CHAPTER 5. ENGINEERING ANALYSIS

TABLE OF CONTENTS

5.1 INTRODUCTION

................................ ................................ ................................ ........... 5

- 0

5.2 METHODOLOGY OVERVIEW

................................ ................................ .................... 5

- 0

5.3 PRODUCT CLASSES

................................ ................................ ................................ ..... 5

- 2

5.3.1 Furnaces

................................ ................................ ................................ ............... 5

- 2

5.3.2 Central Air Conditioners and Heat Pumps

................................ ........................... 5

- 3

5.4 EFFICIENCY LEVELS AN ALYZED

................................ ................................ ............ 5

- 4

5.4.1 Baseline

................................ ................................ ................................ ................ 5

- 4

5.4.2 I ntermediate Efficiency Levels

................................ ................................ ............ 5

- 5

5.4.3 Max

- tech Efficiency Levels

................................ ................................ ............... 5

- 10

5.5 TEARDOWN ANALYSIS

................................ ................................ ............................ 5

- 12

5.5.1 Selection of Units

................................ ................................ ............................... 5

- 12

5.5.2 Generation of Bill of Materials

................................ ................................ .......... 5

- 16

5.6 COST MODEL

................................ ................................ ................................ .............. 5

- 18

5.6.1 Cost Model Overview

................................ ................................ ........................ 5

- 19

5.6.2 Cost Model Assumptions

................................ ................................ ................... 5

- 20

5.7 MANUFACTURER SELLING PRICE

................................ ................................ ........ 5

- 23

5.7.1 Manufacturer Markup

................................ ................................ ........................ 5

- 23

5.7.2 Shipping Costs

................................ ................................ ................................ ... 5

- 24

5.7.3 MSP in the Downstream Analyses

................................ ................................ .... 5

- 31

5.8 NICHE PRODUCTS

................................ ................................ ................................ ..... 5

- 31

5.8.1 Small Duct High Velocity

................................ ................................ .................. 5

- 31

5.8.2 Space

- Constrained Products

................................ ................................ .............. 5

- 34

5.9 INDUSTRY COST

- EFFICIENCY RELATIONS HIPS

................................ ................ 5

- 37

5.9.1 Furnaces

................................ ................................ ................................ ............. 5

- 37

5.9.2 Central Air Conditioners and Heat Pumps

................................ ......................... 5

- 39

5.10 EXPANSION OF ANALYSE S TO A DDITIONAL CAPACITIES

............................. 5

- 48

5.10.1 Furnaces

................................ ................................ ................................ ........ 5

- 48

5.10.2 Central Air Conditioners and Heat Pumps

................................ ................... 5

- 48

5.11 STAN D BY MODE AND OFF MODE

................................ ................................ ......... 5

- 48

5.11.1 Identification and Characterization of Standby Mode and Off Mode Components

................................ ................................ ................................ ................... 5

- 50

5.11.2 Baseline Model

................................ ................................ ............................. 5

- 50

5.11.3 Cost

- Power Consumption Results

................................ ................................ 5

- 51

5.12 MISCELLANEOUS CENTRA L AIR CONDITIONER AND HEAT PUMP SYSTEM

CHARACTERISTICS

................................ ................................ ................................ ............... 5

- 54

5.12.1 Investigation of the Relationship Between SEER and HSPF

....................... 5

- 54

5. 12.2 Calculation of System Weights

................................ ................................ .... 5

- 58

5.13 RESULTS

................................ ................................ ................................ ...................... 5

- 60

5.13.1 Furnaces

................................ ................................ ................................ ........ 5

- 60

5.13.2 Central Air Conditioners and Heat Pumps

................................ ................... 5

- 61LIST OF TABLES

Table 5.4.1 Baseline Unit AFUE for Residential Furnaces

................................ ......................... 5

- 5 Table 5.4.2 Efficiency Levels for Non

- Weatherized Gas Furnaces

................................ ............ 5

- 6 Table 5.4.3 Efficiency Levels for Mobile Home Gas Furnaces

................................ .................. 5

- 6 Table 5.4.4 Efficiency Levels for Non

- Weatherized Oil Furnaces

................................ ............. 5

- 7 Table 5.4.5 Efficiency Levels for Blower Coil Split System Air Conditioners

.......................... 5

- 8 Table 5.4.6 Efficiency Levels for Coil Only Split System Air Conditioners

.............................. 5

- 8 Table 5.4.7 Efficiency Levels for Split System Heat Pumps

................................ ....................... 5

- 9 Table 5.4.8 Efficiency Levels for Packaged Systems

................................ ................................ .. 5

- 9 Table 5.4.9 Efficiency Levels for SDHV Systems

................................ ................................ .... 5

- 10

Table 5.4.10 Max

- Tech Efficiency Levels for Furnaces

................................ ........................... 5

- 11 Table 5.4.11 Split System Max

- Tech Efficiency Levels by SEER for Central Air Cond itioners and Heat Pumps

................................ ................................ ................................ ......................... 5

- 11 Table 5.4.12 Packaged System and Niche Product Max

- Tech Efficiency Levels by SEER for Central Air Conditioners and Heat Pumps

................................ ................................ ................. 5

- 11

Table 5.4.13 Max

- Tech Efficiency Levels by HSPF for Heat Pumps

................................ ....... 5

- 11 Table 5.5.1 Characteristics of Representative Residential Furnaces

................................ ......... 5

- 13 Table 5.6.1 Cost Model Categories and Descriptions

................................ ................................ 5

- 18 Table 5.6.2 Purchased Central Air Conditioner, Heat Pump, and Furnace Components

.......... 5

- 21 Table 5.6.3 Factory Parameter Assumptions

................................ ................................ ............. 5

- 22 Table 5.7.1 Shipping Costs for Non

- weatherized Gas Furnaces

................................ ............... 5

- 25 Table 5.7.2 Shipping Costs for Mobile Home Gas Furnaces

................................ .................... 5

- 25 Table 5.7.3Shipping Costs for Oil

- Fired Furnaces

................................ ................................ .... 5

- 25 Table 5.7.4 Shipping Dimensions for Non

- weatherized Gas Furnaces (60 kBtu/h and 80 kBtu/h Input Capacity)

................................ ................................ ................................ ........................... 5

- 25 Table 5.7.5 Shipping Dimensions for Non

- weatherized Gas Furnaces (100 kBtu/h and 120 kBtu/h)

................................ ................................ ................................ ................................ ....... 5

- 26 Table 5.7.6 Shipping Dimensions for Mobile Home Furnaces (80 kBtu/h Input Capacity)

..... 5

- 26 Table 5.7.7 Shipping Dimensions for Oil

- Fired Furnaces (105 kBtu/h Input Capacity)

........... 5

- 26 Table 5.7.8 Shipping Costs for Split System Central Air Conditioners and Heat Pumps

......... 5

- 26 Table 5.7.9 Shipping Costs for Single Package Central Air Conditioners and Heat Pumps and SDHV Systems

................................ ................................ ................................ .......................... 5

