3

- i CHAPTER 3

. MARKET AND TECHNOLOGY ASSESSMENT

TABLE OF CO NTENTS

3.1 INTRODUCTION

................................ ................................ ................................ ........... 3

- 1

3.2 PRODUCT DEFINITION

................................ ................................ ............................... 3

- 1

3.3 PRODUCT CLASSES

................................ ................................ ................................ ..... 3

- 3

3.4 PRODUCT TEST PROCEDU RES

................................ ................................ ................. 3

- 4

3.5 MANUFACTURER TRADE G ROUPS

................................ ................................ ......... 3

- 5

3.6 MANUFACTURER INFORMA TION

................................ ................................ ........... 3

- 5

3.6.1 Manufacturers and Market Shares

................................ ................................ ................... 3

- 6
3.6.2 Mergers and Acquisitions

................................ ................................ ................................ 3

- 7

3.6.3 Small Business Impacts

................................ ................................ ................................ ... 3

- 7

3.6.4 Distribution Channels

................................ ................................ ................................ ...... 3

- 8

3.7 REGULATORY PROGRAMS

................................ ................................ ....................... 3

- 8

3.7.1 California’s Regulations

................................ ................................ ................................ .. 3

- 8

3.7.3 Canada’s Proposed Energy Conservation Standards

................................ ....................... 3

- 9

3.7.4 Australia and New Zealand Minimum Energy Performance Standards

.......................... 3

- 9

3.8 SHIPMENTS

................................ ................................ ................................ ................. 3

- 10

3.9 PRODUCT RETAIL PRICE S

................................ ................................ ....................... 3

- 10

3.10 INDUSTRY COST STRUCT URE

................................ ................................ ................ 3

- 12

3.11 INVENTORY LEVELS AND CAPACITY UTILIZATION RATES

.......................... 3

- 14

3.12 TECHNOLOGY ASSESSMEN T

................................ ................................ .................. 3

- 15

3.12.1 Portable AC Operations and Components

................................ ................................ ..... 3

- 15

3.12.2 Portable AC Technology Options

................................ ................................ .................. 3

- 17

3.12.3 Energy Efficiency

................................ ................................ ................................ .......... 3

- 24

LIST OF TABLES

Table 3.6.1 Portable AC Original Equipment Manufacturers and Importers*

............................ 3

- 6
Table 3.10.1 Air

- Conditioning and Warm Air Heating Equipment Manufacturing

Industry Employment a nd Earnings

................................ ................................ ... 3

- 12
Table 3.10.2 Air

- Conditioning and Warm Air Heating Equipment Manufacturing

Industry Materials and Wages Cost

................................ ................................ ... 3

- 13 Table 3.10.3 Industry Cost Structure Using SEC Data, Average 2006

– 2012

........................... 3

- 13

Table 3.11.1 Air

- Conditioning and Warm Air Heating Equipment Manufacturing

Industry Inventory Levels

................................ ................................ .................. 3

- 14 Table 3.11.2 Full Production Capacity Utilization Rate for Ventilation, Heating, Air

Conditioning, and Commercial Refrigeration Equipment ,

................................ 3

- 15 Table 3.12.1 Technology Options for Portable ACs

................................ ................................ .. 3

- 183

- ii LIST OF FIGURES

Figure 3.9.1 Retail Price versus Capacity for Single

- Duct Portable ACs

................................ . 3

- 11 Figure 3.9.2 Retail Price versus Capacity for Dual

- Duct Portable ACs

................................ .... 3

- 11 Figure 3.12.1 Single

- Duct Portable Air Conditioner Operation Schematic

.............................. 3

- 17 Figure 3.12. 2 CEC Energy Efficiency and Capacity Data

................................ ......................... 3

- 24 Figure 3.12.3 Distribution of the Capacities of Units in the CEC Database

............................. 3

- 253-1 CHAPTER 3. MARKET AND TECHNOLOG Y ASSESSMENT

3.1 INTRODUCTION

This chapter provides a preliminary assessment of the portable air conditioner (AC) industry in the United States. The U.S. Department of Energy (DOE) developed the market and technology assessment presented in this chapter primarily from publi cly available information. This assessment is helpful in identifying the major manufacturers and their product characteristics, which form the basis for the engineering and the life

- cycle cost (LCC) analyses. Present and past industry structure and industr y financial information help DOE in the process of conducting the manufacturer impact analysis.

3.2 PRODUCT DEFINITION

There currently is no definition of portable ACs included in the Energy Policy and Conservation Act (EPCA), Pub. L. 94

- 163, 42 United States Code ( U.S.C. ) 6291 et seq. or in the Code of Federal Regulations. In July 2013, DOE issued a notice of proposed determination (NOPD) ( hereinafter the “ July 2013 NOPD ” ), in which DOE proposed to define a portable AC as “a consumer product, other than a pac kaged terminal air conditioner, which is powered by a single phase electric current and which is an encased assembly designed as a portable unit that may rest on the floor or other elevated surface for the purpose of providing delivery of

conditioned air t o an enclosed space. It includes a prime source of refrigeration and may include means for ventilating and heating

. ” DOE also noted that this proposed definition is mutually exclusive to the definition for a room AC, which is “designed as a unit for mounti ng in a window or through the wall.” 79 FR 40403, 40404 (Jul. 5, 2013).

As discussed in chapter 2 of this preliminary technical support document (TSD), DOE received multiple stakeholder comments regarding the proposed product definition and resulting scope of coverage. Accordingly, DOE conducted further research into the different types of portable ACs and their typical characteristics.

P ortable ACs typically range in cooling capacity from 5,000 to 14,000 British thermal units per hour ( Btu/h ) when measured according to existing industry test methods, and are most commonly of single

- duct or dual

- duct configuration. P ortable ACs are also available on the market in a spot

- cooler configuration ( i.e. , with no ducting attached to the condenser air stream). According to sizing charts provided by vendors, portable ACs are intended to cool rooms of up to approximately 525 square feet in area. P ortable ACs are often heavier than 50 pounds, so are

de signed with wheels to provide mobility from room to room.3-2

I n a test procedure notice of proposed rulemaking (NOPR) issued on February 12, 2015 (hereinafter the “ February 2015 Test Procedure NOPR ”) a

, DOE did not propose any methods to characterize the performance of spot coolers. For this reason, DOE’s preliminary analysis focuses on single

- duct and dual

- duct portable ACs, and not spot coolers.

DOE also recognizes that certain portable ACs include options for operating as a dehumidifier and/or heater, with heating means provided by either an electric resistance heater or by modifying internal refrigerant flow to operate the unit as a heat pump. The dehumidification function may be achieved in some units by removing the condenser duct(s), and for certain units, disabling the self

- evaporative feature by draining the condensate before it reaches the condenser coils or deactivating the condensate slinger fan when the controls are set to dehumidification mode. In all of these cases, the air flow pattern and psychrometrics differ fundam entally from those of a residential dehumidifier, resulting in different energy efficiencies, even though both products may use a refrigeration system to remove moisture from the air.

