single product coverage category that would not 

have included vapor-compression products.

In a NOPR associated with a simultaneous test procedure rulemaking for miscellaneous 

refrigeration products (hereafter referred to as the Test Procedure NOPR), DOE has proposed 

new test procedures for all the products in this new coverage category. The Test Procedure 

NOPR proposes to establish a regulatory definition for “miscellaneous refrigeration products” 

that would collectively define all the products covered in this rulemaking. These miscellaneous 

refrigeration products are introduced and described in the following sections.

3.2.1.1 Cooled Cabinets

DOE proposed adopting the term “cooled cabinet” to denote consumer refrigeration 

products that do not meet the definition for “refrigerator.”. Such products are typically marketed 

as wine chillers, wine coolers, wine refrigerators, beverage coolers, and beverage centers, 

although other types of cooled cabinets exist. DOE had previously used the term “wine chiller” 

for these products, which is the term used by the California Energy Commission (CEC) and the 

Canadian regulations, but proposed to use the more generic “cooled cabinet” to accommodate the 

fact that not all of these products are designed are marketed specifically for wine storage. 

Although these products may have different design features, they share the common 

characteristic of using a refrigeration system to achieve storage temperatures above 39 °F and 

below ambient temperature. Consequently, they are distinct from refrigerators because they are 

not capable of achieving internal temperatures that are safe for storing fresh food. In the Test 

Procedure NOPR, DOE has proposed to define cooled cabinets as follows:

Cooled cabinet means a cabinet that has a source of refrigeration requiring electric 

energy input only and is capable of maintaining compartment temperatures either (a) no lower 

than 39 °F (3.9 °C), or (b) in a range that extends no lower than 37 °F (2.8 °C) but at least as 

high as 60 °F (15.6 °C).DOE notes that, unlike the definitions for refrigerators, refrigeratorfreezers, and freezers, its proposed cooled cabinet definition does not exclude products that do 

not have a compressor and condenser as an integral part of the cabinet assembly. This proposed 

definition also does not limit coverage to products with alternating current (AC) power input.

Therefore, this definition addresses the possibility that these products may be cooled using nonvapor-compression refrigeration systems, such as thermoelectric systems (which are capable of 

being powered by direct current [DC] power) or absorption systems. DOE proposes to use the 
3-3

term “non-compressor” to describe such products. In fact, as described in section 3.2.5.1, the 

majority of cooled cabinets on the market use thermoelectric refrigeration systems to cool their 

cabinets. In the Test Procedure NOPR, DOE has proposed to define non-compressor cooled 

cabinets as follows:

Non-compressor cooled cabinet means a cooled cabinet that has a source of refrigeration 

that does not include a compressor and condenser unit.

A typical cooled cabinet—in this example, a wine chiller—is depicted in Figure 3.2.1.

Because the primary function of a cooled cabinet is to store beverages (and potentially nonperishable foods), these products feature either shelves (typically found in beverage centers) or 

bottle racks (typically found in wine chillers). Cooled cabinets are similar in appearance to 

refrigerators, although cooled cabinets are typically sold with a glass door, rather than the solid, 

insulated doors found on refrigerators. This feature highlights the secondary function of cooled 

cabinets, which is to display the products (e.g., bottles of wine) stored within.

Figure 3.2.1 Typical Wine Chillera

Cooled cabinets range in size from countertop units that can store only a few bottles of 

wine to large cabinets capable of storing more than 100 bottles. Some cooled cabinets feature 

dual or triple temperature zones, each of which may be independently controlled and some of 

which have their own external doors. This feature allows users to create separate storage 

conditions tailored specifically to different types of products; for example, a zone used to store 

white wine could be set at a lower temperature than a zone used to store red wine. Other units do

 

a http://salestores.com/stores/images/images_747/WC20SD.jpg
3-4

not feature distinct temperature zones, but rather use natural temperature stratification within the 

cabinet to create “zones” that are not actually separated by any physical barrier or boundary. An 

example of a dual-zone, independently-controlled wine chiller is displayed in Figure 3.2.2.

Figure 3.2.2 Dual-Zone Wine Chillerb

DOE has not been able to confirm than any cooled cabinets use manual defrost. Although 

CEC’s database of certified products lists a small number of manual defrost wine chillers, DOE 

found that all but one of these wine chillers were no longer for sale; additionally, it was not 

possible to confirm using publicly available data that the remaining unit did indeed use manual 

defrost. Consequently, DOE’s cooled cabinet analysis is focused solely on automatic defrost 

units. The vast majority of cooled cabinets use passive off-cycle defrost, in which any frost that 

collects on the evaporator during the compressor on-cycle melts during the off-cycle because of 

the warm compartment temperature typical for these products. Nevertheless, some wine chillers 

do use an electric resistance defrost heater. 

As mentioned previously, non-compressor cooled cabinets use either thermoelectric or 

absorption refrigeration technology to provide cooling. As noted in section 3.2.8, absorption 

cooled cabinets are mainly utilized in hotels.

 

b http://www.subzero-wolf.com/s3/www2.subzero-wolf.com/images/products/WS30_product_photo.png?preset=product-detail
3-5

3.2.1.2 Non-Compressor Refrigerators

The section of the Energy Policy and Conservation Act (EPCA) that identifies 

refrigerators, refrigerator-freezers, and freezers as covered consumer products specifies that 

coverage applies only to products that include compressor and condenser units as integral parts

of the cabinet assembly; in other words, products that utilize vapor-compression refrigeration 

technology. (42 U.S.C. 6292(a)(1)(B)) DOE is aware of products that use thermoelectric and/or 

absorption technology that are sold as refrigerators, but is not aware of any such products that are 

sold as refrigerator-freezers or freezers. In the Test Procedure NOPR, DOE has proposed to 

define such products as follows:

Non-compressor refrigerator means a cabinet that has a source of refrigeration that does 

not include a compressor and condenser unit, requires electric energy input only, and is capable 

of maintaining compartment temperatures above 32 °F (0 °C) and below 39 °F (3.9 °C). A noncompressor refrigerator may include a compartment capable of maintaining compartment

temperatures below 32 °F (0 °C). A non-compressor refrigerator also may include one or more 

cellar compartments, if the combined refrigerated volume of these compartments is less than half 

the total refrigerated volume of the product.

As illustrated in Figure 3.2.3, such products strongly resemble vapor-compression 

refrigerators in that they typically use a solid, insulated door to enclose a refrigerated storage 

space, although some non-compressor refrigerators do use glass doors. However, as described in 

the Test Procedure NOPR, DOE has observed through testing that many non-compressor 

refrigerators are unable to maintain temperatures that are safe for food storage (39 °F or below) 

in 90 °F ambient test conditions. DOE requests comment on whether any non-compressor 

refrigerators currently exist that can achieve storage temperatures of 39 °F or below in 90 °F 

ambient tests conditions—see the TSD executive summary.
3-6

Figure 3.2.3 Typical Non-Compressor Refrigeratorc

3.2.1.3 Hybrid Refrigeration Products

DOE proposed adopting the term “hybrid refrigeration product” to denote consumer

refrigeration products that combine products that include warm compartments (such as wine 

storage compartments) that take up at least half, but not all, of the refrigerated volume of 

products that otherwise perform the functions of refrigerators, refrigerator-freezers, or freezers. 

DOE also proposes adopting the term “cellar compartment” to denote such warm compartments. 

Because such products can come in several configurations depending on the combination of 

compartment types, DOE has proposed in the Test Procedure NOPR the following definitions for 

all possible configurations of hybrid refrigeration products:

Hybrid refrigeration product means a hybrid all-refrigerator, hybrid refrigerator, hybrid 

refrigerator-freezer, hybrid freezer, or hybrid non-compressor refrigerator as defined below:

• Hybrid all-refrigerator means a hybrid refrigerator that does not include a 

compartment capable of maintaining compartment temperatures below 32 °F (0 

°C). It may include a compartment of 0.50 cubic-foot capacity (14.2 liters) or less 

for the freezing and storage of ice.

• Hybrid refrigerator means a cabinet that has a source of refrigeration that 

includes a compressor and condenser unit and requires electric energy input only, 

and consists of two or more compartments where (1) at least half but not all of its 

refrigerated volume is comprised of one or more cellar compartments, (2) at least 

 

c http://ecx.images-amazon.com/images/I/31RP-OKLtcL.jpg
3-7

one of the remaining compartments is capable of maintaining compartment 

temperatures above 32 °F (0 °C) and below 39 °F (3.9 °C), (3) the cabinet may

also include a compartment capable of maintaining compartment temperatures 

below 32 °F (0 °C), but (4) it does not provide a separate low temperature 

compartment capable of maintaining compartment temperatures below 8 °F 

(−13.3 °C).

• Hybrid refrigerator-freezer means a cabinet that has a source of refrigeration that 

includes a compressor and condenser unit and requires electric energy input only, 

and consists of three or more compartments where (1) at least half but not all of 

its refrigerated volume is comprised of one or more cellar compartments, (2) at 

least one of the remaining compartments is capable of maintaining compartment 

temperatures above 32 °F (0 °C) and below 39 °F (3.9 °C), and (3) at least one 

other compartment is capable of maintaining compartment temperatures below 8 

°F (−13.3 °C) and may be adjusted by the user to a temperature of 0 °F (−17.8 °C) 

or below.

• Hybrid freezer means a cabinet that has a source of refrigeration that includes a 

compressor and condenser unit and requires electric energy input only, and 

consists of two or more compartments where (1) at least half but not all of its 

refrigerated volume is comprised of one or more cellar compartments, and (2) the 

remaining compartment(s) are capable of maintaining compartment temperatures

at 0 °F (-17.8 °C) or below.

• Hybrid non-compressor refrigerator means a non-compressor refrigerator with at 

least half of its refrigerated volume composed of one or more cellar 

compartments.

Hybrid refrigeration products combine the perishable food storage functionality of a 

refrigerator, refrigerator-freezer, or freezer with the beverage or non-perishable food storage 

functionality of a cooled cabinet. They consist of two or more compartments, of which at least 

one is a cellar compartment. Often, the temperatures in these compartments are controlled 

independently, as the freezer, fresh food compartments, or both must be maintained at lower 

temperatures than the cellar compartments. These compartments may be configured side-by-side 

or in an over-under arrangement. 

Some hybrid refrigeration products also enable the display functionality of a cooled 

cabinet. Often, hybrid refrigeration products have separate doors for the cellar and the freezer or 

fresh food compartments; however, some products use a single door to access all compartments. 

These doors may be either glass, enabling display of the contents, or solid. Frequently, in 

multiple-door units, a glass door is used for the cellar compartment(s) and a solid door is used for 

the fresh food or freezer compartment(s); however, DOE is aware of products that use solid 

doors for all types of compartments, thus eliminating the display function. DOE is also aware of 

hybrid refrigerators that use glass doors for both the cellar and fresh food compartments; 

however, there are no hybrid freezers or hybrid refrigerator-freezers in which access to the 

freezer compartment is through a glass door. A typical hybrid refrigeration product that features 

both a glass door and a solid door is depicted in Figure 3.2.4.
3-8

Figure 3.2.4 Typical Hybrid Refrigeration Productd

3.2.1.4 Ice Makers

In the Test Procedure NOPR, DOE has proposed adopting the following definition for 

“ice maker:”

Ice maker means a consumer product other than a refrigerator, refrigerator-freezer, 

freezer, hybrid refrigeration product, non-compressor refrigerator, or cooled cabinet designed to 

automatically produce and harvest ice, but excluding any basic model that is certified under 

ANSI/NSF 12-2012 Automatic Ice Making Equipment. Such a product may also include a means 

for storing ice, dispensing ice, or storing and dispensing ice.

As indicated by DOE’s proposed definition, the primary function of an ice maker is 

making ice; however, all such products of which DOE is aware also store ice, and some also 

dispense ice. 

Ice makers typically come in two configurations: portable and non-portable. Portable ice 

makers are marked by their small size and their use of an on-board water reservoir, which allows 

use without a fixed water connection, both of which contribute to their portability. Non-portable 

ice makers are similar in size to compact refrigerators and require a fixed water inlet. Some non-

 

d http://www.designerhomesurplus.com/images/WF1061.JPG
3-9

portable ice makers also require connection to a drain. Typical portable and non-portable ice 

makers are depicted in Figure 3.2.5 and Figure 3.2.6, respectively.

Figure 3.2.5 Typical Portable Ice Makere

Figure 3.2.6 Typical Non-Portable Ice Makerf

 

e http://img1.targetimg1.com/wcsstore/TargetSAS//img/p/10/80/10806854.jpg

f http://www.build.com/imagebase/resized/x800/whynterimages/UIM-155_2_bg.jpg
3-10

As evidenced by Figure 3.2.6, typical ice makers have no provisions to store food and 

generally do not have sufficient space for food storage. This characteristic distinguishes them 

from freezers, which are designed to store food.

3.2.2 Product Classes

EPCA requires that DOE separate covered products into different product classes based 

on two criteria: (1) type of energy used, and (2) capacity or other performance-related features 

such as those that provide utility to the consumer or others deemed appropriate by the Secretary 

that would justify the establishment of a separate energy conservation standard. (42 U.S.C. 6295 

(q)) Based on these criteria, DOE intends to separate each product (cooled cabinets, noncompressor refrigerators, ice makers, and hybrid refrigeration products) into product classes. 

For cooled cabinets, DOE proposes to consider one product class: cooled cabinets (CC).

Currently, two types of products are distinguished in the marketplace that DOE classifies as 

cooled cabinets according to the performance-based definition given in section 3.2.1. These are 

vapor-compression and non-compressor wine chillers, also known as wine cellars, wine coolers, 

wine refrigerators, beverage coolers, or beverage centers. DOE is proposing to establish a single 

product class that would include both vapor-compression and non-compressor cooled cabinets 

because it has not identified a difference in utility to the consumer that would justify the use of 

separate classes.

As discussed in Chapter 2 of this technical support document (TSD), CEC classifies wine 

chillers into two product classes based on whether they use manual or automatic defrost;2

however, DOE has been unable to identify any manual defrost wine chillers that are currently on 

the market. Additionally, the vast majority of wine chillers on the market employ passive offcycle defrost, although DOE is aware of at least one unit that utilizes active heat defrost. Because 

active defrost units comprise an extremely small portion of the wine chiller market, and because 

the use of active defrost represents only a three percent increase in energy use (as described in 

chapter 5), DOE proposes not to differentiate cooled cabinet product classes based on defrost 

type.

For non-compressor refrigerators, DOE proposes to consider a single product class: 

non-compressor refrigerators (NCR). This product class will consist of both thermoelectric and 

absorption refrigerators. DOE has been unable to identify any manual defrost non-compressor 

refrigerators; moreover, DOE has been unable to identify any non-compressor refrigerators that 

utilize active heat defrost. Consequently, DOE proposes not to differentiate product classes based 

on defrost type. Currently, two types of products are distinguished in the marketplace that DOE 

classifies as non-compressor refrigerators: thermoelectric refrigerators and absorption 

refrigerators. 

For hybrid refrigeration products, DOE proposes to consider product classes based on 

all existing product classes for refrigerators, refrigerator-freezers, and freezers that will apply to 

products manufactured on or after September 15, 2014, as currently found at 10 CFR 430.32(a). 
3-11

DOE proposes to assign hybrid products to these 40 product classes based on the following 

criteria:

1) A hybrid product is classified as compact or standard-sized based on the entire 

refrigerated volume of the product, including that of the cellar compartment.

2) A hybrid product is classified as a hybrid refrigerator, refrigerator-freezer, or freezer 

based on the temperature ranges of the non-cellar compartments.

3) Automatic defrost and through-the-door ice service is determined as for conventional 

refrigerators, refrigerator-freezers, and freezers.

4) Built-in status is determined as for conventional refrigerators, refrigerator-freezers, 

and freezers.

The numbering of the hybrid product classes proposed by DOE corresponds to the 

numbering of the refrigerator, refrigerator-freezer, or freezer product classes with the relevant 

criteria as identified previously in the final rule (76 FR 57516). The hybrid products identified by 

DOE thus far would fall into one of four product classes; however, additional hybrid products 

identified by DOE in the future could potentially fall into any of the 40 proposed product classes. 