- 27 Table 5.7.10 2 Ton Split Sys tem Air Conditioner Shipping Dimensions

................................ .. 5

- 27 Table 5.7.11 2 Ton Split System Heat Pump Shipping Dimensions

................................ ......... 5

- 28

Table 5.7.12 3 T on Split System Air Conditioner Shipping Dimensions

................................ .. 5

- 28 Table 5.7.13 3 Ton Split System Heat Pump Shipping Dimensions

................................ ......... 5

- 29

Tabl e 5.7.14 5 Ton Split System Air Conditioner Shipping Dimensions

................................ .. 5

- 29 Table 5.7.15 5 Ton Split Heat Pump Shipping Dimensions

................................ ...................... 5

- 30 Table 5.7.16 Single Package Air Conditioner Shipping Dimensions

................................ ........ 5

- 30 Table 5.7.17 Single Package Heat Pump Shipping Dimensions

................................ ............... 5

- 30 Table 5.7.18 SDHV Shipping Dimensions*

................................ ................................ .............. 5

- 31

Table 5.9.1 Additional Cost to Switch from PSC to ECM Blower Motor for Furnaces

........... 5

- 39 Table 5.11.1 Baseline Standby Mode and Off Mode Power Consumption by Component for

Furnaces

................................ ................................ ................................ ................................ ..... 5

- 51Table 5.11.2 Non

- weatherized Gas, Mobile Home Gas, and Electric Furnace Standby Mode and Off Mode Power Consumption and Cost

................................ ................................ ................... 5

- 52

Table 5.11.3 Oil

- fired Furnace Standby Mode and Off Mode Power Consumption and Cost

.. 5

- 53 Table 5.11.4 Split System Blower Coil, Packaged, and Space Constrained Air Conditioner Off Mode Power Consumption and Cost

................................ ................................ ......................... 5

- 53 Table 5.11.5 Coil Only Split System Air Conditioner Off Mode P ower Consumption and Cost

. 5

- 53 Table 5.11.6 Split System, Packaged and Space Constrained Heat Pump Off Mode Power Consumption and Cost

................................ ................................ ................................ ............... 5

- 54 Table 5.12.1 Comparison of Three Ton HSPF Standard Levels with Available Products

........ 5

- 55 Table 5.12.2 Prevalence of HSPF Ratings by SEER Level for Three Ton Split System Heat Pumps w ith Impacts of Suggested HSPF Standards

................................ ................................ .. 5

- 56 Table 5.12.3 SEER/HSPF Relationship for Two and Five Ton Split Heat Pumps

................... 5

- 56

Tabl e 5.12.4 HSPF Standard Levels for Single Package Heat Pumps

................................ ...... 5

- 57 Table 5.12.5 Median HSPF Levels for SDHV Heat Pumps

................................ ...................... 5

- 58

Table 5.12.6 Calculated Typical Split

- System Air Conditioner Unit Weights

.......................... 5

- 58 Table 5.12.7 Calculated Typical Split

- System Heat Pump Unit Weights

................................ . 5

- 59 Table 5.12.8 Calculated Typical Packaged Air Conditioner Unit Weights

............................... 5

- 59 Table 5.12.9 Calculated Typical Packaged Heat Pump Unit Weights

................................ ...... 5

- 60 Table 5.12.10 Calculated Typical SDHV Unit Weights*

................................ .......................... 5

- 60

Table 5.13.1 Cost

- Efficiency Data for Non

- weatherized Gas Furnaces with a PSC Blower Motor

................................ ................................ ................................ ................................ .................... 5

- 60

Table 5.13.2 Cost

- Efficiency Data for Mobile Home Gas Furnaces (80 kBtu/h Input Capacity)

with a PSC Blower Motor

................................ ................................ ................................ .......... 5

- 61

Table 5.13.3 C ost

- Efficiency Data for Oil

- Fired Furnaces (105 kBtu/h Input Capacity) with a

PSC Blower Motor

................................ ................................ ................................ ..................... 5

- 61

Table 5.13.4 Cost

- Efficiency Data for Two Ton Split

- System Air Conditioners: Blower

- Coil 5

- 61

Table 5.13.5 Cost

- Efficiency Data for Three Ton Split

- System Air Conditioners: Blower

- Coil

. 5

- 63

Table 5.13.6 Cost

- Efficiency D ata for Five Ton Split

- System Air Conditioners: Blower

- Coil 5

- 63

Table 5.13.7 Cost

- Efficiency Data for Two Ton Split

- System Air Conditioners: Coil

- Only

... 5

- 64

Table 5.13.8 Cost

- Efficiency Data for Three Ton Split

- System Air Conditioners: Coil

- Only

. 5

- 64

Table 5.13.9 Cost

- Efficiency Data for Five Ton Split

- System Air Condi tioners: Coil

- Only

... 5

- 65

Table 5.13.10 Cost

- Efficiency Data for Two Ton Split

- System Heat Pumps

........................... 5

- 65

Table 5.13.11 Cost

- Efficienc y Data for Three Ton Split

- System Heat Pumps

......................... 5

- 66

Table 5.13.12 Cost

- Efficiency Data for Five Ton Split

- System Heat Pumps

........................... 5

- 66

T able 5.13.13 Cost

- Efficiency Data for Single

- Package Air Conditioners

............................... 5

- 67

Table 5.13.14 Cost

- Efficiency Data for Single

- Package Heat Pumps

................................ ....... 5

- 67 Table 5.13.15 Cost Efficiency Data for SDHV Systems

................................ ........................... 5

- 67

LIST OF FIGURES

Figure 5.2.1 Engineering Analysis Methodology

................................ ................................ ........ 5

- 2 Figure 5.5.1 Efficiencies of Non

- weatherized Gas Furnaces Selected for Teardown

............... 5

- 14 Figure 5.5.2 Efficiencies of Split

- System Outdoor Units Selected fo r Teardown

..................... 5

- 15 Figure 5.5.3 Illustration of System Combinations for Split Systems

................................ ........ 5

- 16Figure 5.5.4 Example of BOM Spreadsheet

................................ ................................ .............. 5

- 18 Figure 5.6.1 Cost Model Methodology

................................ ................................ ...................... 5

- 19 Figure 5.7.1 Components of Manufacturer Selling Price

................................ .......................... 5

- 23 Figure 5.9.1 Illustration of Four Manufacturers’ Absolute Cost versus SEER Relationship

.... 5

- 41 Figure 5.9.2 Illustration of System Cost Translation Proce ss

................................ .................... 5

- 42 Figure 5.9.3 Illustration of Cost Trends

................................ ................................ ..................... 5

- 435

- 0 CHAPTER 5. ENGINEERING ANALYSIS

5.1 INTRODUCTION

The engineering analysis establishes the relationship between manufactu rer selling price (MSP) and energy

- efficiency ( i.e. , annual fuel utilization efficiency (AFUE) for furnaces, seasonal energy efficiency ratio (SEER ) for the residential central air conditioners and heat

pumps , and heating seasonal performance factor (HSPF) for heat pumps) for the products covered in this rulemaking. The cost

- efficiency relationship serves as the basis for subsequent cost/benefit calculations for individual customers, manufacturers, and the Nation. In determining this relationship, the U.S. Department of Energy (DOE) estimates the increase in the manufacturer selling price associated with technological changes that reduce the energy consumption of the baseline models.