DOE also recognizes that although room ACs and portable ACs share many of the same components that operate similarly to provide cooled air to a conditioned space, a portable AC, unlike a room AC, may be entirely located within the conditioned space so that some or all of the condenser air may be drawn from that space, and he at from the refrigeration system and ducting is transferred to the conditioned space as well. These differences lead to differing energy efficiencies between room ACs and portable ACs, even if the products were to incorporate the same components. In additi on, operation of the portable AC without activation of the refrigeration system may be more accurately characterized as “air circulation” rather than “ventilation”, because the portable AC may be operated without drawing air from outside the conditioned sp ace. Thus, DOE proposed in the February 2015 Test Procedure NOPR to clarify in the definition of “portable air conditioner” that the primary function of the product is to provide cooled conditioned air to the space in addition to other functions such as air circulation or heating, and that it is a product other than a room AC or dehumidifier. DOE also proposed a definition for portable AC that would align with the dehumidifier and room AC definitions

. In sum, DOE proposed in the February 2015 Test Pro cedure NOPR to add to 10 CFR 430.2 the following definition for “portable air conditioner”:

An encased assembly , other than a “packaged terminal air conditioner,” “room air conditioner,” or “dehumidifier,” designed as a portable unit for delivering cooled, conditioned air to an enclosed space, that is powered by single

- phase electric current

, which may rest on the

floor or other elevated surface . It includes a source of refrigeration and may include a dditional

means for air ci rculation and heating.

DOE conducted this preliminary analysis according to this proposed definition for a portable AC.

a The test procedure is available at : http://www1.eere.energy.gov/buildings/appliance_standards/product.aspx/productid/79.3-3

3.3 PRODUCT CLASSES

When evaluating and establishing energy conservation standards, DOE generally divides covered products into product classes by the type of energy used or by capacity or other performance

- related features that affect efficiency. Different energy conservation standards may apply to different product classes. ( 42 U.S.C. 6295(q)) Because portable ACs are not currently covered by EPCA, there are not current product classes within this product type. For this preliminary analysis, DOE considered whether it should separate portable ACs into separate product classes b ased on two characteristics: duct configuration and capacity.

Portable ACs are typically available with three types of duct configurations that affect product performance : single

- duct, dual

- duct, and spot cooler

. As mentioned in section 3.2, DOE

did not consider spot coolers for this preliminary analysis. Single

- duct units draw all of the condenser inlet air from the conditioned space without the means of a duct, and discharge the hot condenser outlet air to the unconditioned space through a duct. Du al

- duct units draw some or all of the condenser inlet air from the unconditioned space through a duct, and may draw additional condenser inlet air from the conditioned space. The condenser outlet air is discharged to the unconditioned space by means of a s eparate duct. Single

- duct units typically create more net negative pressure within the conditioned space than dual

- duct units, leading to more infiltration airflow from outside the conditioned space. This typically leads to lower single

- duct unit

efficienc ies than for comparable dual

- duct units when measured according to the method proposed in the February 2015 Test Procedure NOPR.

DOE evaluated whether there is any consumer utility associated with the different duct configurations. DOE considered whe ther all installation locations would be able to accommodate both single

- duct and dual

- duct units. Based on discussions with manufacturer s and a review of the market and the range of possible window connections, DOE tentatively concludes that no

installati on location would preclude the use of either duct configuration. In particular, all

window fixtures are of sufficient width to accommodate connections to two ducts. DOE also investigated whether duct configuration may affect noise performance of a portable AC. Based on a review of published noise data, DOE did not find a correlation between noise levels and duct configuration. Therefore , DOE tentatively concludes that duct configuration does not

warrant separate product classes because it is not aware of any unique consumer utility associated with either configuration. However, because duct configuration does impact portable AC performance, DOE considered ducting configurations in its identification of technology options.

Although DOE did not separate po rtable ACs into product classes based on duct configuration for this preliminary analysis, DOE proposed in the February 2015 Test Procedure NOPR the following definitions for the different product configurations to account for their different testing re quirements :

“Single

- duct portable air conditioner” means a portable air conditioner that draws all of the condenser inlet air from the conditioned space without the means of a duct, and discharges the condenser outlet air outside the conditioned space t hrough a single duct.3-4

“Dual

- duct portable air conditioner” means a portable air conditioner that draws some or all of the condenser inlet air from outside the conditioned space through a duct, and may draw additional condenser inlet air from the conditioned space. The conde nser outlet air is discharged outside the conditioned space by means of a separate duct. Id

.

“Spot cooler” means a portable air conditioner that draws condenser inlet air from and discharges condenser outlet ai r to the conditioned space, and draws evaporator inlet air from and discharges evaporator outlet air to a localized zone within the conditioned space. DOE proposed the spot cooler definition to clarify that testing these products would not be required at t his time.

Id.

Additionally, portable AC efficiencies are a function of product capacity. Higher

- capacity units typically achieve higher efficienc ies than lower

- capacity units when measured according to the method proposed in the February 2015 Test Procedure NOPR. As discussed in the February

2015 Test Procedure NOPR, DOE observed from its test data that this relationship between efficiency and capacity is consistent across the range of measured capacities for products that implement the sam e technologies. DOE did not identify any inherent differences in efficiency for different ranges of capacity that would produce a different efficiency

- capacity relationship. Therefore, DOE is not proposing separate portable AC product classes based on capa city. Instead, DOE is proposing to evaluate potential energy conservation standards based on equations that relate efficiency to capacity.

As a result, DOE is considering a single portable AC product class for this preliminary analysis.

3.4 PRODUCT TEST PROC EDURES

DOE does not currently specify a test procedure for portable ACs, but such a test procedure has been proposed in a separate rulemaking. DOE initiated the test procedure rulemaking by publishing a notice of data availability (NODA) on May 9, 2014 (h ereinafter the “May 2014 NODA”), to request feedback on potential testing options. 79 FR 26639. In the May 2014 NODA, DOE presented data from investigative testing according to the Association of Home Appliance Manufacturers ( AHAM ) PAC

- 1

- 2009 , “Portable Air Conditioners” (AHAM

PAC

- 1

- 2009) and ANSI/American Society of Heating, Refrigerating, and Air

- Conditioning Engineers (ASHRAE) Standard 16

- 1983 (RA 99), “Method of Testing for Rating Room Air Conditioners and Packaged Terminal Air Conditioners” (ANSI/ASH RAE Standard 16

- 1983 ), with certain modifications to allow testing of portable ACs. DOE also presented an alternate test approach, in which testing would be conducted according to ANSI/AHAM PAC

- 1

- 2009, but the calculations for capacity and energy efficien cy ratio (EER) would account for any heat transferred to or from the conditioned space due to infiltration air or a warm or cold product case

.3-5

Based on feedback received in response to the May 2014 NODA and further investigative testing, DOE proposed a t est procedure for portable ACs in the February 2015 Test Procedure

NOPR. The proposed test procedure is consistent with the alternate approach described in the May 2014 NODA; however the February 2015 Test Procedure NOPR references the recently updated version of the PAC

- 1 standard, AHAM PAC

- 1

- 2014 “Portable Air Conditioners” (AHAM PAC

- 1

- 2014). The 2014 version of the standard includes minor revisions to the indoor and outdoor conditions from the 2009 version to fully harmonize with CSA’s test p rocedure.