Product class H-3A-BI, based on the product class 3A-BI for built-in standard-sized allrefrigerators with automatic defrost, would comprise built-in standard-sized hybrid allrefrigerators with automatic defrost. For such products, the cellar compartment could be located 

above, below, or beside the fresh food compartment. Product class H-9I-BI, based on the product 

class 9I-BI for built-in standard-sized upright freezers with automatic defrost and an automatic 

icemaker, would comprise built-in standard-sized hybrid freezers with automatic defrost and an 

automatic icemaker. Product class H-11A, based on the product class 11A for compact allrefrigerators with manual defrost, would comprise compact hybrid all-refrigerators with manual 

defrost. Finally, product class H-13A, based on the product class 13A for compact allrefrigerators with automatic defrost, would comprise compact hybrid all-refrigerators with 

automatic defrost. Thus, hybrid refrigeration products in these product classes will be 

distinguished by their total internal volume, their built-in status, their defrost type, and their 

compartment configuration. Table 3.2.1 lists these and other example hybrid product classes.
3-12

Table 3.2.1 Example Product Classes for Hybrid Refrigeration Products

Product 

Class 

Product Description Defrost 

Type

Ice 

Maker

Built-in 

Status

Standard-sized products

H-3 Refrigerator-freezer-cooled cabinets—

top-mounted freezer

Automatic None No

H-3-BI Refrigerator-freezer-cooled cabinets—

top-mounted freezer

Automatic None Yes

H-3A All refrigerator-cooled cabinets Automatic None No

H-3A-BI All refrigerator-cooled cabinets Automatic None Yes

H-5 Refrigerator-freezer-cooled cabinets—

bottom-mounted freezer

Automatic None No

H-5-BI Refrigerator-freezer-cooled cabinets—

bottom-mounted freezer

Automatic None Yes

H-5A Refrigerator-freezer-cooled cabinets—

bottom-mounted freezer

Automatic Throughthe-doorNo

H-5A-BI Refrigerator-freezer-cooled cabinets—

bottom-mounted freezer

Automatic Throughthe-doorYes

H-7 Refrigerator-freezer-cooled cabinets—

side-mounted freezer

Automatic Throughthe-doorNo

H-7-BI Refrigerator-freezer-cooled cabinets—

side-mounted freezer

Automatic Throughthe-doorYes

H-9 Upright freezer-cooled cabinets Automatic None No

H-9-BI Upright freezer-cooled cabinets Automatic None Yes

H-9I Upright freezer-cooled cabinets Automatic Internal No

H-9I-BI Upright freezer-cooled cabinets Automatic Internal Yes

Compact products

H-11A Compact all refrigerator-cooled 

cabinets

Manual None No

H-13A Compact all refrigerator-cooled 

cabinets

Automatic None No

DOE requests comment on whether there are hybrid refrigeration products currently on 

the market that would not fall into one of the product classes listed in the preceding table. DOE 

also requests comment on whether it should allow separate product classes for built-in hybrid 

refrigeration products—see the TSD executive summary.

For ice makers, DOE proposes to consider three product classes. One product class will 

consist of portable ice makers (IM-P), which DOE has proposed in the Test Procedure NOPR to 

define as means an ice maker that does not require connection to a household water supply for 

operation and is operable using one or more on-board reservoirs that must be manually supplied 

with water. This style of ice maker is also generally small, typically designed for countertop use.
3-13

Both the lack of a fixed water connection and the small size of these units contribute to their 

portability, which DOE considers a unique utility to consumers. 

DOE proposes to categorize non-portable ice makers either as cooled-storage or 

uncooled-storage ice makers. DOE has proposed in the Test Procedure NOPR to define “cooledstorage ice maker” (IM-C) as an ice maker that maintains ice storage bin temperatures below 32 

°F. Such units typically produce crescent-shaped ice that is similar to the type of ice produced by 

the automatic ice makers found in freezers. A cooled-storage ice maker is defined to be distinct 

from an “uncooled-storage ice maker” (IM-U), which DOE has proposed in the Test Procedure 

NOPR to define as an ice maker that does not maintain ice storage bin temperatures below 32 °F. 

Such units produce clear ice using a process similar to that used in many automatic commercial 

ice makers and also require a drain connection to remove the melt water that collects in the bin. 

DOE proposes to use separate product classes for these two types of ice makers because of utility

differences in the types of ice they produce, the requirement for the installation and maintenance 

of a drain connection, and differences in energy use. As discussed in chapter 5 of this TSD, the 

energy consumption of IM-Cs ranges from 411 to 552 kWh/year, whereas the energy 

consumption of IM-Us ranges from 672 to 1,075 kWh/year, indicating significantly higher 

energy consumption. DOE has not yet identified any cooled-storage portable ice makers.

Table 3.2.2 displays the proposed product classes for each type of covered product. Only 

four hybrid product classes, representing the classes for which DOE has thus far identified 

hybrid refrigeration products, are displayed in this table.

Table 3.2.2 Miscellaneous Refrigeration Product Classes

Product Class 

Designation

Description

CC Cooled cabinet

NCR Non-compressor refrigerator

IM-P Portable ice maker

IM-C Cooled-storage ice maker

IM-U Uncooled-storage ice maker

H-3A-BI Built-in standard-sized* hybrid all-refrigerators with automatic defrost

H-9I-BI Built-in standard-sized* hybrid freezers with automatic defrost and an

automatic icemaker

H-11A Compact* hybrid all-refrigerators with manual defrost

H-13A Compact* hybrid all-refrigerators with automatic defrost

* Note: “Compact” products are defined as having a total compartment volume of less than 

7.75 cubic feet; for compartment sizes larger than this, the term “standard-sized” is used.

3.2.3 Product Test Procedures

Because cooled cabinets, non-compressor refrigerators, hybrid refrigeration products, and 

ice makers are not currently covered products, no DOE test procedure has yet been established 
3-14

for them. In the Test Procedure NOPR, DOE has proposed to establish new test procedures for 

all refrigeration products being considered in this rulemaking.

The proposed test procedure for vapor-compression cooled cabinets is almost identical to 

the procedure used by the CEC to test wine chillers.2 Like the CEC test procedure, the proposed 

test procedure would require that vapor-compression cooled cabinets be tested in an ambient 

temperature of 90 °F, and would require that the test be conducted with the light switch, if any, 

in the lowest energy position only. However, the proposed procedure also would require the 

application of a 0.55 usage adjustment factor, which differs from the 0.85 factor used in the CEC 

procedure. As explained further in the Test Procedure NOPR, DOE selected this usage factor to 

yield a closer match of cooled cabinet energy test results to the expected actual energy use of 

these products, as observed from laboratory and field use data. 

The proposed test procedure for non-compressor cooled cabinets is similar to the 

proposed procedure for vapor-compression cooled cabinets except that it would require testing in 

an ambient temperature of 72 °F, rather than 90 °F. To account for the lower ambient 

temperature, this test procedure also would require a usage adjustment factor of 1.2, rather than 

0.55.

DOE proposed a test procedure for non-compressor refrigerators that is nearly identical to 

the existing DOE test procedure for vapor-compression refrigerators (substituting discussion of 

refrigeration system cycles for discussion of compressor cycles, for example, when defining test 

periods). The proposed procedure would require testing in an ambient temperature of 90 °F. 

However, as discussed in the Test Procedure NOPR, DOE is unaware of any non-compressor 

products that can maintain a storage temperature of 39 °F in a 90  ̊F ambient condition. Such 

units would instead be tested and rated at their coldest temperature setting.

The proposed test procedure for hybrid refrigeration products would require that they be 

tested as refrigerators, refrigerator-freezers, or freezers except that a standardized temperature of 

55 °F must be used for all cellar compartments and a usage adjustment factor of 0.85 must be 

applied to energy test results. The proposed hybrid product test procedure also contains 

provisions for testing units containing up to three types of compartments (cellar, fresh food, and 

freezer).

Finally, DOE developed and proposed a new test procedure for ice makers. DOE 

recognized that these products operate differently than automatic commercial ice makers, which 

are covered under DOE’s commercial standards and have their own test procedure. (10 CFR 431

Subpart H) The proposed test procedure for ice makers would require testing in 72 °F ambient 

conditions with 72 °F inlet water temperature (except for portable ice makers, which would be 

tested with their water reservoirs filled initially with 55 °F water). In addition to measuring the 

energy associated directly with icemaking, the proposed procedure would also measure the 

energy associated with ice storage.

3.2.4 Manufacturer Trade Groups
3-15

DOE recognizes the importance of trade groups in disseminating information and 

promoting the interests of the industry that they support. To gain insight into the consumer

refrigeration industry that manufactures the products covered in this rulemaking, DOE 

researched various associations available to manufacturers, suppliers, and users of such 

equipment.

The Association of Home Appliance Manufacturers (AHAM), formed in 1967, is the 

main trade association of the home appliance industry. AHAM provides services to its members 

including government relations; certification programs for refrigeration products; an active 

communications program; and technical services and research. In addition, AHAM conducts 

other market and consumer research studies. AHAM also develops and maintains technical 

standards for various appliances to provide uniform, repeatable procedures for measuring 

specific product characteristics and performance features.

3.2.5 Manufacturer Information

The following section details information regarding manufacturers of cooled cabinets, 

non-compressor refrigerators, hybrid refrigeration products, and ice makers for sale in the United 

States, including estimated market shares (section 3.2.5.1), industry mergers and acquisitions 

(section 3.2.5.2), potential small business impacts (section 3.2.5.3), and product distribution 

channels (section 3.2.5.4).

3.2.5.1 Manufacturers and Market Shares

Table 3.2.3 lists miscellaneous refrigeration product manufacturers selling products in the 

United States. Five out of the ten top cooled cabinet manufacturers by U.S. market share are 

AHAM members. Table 3.2.3 also indicates the types of products that each manufacturer 

produces. Product types include: vapor-compression cooled cabinets, ice makers, thermoelectric 

cooled cabinets and refrigerators, absorption cooled cabinets and refrigerators, and hybrid 

refrigeration products.

Due to the fact that many cooled cabinet manufacturers have product portfolios that 

include vapor-compression and thermoelectric, absorption, and/or hybrid products, the following 

discussion of manufacturer market shares will treat all cooled cabinets, non-compressor 

refrigerators, and hybrid products as one product class.

Table 3.2.3 Miscellaneous Refrigeration Product Manufacturers

Manufacturer Name

VC 

WC

TE 

WC

Absorption 

WC IM

TE 

Refr

Absorption 

Refr Hybrid

AB Electrolux^ Y - - - - - -

Frigidaire Y - - - - - -

Aga Marvel - - - - - - -

Marvel Y - - Y - - Y

Avanti^^ Y Y - Y Y - Y
3-16

Manufacturer Name

VC 

WC

TE 

WC

Absorption 

WC IM

TE 

Refr

Absorption 

Refr Hybrid

Bluestone* - - - Y - - -

BSH Home Appliance 

Corp. - - - - - - -

Bosch Y - - - - - -

Thermador Y - - - - - -

Gaggenau Y - - - - - -

Chard International 

LLC* - - - Y - - -

Conair^^ - - - - - - -

Cusinart - Y - - - - -

Dacor Y - - - - - -

Danby Products Ltd.^ Y Y - Y Y - Y

Distributions 

Avantgarde Inc.* Y - - - - - -

Dometic - Y Y Y - Y -

Emerson Radio 

Corp.*^ - Y - Y - - -

Fisher & Paykel 

Appliances Inc. - - - - - - -

DCS - - - Y - - -

Orien 

(F&P is OEM) - - - Y - - -

GE^^ Y - - Y - - Y

Great Northern* - - - Y - - -

Haier^ - - - - - - -

Aficionado Y - - Y - - -

Haier Y Y - Y - - -

Hoshizaki - - - Y - - -

Kenmore* Y Y - Y - - -

Koolatron - Y - - Y - -

Liebherr-Export AG Y - - - - - Y

Living Direct - - - - - - -

Edgestar Y Y - - - - -

Koldfront Y - - - - - -

Luma Comfort - - - Y - - -

Manitowoc - - - Y - - -

Miele, Inc. Y - - - - - -

Jarden Corporation - - - - - - -

Oster - - - Y - - -

Perlick Y - - - - - Y

Spectrum Brands - - - - - - -

Salton - Y - Y - - -

Scotsman Y - - Y - - -

Supentown (SPT) Y Y - Y - - -

Sub-Zero Y - - Y - - Y

Summit Appliances* Y Y - Y - Y Y
3-17

Manufacturer Name

VC 

WC

TE 

WC

Absorption 

WC IM

TE 

Refr

Absorption 

Refr Hybrid

Thetford Corp. - - - - - - -

Norcold - - - - - Y -

TRUE Y - - - - - -

U-Line Y - - Y - - Y

Vinotemp*^ Y Y - Y - - Y

Whirlpool 

Corporation^^ - - - - - - -

Whirlpool - - - Y* - - -

Amana - - - - - - -

Maytag - - - - - - Y

Magic Chef Y - Y* - - -

Jenn-Air Y - - Y* - - Y

KitchenAid Y - - Y* - - Y

Vissani Y - - - - - -

Whynter* Y Y - Y - - -

Wine Enthusiast*^^ Y Y - - - - -

Team International 

Group - - - - - - -

Kalorik - Y - - - - -

Note: Indented items are brands/operating entities owned by the previous non-indented entity.

Abbreviations used in this table are as follows: “VC” indicates vapor-compression, “CC” indicates a cooled 

cabinet or other cooled cabinet, “IM” indicates an ice maker, “TE” indicates thermoelectric, and “Refr” 

indicates a refrigerator.

*Re-brand (not a manufacturer)

^Top 5 manufacturer by market share

^^Top 10 manufacturer by market share

Using publicly available data (e.g., market assessments done by third parties), DOE 

estimated the market shares for cooled cabinet manufacturers selling products in the United 

States. Manufacturers may offer multiple brand names. Some of the brand names come from 

formerly independent appliance manufacturers that have been acquired over time, and domestic 

manufacturers may put their brand on a product manufactured overseas. Companies included in 

this analysis may also be off-shore manufacturers that maintain a significant domestic presence 

via a U.S. entity.

DOE estimates that there are approximately 30 manufacturers selling cooled cabinets in 

the United States. DOE also estimates that roughly 85 percent of cooled cabinets currently in 

homes use thermoelectric cooling technology and 15 percent use vapor-compression cooling 

technology6 . Figure 3.2.7 illustrates the estimated market shares for the domestic cooled cabinet 

market based on third-party market data for the period from 2005 through 2011. Offering only 

small, inexpensive thermoelectric cooled cabinets, Emerson Radio Corp.’s high market share is 

consistent with the dominance of thermoelectric cooling technology in the market.
3-18

Figure 3.2.7 Market Shares for the Domestic Cooled Cabinet Product Market

3.2.5.2 Mergers and Acquisitions

Due to mergers and acquisitions (M&A), the home appliance industry continues to 

consolidate. The large market shares of a few companies provide evidence in support of this 

characterization. However, despite the consolidation witnessed by the home appliance industry 

in general, the miscellaneous refrigeration industry remains relatively fragmented among both 

the small and specialized and the larger, more generalized home appliance manufacturers. 

According to a third-party source, market data from 2005 to 2011 reveals that three 

manufacturers, Emerson, AB Electrolux, and Haier, comprised roughly 40 percent of the cooled 

cabinet market share during that time (with 13 percent, 11 percent, and 16 percent, respectively). 

The remaining 60 percent of the market was split amongst a large number of other 

manufacturers, with General Electric, Whirlpool, and Avanti holding the largest market shares 

(10 percent, 8 percent, and 8 percent, respectively). 

Recent M&A activities relating to the U.S. miscellaneous refrigeration product market 

include the 2012 acquisition of Fisher & Paykel Appliances Inc. by Haier. Fisher & Paykel 

(F&P) produces ice makers as original equipment manufacturers (OEM) and under its DCS 

brand name, while Haier manufactures both vapor-compression and thermoelectric cooled 

cabinets and ice makers. According to Appliance Magazine, the acquisition is intended to induce 
3-19

an expansion of the F&P brand both locally (in Australia) and globally (including in the United 

States), leading to the “largest release of new products ever launched in the 79-year history of the 

company.”3 New refrigeration products will be among the new products.

In 2008, the U.S. Department of Justice (DOJ) Antitrust Division required the divestiture 

of the Scotsman and Ice-O-Matic brands from Enodis upon the merger of Manitowoc and 

Enodis, which were two of the three significant commercial ice maker manufacturers at the time. 

In 2012, ALI Group—a leading, global designer, manufacturer, and marketer of commercial and 

industrial foodservice equipment based in Milan, Italy—announced plans to acquire Scotsman 

Industries.4 ALI Group owns a variety of commercial refrigeration and ice maker companies. 

Scotsman, although the largest commercial ice machine company in the world, also 

manufactures consumer products, including cooled cabinets and ice makers.

In 2007, two longstanding small household appliance companies, Salton, Inc. and 

Applica Inc., merged their businesses, and in 2009 the Florida-based entity changed its name to 

Russell Hobbs, Inc. In 2010, Spectrum Brands acquired Russell Hobbs. Russell Hobbs sources 

ice makers and thermoelectric cooled cabinets from China, as does Spectrum Brands’ other home 

appliance brand, Remington.

3.2.5.3 Small Business Impacts

DOE considers the possibility of small businesses being impacted by the promulgation of 

energy conservation standards. The manufacturers of the products covered in this rulemaking 

have a primary NAICS code of 335222: Household Refrigerator and Home Freezer

manufacturing or 333415: Air-Conditioning and Warm Air Heating Equipment and Commercial 

and Industrial Refrigeration Equipment Manufacturing. The Small Business Association defines 

a small business as a company that has fewer than 750 employees and fewer than 1,000 

employees for NAICS codes 335222 and 333415, respectively. At this time, DOE has identified 

five small business manufacturers that are based in the United States and produce one or more of 

the covered products.

DOE will conduct further analysis on this manufacturer subgroup to estimate any 

disproportionate impact that a minimum efficiency standard may have on these businesses. This 

will entail calculating a second set of industry cash flows for the small business group.

3.2.5.4 Distribution Channels

Understanding the distribution channels of miscellaneous refrigeration products is an 

important facet of the market assessment. DOE gathered information regarding the distribution 

channels for miscellaneous refrigeration products from preliminary manufacturer interviews.