The primary inputs to the engineering analysis are data from the market an d technology assessment (chapter 3 in the TSD), input from manufacturers, baseline specifications

, and production cost estimates developed using a cost model. The primary output of the engineering analysis is a set of cost

- efficiency relationships that rep resent the average incremental cost of increasing product efficiency above the baseline levels. In the subsequent markups analysis (chapter 6 in the TSD), DOE determines customer prices by applying distribution markups, sales tax, and contractor markups to the manufacturer sales prices (MSPs) developed in the engineering analysis. After applying these markups, the data serve as inputs to the energy use characterization (chapter 7 in the TSD) and the life

- cycle cost and payback period analyses (chapter 8 in the TSD).

In this chapter, DOE discusses : (1) the identification of representative baseline units for

each product class, (2) the methodology used to develop bill s of materials (BOMs) and MSPs, (3) the process for co nstructing the industry cost

- efficienc y relationship s, (4) the development of an engineering examination of niche product classes of central air conditioners and heat pumps, (5) the cost

- efficiency relationship outputs , (6) the scaling of the representativ e analysis to other capacities, (7) th e development of an engineering examination for analysis of standby mode and off mode energy consumption, and (8) the results of the engineering analysis.

5.2 METHODOLOGY OVERVIEW

This section describes the analytical methodology used in the engineering analys is. In this rulemaking, DOE adopted a combination of an efficiency

- level approach (to identify incremental improvements in efficiency for each product class) and a cost

- assessment approach (to develop a cost for each efficiency level) for the analysis of t he AFUE

, SEER, and HSPF efficiency levels, which estimates the incremental cost of increasing product efficiency. (The standby and off mode analysis was performed using a design option approach, which is5

- 1 discussed further in section 5.11 of this chapter). In combination with the efficiency

- level approach, the cost

- assessment approach allowed DOE to determine the manufacturing production cost (MPC) at each efficiency level identified for analysis.

The cost

- assessment is based on teardown data and was validated by manufacturer input. First, DOE used information gathered from manufacturers and /or data from the market and technology assessment and screening analysis to identify baseline units and representative

models and select ed a set of units at the baseline and higher efficiencies for teardown analysis. The baseline unit serves as a starting point for the analysis

, and the units selected for teardown analysis span a range of manufacturers, functionality

, and efficiencies for com mercially available products. A teardown analysis was also conducted for several units outside the representative capacities determined by DOE

, so DOE could accurately scale its analysis at the representative capacity to other capacities. DOE developed a u nit cost estimate for the each of the units selected

for teardown by disassembling each unit , developing a bill of materials

, and inputting the results

i nto a manufacturing cost model, which calculated the MPC.

To determine the MSP of a unit at each effic iency level, DOE applied derived manufacturer markups and added the estimated shipping cost to the MPC. To derive the manufacturer markup, DOE added a typical profit to the fully absorbed cost of product ion by using publicly available industry financial da ta and manufacturer feedback

. DOE developed shipping costs for each product based on the product’s shipping dimensions and the size and cost of a typical trailer. DOE added the shipping costs to the marked

- up MPC to get the total MSP.

The results of the en gineering analysis are a set of cost

- efficiency relationship s, in the form of

MSP versus energy

- efficiency , for each product class. The methodology for the engineering analysis is a logical, concise, and reproducible process, as illustrated in Figure 5.2

. 1

.5

- 2 Figure 5.2

. 1 Engineering Analysis Methodology

5.3 PRODUCT CLASSES

5.3.1 Furnaces

The rulemaking analysis plan (RAP) for furnaces

**•** Gas furnaces (weatherized and non

- weatherized), outlined seven classes of

furna ces:

**•** Oil

- fired furnaces (weatherized and non

- weatherized),

**•** Mobile home furnaces (gas

- fired and oil

- fired), and

**•** Electric furnaces.

Based on the market and technology assessment (MTA, chapter 3) , screening a nalysis (chapter 4) , and stakeholder comments in the November 2007 rule, DOE maintained the same scope of analysis that was used in the previous rulemaking for its analysis of amended AFUE

standards . DOE maintained that due to very low shipment volumes (es sentially zero), mobile

home oil

- fired furnaces and weatherized oil

- fired furnaces have a low potential for energy savings ; and DOE excluded those products from consideration in this analysis. Further, DOE Cos t Model Manufacturer Markup Analysis

Cost

- Efficiency

Relationship (Efficiency vs MPC)

Engineering

Manufacturer

Interviews Physical

Teardown Analysis Virtual

Teardown Analysis

BOMs Selling Price

Efficiency Relationship (Efficiency vs MSP) Baseline unit, Efficiency levels,

Representative

Products

Market and Tech

Assessment (chapter 3) Screening Analy sis (chapter 4) Shipping Cost5

- 3 determined that electric furnaces on the market al ready approach the maximum possible efficiency for those products, and thus, there is little potential for energy savings from those products as well. (DOE found that the reports of furnace manufacturers to the FTC list the efficiency for electric furnaces with a low and a high value of 100

- percent AFUE.) Lastly, when considering weatherized gas furnaces, DOE determined in the market assessment that no furnaces on the market currently exceed the standard set by the November 2007 final rule of

81

- percent AFU E. In addition, during the technology assessment and screening analysis, DOE did not find any viable technologies or prototype designs that allow weatherized gas furnaces to

exceed 81

- percent AFUE. Therefore, because these products already approach the max

- tech efficiency, DOE did not analyze amended AFUE standards for those products

DOE analyzed amended AFUE standards for the following products: (1) non

weatherized gas furnaces, (2) mobile home gas furnaces, and (3) non

- weatherized oil

- fired

furnaces. Addi tionally, DOE analyzed new standby and off mode requirements for the three product classes listed above, as discussed in section 5.11 of this chapter

. DOE also considered standby mode and off mode standards for electric furnaces. DOE did not separately consider new standby and off mode standards for weatherized gas furnaces because those products are always sold as part of a single package air conditioner or heat pump system, and thus, the standby and off mode en ergy consumption are already accounted for as part of SEER and the off mode standards analysis performed for central air conditioners and heat pumps. DOE did not analyze standby and off mode standards for mobile home oil

- fired furnaces and

weatherized oil

- fired furnaces for the same reasons it did not analyzed amended AFUE standards, described above.

5.3.2 Central Air Conditioners and Heat Pumps

As discussed in the MTA (chapter 3 of the TSD), DOE identified the following product classes for its analysis of centra l air conditioners and heat pumps

.