After careful review of both versions of PAC

- 1, DOE does not expect the revisions to that test procedure to have a significant impact on test results.

In the February 2015 Test Procedure NOPR, DOE proposed a combined energy efficiency ratio (CEER) that would account for portable AC performance in each available operating mode; however, DOE conducted this preliminary analysis based solely on portable AC performance in cooling mode, in terms of cooling capacity and cooling energy efficiency ratio (EER c m ) , as determined by the method proposed in the February 2015 Test Procedure NOPR. DOE focused on cooling mode for this analysis because cooling is the primary function of portable ACs

. DOE expects that its proposals in future stages of this standards rulemaking would

be based on CEER after fi nalizing the calculation of that metric in the test procedure rulemaking

.

3.5 MANUFACTURER TRADE G ROUPS

DOE recognizes the importance of trade groups in disseminating information and

pro moting the interests of the industry that they support. To gain insight into the portable AC industry, DOE researched various associations available to manufacturers, suppliers, and users of such equipment.

AHAM b , formed in 1967, aims to enhance the valu e of the home appliance industry through leadership, public education and advocacy. AHAM provides services to its members including government relations; certification programs for room AC s, dehumidifiers and room air cleaners; an active communications pro gram; 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 p roduct characteristics and performance features.

3.6 MANUFACTURER INFORMA TION

The following section details information regarding domestic manufacturers of portable

ACs , including estimated market shares (section 3.6.1 ), industry mergers and acquisitions (section 3.6.2 ), potential small business impacts (section 3.6.3 ), and product distribution

channe ls (section 3.6.4 ).

b For more information, please visit www.aham.org

.3-6

3.6.1 Manufacturers and Market Shares

T he majority of single

- duct and dual

- duct portable AC s are manufactured overseas by

three majo r manufacturers. These products are then imported to the United States and sold under a variety of brands belonging to both appliance manufacturers and importers. Additionally, some foreign original equipment manufacturers (OEM) engage in the direct sale o f portable AC s into

the U.S. m arket under their own brands.

DOE estimates that there are approximately 29 entities selling single

- duct and dual

- duct portable AC s in the United States

. Table 3.6

. 1 lists these manufacturers and importers

.

Table 3.6

. 1 Portable AC Original Equipment Manufacturers and Importers *

American Comfort Worldwide* * Bigwall Enterprises Inc.* * Danby* * DeLonghi America Inc.

Electrolux * *

Friedrich* *

GD Midea Air Conditioning Equipment Co. Ltd. Grainger* * Gree Electric Appliances Inc., of Zhuhai Haier America Trading LLC **

Hisense Kelon Electrical Holdings Co. Ltd.

Hone ywell International Inc.* *

R.E. Hansen Industries Inc. **

LG Electronics Inc. ** Living Direct* * Luzerne Trading Company Inc.* *

Mestek Inc.* *

Motors and Armatures Inc. * *

New Widetech Electric Co. Ltd.

NewAir ** Ningbo Bole Electric Appliance Co. Ltd. Royal Sovereign International, Inc. ** Sealed Unit Parts Co (SUPCO)* * Sears Holding Corporation* * Sharp Electronics Sunpentown International Inc. ** Toyotomi Co. Ltd. Whynter LLC* * Zhejiang Aoli Electric Appliance Co. Ltd.3-7

*These manufacturers and importers represent the entities DOE has identified that would be regulated under any energy conservation standards resulting from this rulemaking.

* * These companies do not manufacture the products covered by this rulemaking; inste ad they source products from
OEMs and rebrand them.

Using publicly available data, DOE estimated the market shares of entities responsible

for the sale of single

- duct and dual

- duct portable AC s in the United States . DOE estimates that

Haier Am erica c and LG each comprise more than 20 percent of the portable AC market, while De'Longhi America

, d American Comfort Worldwide, and Danby each hold approximately a 10 percent share of the market. Other players in the portable AC industry have 5 percent m arket

share or less.

3.6.2 Mergers and Acquisitions

Recent merger and acquisition activities relating to the U.S. portable AC market include the joint venture formed between Chinese manufacturer Gree and U.S.

- based SoleusAir in 2011, which led to the creation of Gree USA, headquartered in City of Industry, CA. Gree USA

manufactures its own brands of heating, ventilation, and air conditioning ( HVAC ) products and OEM private labels, and sells directly to wholesalers. This collaboration has facilitated Gree ’s presence in the United States

. e Also in 2011, LG Electronics acquired LS Mtron’s Air

Conditioning unit, and in November 2012, Corinthian Capital Group acquired Friedrich Air Conditioning Co. from U.S. Natural Resources Inc. According to one source, Texas

- based

Friedrich supported the sale so that it could “aggressively expand.” f

In 2013, Motors and Armatures (d.b.a. MARS), a commercial and residential

HVAC/ refrigeration motors and components supplier acquired Heat Controller, Inc., a commercial and residential HVAC equipment (including portable AC s) supplier. g Also in 2013, Haier America became a wholly owned subsidiary of Hai er Group, which, for Haier, “signifies a continued focus and commitment to serving [its] customers in the Americas.” h

3.6.3 Small Business Impacts

DOE considers the possible impact of energy conservation standards on small businesses. The products covered by this rulemaking are classified under the North American Industry

c A wholly

- owned subsidiary of Haier Group (China).

d A subsidiary of De’Longhi S.p.A. (Italy).

e “Soleu sAir, Gree Electronic Appliances Merge,” Air Conditioning, Heating & Refrigeration News Weekly , April 4,

2011.

f “Corinthian Chills Out With Acquisition of Friedrich Air Conditioning,” Dow Jones LBO Wire , November 29,

2012.

g “MARS Acquires Heat Controlle r, Inc.,” Business Wire , May 25, 2013.

h “Haier America Becomes Wholly Owned Subsidiary of Haier Group,” Globe Newswire , August 15, 2013.3-8

Classification System ( NAICS ) code 333415: Air

- Conditioning and Warm Air Heatin g 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

for both NAICS codes. The 750

- employee threshold includes all employees in a business’s parent company and any other subsidiaries.