The distribution chain for miscellaneous refrigeration products, and most consumer 

appliances, differs from that of commercial products, as the majority of consumers purchase their 

appliances directly from retailers. These retailers include: (1) independent appliance retailers; (2) 
3-20

national big box stores; (3) home improvement and department stores; (4) internet retailers 

(including big box store websites); and (5) kitchen remodelers. For cooled cabinets, the 

distribution method tends to vary according to price point, with higher-end products typically 

being sold by independent retailers and less expensive products being sold by the national 

retailers or online. Ice makers are mostly available through independent dealers and contractors.

In the miscellaneous refrigeration industry, retailers obtain products both directly from 

manufacturers and from regional distributors.

3.2.6 Regulatory Programs

The following section details regulatory programs mandating energy conservation 

standards for cooled cabinets, non-compressor refrigerators, hybrid refrigeration products, and 

ice makers. Section 3.2.6.1 discusses current Federal energy conservation standards, while 

section 3.2.6.2 provides an overview of existing State standards. In addition, section 3.2.6.3

reviews standards in Canada that may impact the companies servicing the North American 

market.

3.2.6.1 Current Federal Energy Conservation Standards

This is the first DOE rulemaking to establish standards for cooled cabinets, noncompressor refrigerators, hybrid refrigeration products, and ice makers; as such, there are no 

current Federal energy conservation standards for these products.

3.2.6.2 State Energy Conservation Standards

As part of its Title 20 Appliance Efficiency Regulations, the CEC has established 

standards for consumer refrigeration products that are not covered by Federal standards, 

including wine chillers. The CEC standards for wine chillers are presented in Table 3.2.4 below.

Table 3.2.4 CEC Wine Chiller Standards2

Appliance Maximum Annual Energy Consumption 

(kWh/year)

Wine chillers with manual defrost 13.7V + 267

Wine chillers with automatic defrost 17.4V + 344

V = volume in cubic feet.

3.2.6.3 Canadian Energy Conservation Standards

Wine chillers are regulated products in Canada under the Canadian Energy Efficiency 

Regulations. The regulations reference Canadian Standards Association (CSA) CAN/CSA-C300-

08, Energy Performance and Capacity of Household Refrigerators, Refrigerator-Freezers, 

Freezers, and Wine Chillers, for the testing procedure and for maximum annual energy 

consumption (MAEC) limits for wine chillers.5 The product classes and MAEC limits in the 
3-21

Canadian regulations are the same as in the CEC standards. DOE’s proposed test procedure is 

also very similar to the CSA test procedure except that it requires the application of a different 

usage adjustment factor and does not require units to be tested with their lights on.

3.2.7 Voluntary Programs

DOE reviewed several voluntary programs promoting energy-efficient residential 

appliances in the United States. Many programs, including the Consortium for Energy Efficiency 

(CEE) and the Federal Energy Management Program (FEMP), establish voluntary energy 

conservation standards for consumer refrigeration products; however, no such voluntary 

standards exist for the miscellaneous refrigeration products covered in this rulemaking.

3.2.8 Saturation in U.S. Homes

DOE obtained estimates from a study that conducted online surveys6 on the saturation of 

miscellaneous refrigeration products in homes.

To obtain data regarding cooled cabinets, these surveys asked about wine chillers. Survey 

results indicated a household saturation of 10.6 percent for wine chillers. The results also 

indicated that approximately 15 percent of wine chillers use vapor-compression cooling 

technology, while 85 percent use thermoelectric cooling technology. 

The surveys in the study also asked about non-compressor refrigerators and freezers. 

Survey results indicated a household saturation of 3.9 percent for non-compressor refrigerators, 

but there was no evidence for the presence of non-compressor freezers. In addition, DOE 

estimates a national stock of approximately 400,000 absorption refrigerators from material 

provided by Dometic (Docket EERE-2011-BT-DET-0072, No. 7 at pp. 40, 42), which are 

believed to be mostly located in hotels. However, if the saturation is estimated based upon 

households, DOE can express this stock as a household saturation of 0.3 percent by dividing by 

the number of U.S. homes (116 million in 2012). Combining these estimates yields an overall 

non-compressor refrigerator household saturation of 4.2 percent. Approximately 90.5 percent of 

non-compressor refrigerators use thermoelectric cooling technology, while 9.5 percent use 

absorption cooling technology.

For ice makers, the study’s surveys found a household saturation of 4.7 percent. Among 

these ice makers, 69 percent were found to be portable ice makers (IM-P), with the remaining 31 

percent being non-portable ice makers. Subsequent analysis of available models on the market

indicates that approximately 8 percent of all ice makers are cooled-storage ice makers (IM-C) 

and 23 percent are uncooled-storage ice makers (IM-U).

For hybrid refrigeration products, the online surveys in the study indicated a household 

saturation of 3.1 percent for hybrid refrigerators and 0.8 percent for hybrid freezers (product 

class H-9I-BI). Analysis of existing models for hybrid refrigerators together with estimated 

product lifetimes indicates that approximately 60 percent are standard-sized units (product class 
3-22

H-3A-BI) and 40 percent are compact units.g Of the compact units, DOE determined that 

approximately 20 percent of products had manual defrost (product class H-11A), and 80 percent 

of products had automatic defrost (product class H-13A).

Household saturation estimates are summarized in Table 3.2.5.

Table 3.2.5 Household Saturation Estimates for Miscellaneous Refrigeration Products

Product class Product description Household 

saturation

Cooled cabinets

CC Vapor compression wine chiller 1.6%

Thermoelectric wine chiller 9.0%

Cooled cabinet subtotal 10.6%

Non-compressor refrigerators

NCR Thermoelectric refrigerator 3.8%

Absorption refrigerator 0.4%

Non-compressor refrigerator subtotal 4.2%

Ice makers

IM-P Portable ice maker 3.2%

IM-C Cooled-storage ice maker 0.4%

IM-U Uncooled-storage ice maker 1.1%

Hybrid products

H-3A-BI Built-in standard-sized hybrid all-refrigerators with automatic 

defrost

1.9%

H-9I-BI Built-in standard-sized hybrid freezers with automatic defrost 

and an automatic ice maker

0.8%

H-11A Compact hybrid all-refrigerators with manual defrost 0.2%

H-13A Compact hybrid all-refrigerators with automatic defrost 1.0%

3.2.9 Historical Shipments

Very few data exist for the historical shipments of miscellaneous refrigeration products.

For cooled cabinets, AHAM and NPD Group provided recent historical shipments 

estimates, while online surveys and Natural Resources Canada (NRCan) (for Canadian 

 

g DOE used an estimate that one-third of hybrid refrigerator shipments were standard-sized and two-thirds were 

compact, together with the estimated lifetimes of these products (17 and 5.6 years, respectively). The estimated 

share of standard-sized units out of the total stock is (17)•(1/3) / [(17)•(1/3) + (5.6)•(2/3)] = 60 percent, and the 

estimated share of compact units out of the total stock is (5.6)•(2/3) / [(17)•(1/3) + (5.6)•(2/3)] = 40 percent.
3-23

households) provided stock estimates from which shipments could be inferred using a calculated 

lifetime of products.

The AHAM data indicate that shipments of “wine coolers” (cooled cabinets) amounted to 

0.4 percent of all U.S. refrigerator, refrigerator-freezer, and freezer shipments in 2005-2006, and

increased to 0.6 percent in 2007. Using these percentages with the total estimated annual 

shipments of refrigerators, refrigerator-freezers, and freezers (that did not include any 

miscellaneous refrigeration products) from the 2011 Energy Conservation Standards for 

Residential Refrigerators, Refrigerator-Freezers, and Freezers Final Rule (hereafter referred to as 

the 2011 R/F Final Rule) results in an annual shipments estimate of approximately 60,000 to 

90,000 cooled cabinets between 2005 and 2007. 76 FR 57516. See Table 3.2.6, where the top 

line is the total estimated shipments of refrigerators, refrigerator-freezers, and freezers from the 

2011 R/F Final Rule.
3-24

Table 3.2.6 Estimated Historical Shipments of Miscellaneous Refrigeration Products

Product 

class Data Source

Estimated Annual Shipments (millions)

2005 2006 2007 2008 2009 2010 2011 2012

All

refrigerators, 

refrigeratorfreezers, and 

freezers

DOE 2011 R/F FR 16.73 15.39 15.09 14.37 14.27 15.02 16.29 17.15

Cooled cabinets

CC AHAM 0.07 0.06 0.09

NPD Group (low 

est.)

0.28 0.75 1.03 0.57 0.46 0.46 0.42

NPD Group (high 

est.)

0.45 1.19 1.64 0.92 0.74 0.73 0.67

Online surveys 2.9

NRCan 1.4*

Non-compressor refrigerators

NCR Online surveys 1.1

Ice makers

IM-P Online surveys 2.24

IM-C Online surveys 0.26

IM-U Online surveys 0.75

Hybrid refrigeration products

H-3A-BI Online surveys 0.13

H-9I-BI Online surveys 0.04

H-11A Online surveys 0.05

H-13A Online surveys 0.20

* Based on a Canadian household saturation of 5.3% extrapolated for the United States. See text.

NPD Group also provided estimates of “wine cooler” (cooled cabinet) shipments between 

2005 and 2011.7 By their own estimation, reported shipments constituted between 25 percent and 

40 percent of the total estimated market share of cooled cabinets. Results for both sets of 

estimates are shown in Table 3.2.6, indicating shipments that peak in 2007 at between 1.03 and 

1.64 million units and drop to an average of between 450,000 and 710,000 units over 2009-2011. 

For the period 2005-2007, the NPD Group estimates are between 4 and 19 times larger than the 

corresponding AHAM data, indicating a large uncertainty between these two sources.

The online surveys from the study indicate even higher shipments of wine chillers, but 

data are only available for 2012. Estimated annual shipments are 2.9 million, based on an 

estimated stock of 12.3 million divided by the estimated average lifetime of the product (4.3 

years; see chapter 8). This estimate is between approximately 4 and 6 times larger than the NPD

Group’s average for 2009-2011.
3-25

The NRCan study estimated a penetration of “wine chillers” (cooled cabinets) in 

Canadian households of 5.3 percent in 2011.8 Assuming this penetration is the same in the 

United States yields an estimated stock of 6.1 million. Dividing by the estimated lifetime 

provides an estimate of 1.4 million annual shipments, lower than the online survey but much 

higher than either AHAM or NPD Group estimates.

The online survey also provided an estimate of 1.1 million annual shipments of 

thermoelectric and absorption cooling refrigerators.

For ice makers and hybrid refrigeration products, the only data available are from online 

surveys. As for cooled cabinets, estimated annual shipments are derived from the estimated stock 

divided by the estimated average lifetime of the product.

For ice makers, estimated annual shipments are 3.24 million, based on the estimated 

stock of all ice makers (5.45 million) divided by the estimated average lifetime of the product 

(1.7 years; see chapter 8). This total is further subdivided into the three product classes (IM-P, 

IM-C, and IM-U) according to the estimated saturations provided in section 3.2.8. See Table 

3.2.6.

For hybrid refrigeration products, estimated annual shipments of built-in standard-sized

hybrid all-refrigerators with automatic defrost (product class H-3A-BI) are 130,000 units, based 

on the estimated stock of these products (2.2 million) divided by the estimated average lifetime 

of the product (17 years, see chapter 8). Estimated annual shipments of built-in standard-sized

hybrid freezers with automatic defrost and automatic ice makers (product class H-9I-BI) are 

40,000 units, based on the estimated stock of these products (900,000) divided by the estimated 

average lifetime of the product (22 years, see chapter 8). Estimated annual shipments of compact 

hybrid all-refrigerators (product classes H-11A and H-13A) are 250,000 units, based on the 

estimated stock of these products (1.4 million) divided by the estimated average lifetime of the 

product (5.6 years, see chapter 8). As discussed in chapter 7, approximately 20 percent of 

compact hybrid products have manual defrost (product class H-11A), and 80 percent have 

automatic defrost (product class H-13A). See Table 3.2.6.

NPD Group also provided market share estimates of cooled cabinet shipments by 

capacity from 2005-2011. Market shares by capacity appear to have changed rapidly between 

2005 and 2007 and appear relatively stable thereafter. Data are presented in Figure 3.2.8.
3-26

Figure 3.2.8 Historical Market Shares of Cooled Cabinet Shipments by Year and Capacity 

from NPD Group

Online surveys provided market share estimates of cooled cabinet stock by capacity in 

2012. Given the short estimated lifetime of cooled cabinets (4.3 years), these data can be 

compared to averaged NPD Group shipments data over the past few years (e.g., 2008-2011), 

especially because NPD Group market shares by capacity appear fairly stable. This comparison 

is illustrated in Table 3.2.7.
3-27

Table 3.2.7 Comparison of Estimated Market Shares of Cooled Cabinets by Capacity

Capacity 

(number of 

wine bottles)

Maximum equivalent 

volume (cubic feet)*

Estimated market shares of cooled cabinets

Online survey 

(stock, 2012)

NPD Group (shipments,

2008-2011 average)

1 to 11 1.3 43.7% 41.7%

12 to 19 2.3 33.2% 36.1%

20 to 29 3.5 14.9% 6.0%

30 to 39 4.7 4.9% 9.1%

40 to 49 6.0 1.5% 5.5%

50 to 59 7.2 1.1% 1.2%

60 to 89 10.8 0.1% 0.1%

90+ 10.9+ 0.5% 0.3%

Total 100.0% 100.0%

* Capacities in number of wine bottles were converted to equivalent volumes in cubic feet using 

the conversion factor 8.22 wine bottles per cubic foot, based on capacity-volume regression

calculations found in Greenblatt, et al. (2013).

3.2.10 Historical Efficiencies

DOE has no data on the historical efficiencies of miscellaneous refrigeration products. 

Current efficiencies based on market data are presented in chapter 7 of this TSD.

3.2.11 Product Retail Prices

3.2.11.1 Cooled Cabinets

Figure 3.2.9 presents the average retail prices (in 2011 nominal dollars) from 2009 through 

2011 for cooled cabinetsh of all capacities as a fraction of total shipments. Ninety-five percent of 

cooled cabinet shipments are priced between $26 and $450, and 50 percent are priced between 

$26 and $100, implying that a large portion of cooled cabinets sold in the U.S. are small-capacity 

units (able to hold fewer than 20 bottles). DOE estimates that 78 percent of cooled cabinet 

shipments (2008-2011 average) have a capacity of 1 to 19 bottles (Table 3.2.8).

 

h Includes all commercially available cooling types (vapor compression and thermoelectric).
3-28

Figure 3.2.9 Average Retail Prices (2009 – 2011) For All Cooled Cabinet Categories

Table 3.2.8 Proportion of Wine Chiller Shipments (2008-2011 Average) by Capacity

Capacity (# of wine bottles) Proportion of Total Shipments

1 to 11 41.7%

12 to 19 36.1%

20 to 29 6.0%

30 to 39 9.1%

40 to 49 5.5%

50 to 59 1.2%

60 to 89 0.1%

90+ 0.3%

DOE conducted an in-depth search of consumer retail prices for vapor-compression 

cooled cabinets available on the market as of April 2013 by gathering consumer prices from nine 

major cooled cabinet retailers: Beverage Factory, Home Depot, AJMadison, Abt, RoseHill Wine 

Cellars, Wine Enthusiast, Appliance Connection, Wine Cellar Creations, and Lowes. DOE 

identified a total of 82 standard vapor-compression cooled cabinet models and 19 different 

brands available on the online market today. DOE used the CECi

and NRCanjdatabases to 

match the rated annual energy consumption data with each cooled cabinet model.

 

i

CEC appliance efficiency database available online at: http://www.energy.ca.gov/appliances/database/.
3-29

Figure 3.2.10 summarizes the data collected by DOE. The figure shows that the 

association between retail price and efficiency for vapor-compression cooled cabinets is not 

easily defined. The consumer retail prices for vapor-compression cooled cabinets ranged from 

$198 to $5,499, with an average of $1,292 (this is the average across all 82 models and does not 

reflect the shipment-weighted average). In order to analyze cooled cabinet efficiency relative to 

retail price, and due to the fact that annual energy use is highly related to capacity, DOE uses the 

“Percent of CEC Baseline Consumption” as the metric for efficiency in this analysis. Vaporcompression cooled cabinets are available with annual energy use between 58 percent and 101 

percent of the CEC baseline annual energy use at all price-points, with an average of 84 percent

of baseline consumption.

Figure 3.2.10 Vapor-Compression Cooled Cabinet Retail Price as a Function of % of CEC 

Baseline Annual Energy Use

In order to further analyze the relationship between retail price and efficiency level for 

vapor-compression cooled cabinets, DOE conducted a regression analysis in which it constructed 

models controlling for other characteristics (beyond efficiency and capacity) that could have an 

 

j

NRCan database available at: http://oee.nrcan.gc.ca/pml-lmp/index.cfm?action=app.searchrecherche&appliance=REFRIGERATORS
3-30

impact on cooled cabinet price (see Table 3.2.9). The “best fit”k among these models includes 

additional explanatory variables for installation type, number of zones, and retailer. The results 

show that there is a significant and positive relationship between vapor compression cooled 

cabinet capacity and retail price, finding that, on average, every cubic foot increase in internal 

capacity is associated with a $70 increase in price, holding other variables constant. The results 

also find a statistically significant relationship between installation types and price, as well as 

between zone types and price. Specifically, the model finds that, on average, free-standing 

vapor-compression cooled cabinets cost $1,206 less than built-in cooled cabinets, and units that 

can be either free-standing or built-in cost $1,138 less than traditional built-in units, holding 

other variables constant. The model finds that, on average, two-zone cooled cabinets cost $383

more than single zone cooled cabinets, while “stratified” cooled cabinets cost $712 less than 

single zone cooled cabinets, holding other variables constant.