**•** Split

- system air conditioners

**•** Split

- system heat pumps

**•** Single

- package air conditioners

**•** Single

- package heat pumps

**•** Small duct, high velocity systems

**•** Space

- constrained air conditioners

**•** Space

- constrained heat pumps

Conventio nal products include the first four classes (split

- system air conditioners, split

system heat pumps, single

- package air conditioners, and single

- package heat pumps). Niche products include the last three classes (small duct, high velocity systems, space

- c onstrained air conditioners, and space

- constrained heat pumps). The space

- constrained product classes are assumed to include through

- the

- wall air conditioners and heat pumps (both split and single5

- 4 package), because through

- the

- wall products no longer exist after January 23, 2010. a

5.8 Therefore,

DOE did not consider those two product classes separately

. The niche product classes are discussed separately and in further detail in section

.

5.4 EFFICIENCY LEVELS AN ALYZED

DOE analyzed mu ltiple efficiency levels for each product class presented in section 5.3 and estimated the manufacturer production costs at those levels. The following subsections provide the full efficiency range from the baseline to maximum technologically feasible (“max

tech”) efficiency for each product class. DOE identified the highest efficiency level by reviewing product literature for commercially available products.

5.4.1 Baseline

DOE selected baseline units as reference points for each pro duct class, against which changes resulting from potential amended energy conservation standards could be measured. The baseline unit in each product class displays the basic characteristics of products in that class. Typically, a baseline unit is a unit t hat just meets, but does not exceed current Federal energy conservation standards and provides basic consumer utility.

DOE used the baseline units for comparison in several analyses, including the engineering analysis, life

- cycle cost (LCC) analysis, payb ack period (PBP) analysis, and national impacts analysis (NIA). To determine energy savings that will result from an amended energy conservation standard, DOE compared energy use at each of the higher energy efficiency levels to the energy consumption of t he baseline unit. Similarly, to determine the changes in price to the consumer that will result from an amended energy conservation standard, DOE compared the price of a baseline unit to the price of a unit at each higher efficiency level.

The identificati on of baseline units requires establishing the baseline efficiency level. In cases where there is an existing standard, DOE defines baseline units as units with efficiencies equal to the current Federal energy conservation standards.

5.4.1.1 Furnaces

The current Federal energy conservation standards for residential furnaces, as measured by AFUE, became effective on January 1, 1992. (42 U.S.C. 6295(f)). However, the November 2007 final rule for furnaces and boilers amended those standards with a compliance date of November 19, 2015. Due to EPCA’s anti

- backsl iding clause, DOE is prohibited from adopting levels below those previously adopted in the November 2007 final rule. As a result, DOE used

a As defined in 10 CFR 430.2, the through

- the

- wall product class applies only to products manufactured prior to January 23, 2010. This provision eliminates through

- the

- wall units as a separate product class after this date.5

- 5 those levels as the baseline efficiency levels in the analysis. Table 5.4.1 presents the baseline unit’s AFUE for each product class of residential furnaces.

Table 5.4

. 1 Baseline Unit AFUE for Residential Furnaces

Product Class Minimum AFUE Rating

%

Non

- weatheriz ed Gas 80

Mobile Home Gas Furnaces 80

Oil

- fired Non

- weatherized Furnaces 82

In order to derive incremental MPCs for intermediate efficiency levels, DOE first identified baseline units, which meet, but do not exceed

, the baseli ne level. Typically, the baseline units are representative of the minimum technology and lowest cost product that manufacturers can produce. In the teardown analysis (see section 5.5 ) the baseline units were a reference point f or determining the cost

- efficiency relationship of units with higher energy efficiencies. DOE compared the design features incorporated into products at the baseline efficiency to units with higher energy efficiencies to determine the change in manufacturi ng, installation, and operating costs (chapter 8).

5.4.1.2 Central Air Conditioners and Heat Pumps

The identification of baseline for central air conditioners and heat pumps units required establishing both a minimum efficiency level (minimum SEER rating) and capa city which best represented the span of capacities of commercially available products. Currently, the standards for conventional central air conditioners and heat pumps (split

- system air conditioners, split

system heat pumps, single

- package air conditioner s, and single

- package heat pumps) are set at 13 SEER/7.7 HSPF. Thus, conventional units that attain only the minimum efficiency rating of 13 SEER/7.7 HSPF will be considered baseline units for those product classes. DOE selected a model or models meeting t he existing minimum Federal energy efficiency standards that are currently offered for sale as baseline products.

5.4.2 Intermediate Efficiency Levels

DOE established intermediate energy efficiency levels for each product class. The intermediate efficiency leve ls are representative of the most common efficiency levels available on the market that manufacturers achieve by employing different technologies that will maintain

cost

- effective designs while increasing energy efficiency. DOE reviewed AHRI’s product

cert ification directories

, 1

5.13 manufacturer catalogs, and other publicly available literature to determine which efficiency levels are the most prevalent for each product class. For each of the representative products, DOE analyzed multiple efficiency levels and estimated manufacturer production costs at each efficiency level. Section contains cost efficiency data for the full efficiency level range that DOE analyzed from the baseline efficiency level to the max tech efficiency le vel for each product class.5

- 6 5.4.2.1 Furnaces

For non

- weatherized gas furnaces, DOE analyzed three efficiency levels in addition to

the baseline and the max

- tech. The efficiency levels were determined by the most commonly shipped furnace AFUEs, and representative units at each efficiency level have the most commonly used efficiency

- related technologies and characteristics. DOE chose each of these efficiency levels because the incremental gains in efficiency correspond to common techniques and technologies manufact urers use to increase energy efficiency. For non

- weatherized gas furnaces, manufacturers use a condensing, secondary heat exchanger to reach efficiency levels 1 and higher. To improve the efficiency further manufacturers increase the surface area of the he at exchangers (primarily of the secondary heat exchanger), which allows manufacturers to achieve efficiency levels 2 and 3. At efficiency level 3, the heat exchanger size is generally maximized to the point that the cabinet begins to constrain further enla rgement ; and as a result, manufacturers

use modulation to achieve the max

- tech efficiency level. As described in the market and technology assessment (chapter 3 of this TSD), modulation allows products to match the actual heating load more closely. To achi eve modulation, manufacturers must implement several components, including a modulating gas valve, multi

- speed inducer fan, and additional controls.

Table 5.4

. 2 Efficiency Levels for Non

- Weatherized Gas Furn aces Efficiency Level AFUE

%

0

– Baseline 80

1 90

2 92

3 95

4

– Max

- tech 98

For mobile home gas furnaces, DOE selected four efficiency levels between the baseline

and max

- tech levels. At and above efficiency level 1, manufacturers incorporate a cond ensing, secondary heat exchanger into the furnace design. Efficiency levels above efficiency level 1 are typically achieved by use of larger or more effective heat exchangers.

Table 5.4

. 3 Efficiency Levels for Mobile Home Gas Furnaces Efficiency Level AFUE

%

0

– Baseline 80

1 90

2 92

3

– Max

- tech 965

- 7 For oil

- fired furnaces, DOE analyzed three efficiency levels between the baseline and

max

- tech. Manufacturers increase energy efficiency of oil

- fired furnace s primarily by improving the heat exchanger design. To achieve the max

- tech efficiency level, manufacturers must incorporate a condensing secondary heat exchanger made from corrosion

- resistant materials.