Using this classification in conjunction with information from industry databases, the SBA member directory, and reports from vendors such as Dun & Bradstreet, DOE has not identified any small, U .S.

- based manufacturers of single

- duct and dual

- duct portable ACs products addressed by this rulemaking. DOE will continue investigate whether there are any small manufacturers of single

- duct and dual

- duct portable ACs based in the U.S

.

3.6.4 Distributi on Channels

Understanding the distribution channels through which portable AC s are sold is an important facet of the market assessment because it helps to define the constraints or motivators

manufacturers face from their customer base . DOE ga thered information regarding the distribution channels for portable AC s from publicly available sources, as well as from preliminary interviews with manufacturers.

Because major OEMs of single

- duct and dual

- duct portable ACs are based overseas, the

distribution channel for these products is often multi

- tiered. In one arrangement, foreign OEMs sell their products to a sourcing company with a greater U.S. presence, which in turn sells the products direct ly to retailers or, to a lesser extent, distributors. Alternatively, OEMs sell their products under their own brands either to distributors or directly to retailers. In either arrangement, these retailers include large discount stores, home improvement sto res, and department stores.

3.7 REGULATORY PROGRAMS

The following section s detail current or proposed regulatory initiatives for portable ACs

.

3.7.1 California’s Regulations

The California Energy Commission (CEC) regulates “spot air conditioner s”, which it
defines as “an air conditioner that discharges cool air into a space and discharges rejected heat back into that space, where there is no physical boundary separ a ting the discharges. ” The metric used for spot AC s is the cooling efficiency ratio (CER), obt ained by dividing the sum of the cooling capacity and the fan electrical input in Btu/h by the electrical input power in watts, using

ANSI/ASHRAE 128

- 2001. i California currently requires only reporting of CER, cooling

i California Code of Regulations, Title 20, Division 2, Chapter 4, Article 4, Sections 1602(d) and 1604(d).3-9

capacity, input power, and fan input p ower in its product database, and does not have energy efficiency regulations for spot AC s.

3.7.3 Canada’s Proposed Energy Conservation Standards

Canada’s energy efficiency regulations proposed to establish energy conservation standards for portable AC s in 2009, based on a minimum energy efficiency that would be a function of cooling capacity. j These proposed standards, based on testing according to Canadian Standards Association (CSA) C370 “Cooling Performance of Portable Air Conditioners” ( CSA

C370 ) k

, which have not been adopted, were defined in terms of a minimum spot cooling efficiency (SCE, equivalent to EER) for air

- cooled portable AC s with cooling capacit ies less than 36,000 Btu/h according to the following equation:

SCE = 7.76 + 0.0164 x C/1000

where C is the cooling capacity in Btu/h

.

Natural Resources Canada (NRCan) estimated that at the time of the proposal, approximately 90 percent of portable ACs on the market would have met the minimum SCE requirement included in the proposal.

3.7.4 A ustralia and New Zealand Minimum Energy Performance Standards

Australia and New Zealand have established energy efficiency regulations, Minimum Energy Performance Standards (MEPS) , for single

- phase and three

- phase air conditioners in

ducted or non

- ducted configurations

. Labeling requirements only specify single

- phase air

conditioners in a non

- ducted configuration, but manufacturers can choose to label three

- phase and ducted air conditioners. MEPS requirements were introduced in Australia in April 2010, and were further modified in April and October 2010. MEPS requirements in New Zealand were revised and implemented in June 2011. The Australia requirements are found in Standards Australia/Standards New Zealand (AS/NZS) 3832.2:2011 and apply to all products i mported after October 2011. The New Zealand requirements are found in AS/NZS 3823.2:2009 and apply to all products imported after June 2011. l The test procedures used for compliance with these
standards are AZ/NZS 3832.1.1:1988 for non

- ducted units and AZ/ NZS 3823.1.2:2001 for

ducted units. m

j Natural Resources Canada

– Office of Energy Efficiency, Bulletin on Developing Standards for Portable ACs

, 2009

. Available online at: http://oee.nrcan.gc.ca/regulations/bulletins/9205

.

k CSA standar ds are available for purchase online at: http://shop.csa.ca/

.

l Additional information can be found at: www.energyrating.gov.au/for

- industry/regulation

- information

- for

industry/product

- standards/overview/asnzs3823/

m Additional test procedure information can be found at: www.energyrating.gov.au/for

- industry/regulation

information

-

for

- industry/product

- standards/overview/3-10

3.8 SHIPMENTS

In the July 2014 NOPD, DOE estimated that 973.7 thousand units were shipped in North America in 2012, with a projected growth to 1743.7 thousand units by 2018, representing nearly

80

- percent growth in 6 years. n

3.9 PRODUCT RETAIL PRICE S

DOE used the CEC Appliance Efficiency Database

, o supplemented with web based research, to compile a database of portable AC products. DOE identified a total of 251 models of portable AC s, which encompass 36 different brands. Of thes e, DOE was able to colle ct consumer retail price data for 118 single

- duct units and 26 dual

- duct units using the websites of five types of retailers: “ b ig b ox” stores, discount department stores, wholesale club s, manufacturer websites, and online appliance retailers ( e.g. , AJ Madison ).

Figure 3.9

. 1 and Figure 3.9

. 2 summarize the data collected by DOE. These figures generally suggest that retail price is positively related to capacity for both single

- duct and dual

duct portable AC s. The consumer retail prices for single

- duct portable ACs ranged from $1 50 to $ 998 , with a model

- weighted average of $ 446

. Single

- duct p ortable AC s are available with

manufacturer

- rated capacities ranging from 1,000 Btu/h to 14,000 Btu/h, with a model

- weighted

ave rage capacity of 9, 400 Btu/h.

n Transparency Media Research, A ir Conditioning Systems Market

- Global Scenario, Trends, Industry Analysis, Size, Share and Forecast, 2012

– 2018 , January 2013.

o The California Energy Commission Appliance Efficiency Database reports data for “spot ACs”: www.appliances.energy.ca.gov/AdvancedSearch.aspx3-11 Figure 3.9

. 1 Retail Price versus Capacity for Single

- Duct Portable ACs

The consumer retail prices for dual

- duct portable ACs ranged from $ 351 to $ 799 , with a

model

- weighted average of $ 497

. Dual

- duct units range in manufacturer

- rated capacity from 9,000 Bt u/h to 14,000 Btu/h , with a model

- weighted average capacity of 11, 500 Btu/h

.