Supporting the initial scatterplot of retail price versus efficiency, our model shows that 

the relationship between retail price and efficiency is not statistically significant at the 90 percent

confidence level, but the trend is toward increasing price with increasing efficiency (decreasing 

percentage of CEC baseline). Likewise, the retailer from which the unit is purchased is found to 

have no significant impact on price.

 

k This model had an adjusted R2 equal to 0.53. The model specification was as follows: Y = ß0 + ß1(internal volume)

+ ß2(% above standard efficiency) + Σyi(installation type dummies) + Σμi (zone type dummies) + Σσi (retailer 

dummies); To avoid multicollinearity, one variable from each dummy variable category is omitted from the model, 

thereby making it the reference case. 
3-31

Table 3.2.9 Cooled Cabinet Price Regression Analysis

Coefficients Standard Error t Stat

Intercept 2,578 758 3.40

Internal Volume 

(ft3)**

70 21 3.40

% of CEC Baseline (1,007) 808 -1.25

Free-Standing** (1,206) 277 -4.36

Free-Standing and 

Built-In Capable**

(1,138) 233 -4.90

2-Zone** 383 186 2.06

Stratified* (712) 403 -1.77

Beverage Factory (251) 512 -0.49

Home Depot (531) 466 -1.14

AJ Madison 93 470 0.20

Abt 38 676 0.06

RoseHill Wine Cellars 283 612 0.46

Wine Enthusiast (637) 543 -1.17

Appliance Connection (401) 634 -0.63

Wine Cellar Creations 251 691 0.36

**Statistically significant at the 95% confidence level.

*Statistically significant at the 90% confidence level.

An in-depth analysis of the relationship between retail price and efficiency could not be 

conducted for thermoelectric cooled cabinets due to a lack of available data on the annual energy 

use of these products. However, DOE does find based upon available information that 

thermoelectric products tend to be less expensive as well as less efficient than vapor compression 

products. 

DOE also compared the NPD price data to online survey data disaggregated by capacity.

Due to data limitations in the survey data, only the 1-11, 12-19 and 20-29 bottle capacities are 

shown, as well as average prices for all capacities. See Figure 3.2.11 through Figure 3.2.14.

While some differences can be observed in the details of the distributions, and a bias in the NPD 

data toward lower prices at all capacities, there is general agreement in the price trends as 

functions of capacity, and significant overlap in the price ranges between the online survey and 

NPD data, including the clustering at low and high prices in the 20-29 bottle capacity data. It 

should be noted that the NPD data is based on sales, whereas the survey data is based on stock.
3-32

Figure 3.2.11 Average Price Distributions for 1-11 Bottle Cooled Cabinets. Note: WC1 

indicates survey data.

Figure 3.2.12 Average Price Distributions for 12-19 Bottle Cooled Cabinets. Note: WC1 

indicates survey data.
3-33

Figure 3.2.13 Average Price Distributions for 20-29 Bottle Cooled Cabinets. Note: WC1 

indicates survey data.

Figure 3.2.14 Average Price Distributions Across Cooled Cabinet Capacities. Note: WC1 

indicates survey data.
3-34

3.2.11.2 Non-Compressor Refrigerators

Insufficient data were available on prices paid for non-compressor refrigerators. 

However, due to the similarity in design of non-compressor refrigerators and cooled cabinets, 

DOE assumes the price ranges would be similar. 

3.2.11.3 Hybrid Refrigeration Products

No data were available on prices paid for hybrid refrigeration products.

3.2.11.4 Ice Makers

Figure 3.2.15 presents purchase price of new ice makers based on online survey data. All 

prices are in 2012 nominal dollars, and do not include taxes or rebates. The median purchase 

price was just over $200, with the highest price paid reported between $2,501 and $3,000.

Figure 3.2.15 Purchase Prices of Ice Makers
3-35

3.2.12 Industry Cost Structure

DOE developed the household appliance industry cost structure from publicly available 

information from the Annual Survey of Manufacturers (ASM) and Economic Census (Table 

3.2.10 and Table 3.2.12) and the U.S. Securities and Exchange Commission (SEC) 10-K reports 

filed by publicly owned manufacturers (summarized in Table 3.2.14). Table 3.2.9 presents the 

major appliance manufacturing industry (NAICS code 335222) employment levels and earnings 

from 2002-2011. The statistics illustrate a steady decline in the number of production and nonproduction workers in the industry since 2002. 

DOE converted the payroll data to constant 2011 dollars using the Gross Domestic 

Product Implicit Price Deflator published by the U.S. Bureau of Economic Analysis.

9 Table

3.2.10 shows that as industry employment levels decline, the industry payroll in constant 2011 

dollars also decreases. The percent decrease in total industry employees tracks relatively closely 

with the percent decrease in payroll for all U.S.-based employees. 

Table 3.2.10 Major Appliance Manufacturing Industry Employment and Earnings9

Total Payroll

(2011 $ Mil)

2011 30,316 34,742 $1,428

2010 31,924 36,475 $1,555

2009 32,875 37,905 $1,564

2008 39,208 45,152 $1,870

2007 45,370 52,045 $2,090

2006 49,360 56,174 $2,355

2005 54,083 62,877 $2,487

2004 57,660 68,213 $2,767

2003 58,289 68,593 $2,804

2002 59,234 70,013 $2,935

All 

Employees Year Production 

Workers

 $-

 $500

 $1,000

 $1,500

 $2,000

 $2,500

 $3,000

 $3,500

 $4,000

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

2002 2004 2006 2008 2010

tayroll (2011 $ ail)

No. 9mployees

aajor Appliance Industry 

9mployment

All 9mployees

troduction Workers

Total tayroll

Table 3.2.11 presents the employments levels and payroll for just the “household 

refrigerator and home freezer portion” of the major appliance industry. Statistics for both 

employment levels and payroll show a slight decrease from 2002 to 2011. The decrease is of a 

much larger magnitude than for the major appliance industry overall.
3-36

Table 3.2.11 Household Refrigerator and Home Freezer Manufacturing Industry 

Employment and Earnings9

Total Payroll

(2011 $ Mil)

2011 7,651 8,582 $360

2010 8,702 9,877 $455

2009 9,156 10,449 $453

2008 10,805 12,310 $581

2007 12,179 13,971 $647

2006 14,714 16,539 $740

2005 17,505 20,319 $812

2004 20,136 23,380 $953

2003 20,162 22,989 $960

2002 20,530 23,487 $1,002

Year Production 

Workers All Employees

 $-

 $300

 $600

 $900

 $1,200

 $1,500

 -

 5,000

 10,000

 15,000

 20,000

 25,000

2002 2004 2006 2008 2010

tayroll (2011 $ ail)

No. 9mployees

Household Refrigerator and Home 

Freezer aanufacturing 9mployment

troduction Workers

All 9mployees

tayroll for All 9mployees

Table 3.2.12 presents the costs of materials and industry payroll as a percentage of value 

of shipments from 2002-2011. The cost of materials as a percentage of value of shipments has 

remained fairly constant over the 9-year period, with small fluctuations, particularly between 

2008 and 2011. DOE notes that fluctuations in raw material costs are common from year to year.

The cost of payroll for both production and non-production workers as a percentage of value of 

shipments has declined since 2002.

Table 3.2.12 Major Appliance Manufacturing Industry Materials and Wages Cost9

Table 3.2.13 shows the cost of materials and industry payroll as a percentage of value of 

shipments for the Household Refrigerator and Home Freezer Manufacturing industry from 2002-

Year Materials

Payroll for 

Production 

Workers

Payroll for All 

Other 

Employees 

2011 56% 7% 2%

2010 58% 8% 2%

2009 55% 8% 2%

2008 61% 8% 2%

2007 58% 8% 2%

2006 59% 8% 2%

2005 57% 8% 2%

2004 58% 9% 3%

2003 57% 10% 3%

2002 57% 10% 3%

Cost as a Percentage of Value of Shipments 

(%)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

Percentage of Total Shipments(%)

Materials and Wages as Percentage 

of Shipments Value - Major 

Appliances

Payroll for All Other Employees

Payroll for Production Workers

Materials
3-37

2011. The graph excludes 2010 and 2011, as materials prices were unavailable for those years.l

Material prices as a percentage of value of shipments have remained relatively constant between 

2002 and 2009, with fluctuations from year-to-year. The cost of payroll for production workers 

as a percentage of value of shipments has generally decreased since 2002, from 12 percent to 8.1 

percent in 2011. The cost of non-production payroll has remained relatively constant over the 11-

year period, with fluctuations from year-to-year. DOE notes that, overall, wages and cost of 

materials combined represent a larger percentage of the total shipments value for the other major 

appliance industry than for the major appliance industry as a whole.

Table 3.2.13 Household Refrigerator and Home Freezer Manufacturing Industry Materials 

and Wages Cost9

Table 3.2.14 presents the industry cost structure derived from SEC 10-K reports of U.S.-

based, publicly owned home appliance manufacturers who are considered major producers of 

cooled cabinets. DOE averaged the financial data from 2006–2012 of these manufacturers to 

obtain an industry average. Each financial statement entry is presented as a percentage of total 

revenues.

 

l

Materials numbers for 2010 and 2011 were withheld to avoid disclosing data for individual companies.

Year Materials

Payroll for 

Production 

Workers

Payroll for All 

Other 

Employees 

2011 - 8% 2%

2010 - 10% 3%

2009 54% 9% 3%

2008 62% 10% 3%

2007 57% 8% 2%

2006 53% 9% 2%

2005 58% 10% 2%

2004 61% 11% 2%

2003 56% 11% 3%

2002 59% 12% 3%

Cost as a Percentage of Value of Shipments 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2002 2003 2004 2005 2006 2007 2008 2009

Percentage of Total Shipments(%)

Materials and Wages as Percentage of 

Shipments Value - Major Appliances

Payroll for All Other Employees

Payroll for Production Workers

Materials
3-38

Table 3.2.14 Industry Cost Structure Using SEC Data, Average 2006-2012

Financial Statement Entry Percent of 

Revenues

Cost of sales 80.9%

EBIT 7.1%

Selling, general and administrative 13.1%

Capital expenditure 1.3%

Research and development 1.4%

Depreciation and amortization 1.5%

Tax Rate 30.9%

Net plant, property and equipment 8.1%

Working capital 9.4%

A detailed financial analysis is presented in the manufacturer impact analysis (MIA)

(Chapter 12 of this TSD). This analysis identifies key financial inputs including cost of capital, 

manufacturer markups, etc.

3.2.13 Inventory Levels and Capacity Utilization

Table 3.2.15 and Table 3.2.16 show the end-of-year (EOY) inventory for the household 

refrigerator and home freezer manufacturing as well as the air-conditioning and warm air heating 

industries, according to the ASM. The trend in the value of EOY inventory expressed as a 

percentage of the total value of shipments for the household refrigerator and home freezer 

manufacturing industry shows a steady increase between 2006 and 2010, averaging 20-percent 

growth per year through that period. This increase, coupled with the relative steady dollar value 

of EOY inventories, illustrates the substantial contraction in shipment values through this period. 

In contrast, the value of the EOY inventories in the air-conditioning and warm air heating 

equipment manufacturing industry roughly tracks the value of EOY inventory as a percentage of 

the value of shipments owing to stable overall shipments through this period.
3-39

Table 3.2.15 Household Refrigerator and Home Freezer Manufacturing Industry 

Inventory Levels9

Year

EOY 

Inventory 

(2012 $ Mil)

EOY 

inventory as 

% of 

Shipments 

Value

2010 344 10%

2009 346 9%

2008 366 8%

2007 363 6%

2006 289 5%

2005 323 5%

Table 3.2.16 Air-Conditioning and Warm Air Heating Equipment Manufacturing Industry 

Inventory Levels9

Year

EOY 

Inventory 

(2012 $ Mil)

EOY inventory 

as % of 

Shipments 

Value

2011 2,667 9%

2010 2,742 9%

2009 2,861 10%

2008 3,254 10%

2007 3,504 11%

2006 3,442 11%

2005 3,294 10%

DOE obtained full production capacity utilization rates from the U.S. Census Bureau’s

Survey of Plant Capacity from 2004–2006. After 2006, the Census Bureau discontinued this 

survey, and began a new Quarterly Survey of Plant Capacity Utilization. However, this survey 

does not collect utilization data beyond the 4 digit NAICS codes for the “all household 
3-40

appliances”m and “ventilation, heating, air-conditioning, and commercial refrigeration 

equipment”n industries. Table 3.2.17 presents utilization rates for these umbrella industries.

Full production capacity is defined as the maximum level of production an establishment 

could attain under normal operating conditions.o In the Survey of Plant Capacity reports, the full 

production utilization rate is a ratio of the actual level of operations to the full production 

capacity. The full production utilization rate for all household appliances was fairly steady

between 74 and 77 percent from 2004 through 2007, with a more significant decrease to less than 

60 percent from 2008 through 2009, and then a partial rebound between 2010 and 2012. Plant 

capacity utilization for ventilation, heating, air-conditioning, and commercial refrigeration 

manufacturers peaked in 2008, at 67 percent, and reached a low of 55 percent in 2012. 

Table 3.2.17 Full Production Capacity Utilization Rates10, 11

Year

Plant Capacity Utilization Rates 

(%)

All Household 

Appliances

Ventilation, 

heating, airconditioning, 

and 

commercial 

refrigeration 

equipment 

mfg.

2012 65% 55%

2011 62% 60%

2010 64% 60%

2009 58% 60%

2008 59% 67%

2007 76% 66%

2006 77% 62%

2005 74% 66%

2004 76% 61%

 

m “All Home Appliances” is the umbrella NAICS category 3352 that includes NAICS code 335222 for “household 

refrigerator and home freezer” manufacturing.

n “Ventilation, heating, air-conditioning, and commercial refrigeration equipment” is the umbrella NAICS category 

3334 that includes NAICS code 333415 for “air-conditioning and warm air heating equipment and commercial and 

industrial refrigeration equipment.”

o http://www.census.gov/manufacturing/capacity/definitions/index.html
3-41

3.3 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 miscellaneous refrigeration products.

Contained in this technology assessment are details about product operation (section 3.3.1), 

details about baseline equipment components (section 3.3.3), an examination of possible 

technological improvements for each product (section 3.3.4), and a characterization of the 

product efficiency levels currently available on the market (section 3.3.4).

3.3.1 Product Operation 

Cooled cabinets, non-compressor refrigerators, and hybrid refrigeration products are 

household appliances designed for the refrigerated storage of food products and/or beverages, 

such as wine, while ice makers are household appliances designed to produce and store ice. 

Definitions for these product types are discussed in section 3.2.1.

A typical consumer refrigeration product consists of a refrigeration system contained 

within an insulated cabinet. Refrigeration products that are currently being sold in the U.S. 

market use one of the following three refrigeration technologies to achieve compartment cooling

and/or ice production: vapor-compression, thermoelectric, and absorption cooling. However, 

DOE is not aware of any thermoelectric or absorption ice makers.

3.3.1.1 Vapor-Compression Refrigeration Technology

Figure 3.3.1 shows a schematic representation of a typical refrigeration circuit used in 

vapor-compression refrigeration products, including hybrid refrigeration products, ice makers, 

and many cooled cabinets. As described by the American Society of Heating, Refrigerating and 

Air-Conditioning Engineers (ASHRAE) Refrigeration Handbook,12 the refrigeration process 

consists of the following steps:

1. Electrical energy is supplied to a motor that drives a compressor, which draws in cold, 

low-pressure refrigerant vapor from the evaporator and compresses it.

2. The resulting high-pressure, high-temperature discharge gas then passes through the 

condenser, where it is cooled to saturation condition, condensed to a liquid, and possibly 

sub-cooled, while the heat removed from the refrigerant is rejected to the ambient air.

3. Liquid refrigerant passes through a metering (pressure-reducing) capillary tube to the 

evaporator, which is at low pressure.

4. The low-pressure, low-temperature liquid in the evaporator absorbs heat from its 

surroundings, evaporating to a gas, which is again withdrawn by the compressor.
3-42

Figure 3.3.1 Typical Vapor-Compression Refrigeration Circuit

3.3.1.2 Thermoelectric Refrigeration Technology

Thermoelectric refrigeration systems operate using solid-state thermoelectric cooling 

modules, which are powered by DC electric input. These modules function due to the Peltier 

Effect, which is the temperature differential created across the device when a voltage is placed 

across it. This creates a cold side, which cools the cabinet air inside a refrigeration product, and a 

hot side, which rejects heat to the ambient air behind the product. 

3.3.1.3 Absorption Refrigeration Technology

Absorption-based refrigeration products work by using a heat source, powered by either 

electricity or fuel (e.g., natural gas or propane), to provide the energy needed to drive the cooling 

system. Absorption refrigeration products use the ammonia-water absorption cycle to cool the 

storage cabinet. Electrically powered absorption units are typically used by the hotel industry for 

in-room refrigeration cabinets as they are quieter than compressor-based units, while gas or 

propane units are designed for use in mobile applications and remote locations that do not have 

access to electricity.