Table 5.4

. 4 Efficiency Levels for Non

- Weatherized Oil Furnaces Efficiency Level AFUE

%

0

– Baseline 82

1 83

2 84

3 85

4

– Max

- tech 97

5.4.2.2 Central Air Conditioners and Heat Pumps

For split system air conditioners, DOE analyzed up to thirteen efficiency levels in

addition to the baseline and the max

- tech depending on the nominal cooling capacity . The efficiency levels were determined by the most commo nly shipped SEER values with representative units at each efficiency level have the most commonly used efficienc y

- related technologies and characteristics. For split system air conditioners, manufacturers increase the

surface area of the heat exchanger s to reach efficiency levels 1 and higher. To improve the efficiency further manu facturers increase the use of modul ating equipment as efficiency levels

increase. As described in the market and technology assessment (chapter 3 of this TSD), modulation allows products to match the actual cooling load more closely. To achieve modulation, manufacturers must implement sever al c omponents, including a multi stage compressor, variable speed fan motors , and additional controls.5

- 8 Table 5.4

. 5 Efficiency Levels for Blower Coil Split System Air Conditioners

SEER
Efficiency Level 2 Ton 3 Ton 5 Ton

0

– Baseline 13 13 13

1 13.5 13.5 13.5

2 14 14 14

3 14.5 14.5 14.5

4 15 15 15

5 15.5 15.5 15.5

6 16 16 16

7 16.5 16.5 16.5

8 17 17 17

9 18 18

10 19 19

11 20 20

12 21 21

13 22

14 23

15

- Max Tech 24.5 22 18

To impro ve from the baseline efficiency level, coil only units follow a similar path to the blower coil units and DOE analyzed up to 8 levels in addition to the baseline and max tech. However, because coil only units do not have an indoor fan, these units are not capable of achieving the same high efficiency levels as for blower coil units. Additionally, because improving the indoor fan is not an option, manufacturers tend to increase the size of the coil at a faster rate for coil only units than for the blower coi l units.

Table 5.4

. 6 Efficiency Levels for Coil Only Split System Air Conditioners

SEER
Efficiency Level 2 Ton 3 Ton 5 Ton

0

– Baseline 13 13 13

1 13.5 13.5 13.5

2 14 14 14

3 14.5 14.5 14.5

4 15 15 15

5 15.5 15.5 15.5

6 16 16

7 16.5 16.5

8 175

- 9 9

- Max Tech 18 17 16

For split system heat pumps, the pathway of efficiency improvements is also similar to the split system blower coil air conditioners. First, the surface area of the heat exchanger s is increased, followed by improvements to fan motors ( i.e. ECM motors) and modulating equipment. However, heat pumps have additional losses associated with the reversing valve, which enables the heat pump to provide both heating and cooling and also with trying to optimize for both heating and cooling, instead of just cooling. For split system heat pumps, DOE analyzed up to twelve additional efficiency levels depending on the cooling capacity.

Table 5.4

. 7 E fficiency Levels for Split System Heat Pumps

SEER Efficiency

Level 2 Ton 3 Ton 5 Ton

0

– Baseline 13 13 13

1 13.5 13.5 13.5

2 14 14 14

3 14.5 14.5 14.5

4 15 15 15

5 15.5 15.5 15.5

6 16 16 16

7 16.5 16.5 16.5

8 17 17 17

9 18 18

10 19 19

11 20 20

12 21

13

– Max Tech 22 21 18

Packaged systems have slightly different constraints from split systems because all components must fit within a single package. This requirement places a premium on space and

also creates additional losses which prevent units from achieving the same efficiency levels as split system units, and therefore, there six analyzed efficiency levels between the baseline and

max tech.

Table 5.4

. 8 Efficiency Levels for Packag ed Systems5

- 10 Packaged AC Packaged Heat Pump
Efficiency Level SEER SEER

0

– Baseline 13 13

1 13.5 13.5

2 14 14

3 14.5 14.5

4 15 15

5 15.5 15.5

6 16 16

7

– Max Tech 16.6 16.4

As discussed in chapter 5 of this TSD, SDHV units are matched with an outdoor unit

from a conventional manufacturer

, and SDHV systems achieve higher efficiency by pairing with a higher efficiency outdoor unit. However, the unique operating characteristics of these systems prevent them from achieving the same incremental effi ciency increases that conventional systems do ( i.e. increasing the outdoor unit efficiency by one SEER does not improve the SEER of the combined SDHV system by one SEER) and le a d to only two efficiency levels in addition

to the baseline and the max tech.

Table 5.4

. 9 Efficiency Levels for SDHV Systems
Efficiency Level SEER

0

- Baseline 13

1 13.5

2 14

3

– Max Tech 14.3

5.4.3 Max

- tech Efficiency Levels

As part of the engineering analysis, DOE determined the maxi mum technologically feasible improvement in energy efficiency for the covered product s, as required by section 325(o) of EPCA. (42 U.S.C. 6295(o)) In the market and technology assessment (chapter 3 of this TSD), DOE conducted a survey of the market s for th e covered products and their supporting

research areas. The max

- tech product in each product class was the highest efficiency product

and no working products or prototypes are currently available at efficiency levels above that of

the max

- tech product.

5.4.3.1 Fu rnaces

The max

- tech levels identified for furnaces are shown in Table 5.4

. 10

. For non

weatherized gas furnaces, DOE identified a max

- tech efficiency level design with a condensing secondary heat exchanger and modulating operation, resulting in an AFUE of 98 percent. For5

- 11 mobile home gas furnaces, DOE identified the max

- tech efficiency level as 96 percent AFUE, which can be reached using a condensing secondary heat exchanger, along with an increased heat exchanger area . For oil

- fired furnaces, DOE identified the max

- tech efficiency level as 97 percent AFUE. Manufacturers are able to achieve this efficiency level by incorporating condensing heat exchanger technology into the oil furnace.

Table 5.4

. 10 Max

- Tech Efficiency Levels for Furnaces

Product Class Representative Input Capacity ( Btu/h ) Max

- Tech Efficiency Level ( AFUE )

Non

- Weatherized

Gas 75,000 98

Mobile Home Gas 80,000 96

Non

- Weatherized Oil 105,000 97

5.4.3.2 Central Air Conditioners and Heat Pumps

The highest efficiency level in each of the seven product classes was identified through a review of products listed in the AHRI certified directories , manufacturer catalogs, and other publicly available documents

. The max

- tech efficiency l evels are shown in Table 5.4

. 11

, Table

5.4

. 12 , and Table 5.4

. 13

.