Figure 3.9

. 2 Retail Price versus Capacity for Dual

- Duct Portable ACs3-12

3.10 INDUSTRY COST STRUCT URE

DOE developed the cost structure for the industry classification associated with the portable AC industry from publicly available information from the U.S. Census Bureau’s Annual Survey of Manufactures ( ASM ) and Economic Census

, and the U.S. Securities and Exchange Commission (SEC) 10

- K reports filed by publicly

- owned manufacturers.

Table 3.10

. 1 presents the employments levels and payroll for NAICS code 333415 for

air

- conditioning and warm air heating equipment and commercial and industrial refrigeration equipment manufacturing

. DOE converted the payroll data to constant 2013 dollars using the

Gross Domestic Product Implicit Price Deflator published by the U.S. Bureau of Economic Analysis. p Both employment and earnings for the industry decline between 2007 and 2009 with

levels rem aining largely flat thereafter through 2011. The percent change in production and total industry employees tracks relatively closely with the percent change in payroll for all employees.

Table 3.10

. 1 Air

- Cond itioning and Warm Air Heating Equipment Manufacturing Industry Employment and Earnings 1

Year Production

Workers All

Employees Total

Payroll ( 2013 $ Mil )

2011 62,009 83,969 $3,887

2010 61,380 83,054 $3,974

2009 60,041 86,454 $3,908

2008 70,787 96,610 $4,319

2007 74,728 101,485 $4,418

2006 74,909 102,354 $4,519

2005 76,011 98,097 $4,568

Table 3.10

. 2 shows the cost of materials and industry payroll as a percentage of value of shipments for the air

- conditioning and warm air heating equipment and commercial and industrial refrigeration equi pment manufacturing industry from 2005

– 2011. Material prices as a percentage of value of shipments have increased slightly over the 7

- year period, with small fluctuations from year to year. The cost of payroll for production workers as a percentage of

valu e of shipments has decreased slightly since 2005. Finally, over the 7

- year period, the cost of

non

- production payroll has remained relatively constant, with fluctuations from year to year. DOE notes that, overall, wages and cost of materials combined repre sent approximately the same percentage of the total shipments value in 2005 and 2011 (68 percent ).

p Available online at www.bea.gov/iTable/iTable.cfm?ReqID=9&step=1#reqid=9 &step=1&isuri=13-13

Table 3.10

. 2 Air

- Conditioning and Warm Air Heating Equipment Manufacturing Industry Materials and Wages Cost 2

Cost as a Percentage of Value of Shipments ( % )

Year Materials Payroll for

Production

Workers Payroll for

All Other Employees

2011 55.1% 7.5% 5.2%

2010 52.9% 7.8% 5.7%

2009 55.1% 7.9% 6.0%

2008 54.6% 8.1% 5.4%

2007 55.6% 8.2% 5.3%

2006 53.2% 8.9% 4.9%

2005 53.8% 8.5% 5.3%

Table 3.10

. 3 presents the portable AC industry cost structure derived from SEC 10

- K reports of publicly

- owned manufacturers. DOE averaged the financial data from 2006

– 2012 of

U.S.

- based appliance manufact urers to obtain an industry average. Each financial statement entry is presented as a percentage of total revenues.

Table 3.10

. 3 Industry Cost Structure Using SEC Data q , Average 2006

– 2012

Financial Statement Entry Percent of

Revenues

Cost of sales 72.1%

EBIT 9.1% Selling, general and administrative 19.0% Capital expenditure 2.8% Research and development 1.5% Depreciation 2.7% Net plant, property and equipment 13.5% Working capital 19.4%

A detailed financial analysis is presented in the manufacturer impact analysis (MIA, chapter 12 of this preliminary TSD). This analysis identifies key financial inputs including cost of capital, working capital, depreciation, capital expenditures, etc

.

q SEC 10

- K filings are available at: www.sec.gov/edgar/searchedgar/companysearch.html3-14

3.11 INV ENTORY LEVELS AND CA PACITY UTILIZATION R ATES

Table 3.11

. 1 shows the year

- end inventory for the air

- conditioning and warm air heating industries, according to the ASM

. The value of the end

- of

- year (EOY) inventories increased from

2005 to 2007 and decreas ed overall from 2007 to 2011. A s a percentage of the value of shipments , value of inventories data shows a slight upward trend from 2005 to 2007 and a decreasing trend fr om 2009 to 2011 (likely a reaction to over

- supply during the recession)

.

Table 3.11

. 1 Air

- Conditioning and Warm Air Heating Equipment Manufacturing Industry Inventory Levels 3

Year End

- of

Year Inventory ( 2013 $

Mil ) EOY

inventory
as % of Shipments

Value

2011 2,755 9.0%

2010 2,718 9.3%

2009 2,807 10.0%

2008 3,127 9.7%

2007 3,325 10.1%

2006 3,246 9.9%

2005 3,114 9.4%

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 ventilation, heating, air

conditioning, and commercial refrigeration equipment r industr y

. Table 3.11

. 2 presents utilization

rates for th is umbrella industr y

.

r “ Ventilation, heating, air

- conditioning, and commercial refrigeration equipmen t” 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.”3-15

Table 3.11

. 2 Full Production Capacity Utilization Rate for Ventilation, H eating, A ir

C onditioning, and C ommercial R efrigeration E quipment 4
, 5

Year Plant Capacity
Utilization Rate ( % )

2013 55%

2012 55%

2011 60%

2010 60%

2009 60%

2008 67%

2007 66%

2006 62%

2005 66%

2004 61%

Full production capacity is defined as the maximum level of production an establishment could attain under normal operating conditions. s 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 ventilation, heating, air

- conditioning , and commercial refrigeration manufacturers reached a peak in 2008, at 67 percent, and hit a low of 55 percent in 2012 and 2013

. Decreased capacity utilization in the industry may reflect the impact of the 2007

– 2009 recession.

3.12 TECHNOLOGY ASSESSMEN T

This section provides a technology assessment for portab le ACs . Contained in this technology assessment are details about product characteristics and operation (section 3.12.1 )

and an examination of possible technologic al improvements (section 3.12.2 )

.

3.12.1 Portable AC Operations and Components

S ingle

- duct and dual

- duct p ortable AC s are self

- contained, refrigerat ion

- based product s that provide cool air to a conditioned space and reject heat outside of the conditioned space. Similar to room ACs, these product s remove both latent and sensible heat from the ambient air ; h owe ver, unlike room ACs

, they are no t permanently installed through a wall or in a window.

s See: www.census.gov/manufacturing/capacity/definitions/index.html3-16

Portable ACs are typically designed with wheels to allow for moving the units from room to

room , weigh in the range of 50 to 90 pounds, and are generally 28 to 36 inches tall.