3.3.1.4 Ice Maker Operation

Ice makers are household appliances designed for the production and storage of ice. The 

process used to make ice differs for the various types of ice. In cooled-storage ice makers, ice is 

formed by circulating cold air over a mold filled with water. When the cubes have fully formed, 

a heater frees them from their mold and they are mechanically released into the storage bin.
3-43

In uncooled-storage and portable ice makers, the ice is formed directly on the evaporator, 

which is specifically designed to form ice cubes. The cube-type evaporator is constructed of 

copper tubing attached to copper or stainless steel ice making surfaces. There may be plastic 

attached to the ice making surface to act as an insulator to promote the formation of individual 

cubes. In such ice makers, ice is formed by passing a film of water over the evaporator, allowing 

some of the water to freeze, while the remaining water falls to the sump to be recirculated by a 

pump. The ice layer gradually grows, while solids and gases dissolved in the water are carried 

away by the remaining liquid. This process allows production of clear ice. Portable ice makers 

work similarly except that the evaporator consists of downward-facing prongs around which ice 

forms. When the batch is complete, the compressor directs hot gas into the evaporator, which 

releases the ice. The harvested cubes are then stored in a bin and the remaining sump liquid is 

drained. Figure 3.3.2 illustrates the steps of the batch process.

Figure 3.3.2 Batch Icemaking Process

The batch process has the following characteristics:

13

1. The sump usually contains 10 to 40 percent more water than required to make a given 

batch of ice. This water is cooled to freezing temperatures but then dumped to a drain at 

the end of the icemaking cycle; thus, the process requires more refrigeration than just the 

amount required to freeze the harvested ice.

1. Water fills 

sump.

2. Refrigeration 

system is activated. 

Water is circulated 

over the evaporator. 

3. Water 

cools down 

and 

gradually 

freezes on 

evaporator.

4. Ice batch 

weight is 

detected.

5. Ice cubes are 

harvested.

6. Sump 

water is 

purged. 

Fresh 

potable 

water is 

used to flush 

the system.
3-44

2. Ice harvest occurs when the ice maker has produced a sufficient amount of ice. Ice 

makers can detect batch weight by measuring sump water level, compressor suction 

pressure, or thickness of ice on the plate.

3. Many ice makers use hot-gas harvest, in which hot refrigerant vapor is directed from the 

compressor to the evaporator to warm the evaporator and melt enough ice to free the ice 

on the plate. Typically, 10 to 20 percent of the ice is melted during the harvest process. 

Some makers use a limited amount of hot gas for melt combined with mechanical means 

for removing the ice. Other styles allow a slab of ice to drop onto electric heater wires 

arranged in a grid pattern so that the slab can be separated into cubes.

In continuous-type ice makers, an auger is used to drive water upwards through a 

cylindrical evaporator. The flake- or nugget-type evaporator is typically a stainless steel cylinder 

with an auger that moves ice upward. The cold surface of the evaporator causes ice to form on 

the inside surface of the cylinder. The ice is pushed through an extrusion head and directed to the 

storage bin. The extrusion head for a nugget ice maker has smaller holes than that of a flake ice 

maker, causing the ice to be compressed into nuggets as it leaves the evaporator. 

3.3.2 Product Operation and Components

This section provides a brief description of the components and operation of the different 

types of miscellaneous refrigeration products. These descriptions provide a basis for 

understanding the technologies used to improve product efficiency.

The illustration in Figure 3.3.3 shows the components and layout of a typical vaporcompression refrigerator-freezer. The components and layout are similar in hybrid refrigeration 

products, cooled cabinets, and non-compressor refrigerators, though cooled cabinets may have 

only one compartment and non-compressor refrigerators do not feature the components unique to 

a vapor-compression system. The text that follows describes the following operations or 

components that are common to most refrigeration products, regardless of their cooling system: 

automatic defrost, temperature control, lighting, and door seals and hinges.
3-45

Figure 3.3.3 Components of a Vapor-Compression Refrigerator-Freezerp

3.3.2.1 Automatic defrost

Manual defrost is still used in cooled-storage ice makers. However, all cooled cabinets, 

uncooled-storage and portable ice makers, and non-compressor refrigerators, as well as almost 

all hybrid refrigeration products, are self-defrosting. Self-defrosting refrigeration products

automatically melt frost that accumulates in the cabinet and on the evaporator. Automatic defrost 

may be passive or it may use an active control sequence. Passive defrost units defrost during 

compressor off-cycles, when the refrigerant in the evaporator is allowed to warm. Active defrost 

units use a heater to warm the evaporator to melt frost. The defrost control sequence is generally 

initiated after a prescribed number of compressor running hours. The typical mechanicallycontrolled active defrost system has three functional components: a defrost timer, a defrost 

heater, and a defrost thermostat. 

• Defrost timer: The timer is a clock that is energized with the compressor. The timer 

initiates defrost after a set interval of compressor operation. 

 

p http://www.remodelguide.com/improve/appliances/refrigerators/refrigerators_works.html
3-46

• Defrost heater: The defrost heater is an electric resistance heating element that melts 

any ice or frost that builds up. A heater is typically also energized in the drip pan to prevent 

freeze of melted condensate and clogging of the drip pan drain.

• Drip pan: As the frost and ice melt, the resulting water drips into a drip pan. The pan is 

connected to a tube that drains the water into a shallow pan underneath the insulated cabinet 

floor at the bottom of the refrigerator-freezer or freezer. The water is then evaporated by air 

which is drawn by a fan through the condenser and over the compressor shell. In some products 

which do not use forced convection condensers, a special pan is mounted on top of the 

compressor shell and the water is evaporated using heat from the compressor.

• Defrost thermostat: The process ends when the defrost thermostat mounted on the 

evaporator tubing senses that a sufficiently high temperature has been attained.

3.3.2.2 Temperature control 

Most refrigeration products have a thermostat or electronic temperature control to 

maintain the proper temperature. Thermostats are mechanical devices which interrupt the 

electricity connection to the compressor when the temperature is sufficiently low. Electronic 

control systems generally use thermistors as temperature sensors, using relays mounted on the 

circuit boards to activate the compressor and other components such as the evaporator and 

condenser fans.

3.3.2.3 Lighting 

Refrigeration products with internal lighting normally have only one functional lighting 

component, the switch, which is usually a white push-button mounted to be depressed by 

operation of the door. Closing the door turns off the light, although some wine chillers also have 

external light switches to keep the lights on when the door is closed. Refrigeration products 

traditionally used standard appliance incandescent light bulbs, but many new designs are using 

LED lighting.

3.3.2.4 Door Seals 

All refrigeration products, except for some portable ice makers, have a seal—a vinyl 

gasket attached to the door(s). The seal prevents infiltration of warm ambient air into the cabinet. 

The seal is lined with a magnet which helps to hold the door closed and create a tight seal. The 

magnetic portion of the gasket is aligned to face the steel extension of the cabinet’s external shell 

which wraps partially around the front face of the cabinet. Some gasket systems use opposing 

magnets on the cabinet side to improve door sealing force.
3-47

3.3.2.5 Vapor-Compression Cooling

The following text provides descriptions for each of the components found in a vaporcompression refrigeration product.

• Compressor: The compressor compresses refrigerant, providing the energy input 

necessary to drive the cycle. In most refrigeration products, the compressor is located at the 

bottom rear of the unit. In built-in cooled cabinets or hybrid refrigeration products, the 

compressor is often located on top of the unit behind a grill or grate. The compressor runs 

whenever the thermostat calls for cooling.

• Condenser: The condenser is a heat exchanger located on the outside of the unit. The 

three most prevalent condenser configurations are as follows: 

– Forced-convention condensers use fans to move air through them to provide cooling. 

These condensers are usually located under or above the unit, near the compressor. They can be 

fabricated of steel tubes with steel wire fins or copper or aluminum tubes with aluminum fins. 

– Natural convection “static” condensers, which do not use fans, are mounted to the back 

of the unit. They generally have steel tubes and steel wire fins. 

– Hot wall condensers are integrated into the outer shell of the unit. A serpentine of 

tubing is attached to the inside of the shell and provided with good thermal contact to the shell. 

This is a common configuration in compact cooled cabinets. 

• Metering or Flow Control Device (Capillary Tube): The metering device in most vaporcompression consumer refrigeration products is a capillary tube. There are two common types of 

capillary tubes: adiabatic and non-adiabatic. Non-adiabatic capillary tubes, which are the most 

common, are soldered to the suction line to evaporate the residual liquid and warm the vapor, 

thereby increasing the refrigeration capacity of the system. Adiabatic capillary tubes do not 

exchange heat with the suction line and therefore allow the refrigerant to expand adiabatically

(i.e., without heat transfer). The capillary tube controls the pressure and flow of the refrigerant as 

it enters the evaporator.

• Evaporator: The evaporator is a heat exchanger located inside the unit. Similar to the 

condenser, there are three main configurations for evaporators: 

– Forced-convection evaporators use fans to move air through them to provide cooling. 

They are constructed of aluminum tubes and aluminum fins or copper tubes and aluminum fins. 

They are generally located on the rear wall of the compartment behind a panel. They can also be 

located in the mullion separating compartments, as shown in Figure 3.3.3. The evaporator fan 

circulates air through the evaporator and into the compartments. Because the evaporator absorbs 

heat, it is very cold, thereby causing any water vapor in the air to freeze on it as frost. Many

refrigeration products using this type of evaporator employ automatic defrost. 
3-48

– Roll-bond evaporators fabricated from layers of aluminum sheet primarily use natural 

convection cooling. The refrigerant passages are formed into the evaporator walls. They are 

common in cooled cabinets and are configured as a flat plate at the rear of the cabinet. While 

these evaporators generally use natural convection and do not use an evaporator fan, some 

products with rear-mounted flat roll-bond evaporators use fans for performance enhancement. 

– Coldwall evaporators are integrated within the walls of the cabinet. This configuration 

is used in very compact cooled cabinets. The evaporator consists of tube serpentines attached to 

the insulation side of the cabinet interior liner. These evaporators use natural convection heat 

transfer. 

3.3.2.6 Thermoelectric Cooling

Besides the thermoelectric modules themselves, which can be connected in series to 

increase cooling capacity, thermoelectric refrigeration products typically employ aluminum heat 

sinks on one or both sides of the module in order to maximize heat transfer. Most thermoelectric 

refrigeration products also employ small, DC-powered fans, similar to the fans used to cool 

computers, to improve heat transfer across the heat sinks.

Some thermoelectric units employ a “condensing” heat pipe on the rear of the unit. Such 

heat pipes are filled with refrigerant that carries the heat away from the hot side of the module, 

reducing the need for fans or heat sinks to improve heat transfer.

3.3.2.7 Absorption Cooling

Absorption refrigeration products utilize the Platen-Munters three-fluid absorption 

process first commercialized in 1923 by AB Arctic. The process uses ammonia refrigerant, water 

sorbent, and hydrogen or helium gas, which is used on the “low-pressure” side of the system to 

allow a low refrigerant partial pressure while maintaining total pressure equal to that of the 

generator and condenser. This allows the system to operate without a pump, instead causing 

circulation of the sorbent through thermal siphon action, similar to the process used to transfer 

heated water in a coffee maker. The generator and absorber of an absorption system act as a 

“thermal compressor” that raises the partial pressure of the ammonia refrigerant drawn from the 

evaporator to a high level corresponding to a saturation temperature sufficiently high to recondense the ammonia using ambient air in the condenser. The condenser and evaporator of an 

absorption refrigerator operate similarly to those found in vapor-compression refrigeration 

products, although, as mentioned above, a low-density third fluid is used to maintain high total 

pressure while the refrigerant has a low partial pressure in the evaporator. The systems’ key 

components include the following.

• Evaporator: The evaporator is a heat exchanger located inside the product’s cabinet 

storage volume. The heat transferred from the cabinet interior evaporates the ammonia supplied 

from the condenser. Hydrogen or helium mixes with the ammonia between the condenser and 
3-49

evaporator and makes up the balance of the pressure. The gas mixture passes to the absorber 

after exiting the evaporator.

• Absorber: In the absorber, the vapor-phase ammonia is absorbed in the water sorbent, 

giving off its heat of absorption. The liquid ammonia-water solution passes to the bottom of the 

absorber, while the gaseous hydrogen or helium collects at the top and is returned to the 

condenser exit to recirculate through the evaporator.

• Generator: In the generator, heat is applied (from either an electric resistance heater or 

burning fuel), which preferentially evaporates the ammonia, which has a much higher vapor 

pressure than water. The boiling action promotes circulation of the solution through the generator 

and absorber. The vapor exiting the generator is mostly ammonia but includes a small amount of 

water vapor.

• Separator: The separator provides some ambient cooling of the vapor exiting the 

generator to preferentially condense out most of the remaining water vapor. This component is 

oriented such that the liquid flows back to the generator. The operation also relies on some 

thermal and mass exchange between the generator and the ambient-cooled separator to maximize 

separation of the remaining water vapor.

• Condenser: As in vapor-compression refrigeration products, the condenser is a heat 

exchanger exposed to the ambient air. The condenser transfers heat to the ambient air thus 

allowing the ammonia to condense.

3.3.2.8 Icemaking

A typical ice maker consists of a vapor-compression refrigeration system, a water supply 

system, and an integrated storage bin contained within an insulated case. The components of the 

vapor-compression refrigeration system (e.g., the compressor or condenser) are similar to the 

components found in hybrid refrigeration products and vapor-compression cooled cabinets, 

although the evaporator of uncooled storage ice makers and most portable ice makers are 

designed to freezer water directly, rather than to cool air. The evaporator and ice mold 

configurations can differ depending on the product class and ice type, as described in section 

3.3.1. The components of the water supply system depend on the configuration of the ice maker. 

Non-portable units contain solenoid valves, which are connected to external water supplies and 

allow fresh water to be admitted to the ice maker, while portable units contain a reservoir that is 

typically manually filled by the consumer. Uncooled-storage units use a pump to circulate water 

from the sump or reservoir to the distribution system that spreads the water over the evaporator 

surface, and non-portable uncooled-storage units contain a drain for removal of melt and waste 

water. The typical components of an ice maker’s water supply system are summarized in Table 

3.3.1.
3-50

Table 3.3.1 Primary Water System Components

Component Description of Typical Unit

Potable Water Supply Connection 

and Water Supply Control Valve

(Non-portable ice makers only)

Solenoid valve with connection for external hose or tubing

Water Sump Plastic basin

Water Circulation Pump Centrifugal sump pump powered by shaded pole motor 

(SPM)

Water Circuit Plastic tubing and evaporator water distributor

Drain (Uncooled-storage ice makers only)

3.3.3 Technology Options

Table 3.3.2 lists the technology options for improving the efficiency of miscellaneous 

refrigeration products. The technology options are categorized by their associated component or 

system. Each technology option category and the options available for improving the component 

or system category are discussed below.
3-51

Table 3.3.2 Technology Options 

Technology Options

Compressor

Improved compressor efficiency

Variable-speed compressor

Linear compressor

Evaporator

Increased surface area

Enhanced heat exchanger

Forced-convection evaporator

Condenser

Increased surface area 

Enhanced heat exchanger

Forced-convection condenser

Fan and Fan Motor Higher-efficiency fan motors

Higher-efficiency fan blades

Insulation

Improved resistivity of insulation

Increased insulation thickness

Vacuum-insulated panels

Gas-filled panels

Gasket

Improved gaskets

Double-door gaskets

Improved door face frame

Doors Improved resistivity of glass door

Solid door

Expansion Valve Improved: thermostatic expansion valves (TXV) or electronic 

expansion valves (EEV)

Cycling Losses Fluid control or solenoid valve

Defrost

Off-cycle defrost

Reduced energy

Adaptive defrost

Hot-gas bypass

Controls Electronic temperature control

Alternative 

Refrigeration System Conversion to alternative refrigeration system

Alternative Heat 

Transfer Heat pipe

Other Component location

3.3.3.1 Compressor

The compressor is the primary energy-consuming component in a vapor-compression 

product. Consumer refrigeration products use hermetic reciprocating compressors, in which the 

entire motor-compressor assembly is hermetically sealed in the welded steel shell.
3-52

Almost all compressors are directly driven by two-pole squirrel-cage induction motors 

running at approximately 3,000 rpm on 60 Hz power. Three types of induction motors have been 

used in cooled cabinet compressors: resistance start/induction run (RSIR), capacitor 

start/induction run (CSIR), and resistance start/capacitor run (RSCR). Of the three motor types, 

the RSIR motor is the least efficient. As a result of the U.S. energy efficiency standards that took 

effect in 1993 and 2001, the vast majority of compressor motors now use the RSCR type.

Cooled cabinet and ice maker compressor capacities typically range from approximately 

200 to 600 Btu/hr, although most cooled cabinet compressor capacities fall between 300 and 400 

Btu/hr. Two organizations have established conditions for rating the performance of refrigerator 

compressors: ASHRAE and Comité Européen des Constructeurs de Matériel Frigorifique 

(CECOMAF).q Table 3.3.3 below shows the rating conditions of these two organizations. The 

rating conditions are almost identical, except for the liquid temperature—this is the temperature 

leaving the condenser. Because the CECOMAF liquid temperature is higher, compressor 

capacities and efficiencies under ASHRAE rating conditions are approximately 30 percent 

higher than for CECOMAF conditions. The actual operating conditions for compressors in 

cooled cabinets under proposed DOE energy test conditions can be significantly different than 

these rating conditions. Most notably, the evaporating temperatures are generally significantly 

higher than -10  ̊F. However, hybrid refrigeration products and ice makers operate at lower 

evaporating temperatures than cooled cabinets do.