Table 5.4

. 11 Split System Max

- Tech Efficiency Levels by SEER for Central Air Conditioners and Heat Pumps Split AC : Blower

- coil Split AC: Coil

- only b Split HP

2 Ton 3 Ton 5 Ton 2 Ton 3 Ton 5 Ton 2 Ton 3 Ton 5 Ton

Max Tech Efficiency Level 24.5 22 18 18 17 16 22 21 18

Table 5.4

. 12 Packaged System and Niche Product Max

- Tech Efficiency Levels by SEER for Central Air Conditioners and Heat Pumps Packaged

AC Packaged

HP Space

- Constrained

AC Space

- Constrained

HP SDHV

Max Tech Efficiency Level 16.6 16.4 12 12 14.3

Table 5.4

. 13 Max

- Tech Efficiency Levels by HSPF for Heat Pumps

b Blower

- coil and coil

- only split air conditioners are contained within a single product class, split air conditioners.5

- 12 Split HP Packaged

HP SDHV

2 Ton 3 Ton 5 Ton 3 Ton 3 Ton

Max Tech Efficiency Level 10.30 10.70 9.75 9.00 8.90

In the preliminary analysis of split sys tem air conditioners and heat pumps , DOE only

examined products at the representative three

- ton capacity . For the final rule , DOE performed additional analyses for two

- and five

- ton products. Therefore, the efficiency levels analyzed for split system prod ucts were expanded to include the relevant efficiency levels at the additional cooling capacities. For single package central air conditioners and heat pumps, as well as SDHV systems, the efficiency levels did not change from the preliminary analysis.

For space

- constrained products, the AHRI c ertifi cation d irectory listings and manufacturer catalogs only contain units rated at a single efficiency level. DOE defined the baseline for space

- constrained products as the baseline efficiency on the market ( i.e., 12 SEER). However, this baseline SEER value coincided with the max

- tech value ; therefore

, the standards

cannot be raised above the current level of 12 SEER

. Further discussion on this topic is

contained in section 5.8.2

.

5.5 TEARDOWN A NALYSIS

Other than obtaining detailed manufacturing costs directly from a manufacturer, the most accurate method for determining the production cost of a product is to disassemble it piece

- by

piece, compile a bill of materials (BOM), and estimate the mate rial and labor cost of each component. DOE refers to this practice as a physical teardown. A suppleme ntary method, called a catalog teardown (or “virtual teardown”) , uses published manufacturer product literature and supplementary component data to estima te the major physical differences between the catalog teardown unit and a similar physical teardown unit. One alternative to the teardown method is to conduct price surveys to determine the production cost instead , but this price survey approach only provi des insight into costs under the current standards, whereas the teardown approach provides insight into how products may change due to amended energy conservation standards

.

Units selected for physical teardowns were dismantled, and each part was charac terized according to weight, manufacturing processes, dimensions, material, and quantity, in order to facilitate the creation of a complete BOM for the product. Bills of materials for catalog teardowns are generated by modifying the BOM of a similar unit t hat has been physically torn down to reflect major physical differences. These modifications are based on data taken from manufacturer specification sheets and supplementary component data.

5.5.1 Selection of Units5

- 13 5.5.1.1 Furnaces

For the teardown analysis of furnace s, DOE included 39 physical teard owns and 31

additional virtual teardowns

. DOE identified and selected representative units across the entire range of efficiencies that are currently available to consumers. To the extent possible, all major efficiency leve ls and technologies were captured in the selection of models for teardown analysis. Each product class was considered separately.

Teardown units must be representative of the product class, and as such the input capacities and characteristics of the tear down units were chosen as close as possible to the representative input capacity and characteristics for each respective product class shown in Table

5.5.1 . DOE also required that teardown units be manufactured in considerable volume, be commonly available, and have the most popular features.

Table 5.5

. 1 Characteristics of Representative Residential Furnaces

Product

Class Input Capacity

Btu/h Blower Capacity

cfm Confi guration Heat Exchanger Type Ignition Draft

Non

Weatherized

Gas Furnaces 80,000 1200 Upflow Clamshell/

Tubular Hot

Surface Induced

Mobile Home

Gas Furnaces 80,000 1200 Downflow Clamshell/

Tubular Hot

Surface Natural

Non

Weatherized

Oil Furnaces 105,000 12 00 Upflow Drum Intermittent Ignition Forced

DOE also adopted more specific criteria to guide the selection process. In order to understand incremental manufacturing costs in improving efficiency, products chosen for

teardowns were taken from the same man ufacturer and product series to the extent possible. This

minimized the cost effects of non

- efficiency

- related design differences between models. The manufacturers that were chosen have large market shares of the particular product class. DOE made an excep tion to this criterion for the highest efficiency product (or max

- tech product) in each product class; as such, the max

- tech products for teardown were chosen irrespective of manufacturer. The teardown selections used for the analysis of amended AFUE stand ards also

minimized the occurrence of non

- efficiency

- related premium features, which could inflate the incremental manufacturing cost of achieving higher

- efficiency levels. However, for consideration in the standby and off mode analysis, DOE did analyze se veral furnaces with premium features because these features impact the standby and off mode power consumption.

DOE surveyed the residential furnaces industry and identified products available to consumers as well as prototypes developed by manufacturers’ r esearch efforts. DOE then applied the aforementioned criteria and selected baseline, intermediate, and max

- tech units that were as5

- 14 close to the representative characteristics as possible, met the energy efficiency levels being analyzed, and included the mo st prevalent technologies on the market. In several cases, DOE substituted a virtual teardown in the place of a physical teardown. For example, if two furnaces differed only by an extra heat exchanger tube, one was physically torn down and the additional

m aterial and manufacturing costs ( e.g. , extra sheet metal, additional burner orifice, additional heat exchanger tube) were added to the cost of the physically torn down model to determine the MPC of the virtually torn down model.

Because the large majority of residential furnace shipments fall into the non

- weatherized gas product class, DOE focused its teardown analysis heavily on non

- weatherized gas

- fired furnaces. As a result, DOE selected units for teardown that include 25 non

- weatherized gas

- fired

furnac es, 6 mobile home gas

- fired furnaces, and 8 non

- weatherized oil

- fired furnaces. The furnaces selected spanned the range of efficiency levels from baseline to max

- tech being analyzed for each product class

. Figure 5.5

. 1 shows the efficiencies of products analyzed for the

non

- weatherized gas furnace analysis. DOE examined products with both PSC and ECM blower motors, as well as single stage, two stage, and fully modulating burner operation. Lastly, DOE conducted physical teardowns o f a unit at an input capacity both above and below the representative input capacity to allow the analysis to be accurately scaled to the full range of input capacities analyzed. DOE did not identify the model number or manufacturer of the units

examined d uring the teardown analysis because this could expose sensitive information about individual manufacturers’ products.

Figure 5.5

. 1 Efficiencies of Non

- weatherized Gas Furnaces Selected for Teardown

5.5.1.2 Central Air Conditioners and Heat Pumps5

- 15 The tear down analysis performed for the central air conditioners and heat pumps engineering analysis includes a total of 24 physical teardowns, including 1 2 outdoor units (see Figure 5.5

. 2 ) , 8 indo or units, and 3 evaporator coils. The 12 outdoor units consisted of one 13

SEER /8.2 HSPF heat pump and 11 air conditioners of varying efficiency levels. It also included 7 catalog teardowns for indoor units. Regarding the representative capacity, this rule making applies to units with capacities below 65,000 Btu /h . For conventional and SDHV product classes, 36,000 Btu /h ( i.e.