Portable ACs operate with a similar refrigeration circuit as for room ACs or dehumidifiers, but with a different air flow pattern. Components of the refrigeration system include an evaporator, expansion valve or capillary tube, a condenser, and a compressor. Single

duct and d ual

- duct p ortable ACs typically operate as follows:

1. A circulating blower draws air from the conditioned space via an intake grille;

2. The air is pulled across an evaporator heat exchanger that is cooled by the electrically

powered vapor compression refrigeration system;

3. The evaporator cools the air, and moisture from the air condenses on the evaporator and drips down across the hot condenser heat exchanger, where some or all of it evaporates

and the excess is collected in a drip pan below the condens er; 4. The cooled, drier evaporator air is exhausted to the conditioned space;

5. At the same time, a blower draws air in a separate flow stream across the hot condenser heat exchanger;

a. Single

- duct u nits draw condenser inlet air from the conditioned space;

b. Dual

- duct units draw some or all of the condenser inlet air from the unconditioned space through a duct, and may draw additional condenser inlet air directly from the conditioned space ; 6. Certain units with an “auto evaporative” feature deliver any accumulated co ndensate back onto the condenser heat exchanger by means of a slinger wheel or pump to evaporate as much of it as possible; and

7. The warm, moist condenser outlet air containing evaporated condensate from the

conditioned air stream is discharged to the uncon ditioned space by means of a duct.3-17 Source: Adapted from kingersons.com 6

Figure 3.12

. 1 Single

- Duct Portable Air Conditioner Operation Schematic

The intake of condenser air from the conditioned space and its exhaust to the unconditioned space results in a net negative pressure in the conditioned space. In turn, this results in air infiltration to the conditioned space from other locations. Because all of their

condenser air is drawn from the conditione d space, s ingle

- duct units typically create more net negative pressure within the conditioned space than dual

- duct units, leading to more infiltration airflow from outside the conditioned space.

3.12.2 Portable AC Technology Options

DOE identified several possible technologies that manufacturers may use to improve the efficiency or performance of portable ACs. These technology options were initially identified during the residential dehumidifier and room AC energy conservation standards rulemakings

because of their similarities to portable ACs. The technology options for portable ACs are listed

in Tabl e 3.12

. 1 and described in greater detail later in this section

.3-18

Tabl e 3.12

. 1 Technology Options for Portable ACs

Increased Heat Transfer Surface Area

Improving the overall heat transfer surface area of the condenser and evaporator coils would result in improved efficiency of the refrigeration system. With a larger surface area, a coil can transfer the same amount of heat as a smaller coil while using a higher (in the case of an evaporator) or lower (in the case of a condenser) refrigerant temperature. This decreases the pressure difference betw een the two sides of the refrigerant cycle, lowering the necessary compressor power input

.

Manufacturers have multiple options t o increase the heat transfer surface area, including increasing cross

- sectional area, heat exchanger depth, and fin density. W hile these heat exchanger changes improve coil performance, there are some additional tradeoffs. O perating the evaporator coil at a higher temperature in cooling mode may limit the unit’s ability to dehumidify the cool air stream , a significant component t o increasing comfort in the conditioned

space

. Increasing cross

- sectional area and heat exchanger depth will increase unit weight and possibly case size , thereby increasing the unit manufacturing and shipping cost and reducing consumer portability . Increas ing heat exchanger depth and fin density both require increasing blower capacity to offset the greater pressure drop for the airstream passing over the heat exchanger. Additionally, a greater fin density could result in more water retention in the
evaporat or, or accumulation of dust and dirt leading to decreased heat transfer over time. Increased Heat

- Transfer Surface Area
1. Increased frontal coil area 2. Increased depth of coil (add tube rows) 3. Increased fin density

4. Add subcooler to condenser coil

Increased Heat

- Transfer Coefficients

5 . Improved fin design

6 . Improved tube design

7 . Spray condensate onto condenser coil

8 . Microchannel heat exchangers Component Improvements

9 . Improved compressor efficiency

10 . Improved blower/fan efficiency

1 1 . Low

- standby

- power electronic controls

1 2

. Ducting insulation

13. Improved d

uct connections

1 4 . Case insulation

Part

- Load Technology Improvements

1 5 . Variable

- speed compressors

1 6 . Thermostatic or electronic expansion valves3-19

Subcoolers are added between the condenser coil outlet an d the capillary tube inlet and

are either submerged near the condenser in the condensate produced by the evaporator or sent through a heat exchanger with the cooler refrigerant gas coming off of the evaporator . Adding a subcooler effectively increases the size of the condenser coil as it further cools the refrigerant coming out of the condenser. However, it m ay be difficult to incorporate subcoolers within the portable AC case, and they may have limited efficiency improvements.

Increased Heat

- Transfer Coefficients

Manufacturers may make further improvements to the evaporator or condenser beyond increasing surface area to improve the heat transfer capability of the heat exchangers. Different fin designs, including louvered or slit

- type fins, result in more turbulent air flow through the heat exchanger, increasing the air

- side heat

- transfer coefficient. Simil ar to increasing fin density, as described above, adjusting fin design may result in water retention in the evaporator or fouling due to dirt and dust collection. To improve refrigerant

- side heat

- transfer coefficients, manufacturers may incorporate refrige rant tubes with a grooved interior surface. This significantly increases the refrigerant

- side heat

- transfer coefficient compared to a typical

smooth

- surface refrigerant tube. Manufacturers may also improve the condenser heat

- transfer coefficient by sprayin g or dripping condensate from the evaporator over the condenser. The condensate evaporating off of the warm condenser surface enhances the heat transfer compared to a condenser rejecting heat only to an air stream.

Microchannel heat exchangers may also i ncrease heat transfer coefficients compared to typical tube

- and

- fin heat exchangers. Microchannel heat exchangers use many small rectangular channels with aluminum fins brazed between the rectangular tubes to increase heat transfer while reducing pressure drop compared to conventional coils. However, DOE is not aware of any portable ACs that incorporate microchannel heat exchangers, likely due to the much higher investment cost required for the equipment needed to fabricate these heat exchangers ( i.e.

, braz ing ovens) as compared with equipment used for fabrication of conventional heat exchangers.