Table 3.3.3 Compressor Rating Conditions

Rating Condition ASHRAE CECOMAF

Evaporator -10 oF (-23.3 oC) -10 oF (-23.3 oC)

Condenser 130 oF (54.4 oC) 131 oF (55 oC)

Ambient 90 oF (32.2oC) 89.6 oF (32 oC)

Suction Gas 90 oF (32.2oC) 89.6 oF (32 oC)

Liquid 90 oF (32.2 oC) 131 oF (55 oC)

Compressor efficiency is also a function of refrigeration capacity. As part of the 

engineering analysis, DOE collected performance data on the low-back-pressure R-134a 

compressors typically used in miscellaneous refrigeration products. As evidenced by Figure 

3.3.4, which presents these data, efficiency drops off with decreasing cooling capacity. The 

reduced efficiency for lower-capacity compressors has been attributed to optimization of 

performance for higher-capacity compressors14 and to the higher importance of mechanical 

losses and losses associated with re-expansion of gases left in the clearance volume as the swept 

volume of the reciprocating piston decreases. 

 

q CECOMAF is a European appliance manufacturer trade association formed in 1958. It merged with EUROVENT 

in 1996 to become EUROVENT/CECOMAF. This organization is now called EUROVENT.
3-53

Figure 3.3.4 All Low-Back-Pressure R-134a Compressors <700 Btu/hr, Excluding 

Variable-Speed

The highest-efficiency single-speed compressors identified during this analysis are 

presented in Table 3.3.4.
3-54

Table 3.3.4 Maximum Available Compressor Efficiencies for Miscellaneous Refrigeration 

Products

Capacity Range (Btu/h) * Highest EER (Btu/hr-W) *

201-250 4.1

251-300 4.4

301-350 4.9

351-400 4.5

401-450 4.9

451-500 5.2

501-550 5.6

551-600 5.6

* Performance based on ASHRAE rating conditions and the 

use of R-134a refrigerant.

Improved Compressor Efficiency

Conversion to high-efficiency compressors is fairly straightforward for manufacturers to 

implement as long as the appropriate compressors are available. As indicated above, most cooled 

cabinet compressor capacities fall between 300 and 400 Btu/hour. Table 3.3.4 indicates that the 

maximum efficiency in this capacity range is 4.9 Btu/hr-W, while Figure 3.3.4 illustrates that 

many compressors in this capacity range have EERs between 3.0 and 4.0. This indicates 

significant potential for efficiency improvement in many cooled cabinets. 

Variable-Speed Compressors

Variable-speed compressors allow efficiency improvement as compared to single-speed 

compressors because they can provide a better match of thermal loads during the vast majority of 

hours when the loads are low. Most of the time, the compressor would operate at low speed with 

a high percentage of on-time. This would lower energy consumption by reducing off-cycle losses

and by allowing the heat exchangers to operate with lower mass flow, thus boosting their 

effectiveness. However, careful consideration must be given to how variable-speed compressors 

are implemented, because increased fan run times could negate compressor energy savings.

Variable-speed compressors use electronics to vary their speed. They use either inverterdriven induction motors or permanent magnet motors. Most U.S. consumer refrigeration 

products do not currently use variable-speed compressors, but the use of these compressors is 

becoming more common. 

Various past studies have illustrated a range of energy savings achievable through use of 

variable-speed compressors. Arthur D. Little reported savings of approximately 25 percent 

compared to single-speed motor systems in 1999.15 Research conducted by Tecumseh Products 

Company demonstrated that energy savings of 15 percent as well as reduction of sound and 

vibration levels.16 Simulation analyses conducted at the University of Illinois demonstrated that 

steady-energy savings ranging from 4 to 14 percent could be realized through the use of a twospeed compressor in concert with multiple-speed evaporator and condenser fans. The research 
3-55

also demonstrated that an additional 0.5 to 4 percent in energy consumption could be saved 

through the reduction of cycling frequency, i.e., the number of starts.17

Embraco has developed its third generation variable-speed compressor that utilizes a

permanent magnet motor controlled by a programmable electronic unit.18 Table 3.3.5 presents 

the rated performance of some of Embraco’s variable-speed compressors. The rated efficiencies 

of these variable-speed compressors are not necessarily higher than the best efficiencies of 

single-speed compressors — evaluation of the benefits of variable-speed compressors requires 

consideration of the system performance rather than just rated performance.

Table 3.3.5 Efficiencies of Some of Embraco’s Variable-Speed Compressor Models

Model Capacity Range (Btu/hr) * EER (Btu/hr-W) *

VEGY6H 330-510 5.9-6.1

VEGY7H 380-595 6.0-6.2

VEGY8H 450-555 5.9-6.0

* Based on ASHRAE rating conditions. Models use R-134a refrigerant. Minimum and maximum 

EERs represent the efficiencies at the minimum and maximum capacities, respectively.

Linear Compressors

Linear compressors employ a different design than either reciprocating or rotary 

compressors and are reportedly more efficient than either. These compressors use a linear rather 

than rotary motor, thus eliminating the crankshaft and linkage which converts the rotary motion 

to the linear motion of the piston of a reciprocating compressor. Elimination of the mechanical 

linkage reduces friction and side-forces. The linear motor requires power electronics and a 

controller to assure proper piston throw. Most linear compressor designs use a free piston 

arrangement and can be controlled for a range of capacities through adjustment of piston 

displacement. Early work on the concept suggested that the compressors can operate without 

requiring oil, which could provide additional energy benefit by improving heat transfer in the 

evaporator. Noise levels can also be reduced by utilizing linear compressors in the same way that 

can be done with variable-speed compressors, by operating most of the time at low capacity.19

An early version of the linear compressor design was developed by Sunpower for 

integration into refrigerators for the European market using isobutane (R-600a) as a refrigerant.20

LG has developed a linear compressor for household refrigerators which does require use of oil. 

LG claims that its line of linear compressors is up to 20 percent more efficient than reciprocating 

designs.21 Table 3.3.6 presents the rated efficiencies of LG’s linear compressors that would be 

appropriate for miscellaneous refrigeration applications (i.e., voltage of 115 V, R-134a 

refrigerant, and capacities within the range described above).

22 LG reports the efficiency of its 

linear compressors only at “LG Reference Conditions,” which are significantly different than the 

ASHRAE rating conditions. Under ASHRAE conditions, compressors are rated with evaporating 

and condensing temperatures of -10oF (-23.3oC) and 130oF (54.4oC), respectively, while the “LG 

Reference Conditions” are based on evaporating and condensing temperatures of-14.8oF (-26oC) 

and 100.4oF (38oC), respectively. It is not clear what the liquid and suction vapor temperatures 

for the LG conditions are—these temperatures also impact capacity and power input. At the 
3-56

same evaporating and condensing temperatures and with liquid and suction vapor conditions 

consistent with the ASHRAE test conditions, a high efficiency rotating-shaft reciprocating 

compressor such as the Embraco EGX70HLC would have an operating EER of about 6.9 Btu/hrW. Hence, the LG linear compressor may be about 9 percent more efficient than the best currenttechnology rotating-shaft reciprocating compressors.

Table 3.3.6 Efficiencies of LG’s Current Linear Compressor Models

Model Capacity (Btu/hr) * Efficiency (Btu/hr-W) *

DLF81LACT 267 7.2

FB72LACT 237 7.4

* Performance based on LG reference conditions. Models use R-134a refrigerant.

In the trade press, LG has expressed willingness to license the linear compressor 

technology to competitors. Additionally, in 2010, Embraco announced that it had developed a 

new oil-less linear compressor design.23 However, because the LG and Embraco designs are

proprietary, the widespread use of linear compressors is uncertain.

3.3.3.2 Evaporator

The evaporator is a key component of the refrigeration system and is located within the 

cabinet or just on the other side of the cabinet’s inner lining. There are three basic evaporator 

designs in cooled cabinets: a forced-convection finned-tube design; a roll-bond design; and a 

“coldwall” evaporator that is integrated within the shell of the unit. In the case of the finned-tube 

designs used in larger cooled cabinets, design, modeling, and experimental studies have been 

conducted to evaluate their heat transfer performance.24,25 Evaporator performance can be 

enhanced by increasing the heat exchanger surface area or improving the heat exchange 

performance.

As explained further in chapter 5, DOE did not conduct a design option analysis for ice

makers; instead, it took an efficiency-level approach, which calculates the relative costs of 

achieving increases in efficiency levels without regard to the particular design options used to 

achieve such increases. However, in order to calculate the costs associated with these efficiency 

increases, DOE did have to consider whether the ice makers that it directly analyzed and reverseengineered utilized different evaporator technologies and whether those technologies would be 

associated with evaporator efficiency.

In portable ice makers, the evaporator consists of downward-facing prongs around which 

ice forms. DOE did not observe any design differences between the two portable units that it 

reverse-engineered and is unaware of any design options that would improve the efficiency of 

such an evaporator.

In cooled-storage ice makers, the evaporator consists of a roll-bond design that is directly 

exposed to the cabinet air on four of the inner surfaces of the cabinet. The efficiency of such an 

evaporator could be improved by increasing its surface area.
3-57

In uncooled-storage, non-portable ice makers, DOE observed two different evaporator 

designs in the two units that it reverse-engineered. The less-efficient unit featured an evaporator 

similar to those found in automatic commercial ice makers. Such an evaporator consists of a 

vertically-mounted ice cube mold with stainless steel surfaces and harvests ice using hot-gas 

bypass, which causes the ice to melt out of the mold and fall to the bin below. The more-efficient 

unit featured a horizontal evaporator onto which ice was frozen in a single large slab. Such an 

evaporator harvests ice using hot-gas bypass to cause the ice slab to slide off the icemaking 

surface onto electric heater wires arranged in a grid pattern that separates the slab into cubes.

Increased Surface Area

Increasing the heat exchanger surface area can be achieved by increasing the face area of 

the evaporator or adding more tube rows. These measures are limited by the geometry of the 

cooled cabinet. There is a tradeoff between increasing the volume occupied by the heat 

exchanger and reducing the interior volume of the cooled cabinet.

As discussed in the 2011 residential refrigeration products TSD (hereafter referred to as 

the 2011 TSD),26 in its 1995 Residential Refrigerator TSD, DOE considered increasing the 

evaporator surface area for most of the product classes analyzed; this resulted in an estimated 1

to 2-percent reduction in annual energy consumption. In the 1995 TSD, DOE based cost and 

efficiency improvements for this technology on estimates by manufacturers. No details were 

provided on how exactly the evaporator surface area was increased, and no additional 

investigation was conducted during the 2011 rulemaking. Therefore, it is uncertain to what 

extent design efforts to increase the evaporator surface area have been employed in current U.S. 

refrigerator-freezer, or cooled cabinet, designs.

Improved Heat Exchange

Improving heat exchanger performance can be achieved through the use of enhanced fins 

and/or tubes. These types of fin and tube enhancements are common in air-conditioning 

applications where slit and louvered designs are used to enhance the fin surface and different 

types of internally-grooved surfaces are used to enhance the tubing. As described in the 2011 

TSD, in its 1995 Residential Refrigeration TSD, DOE considered enhancing the evaporator’s 

heat exchange performance for many of the product classes analyzed; this resulted in an 

estimated one to two percent reduction in annual energy consumption.26 In the 1995 TSD, DOE 

based cost and efficiency improvements for this technology on estimates by manufacturers. No 

details were provided on how exactly the evaporator heat exchange performance was enhanced. 

Therefore, it is uncertain to what extent design efforts to enhance the evaporator heat exchange 

performance have been employed in current U.S. cooled cabinet designs.

Another heat exchanger technology that could potentially improve evaporator 

performance is microchannel heat exchangers. Past research has demonstrated that the use of 

such heat exchangers in domestic refrigerators can provide system efficiencies comparable to 

current technologies while reducing refrigerant charge.27

Forced-Convection Evaporator
3-58

Most compact-size cooled cabinets use coldwall or roll-bond evaporators, whereas most 

standard-size cooled cabinets use forced-convection evaporators. The forced convection 

evaporator configuration can provide higher heat transfer effectiveness. However, space for 

housing a forced convection evaporator and its associated fan is not always available. The 

consideration of conversion to forced-convection evaporators will depend on whether a 

particular product is designed in a way that allows housing of the evaporator and fan in a suitable 

location.

3.3.3.3 Condenser

The condenser is another key component of the refrigeration system and is located on the 

outside of the cabinet. As discussed in section 3.3.2.5, there are three basic condenser designs: a 

forced-convection finned-tube or wire-and-tube design; a wire-and-tube “static” design which 

uses natural convection cooling; and a hot wall condenser that is integrated within the shell of the 

unit. In the case of the static condensers used in compact units, modeling studies have been 

conducted to evaluate their heat transfer performance.28 Modeling studies have also been 

performed on hot-wall condensers.29,30 Condenser performance can be enhanced by increasing 

the heat exchanger surface area or improving the heat exchange performance.

Increased Surface Area

Increasing the heat transfer surface area of condensers can be achieved by (a) increasing 

the width of the rows of tubes, (b) adding more tube rows along the direction of air flow, or (c) 

adding more tube rows across the direction of air flow. These measures can be limited by the 

geometry of the cooled cabinet. Increasing tube width can also result in an increased refrigerant 

pressure drop across the condenser, so there is a tradeoff between improving heat transfer and 

increasing compressor work. Similarly, adding tube rows can increase the air pressure drop 

through the condenser, so there is a tradeoff between improving heat transfer and increasing fan 

work.

As described in the 2011 TSD, DOE previously evaluated this subject in its 1995 

Residential Refrigerator TSD in which it considered increasing the condenser surface area for 

many of the product classes analyzed; this resulted in an estimated 1 to 2-percent reduction in 

annual energy consumption.26 In the 1995 TSD, DOE based cost and efficiency improvements 

for this technology on estimates by manufacturers. No details were provided on how exactly the 

condenser surface area was increased. Therefore, it is uncertain to what extent design efforts to 

increase the condenser surface area have been employed in current U.S. refrigerator-freezer, or 

cooled cabinet, designs.

Improved Heat Exchange

As for evaporators, improving heat exchanger performance can be achieved through the 

use of enhanced fins and/or tubes. As described in the 2011 TSD, in its 1995 Residential 

Refrigerator TSD, DOE considered enhancing the condenser’s heat exchange performance for 

some freezer and compact refrigerator product classes; this resulted in approximately a two 
3-59

percent estimated reduction in annual energy consumption.26 In the 1995 TSD, DOE based cost 

and efficiency improvements for this technology on estimates by manufacturers. No details were 

provided on how exactly the condenser heat exchange performance was enhanced. Therefore, it 

is uncertain to what extent design efforts to enhance the condenser heat exchange performance 

have been employed in current U.S. cooled cabinet designs.

Other heat exchanger technologies could also be employed to improve condenser 

performance. As with evaporators, microchannel heat exchangers are also applicable to 

condensers.

Forced-Convection Condenser

Most standard-size cooled cabinets and all ice makers use forced-convection condensers. 

However, some smaller, “countertop” cooled cabinets use hotwall condensers. The forced 

convection condenser configuration can provide higher heat transfer effectiveness. However, 

space for housing a forced convection condenser and its associated fan is not always available. 

The consideration of conversion to forced-convection condensers will depend on whether a 

particular product is designed in a way that allows housing of the condenser and fan in a suitable 

location.

3.3.3.4 Fan and Fan Motor (Forced-convection units only)

Fans are used to increase condenser and evaporator heat transfer. Because most 

miscellaneous refrigeration products use forced-convection condensers which rely on fans for air 

movement, fan and fan-motor technology options for the condenser are applicable. However, 

many cooled cabinets use static and/or natural convection evaporators and, as a result, do not use 

fans and fan motors for their evaporators. 

For those miscellaneous refrigeration products that do utilize fans, refrigerator 

manufacturers often purchase fan blades and fan motors from outside vendors. Therefore, 

conversion to more-efficient fan motors and blades can be accomplished relatively easily when 

more-efficient fans and fan motors are available.

Higher-Efficiency Fan Motors

Fans used in miscellaneous refrigeration products typically have an axial design. Because 

the evaporator fan and fan motor are located within the refrigerated cabinet and the electric 

energy input adds to the refrigeration load, more-efficient evaporator fan or evaporator fan motor 

designs contribute to efficiency improvements in two ways: (1) reducing the power consumption 

of the fan motor and (2) reducing the power consumption of the compressor due to decreased 

heat losses into the cabinet from the fan motor.

Most evaporator and condenser fan motors used in miscellaneous refrigeration products

today have shaded pole induction designs with efficiencies between 10 and 15 percent and power 

input ranging from 5 to 25 Watts (W). Higher-efficiency motor designs include permanent split 
3-60

capacitor (PSC) induction motors, which reach efficiencies of 20 to 30 percent, and brushless DC 

motors, which reach nearly 65-percent efficiency.