, three

- tons) was selected as the representative capacity for analysis because units at this capacity are ubiquitous across manufacture rs, have high sales volumes, and span a relatively large range of efficiencies. Baseline units serve as a starting point for the engineering analysis and guide the selection process for the teardown analysis. DOE acknowledges, however,

that manufacturers t end to optimize residential central air conditioner and heat pump systems

around the three

- ton capacity. DOE perform ed additional engineering analyses on two

- and five

ton capacity products to account for potential capacity

- related impacts on the cost

- effi ciency relationship (see section 5.10 ).

Figure 5.5

. 2 Efficiencies of Split

- System Outdoor Units Selected for Teardown

The collection of products selected for teardown is intend ed to closely represent the market and expose the incremental cost of increasing product efficiency. To accomplish this, DOE selected the products for physical teardown and catalog teardown based on the following guidelines:

The selected products, taken t ogether, cover the full range of efficiency levels considered in the analysis with emphasis placed on efficiencies in the 13

- 16 SEER range. Figure 5.5

. 35

- 16 illustrates how indoor and outdoor units from a single manufacturer can be co mbined to provide multiple ratings.

OUTDOOR UNIT SEER INDOOR UNIT

Figure 5.5

. 3 Illustration of System Combinations for Split Systems

From most manufacturers, DOE selected at least one low

- efficiency product and one high

efficiency product, preferably sharing similar characteristics ( e.g. , same product line). The selected products are produced by manufacturers that have relatively large market shares in the residential central air conditioning market, and thus are representative of typical design approaches. The selected products have minimal product features o r options that add cost

without affecting product efficiency. For split

- systems , indoor products were selected based on universality (ability to be paired with selected outdoor units) to maximize the number of systems

that could be modeled.

5.5.2 Generation of Bill of Materials

The end result of each teardown i s a structured BOM, describi ng each product component and its relationship to the other parts in the estimated order in which manufacturers assembled them. The BOMs describe each fabrication and assembly operation in detail, including the type of product needed ( e.g. , presses, drills ) and the process cycle times. The result is a thorough and explicit model of the production process. The BOMs incorporate all materials, components, and fasteners classified as either raw materials or purchased parts and assemblies. The classification

int o raw materials or purchased parts is based on DOE’s previous industry experience, recent information in trade publications, and discussions with high

- and low

- volume original equipment manufacturers (OEMs). DOE also visited several manufacturing plants to reinforce its understanding of the industry’s current manufacturing practices. Information was gathered to account for product designs specific to furnaces, central air conditioners

, and heat pumps and ensure that the teardown analysis methodology and pri cing were accurate. For purchased parts,

OUTDOOR UNIT

- A

OUTDOOR UNIT

- B

OUTDOOR UNIT

- C INDOOR UNIT

- A

INDOOR UNIT

- C INDOOR UNIT

- B 13

14

16

18

205

- 17 the purchase price is an estimate based on high

- volume price quotations and detailed discussions with suppliers and manufacturers . For fabricated parts, the price of intermediate materials ( e.g. , tube, sheet metal) and the cost of transforming them into finished parts is an estimate based on current industry pricing. For a continued discussion of the cost details and assumptions, refer to

section 5.6.2

.

The BOM for a cata log teardown is identically structured and provides a description in equal detail to the BOM of a physical teardown. However, it is generated using a slightly different methodology. As stated previously, BOMs for catalog teardowns are generated by modify ing the BOM of a similar unit that has been physically torn down. These modifications reflect the major physical differences between the units. Specific to this engineering analysis, the catalog teardown methodology was employed to generate bills of mate rials for evaporator

coils and air handlers for the central air conditioner and heat pump analysis . DOE physically tore

down three evaporator coils and eight air handlers. Based on these physical teardowns, DOE

executed four supplementary evaporator coil catalog teardowns and seven supplementary air handler catalog teardowns. In addition, catalog teardowns were used to provide additional data for the scaling of the cost

- efficiency relationship to additional input capacities for furnaces. DOE physically tor e down a unit at an input capacity above and below the representative input capacity and relied on information from those two physical teardowns and the catalog teardowns to scale the analysis to other input capacities.

Figure 5. 5

. 4 below shows an example of a section of a BOM spreadsheet. Each row of the spreadsheet represents a single part of the unit assembly and includes a description of the part, a material type, initial and final dimensions, and weight. These rows also incl ude placeholders for the type and number or duration of fabrication processes (stamping, drilling, etc.) required to create that part. From this information, a part cost is generated, and the part

costs are summed across the sheet to create a cost estimate for the entire unit. While the teardown analysis only considers technologies in observed in the today’s units, DOE does not

believe that the implementation of technologies would di ffer based on amended standards because manufacturers of these products gen erally already incorporate the most cost

- effective methods for improving efficiency into their products.5

- 18 Figure 5.5

. 4 Example of BOM Spreadsheet

5.6 COST MODEL

The cost model is a detailed, component

- foc used, activity

- based tool for estimating the manufacturing cost of a product. Once teardown s were completed

, DOE implement ed a cost model that could translate the physical information from the BOMs into manufacturing costs. The cost model is based on produ ction activities and divides factory costs into materials, labor

, depreciation, and overhead

. DOE defines the cost inputs of these broader categories in Table

5.6.1

.

Table 5.6

. 1 Cost Model Categories and Descriptions Major Category Sub

- Category Description

Material Costs Direct Raw materials ( e.g

. , coils of sheet metal) and purchased parts ( e.g

. , fan motors, compressors )

Indirect Material used during manufacturing ( e.g. , w elding rods, die oil, release media )

Manufacturing

Labor Assembly Part/ unit assembly on manufacturing line

Fabrication Conversion of raw material into parts ready for assembly

Indirect Fraction of overall labor not associated dire ctly with

pro duct manufacturing ( e.g

. , forklift drivers, quality

control ) Supervisory Fraction of indirect labor that is paid a higher wage Depreciation Equipment, Straight line depreciation over expected life5

- 19 Conveyor, Building

Tooling Cost is allocated on a per

- use basis or obsolescence,

whichever is shorter

Other Overhead Utilities A fixed fraction of all material costs meant to cover electricity and other utility costs

Maintenance Based on installed equipment and tooling investment Property Tax and

Insura nce A fixed fraction based on total unit costs

DOE input the cost data from all the BOMs

— whether they were obtained through physical teardowns or catalog teardowns

— into the cost model. The cost model analysis created

cost estimates for each of the produc ts analyzed in the teardown analysis. The cost model uses specific assumptions to provide cost estimates ; the following sections describe these assumptions.

5.6.1 Cost Model Overview

This section provides a general overview of the process by which the cost model converts the physical information in each product’s BOM into cost information. After gathering component information through physical teardowns and organizing it into BOMs, the resulting data were used as inputs for the cost model spreadsheet. To determin e the costs, DOE follow ed

one of two different paths, depending on whether a subassembly was purchased (out

- sourced) or produced in

- house. For purchased parts, DOE gathered price quotations from major suppliers at different production volumes. For parts pr oduced in

- house, DOE reconstructed manufacturing processes for each part using modeling software based on internal expertise. For example, for an access panel, DOE deduced the time required for setup, handling, changeover, and punching holes, as well as th e number of holes and hits. By repeating this process, DOE was able to assign labor time, equipment utilization, and other important factors to each subassembly in each of the units considered for this analysis. The last step was to convert the information into dollar values. To perform this task, DOE collected information on such factors as labor rates, tooling depreciation, and costs of purchased raw materials. DOE assumed values for these parameters using internal expertise and confidential information a vailable to its contractors. Figure 5.6

. 1 provides an illustration of the cost model methodology.