Research has compared the performance of a window

- mounted room air conditioner with microchannel condensers to a baseline system with a conventional tube

- and

- fin condenser. The results showed the heat transfer rates per unit core volume of the microchannel heat exchangers were 14 to 331 percent higher than the conventional heat exchangers. However, the overall efficiencies of two systems using the microchannel cond enser heat exchanger were 1 to 3 percent lower than the baseline system. The lower efficiencies attained by this work were believed to be due, in part, to the un

- optimized condensate slinger ring and decreased subcooling of the microchannel systems. The re sults did show reductions in refrigerant charge, condenser core volume, and weight of 35, 55, and 35 percent, respectively, using microchannel condensers. 7

More recent research performed in 2006 indicated that a microchannel condenser with the

same area as a fin

- and

- tube configuration requires 49

- percent less internal refrigerant flow

volume and 10

- percent lower refrigerant charge, and results in a 6 to 10

- percent increase in the steady

– state coefficient of performance (COP), defined as the cooling capaci ty divided by the3-20

power consumption . This COP increase is due to a decrease in the compressor power consumption rather than an in crease in the cooling capacity. The r esearch also indicated that a microchannel condenser system with the same frontal area as a traditional fin

- and

- tube configuration results in a greater than 7

- percent increase in seasonal efficiency. 8

Additional research performed in 2009 for mobile air conditioning indicated that microchannel heat exchangers provide volume benefits (17.2

- p ercent and 15.1

- percent volume reduction for evaporator and condenser, respectively) and weight benefits (2.8

- percent and 14.9

- percent weight reduction for evaporator and condenser, respectively) when compared with fin

and

- tube heat exchangers. The overall cooling capacity and COP of the microchannel heat exchanger system w ere increased by about 5 percent and 8 percent, respectively, under ideal

conditions. 9

Improved Compressor Efficiency

Portable ACs typically use rotary R

- 410A compressors. Rotar y R

- 410A compressors are available in a range of efficiencies, from an EER of 9 Btu per watt

- hour (Btu/Wh) up to roughly 10.5 Btu/Wh, where EER represents the cooling capacity of the compressor divided by its power input. “Inertia” compressors and scroll c ompressors have higher efficiencies than the traditional
rotary compressors . However, manufacturer interviews and DOE’s market research indicated

that finding a suitable high

- efficiency compressor at the capacities and price points ne eded for a portable AC is a challenge.

The inertia compressor is a technology that allows reciprocating compressors to approach an energy efficiency ratio EER of 12.0 Btu/Wh. “Inertia” compressors utilize lightweight, responsive valve technology and an i nnovative refrigerant flow path to reduce losses and improve cylinder volumetric efficiency.

Scroll compressors require high precision to produce their internal components and are typically found in higher

- efficiency central air

- conditioning systems. S croll compressors compress gas in a fundamentally different manner from traditional compressors

— between two spirals, one fixed and one nutating. Scroll compression is inherently more efficient than traditional compression methods.

Both inertia and scro ll compressors are, however, substantially larger, heavier, and sometimes noisier than their rotary counterparts, and, as such, are not well

- suited for use in portable ACs.

Improved Blower/Fan Efficiency

The air

- circulation system of a portable AC usual ly consists of permanent split capacitor (PSC) fan motors that drive the evaporator and condenser blowers.

Fans and blowers for portable ACs are generally molded plastic parts with fairly advanced geometries. The housings for the fans and heat exchangers are also molded plastic3-21

parts designed for each particular unit. Air system efficiency could possibly be improved through more advanced fan and blower design; however

, this would likely be a relatively costly design option for a manufacturer in relation t o the minimal efficiency benefit. The air system efficiency could also be improved by reducing restrictions to air flow; however, improving the efficiencies of the heat exchangers often corresponds to restricting air flow, as discussed in the sections

addr essing heat exchangers above.

Given the limited opportunity to improve air system efficiency, manufacturers would likely consider efficiency improvements to the fan motor only.

In a PSC motor, the start

- up winding is electrically connected in parallel with the main winding and in series with a capacitor. At start

- up, the interactions between the magnetic field generated by the start

- up winding and that generated by the main winding induce rotation. As the capacitor charges, the current flowing through the start

- up winding decreases and the start

- up winding becomes an auxiliary winding after the motor reaches running speed. Consequently, the

current to the start

- up winding is cut off once the capacitor is fully charged and the motor reaches steady

- state speed. Because of this, PSC motors are substantially more efficient than

their shaded

- pole counterparts, with motor efficiencies ranging from 60 to 65 percent. Like

shaded

- pole motors, PSC motors are produced in large quantities and are relatively inexpens ive. 10

Electric motors with even higher efficiencies can be implemented by switching to
permanent

- magnet motors, which come in many varieties. The most widely

- known variety is the electronically

- commutated motor (ECM), though DC motors can also be used. Permanent magnet motors are less noisy and substantially more efficient than either shaded

- pole or PSC motors. ECM motors convert single

- phase AC input power into three

- phase power, and have motor efficiencies approaching 80 percent. 11 However, ECM motors can weigh twice as much as equivalent PSC motors, potentially necessitating a redesign of the portable AC chassis. In addition, ECM motors are complex, are not currently produced in large volumes, and can cost roughly twice as much as a PSC motor. 12

Low

- S t andby

- Power E lectronic C ontrols

Electronic controls may consume power even when the portable AC is not performing its intended function. Depending on the implementation of the controller, standby power is required

to enable the electronic controls to det ect user input without the user first having to turn on a mechanical power switch or to enable displays, illuminate switches, etc . Reducing the standby power consumption of electronic controls will reduce the annual energy consumption of the portable AC, b ut will not impact the energy consumption of the unit during operation in cooling

mode.

Ducting Insulation

In the February 2015 Test Procedure NOPR, DOE proposed a portable AC test method that would account for any heat lost to the conditioned space from the duct(s). Under the3-22

proposed test conditions in cooling mode, DOE testing demonstrated that t he condenser exhaust

duct carries air that is on average 40 degrees Fahrenheit ( °F ) warmer than the 80 °F temperature
of the indoor side test chamber. Accordingly, the warm exhaust duct transfers heat to the conditioned space. For dual

- duct units, the condenser inlet duct also has a net heating effect, although not as significant because it carries air at 95 °F , only 15 °F warmer than the indoor side

test chamber . Manufacturers may choose to insulate duct s to minimize heat lost to the conditioned space. However, DOE notes that it is not aware of any portable ACs that utilize insulated ducting. DOE observed that manufacturers use accordion

- style plastic ducts that ship in a compacted state , and thus insulation opportunities would be limited

.

Improved Duct Connections

DOE is aware that the duct connections at the window mounting bracket or portable AC

are often not well sealed. A ir leak ing through these duct connections may be up to 40 °F warmer

than the ambient temperature, and may leak from the condenser exhaust stream to the conditioned space

. DOE

, therefore

, acknowledges the overall cooling performance benefit of tightly

- seal ed duct connections. However, DOE did not observe any units in the test sample that provided additional sealing in the duct connections. DOE also did no t observe any significant gaps in any of the duct connections (either at the portable AC or the window mounting bracket) for units in its test sample. DOE lacks detailed information regarding the heat impacts of air leakage at the duct connections

.