Higher-Efficiency Fan Blades

One source of inefficiency for axial fans lies in their tendency to throw air outward. The 

Pax GroupTM has developed a fan (PAX fan) that employs streamlined blades with patented 

geometrical shapes which reportedly provide better airflow direction and improved efficiency. 

Tests performed with the PAX fan have demonstrated a reduction in fan-motor power of 23 

percent and an overall reduction in refrigerator energy consumption of 3.9 percent relative to a 

refrigerator with a typical axial fan blade design.31 However, because the PAX fan is proprietary, 

the widespread use of the design is highly uncertain.

3.3.3.5 Insulation

Insulation is used around the evaporator compartment to minimize the thermal load 

through the walls of the cabinet. Increased thickness and improved resistivity are both options to 

reduce the thermal load on the refrigeration system, resulting in less energy consumed. 

Miscellaneous refrigeration product manufacturers typically use polyurethane (PU) foam as 

insulation.

Improved Resistivity of Insulation

Past research has investigated improving the resistivity of PU foam insulation through the 

use of additives in the foam. 

Research conducted in 1996 demonstrated that adding carbon black provides a means of 

improving the thermal insulation properties of PU foam. The research showed that PU foam 

systems using carbon black in conjunction with either HCFC-141b or cyclopentane was able to 

lower k-factors by six to nine percent in panels and in cabinets.32

Increased Insulation Thickness

Current miscellaneous refrigeration product designs include 1 to 2 inches of insulation in 

their walls, although some portable ice makers contain no insulation. It is possible to increase the 

insulation thickness to improve the overall energy efficiency of the product.

Although the technology to implement increased insulation thickness is readily available, 

manufacturers have indicated that significant investments would be required in foaming systems, 

tooling, and molding to accommodate thicker insulation. Increased packaging and shipping costs 

must also be considered. Greater insulation thickness results in either decreased interior volumes, 

increased exterior dimensions, or some combination of both. Because kitchen dimensions and 

designed spaces for cooled cabinets are limited, there are restrictions on increasing the exterior 

size of the product. Reduced interior volume is considered undesirable because it impacts 

consumer utility.
3-61

Vacuum-Insulated Panels

Vacuum-insulated panel (VIP) technology is based on the reduction in thermal 

conductivity which occurs in a low vacuum, the same concept which is used to reduce heat 

leakage in thermos bottles. VIPs used in refrigeration products consist of a sealed package with a 

fill material which provides support to prevent the panel from collapsing and interferes with 

molecular mean free path as the intermolecular spacing increases at lower vacuum levels. VIPs 

can be incorporated into the cabinet walls to decrease the heat leakage and energy required to 

maintain the cabinet at low temperature, typically by foaming them in place between the cabinet 

liner and wrapper. Different configurations are commercially available through advances in 

manufacturing technologies. As a result, VIPs are available in a variety of geometries (e.g., flat, 

curved, cylindrical) with added features (e.g., holes, cut-outs).33 Typical VIPs generally consist 

of a core material and an airtight envelope. Some VIPs also include absorber to absorb gas which 

leaks through the envelope. 

Several core materials have been used in the manufacture of VIPs including polystyrene, 

open-cell PU, silica powder, and glass fiber. Research sponsored by the European Commission 

has evaluated these core materials based on their cost and characteristics, including density and 

manufacturing time. Table 3.3.7 below summarizes the VIP characteristics manufactured with 

the above core materials.34 Each of the core materials has associated advantages and 

disadvantages that dictate their acceptability for an appliance application.

Table 3.3.7 Comparison of Various VIP Core Materials

Property Polystyrene Open-cell PU Silica Powder Glass Fiber

Thermal 

Conductivity 

at 10 Pascals 

(Pa) abs. (0.1 

millibar

(mbar))

(mW/mK) 4.8 – 5.8 9.7 5.8 2.4

(Btuin/hrft2-oF)

0.033 – 0.040 0.067 0.040 0.017

Manufacturing Time Fast Medium Medium Long

Density (kg/m3) 80 – 144 64 192 128

Drying Need No Yes Yes No

Thermal Stability Low Medium Good Very Good

Recyclability Yes Difficult Yes NA

Cost Low Medium High Very High

Source: European Commission, 2000.34

ORNL also has evaluated the performance of three types of VIPs: a silica powder filler 

encapsulated in a polymer barrier film; a fibrous glass insulation filler encapsulated in a stainless 

steel barrier; and an undisclosed insulation filler encapsulated in a stainless steel barrier. Table 

3.3.8 summarizes the center-of-panel thermal conductivities of the panels. For the silica powder 

and glass fiber filled VIPs, the thermal conductivities in Table 3.3.8 are comparable to those in 

Table 3.3.7.

35
3-62

Table 3.3.8 Center-of-Panel Thermal Conductivity of VIPs

Property Silica Powder Glass Fiber Unknown

Thermal 

Conductivity *

(mW/m-K) 5.2 – 5.4 2.0 – 2.6 2.7 – 3.1

(Btu-in/hr-ft2-°F) 0.034 – 0.038 0.014 – 0.018 0.019 – 0.022

* For each filler, the reported thermal conductivities are a range of values from nine separate 

VIPs.

Source: Vineyard et al., 1998.35

ORNL also determined the thermal performance of the VIPs it studied as part of a 

composite panel. The composite panel consisted of a one-inch VIP surrounded by PU foam 

insulation to form a two-inch-thick panel. The PU foam insulation was blown with a variety of 

bowing agents, but, due to the age of the study (from the mid-1990s), ORNL considered neither 

HFC- nor HC-based blowing agents. For the three VIPs presented in Table 3.3.8, silica power, 

glass fiber, and unknown, the average composite panel thermal resistances were 21.5, 20.7, and 

20.9 hr-ft2-oF/Btu, respectively.35 The lower thermal conductivities reported in Table 3.3.8 for 

the glass fiber and unknown filled VIPs relative to the silica powder VIP were offset by the heat 

conduction through their stainless steel encapsulation material. 

Of significant concern in the use of VIPs is their long-term thermal conductivity integrity. 

VIP thermal conductivity increases dramatically as the pressure within the VIP exceeds 100 Pa 

abs. (1 mbar). The pressure increase in the VIP over time is related to several factors, including: 

residual gases in the VIP after vacuum, degassing from the VIP core material, and gas diffusion 

through the envelope pores. Improved envelopes and absorbers have been developed to prevent 

pressure increases from occurring in VIPs. For example, for the three composite VIPs that it 

analyzed, ORNL measured only a five-percent reduction in overall thermal resistance over a 

three-year period. ORNL demonstrated that this reduction in thermal resistance was less than the 

corresponding reduction for a panel without any VIPs, i.e., panels consisting only of PU foam 

insulation.35

Recent announcements regarding VIPs include the following:

• Matsushita’s VIP technology (trade name of “U-Vacua”) was awarded the Minister of 

Economy, Trade and Industry Prize at the 17th Energy Conservation Awards sponsored by the 

Energy Conservation Center of Japan in January, 2007.36 Matsushita claims that its VIP

technology has achieved the world’s highest level of insulation efficiency with a thermal 

conductivity of 1.2 mW/m-K (0.008 Btu-in/hr-ft2-oF) at 24 oC (75.2 oF).37

• Electrolux announced in 2003 the use of VIP technology in a freezer that they claimed 

reduced energy use by 35 percent relative to PU foam insulation.38 Va-Q-tek has recently 

introduced its Va-Q-plus VIP technology.39

Gas-Filled Panels

Gas-filled panels (GFPs) use thin polymer films and low-conductivity gas to create a 

device with excellent thermal insulation properties. GFPs are essentially hermetic plastic bags 
3-63

that can take on a variety of shapes and sizes. Inside the outer barrier is a cellular structure called 

a baffle which is filled with the low-conductivity gas. 

Research conducted at LBNL in the mid-1990s demonstrated the effectiveness of GFPs 

based on the use of different gases, including xenon and krypton. Table 3.3.9 below summarizes 

the thermal performance characteristics of different GFPs, based on their center-of-panel and 

whole-panel performance.40 LBNL has also conducted research to demonstrate that GFPs, when 

used in refrigerator-freezers, can reduce energy consumption by approximately eight percent 

relative to PU foam insulation.41

Table 3.3.9 Comparison of Various Gas-Filled Panel Core Materials

Gas 

Fill

Center of Panel 

Performance Whole Panel Performance

Thermal 

Conductivity

Panel 

Thickness Mean Temp. Thermal Conductivity

mW/m-K Btu-in/hrft2-oFmm inches oC oF mW/m-K Btu-in/hrft2-oF

Xenon 7.4 0.051 24.1 0.95 6.8 44.2 7.4 0.051

Krypton 11.6 0.080 25.2 0.99 11.9 53.4 10.77 0.074

49.8 1.96 12.3 54.1 1.17 0.008

Argon 19.9 0.138 N/A N/A N/A N/A N/A N/A

Air 28.1 0.195 N/A N/A N/A N/A N/A N/A

Source: LBNL40

In addition, ORNL determined the thermal conductivity of an insulation panel containing 

radiation baffles within a polymer barrier film and filled with krypton gas at atmospheric 

pressure. The range of thermal conductivities of nine of these GFPs ranged from 0.088 to 0.092 

Btu-in/hr-ft2-oF (12.6 to 13.2 mW/m-K). ORNL also analyzed the GFPs as part of a composite 

assembly consisting of a one-inch panel surrounded by PU foam insulation to form a two-inchthick panel. The average composite panel thermal resistance was determined to be 18.2 hr-ft2-

oF/Btu. Finally, ORNL measured only a five-percent reduction in overall thermal resistance over 

a three-year period, which was less than the reduction observed in a panel consisting only of PU 

foam insulation.35

Although research has demonstrated that GFPs have better thermal performance than PU 

foam insulation, no known refrigeration products are using the technology. A significant problem 

in using GFPs is their lack of structural integrity in the resulting product.

3.3.3.6 Gasket

A significant portion of the heat gain to miscellaneous refrigeration products occurs 

around the edges of the doors and through the gaskets on the door edges. An analysis of thermal 

loads on an 18.6 ft3 top-mount refrigerator-freezer revealed that over 28 percent of the total heat 

load into the cabinet came from ‘edge’ loads, i.e., loads due to heat transfer into the food 
3-64

compartments via paths around the perimeter of the cabinet aperture.42 If the ‘edge’ effect losses 

can be reduced, the efficiency of the refrigerator can be increased. 

Improved Gaskets

Design of door gaskets is a balance between improving the thermal-efficiency 

performance of the gasket and ensuring that the door is not difficult to open. If the gasket magnet 

force is too strong, it becomes difficult to open the door. Based on a European Commission 

study, door handles have been designed specifically to facilitate door openings by providing 

leverage and by freeing a small section of the gasket before the door is opened to relieve the 

pressure differential that can build up when the door is closed. Although materials and designs 

for improving the air tightness of door gaskets exist, apparently no general criteria have been 

established to enable different designs to be classified. 

An EPA report from 1992 describes theoretical modeling and experimental research on 

gasket heat loads and concludes that replacing about half of either the metal door flange or 

cabinet flange with plastic can reduce the heat flow through the gasket region by 25 percent.43

However, this study did not address the impacts on the convection on the cabinet side of the 

gasket associated with different geometries of the “throat” region between the door dikes and the 

cabinet wedge or with different evaporator air flow rates. As described in the 2011 TSD, based 

on DOE’s 1995 TSD, improvements in gasket design can reduce refrigerator-freezer annual 

energy consumption by one to three percent.26 Due to the age of both the EPA and DOE 

research, the extent to which gaskets can be further improved is uncertain.

Double Door Gaskets

A double door gasket is an additional inner door seal gasket that is added to the gasket 

design. This further reduces heat leakage and infiltration into the refrigerator and freezer. 

Based on information drawn from DOE’s 1995 TSD, residential refrigeration 

manufacturers did not introduce double door gaskets in the mid-1990s because of performance 

problems and cost. Ice can form between the gaskets, greatly reducing their effectiveness. In 

addition, the gaskets are visually unattractive and they increase the difficulty of meeting safety 

regulations for minimum door-opening force.

Improved Door Face Frame

As discussed above, cabinet heat loads stem not only from conduction though the cooled 

cabinet walls but also from conduction along the external metal casing. The metal shell provides 

the structural integrity; however, its presence means that heat loads are transferred along the 

metal shell into the cabinet. This heat transfer into the cabinet is also referred to as the ‘edge 

effect.’

Using a plastic cover on the internal flange can reduce the ‘edge effect’ heat losses by 

approximately 50 percent.42 The use of low-conductivity plastics to reduce conduction losses in 

this area are already being employed in some current U.S. cooled cabinet designs.
3-65

3.3.3.7 Doors

Unlike refrigerators, refrigerator-freezers, freezers, and ice makers, which enclose their 

refrigerated compartments with solid insulated doors, cooled cabinets typically utilize doublepaned glass doors, which enable the cooled cabinet to act as both a refrigerated compartment and 

a display case. However, the thermal resistance of glass doors can be up to three times lower 

than the thermal resistance of traditional solid, insulated refrigerator doors; therefore, door losses 

can account for a substantial portion of the thermal load in a cooled cabinet. 

Improved Resistivity of Glass Door

The thermal resistance of glass doors can be improved by making improvements to the 

glass pack such as adding a low-emissivity coating, an inert gas (e.g., argon, krypton, or xenon) 

filling, or a third pane of glass. Such design changes could significantly increase the door’s Uvalue, thus reducing conductive and radiative heat transfer through the door. Table 3.3.10

presents the U-values and thermal resistivities of the three glass door designs that DOE 

considered in its engineering analysis, as described further in chapter 5 of this TSD. 

Table 3.3.10 Glass Door Resistivity Options

Door Design U-Value (W/m2-K)* Resistivity (m-K/W)

Baseline

(Dual-pane, no coating, air filling) 3.044 0.016

Medium-Tech

(Dual-pane, low-e coating, argon filling) 1.709 0.029

Max-Tech

(Triple-pane, low-e coating, krypton filling) 1.143 0.043

* Calculated using the WINDOW 6 software, as described further in chapter 5 of this TSD

Solid Door

Alternatively, the glass door can be replaced by a solid, insulated door, identical to the 

style of door used in refrigerators, refrigerator-freezers, and freezers. Although this would 

dramatically reduce heat loss through the door, as the resistivity of PU foam is 50 m-K/W and 

thus significantly higher than the resistivity of glass doors, it would also eliminate the cooled 

cabinet’s function as a display case.

3.3.3.8 Expansion Valve

The metering device in most miscellaneous refrigeration products is a capillary tube. As 

discussed above in section 3.3.2.5, there are two common types of capillary tubes—adiabatic and 

non-adiabatic. In the non-adiabatic configuration, the capillary tube is soldered to the suction line 

to evaporate the residual liquid in the suction line and to warm the vapor to near-ambient 

temperature. The suction line heat exchanger (or the non-adiabatic capillary) improves efficiency 

because it increases the refrigeration capacity of the system by the amount of heat being 

transferred from the capillary to the suction side. Non-adiabatic capillary tubes are the most 
3-66

common type of metering device in miscellaneous refrigeration products. The other type of 

metering device, an adiabatic capillary tube, is used in some miscellaneous refrigeration 

products. In this configuration, the capillary tube does not exchange heat with the suction line 

and the refrigerant expands from the high pressure to the low pressure adiabatically. Research 

has been conducted to develop models to study the performance of both types of capillary 

tubes.44,45

Improved Expansion Valve

Automatic, adjustable thermostatic or electronic expansion valves may provide improved 

performance. The technology for this design option is available; however, a modification in 

system design is required. In past rulemakings, DOE has not identified any data demonstrating 

that improved expansion valves will save energy in refrigeration products.

3.3.3.9 Cycling Losses

Off-cycle refrigerant migration reduces a refrigeration product’s efficiency by 

transferring heat from outside the cabinet into the evaporator. Changes in miscellaneous 

refrigeration product design that reduce this aspect of cycling losses can increase the unit’s 

efficiency.

Fluid Control or Solenoid Valve

A fluid control or solenoid valve installed after the condenser can be used to effectively 

isolate the evaporator from the condenser during the off-cycle and prevent any refrigerant 

migration. Research has demonstrated that solenoid valves can yield substantial energy 

savings.46 However, there are drawbacks to using solenoid valves. First, refrigeration migration 

allows the system pressure to equalize, reducing the required starting torque of the compressor 

motor. A solenoid valve would increase the required starting torque of the compressor motor. 

Second, adding such a valve could negatively affect system reliability.

3.3.3.10 Defrost System

Section 3.3.2.1 provides a description of typical automatic defrost systems for 

refrigeration products. Most ice makers are manually defrosted, and most cooled cabinets simply 

defrost during their off-cycles; however, there are a few cooled cabinets that use electric heaters 

to defrost the evaporator. Energy use associated with defrost includes the energy input for the 

heater and also the refrigeration system energy used to remove the defrost heat from the cabinet.

Off-Cycle Defrost

Because cooled cabinets maintain warmer storage temperatures than refrigerators and 

freezers, they have less need for active defrost, particularly when they are exposed to the warm 

90 °F ambient temperature required during an energy test. Therefore, energy savings can be 

achieved by using off-cycle (passive) defrost rather than active heater defrost when compartment 

temperatures are sufficiently warm.
3-67

Reduced Energy for Automatic Defrost

In some cases, the defrost heat supplied is more than required. Thus, energy savings can 

be achieved by reducing the defrost heat by either using a smaller heater, reducing the heater ontime, reducing the frequency of defrost, or a combination of these. 

As described in the 2011 TSD, DOE found in the 1995 TSD that most manufacturers had 

already significantly reduced the electric heat for auto defrost in order to comply with the energy 

efficiency standards that became effective in 1993.26 There may be limited additional energy 

savings possible through optimization of automatic defrost.

Adaptive Defrost

To reduce the energy used for defrost, adaptive defrost can be used. An adaptive defrost 

system can control both the defrost time and the amount of defrost heat. Adaptive defrost 

systems make use of controls to adjust the time between defrost cycles to the appropriate amount 

for the door opening frequency, ambient conditions, and other consumer usage patterns which 

affect the introduction of moisture into the cabinet. In a typical automatic defrost system, a 

mechanical timer initiates defrost after a specified time period, usually 10 to 12 hours of 

compressor on-time. By allowing adjustment of the time between defrosts, energy use can be 

reduced. The DOE energy test procedure includes modified test procedures for evaluating the 

energy use of products with adaptive defrost. As described in the 2011 TSD, in its 1995 TSD, 

DOE estimated that energy consumption can be reduced by three to four percent with adaptive 

defrost.26 It is unclear what percentage of the cooled cabinet market currently uses adaptive 

defrost.

Hot-Gas Bypass

Another method of reducing the energy required for defrost is to eliminate the need for 

electric heaters by substituting condenser hot gas in their place. In a condenser hot gas defrost 

system, the compressor continues to run and a valve opens allowing hot compressed refrigerant 

to flow to the evaporator. Many frost-free refrigerator-freezers in the 1960s and 1970s used such 

a defrost system.

3.3.3.11 Controls

The control systems discussed here pertain to those controlling the temperature and airdistribution within the miscellaneous refrigeration product.

Electronic Temperature Control

Conventional thermostats are thermomechanical devices that are not very accurate. The 

inaccuracy of these devices may produce large temperature fluctuations within the cabinet and, 

in turn, thermodynamic inefficiencies. Electronic thermostats are available that can provide more 

precise and repeatable temperature control than conventional thermostats. This can result in 

improved efficiency. Electronic thermostat systems can also account for more parameters than 
3-68

just the cabinet temperature, such as the room temperature, to better regulate product operation 

and reduce compressor run times.

3.3.3.12 Conversion to Alternative Refrigeration Systems

As discussed earlier in this chapter, three different refrigeration technologies are used in 

miscellaneous refrigeration products: vapor compression, thermoelectric, and absorption. 

Vapor compression has been the dominant refrigeration technology for more than 50 

years and is found in all standard-sized refrigeration products, all hybrid refrigeration products, 

all ice makers, many compact refrigerators, and many cooled cabinets. As discussed in section 

3.3.1, the efficiencies of compressors suitable for miscellaneous refrigeration products typically 

range from approximately 3.0 to 4.9 Btu/hr-W, corresponding to coefficients of performance 

(COPs) of 0.9 to 1.4. 

Thermoelectric cooling devices are used in many cooled cabinets and several compact 

refrigerators. However, they have comparatively low efficiency. One thermoelectric module 

manufacturer cites typical module COPs as ranging from 0.3 to 0.7.47 DOE testing suggests that 

module COPs are even lower for typical cooled cabinet operating conditions. This testing 

suggests that COPs range from 0.1 to 0.2. Like thermoelectric systems, absorption refrigeration 

systems are also and less efficient than vapor-compression systems, with typical COPs ranging 

from 0.5 to 0.8.

48 The higher efficiency levels associated with vapor compression refrigeration 

technology suggest that it can be considered as a design option for existing products that use 

thermoelectric or absorption technology.

3.3.3.13 Alternative Heat Transfer

Heat Pipes

One of the thermoelectric refrigerators tested and reverse-engineered by DOE featured a 

heat pipe in direct contact with the hot side of the unit’s thermoelectric module. A heat pipe is a 

heat transfer device containing a working fluid that evaporates at the heated end of the pipe (the 

end in contact with the thermoelectric module), travels to the top of the pipe, condenses upon 

rejecting heat to the ambient air, and trickles back down to the heated end of the pipe via gravity. 

Integrating a heat pipe with a thermoelectric module can reduce the hot-side temperature of the 

module, enabling lower cool-side temperatures and thus improving cooling performance. It may 

also reduce the fan power necessary to cool the hot side of the thermoelectric module, thus 

reducing energy consumption.

3.3.3.14 Component Location

In its 1995 TSD, DOE saw energy savings potential in more optimal placement of certain 

components. For example, if the compressor and condenser are located on the top of the cabinet, 

DOE determined that they can operate more efficiently because heat is more readily convected 
3-69

away from the system and, in addition, the condenser fan can be eliminated. As described 

previously, traditionally, the compressor and condenser are located at the bottom rather than the 

top of the cabinet so the user can have easy access to the food compartments, to key center of 

gravity low, and to provide air flow and a heat source near the tray which collects defrost water 

to assure quick re-evaporation of water. Locating the condenser and compressor at the top of the 

unit would require modification of product design that may conflict with traditional practice and 

consumer preference, and that could potentially increase manufacturing costs. 

Another option is to locate the evaporator fan motor outside the cabinet to reduce internal 

loads from the heat loss of the motor. However, it is difficult to prevent air leakage where the 

motor shaft penetrates the cabinet wall. As described in the 2011 TSD, the 1995 TSD concluded 

that the lack of experimental data prevented the evaluation of component relocation.26

3.3.4 Energy Efficiency

Of the four product types addressed in this rulemaking, only cooled cabinets have energy 

use information widely available, although at least one ice maker manufacturer reports energy 

performance based on the DOE test procedure for automatic commercial ice makers. DOE 

gathered data on the energy use of cooled cabinets currently available in the marketplace by 

surveying the CEC and NRCan databases as well as manufacturers’ websites. Figure 3.3.5 shows

energy consumption (measured using the test procedure required by the CEC) as a function of 

interior volume. As mentioned in Chapter 2 of this TSD, neither of these databases contains 

energy consumption information on non-compressor cooled cabinets; hence, Figure 3.3.5 only 

includes vapor-compression products.
3-70

Figure 3.3.5 Cooled Cabinet Energy Consumption as a Function of Interior Volume
3-71

REFERENCES

 

1 U.S. Department of Energy – Office of Energy Efficiency and Renewable Energy, Building Technologies Office. 

Rulemaking Framework Document for Wine Chillers and Miscellaneous Refrigeration Products. 

http://www1.eere.energy.gov/buildings/appliance_standards/pdfs/wc_misc_refr_framework_02_06_12.pdf

2 California Energy Commission, 2010 Appliance Efficiency Regulations, December 2010. CEC-400-2010-012. 

http://www.energy.ca.gov/2010publications/CEC-400-2010-012/CEC-400-2010-012.PDF.

3 “Fisher & Paykel in Expansion Mode,” Appliance Magazine.com, March 14, 2013.

4 “ALI Group to Acquire Scotsman Industries from Warburg Pincus,” PR Newsire, November 6, 2012.

5 Canadian Standards Association. Energy Performance and Capacity of Household Refrigerators, RefrigeratorFreezers, Freezers, and Wine Chillers. CAN/CSA-C300-08.

6 Greenblatt, J. B., S. J. Young, H.-C. Yang, T. Long, B. Beraki, S. Price, S. Pratt, H. Willem, L.-B. Desroches, and 

S. M. Donovan (2013). “U.S. Residential Miscellaneous Refrigeration Products: Results from Amazon Mechanical 

Turk Surveys,” Lawrence Berkeley National Laboratory, LBNL-6537E, November.

7 NPD (2011). The NPD Group/NPD Houseworld – POS. The NPD Group, Inc., Port Washington, NY. 

https://www.npd.com/wps/portal/npd/us/industry-expertise/home/.

8 Parekh, A., P. Wang and T. Strack (2012), “Survey Results of User-Dependent Electricity Loads in Canadian 

Homes,” ACEEE Summer Study 2012, Paper 482, August 12-17, Pacific Grove, CA. 

http://www.aceee.org/files/proceedings/2012/data/papers/0193-000283.pdf, accessed 23 August 2012; Strack and 

Associates (2012). Residential Electricity Usage: Electricity Study for the EnerGuide Rating System, Housing 

Division, Office of Energy Efficiency, Natural Resources Canada, March.

9 U.S. Department of Commerce, Bureau Economic Analysis. Gross Domestic Product Implicit Price Deflator. 

(Last accessed in 2011.) https://bea.gov/bea/dn/nipaweb/TableView.asp#Mid 

10 U.S. Census Bureau, Survey of Plant Capacity, 2004 to 2006.

11 U.S. Census Bureau, Quarterly Survey of Plant Capacity Utilization, 2007 to 2012.

12 American Society of Heating, Refrigeration, and Air-Conditioning Engineers, Inc. 2006 ASHRAE Handbook, 

Refrigeration. Atlanta, GA. Chapter 48, Household Refrigerators and Freezers.

13 U.S. Department of Energy-Energy Efficiency and Renewable Energy Building Technologies Program. Energy 

Savings Potential and R&D Opportunities for Commercial Refrigeration, Final Report, September 23, 2009. 

Prepared by Navigant Consulting, Inc. Washington, DC. 

http://apps1.eere.energy.gov/buildings/publications/pdfs/corporate/commercial_refrig_report_10-09.pdf

14 U.S. Environmental Protection Agency. State of the art survey of hermetic compressor technology applicable to 

domestic refrigerator/freezers, 1993. EPA-430-R-93-010. 
3-72

 

15 U.S. Department of Energy, Opportunities for Energy Savings in the Residential and Commercial Sectors with 

High-Efficiency Electric Motors, Final Report, December 1, 1999. Prepared by Arthur D. Little, Inc., Washington, 

DC. No. DE-AC01-90CE23821.

16 DuMoulin, T.R. and Colling, D.A. “Higher Efficiencies by Means of Variable-Speed Technology in a Domestic 

Refrigeration Application,” ASHRAE Transactions, 1998, Vol. 104, Pt. 2.

17 Woodall, R.J. and Bullard, C.W. “Simulating Effects of Multispeed Compressors on Refrigerator/Freezer 

Performance,” ASHRAE Transactions, 1997, Vol. 103, Pt. 2.

18 Embraco. Embraco VCC® 3rd Generation, The Intelligent Compressor, Version 00, September 2006. 

<http://www.embraco.com.br/portugue/produtos/03010.pdf> (Accessed September 26, 2007.) 

19 James, Stephen J. "Developments in domestic refrigeration and consumer attitudes," Food Refrigeration and 

Process Engineering Research Centre (FRPERC), 2003. University of Bristol, UK. Bulletin of the IIR - No 2003-5. 

http://www.iifiir.org/en/doc/1051.pdf

20 Unger, R. “Development and Testing of a Linear Compressor Sized for the European Market,” Proceedings of the 

International Appliance Technology Conference, May, 1999. Sunpower, Inc., Athens, OH. 

http://www.sunpower.com/lib/sitefiles/pdf/publications/Doc0074.pdf

21 LG Electronics. "Green Technology Linear DIOS," 2004. www.aceee.org_conf_mt04_wbprsnt_Lee-R3.pdf

(Accessed July 25, 2007.)

22 LG Electronics. LG Linear Compressor Models. http://www.lg.com/global/products/components/compressor/refcompressor/linear-identification.jsp (Accessed July 12, 2013.)

23 ACR News. “Embraco claims oil-less compressor breakthrough.” ACR News, September 21, 2010. 

http://www.acr-news.com/news/news.asp?id=2231.

24 Bansal, P.K., Wich, T., Browne, M.W., and Chen, J. “Design and Modeling of New Egg-Crate-Type Forced Flow 

Evaporators in Domestic Refrigerators,” ASHRAE Transactions, 2001, Vol. 107, Pt. 2.

25 Bansal, P.K. and van Neuren, O.S. “An Experimental Study on New Egg-Crate Type Evaporators in Domestic 

Refrigerators,” ASHRAE Transactions, 1998, Vol. 104, Pt. 2.

26 U.S. Department of Energy-Office of Energy Efficiency and Renewable Energy, Building Technologies Office. 

Technical Support Document: Energy Conservation Standards for Refrigerators, Refrigerator-Freezers, and 

Freezers, September 15, 2011.

27 Goslovich, K.S. and Bullard, C.W. “Potential for Using Enhanced Aluminum Extrusions for Refrigerator Heat

Exchangers,” ASHRAE Transactions, 1997, Vol. 103, Pt. 1.

28 Bansal, P.K. and Chin, T.C. “Modeling and optimisation of wire-and-tube condenser,” International Journal of 

Refrigeration, 2003, 26 (2003), 601-613.

29 Bansal, P.K. and Chin, T.C. “Design and modeling of hot-wall condensers in domestic refrigerators,” Applied 

Thermal Engineering, 2002, 22 (2002), 1601-1617.
3-73

 

30 Rebora, A. and Tagliafico, L.A. “Thermal performance analysis for hot-wall condenser and evaporator 

configurations in refrigeration appliances,” International Journal of Refrigeration, 1997, Vol. 21, No. 6, 490-502.

31 U.S. Department of Energy. Final ENERGY STAR Program Requirements and Criteria for Residential 

Refrigerators and Freezers, August 3, 2007. Washington, DC. 

http://www.energystar.gov/ia/partners/prod_development/revisions/downloads/refrig/REF_ProgramRequirements_2

008.pdf

32 Pisipati, J.S. and Godbey, J.A. “Performance of Carbon Black-Containing Polyurethane Foam in Domestic 

Refrigerators,” Journal of Cellular Plastics, 1996. Vol. 32, No. 2, 108-138. 

http://cel.sagepub.com/cgi/content/abstract/32/2/108

33 Manini, P., Rizzi, E., Pastore, G., Gregorio, P. “Advances in VIP Design for Super Insulation of Domestic 

Appliances,” Appliance Magazine, June 2003. Presented at the 54th International Appliance Technical Conference, 

March 10-12, 2003, West Lafayette, IN. 

http://www.appliancemagazine.com/latin/editorial.php?article=45&zone=32&first=1

34 European Commission. Cold II, The revision of energy labeling and minimum energy efficiency standards for 

domestic refrigeration appliances, Final Report, December 2000. Prepared by ADEME, France and PW Consulting, 

United Kingdom. http://www.ceecap.org/img_assets/File/Cold%20II.pdf 

35 Vineyard, E.A., Stovall, T.K., Wilkes, K.E., and Childs, K.W. “Superinsulation in Refrigerators and Freezers,” 

ASHRAE Transactions, 1998, Vol. 104, Pt.2.

36 Japan for Sustainability. “Matsushita’s Vacuum Insulation Wins 2006 Energy Conservation Award,” Information 

Center, July 15, 2007. http://www.japanfs.org/db/1773-e

37 Matsushita Electric Industrial Co., Ltd.. U-Vacua Technical Information, 2007. 

http://panasonic.co.jp/appliance/environment/eco_h1804.html (Accessed September 26, 2007.)

38 “Electrolux's New Vacuum Insulated Freezer Technology,” Appliance Magazine, August 2003. 

http://www.appliancemagazine.com/new_products.php?article=4971&zone=204&first=1

39 Va-Q-plus Product Data Sheet. http://www.va-q-tec.com/produkte/en/pplus/prod/va-q-plus_pdb_en.pdf

40 Lawrence Berkeley National Laboratory. Gas-Filled Panels – How effectively do GFPs insulate? Berkeley, CA. 

http://gfp.lbl.gov/performance/default.htm (Accessed September 26, 2007.)

41 Griffith, B.T., Arasteh, D., and Turler, D. “Energy Efficiency Improvements for Refrigerator/Freezers Using 

Prototype Doors Containing Gas-Filled Panel Insulating Systems,” Proceedings of the 46th International Appliance 

Technical Conference, May 1995. Lawrence Berkeley National Laboratory, Berkeley, CA. 

http://gfp.lbl.gov/papers/lbl-36658.pdf

42 Boughton, B.E., Clausing, A.M., and Newell, T.A. “An Investigation of Household Refrigerator Cabinet Thermal 

Loads,” HVAC&R Research, 1996, Vol. 2, No. 2. April. 

43 U.S. Environmental Protection Agency. Finite Element Analysis of Heat Transfer Through the Gasket Region of 

Refrigerators/Freezers, October, 1992. Washington, DC. EPA/430/R-92/009. 
3-74

 

44 Bansal, P.K. and Rupasinghe, A.S. “An Homogenous Model for Adiabatic Capillary Tubes,” Applied Thermal 

Engineering, 1998, Vol. 18, Nos. 3-4, 207-219. 

45 Bansal, P.K. and Rupasinghe, A.S. “An empirical model for sizing capillary tubes,” International Journal of 

Refrigeration, 1996, Vol. 19, No. 8, 497-505. 

46 Coulter, W.H. and Bullard, C.W. “An Experimental Analysis of Cycling Losses in Domestic RefrigeratorFreezers,” ASHRAE Transactions, 1997. Vol. 103, Pt. 1. 

47 TE Technology, Inc. “FAQ & Technical Information.” http://www.tetech.com/FAQ-TechnicalInformation.html#5.

48 Erickson, Donald. “Extending the Boundaries of Ammonia Absorption Chillers.” ASHRAE Journal, Volume 49, 

April 2007.