Case I nsulation

The February 2015 Test Procedure NOPR would also account for any heat lost to the conditioned space through the product case. Portable AC product cases house internal components that may operate at high temperatures, such as the compressor, which may result in locally high case surface temperatures and heat transferred to the conditioned space.

Manufacturers could potentially limit this heat loss using insulated cases. Although DOE is aware that certain portable ACs incorporate insulation to seal the air flow between the heat exchanger compartments

, DOE is not aware of any portable ACs that use additional insulation on the external product case to limit heat transfer to the room. Therefore, DOE does not have information regarding the performance and reliability effects of restricting the heat rejection from the internal components.

Variable

- Speed Compressors

Variable

- speed compressors are typically implemented through the use o f an electronic control that varies the input frequency of the power supply for the compressor motor. Variable

speed compressors enable modulation of the refrigeration

- system cooling power beyond simple on/off control, allowing the portable AC to better ma tch the compressor power to the load, increasing compression efficiency. DOE is not aware of variable

- speed compressor technology implemented in portable ACs to date, and it is therefore difficult to predict the energy efficiency improvements that could be achieved through its use. However, DOE expects that a variable

speed compressor in a portable AC could provide more precise control of the evaporator coil3-23

temperature to ensure more efficient heat removal, especially at low temperatures where ice buildup may occur.

The greatest benefit of variable speed systems is to save energy under varying operating conditions. However, the test procedures proposed in the February 2015 Test Procedure NOPR would require testing under constant steady

- state conditions . Accordingly, the test procedure would not reflect efficiency improvements at different operating conditions. DOE notes that in central air conditioning systems, research shows that variable

- speed compressors may produce energy savings from 15 to 40 perce nt. 13

, 14

, 15

Thermostatic or Electronic Expansion Valves

Nearly all portable AC s use capillary

- tube s for flow control. The capillary

- tube expansion valve is a pressure

- reducing device that consists of a small

- diameter line that connects the outlet of the condenser to the inlet of the evaporator. It is designed to provide optimum energy characteristics at one design point. If sized properly, the capillary

- tube expansion valve compensates automatically for load and system variations and gives acceptable performance over a wide range of operating conditions. Because ambient temperatu re and humidity vary, how ever, portable ACs sometimes operate under conditions outside of the target conditions, leading to reduced efficiency.

The thermostatic expansion valve (TXV)

— a flow

- control alternative to the capillary

tube

— is commonly used in higher

- efficiency centra l air

- conditioning systems. TXVs regulate the flow of liquid refrigerant entering the evaporator in response to the superheat of the refrigerant leaving it. TXVs can adapt better to changes in operating conditions such as those due

to variations in ambient temperature, which affect the condensing temperature. As a result, TXVs can lead to a somewhat increased seasonal operating efficiency.

Electronic expansion valves (EEVs) are similar to TXVs, but unlike TXVs, they can be actively controlled. While a TXV relies on a single temperature sensor for feedback, digital controllers can use multiple sensors for feedback control and respond using multiple approaches. For example, besides modulating the refrigerant flow, the controller may also vary the fan speed

to optimize efficiency under varying conditions. As with TXVs, EEVs can use the superheat control method to regulate refrigerant flow. Other methods, such as controlling compressor discharge temperature, can also be used.

During the reverse

- engineering an alysis, DOE did not observe any units with either TXVs or EEVs. Given the cost of TXVs and EEVs, it is unlikely that manufacturers would implement them in portable ACs. Additionally, because DOE proposed testing under constant ambient conditions, the test procedure may not capture efficiency gains associated with these technologies.3-24

3.12.3 Energy Efficiency

In preparation for the screening and engineering analyses, DOE gathered data on the energy efficiency of residential portable ACs currently available in the m arketplace. These data

are taken from the CEC Appliance Efficiency database. While this section is not intended to provide a complete characterization of the energy efficiency of all portable ACs currently available and in use, it does provide a general ov erview of the energy efficiency of these products

. Figure 3.12

. 2 and Figure 3.12

. 3 display a scatter plot of the energy efficiency data and

a distribution of the capa cities , respectively, of portable ACs currently listed in the CEC product

database.

Figure 3.12

. 2 CEC Energy Efficiency and Capacity Data 0 2 4 6 8 10 12 14 16 18

0 5000 10000 15000 EER (Btu/Wh)

Capacity (Btu/h)3-25

Figure 3.12

. 3 Di stribution of the Capacities of Units in the CEC Database 0 10 20 30 40 50 60 70 80 90 100

<= 6,000 6,001 - 8,000 8,001 - 10,000 10,001 -

12,000 12,001 -

14,000 Number of Models

Capacity Bins (Btu/h)3-26

REFERENCES

1 U.S. Census Bureau. 200 5

– 2011. “Annual Survey of Manufactures: General Statistics: Statistics for Industry Groups and Industries,” ASM . Available online at: http://factfinder2.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=ASM_ 2011_31GS101&prodType=table

.

2 Ibid.

3 Ibid.

4 U.S. Census Bureau, Survey of Plant Capacity , 2004 to 2006.

5 U.S. Census Bureau, Quarterly Survey of Plant Capacity Utilization , 2007 to 2012.

6 www.kingersons.com/how_it_works.html

7 M.H. Kim and C.W. Bullard. 2002. “Performance E valuation of a Window Room Air
Conditioner with Microchannel Condensers.” Journal of Energy Resources Technology

. Vol. 124, Issue 1, pp. 47

– 55.

8 R. Yun, Y. Hwang, R. Radermacher, and R. Zecirovic. 2006. “Comparison of

Performance of Residential Air

- Conditioning System Using Microchan nel and Fin

- and

Tube Heat Exchanger.” International Refrigeration and Air Conditioning Conference at Purdue, July 17

- 20, 2006.

9 Z. Qi, Y. Zhao, J. Chen. 2009. “Performance enhancement study of mobile air conditioning system using microchannel heat excha ngers

. ” International Journal of Refrigeration. Issue 33, pp. 301

- 312.

10 U.S. DOE. 1997. Op. cit.

11 Simmons. 2003. Op. cit.

12 Ibid.

13 H.I. Henderson, Jr. 1990. “A Side

- by

- Side Field Test of Variable

- Speed and Constant

Speed Air Conditioners.” ASHRAE Transactions. 96(1): pp 683

– 692.

14 V. Bahel and S.M. Zubair. 1989. “An Assessment of Inverter

- Driven Variable

- Speed Air Conditioners: Sample Performance Comparison with a Conventional System. ASHRAE

Transactions . 95(1): pp 455

– 464.3-27

15 M. Hori, I. Akamine, and T. Sakai. 1985. “1985. “Seasonal Efficiencies of Residential Heat Pump Air Conditioners with Inverter

- Driven Compressors.” ASHRAE Transactions

. 91(2B): pp 1585

– 1595.