Figure 5.6

. 1 Cost Model Methodology Purchased Parts Bill of

Materials Fabrication

Processes Assembly

P rocesses Teardown

Observatio n Production

Cost Raw

Materials Finished

Materials5

- 20 In sum, DOE as signed costs of labor, materials, and overhead to each part, including coils, whether purchased or produced in

- house. DOE then aggregated single

- part costs into major assemblies ( e.g. , for central air conditioners and heat pumps this would include the cabi net assembly, condensing unit, evaporator unit, controls, packaging, condenser coil assembly, and evaporator coil assembly) and summarized these costs in a spreadsheet. DOE repeated this same process for each unit in the engineering analysis, representing a specific efficiency level at the chosen capacity and mapped the resulting c ost

- efficiency points to use as a basis for developing

the cost

- efficiency relationship s.

5.6.2 C

Assumptions about manufacturer practices and cost structure play a n important role in estimating the final cost of the products. DOE used assumptions regarding the manufacturing

process parameters, ( e.g. , equipment use, labor rates, tooling depreciation, and cost of purchased

raw materials ) to determine the value of each component. It then summed the values of the components into assembly costs and, finally, the tota l MPC for the product. The MPC includes the material, labor, depreciation, and overhead costs associated with the manufacturing facility.

The material costs i nclude both raw materials and purchased part costs. The labor costs include fabrication, assembly, and indirect and overhead (burdened) labor rates. The depreciation costs include equipment depreciation, tooling depreciation, and building depreciation. The overhead costs include indirect process costs, utilities, equipment and building maintenance, and rework. The following sections describe the cost model assumptions related to material prices, purchased parts and factory parameters. ost Model Assumptions

5.6.2.1 Material Prices

DOE d etermined the cost of raw materials by using prices for copper, steel, and

aluminum from the American Metals Market. 2 DOE noted that there have been drastic fluctuations in metal prices over the last few years. To account for these large fluctuations, DOE used prices of metals that reflect a five

- year average of the Bureau of Labor Statistics Producer Price Indices (PPIs) spanning 2004 to 2009. 3 DOE used the PPIs for steel mill products and copper rolling, drawing, and extruding, and adjusted to 2009$ usi ng the gross domestic product implicit price deflator. 4

5.6.2.2 Fabricated Parts and Purchased Parts

DOE characterized parts based on whether manufacturers fab ricated them in

- house or purchas ed them from outside suppliers. For fabricated parts, DOE estimated the price of intermediate materials ( e.g. , tube, sheet metal) and the cost of forming them into finished parts. For purchased parts, DOE estimated the purchase price for OEMs based on discussions with the manufacturers. Whenever possible, DOE obtained price qu otes directly from suppliers of the manufacturers of the units being analyzed. DOE assumed that the components in Table 5.6

. 2 were purchased from outside suppliers.5

- 21 Table 5.6

. 2 Purch ased Central Air Conditioner

, Heat Pump , and Furnace Components Assembly Purchased Sub

- Assemblies

Central Air Conditioner and Heat Pump Condensing Unit Compressor

Condenser Fan Blade

Condenser Fan Motor Filter/Dryer

Hi/Low Pressure Switch

Accumu lator Reversing/Shutoff Valve

Plastic Parts

Central Air Conditioner and Heat Pump Evaporating Unit Evaporator Blower Evaporator Fan Motor

TXV/EEV/Orifice

Plastic Parts

Furnace Gas Valve Oil Burner Assembly Hot Surface Igniter

Furnace Bl ower Fan Blade

Furnace Blower Fan Motor Draft Inducer Assembly

Controls (for all product types) Control Boards Capac i tors, transformers, contactors, switches, etc.

V ariability in the costs of purchased parts can account for large changes in the o verall MPC values calculated. The purchased part prices utilized in this study were typical values based on estimated production volume s and other factors. In actuality

, p urchased part costs can vary significantly based on the quantities desired and the co mponent suppliers chosen . The role of purchase part prices in the MPC calculation is further magnified because these parts comprise significant portions ( e.g. , roughly 50

- 60 percent for air conditioners) of these systems by cost.

Additi onally, some parts, such as molded plastic components, may be produced in

- house by some manufacturers and purchased by others. The choice between these options would result in changes to the calculated overall system costs. Manufacturer feedback was solicited on these

costs a nd used to further calibrate the numbers prior to conducting the final rule analyses to minimize the uncertainty caused by the variability in costs.

5.6.2.3 Factory Parameters

Certain factory parameters, such as fabrication rates, labor rates

, and wages

, also af fect the cost of each unit produced. DOE factory parameter assumptions were based on internal expertise and manufacturer feedback. Table 5.6.3 below lists the factory parameter assumptions5

- 22 used in the cost model. T hese factory parameters are independent of the efficiency level of the unit produced and do not vary between the major central air conditioner and heat pump product

classes analyzed in the engineering analysis

. This assumption is consistent with the fact that all major manufacturers produce units in all of these product classes and across a range of efficiency

levels. The annual production volume assumed for furnaces varies from that estimated for central air conditioners and heat pumps due to the lower s hipment volumes for these products. Non

weatherized gas furnaces and mobile home gas furnaces are assumed to have the same production volumes because major manufacturers produce these units, which generally use the

same components as non

- weatherized gas fu rnaces. However, because oil

- fired furnace manufacturers are typically only focused on oil

- fired furnace products, the production volume for those manufacturers was assumed to be even lower due to the significantly smaller market for

oil

- fired furnaces. Ad ditionally, these assumptions are generalized to represent typical production and are not intended to model a specific factory.

Table 5.6

. 3 Factory Parameter Assumptions

Parameter Central Air

Conditioners a nd Heat Pumps

Estimate Non

weatherized Gas

Furnaces

Estimate * Oil

- fired

Furnace Type

Estimate

Actual Annual Production Volume (units/year) 1,250,000 500,000 40,000

Work Days Per Year (days) 250 250 250 Assembly Shifts Per Day (shifts) 2 2 2

Fabrication Shifts Per Day (shifts) 2.5 2.5 2.5 Fabrication Labor Wages ($ /h ) 16 16 16 Assembly Labor Wages ($ /h ) 16 16 16 Length of Shift (hrs) 8 8 8 Average Equipment Installation Cost (% of purchase price) 10% 10% 10%

Fringe Benefits Ratio 50% 50% 50%

Indire ct to Direct Labor Ratio 33% 33% 33% Average Scrap Recovery Value 30% 30% 30% Building Cost ($/ft 2 177 ) 177 177

Worker Downtime 10 % 10% 10% Building Life (in years) 30 30 30 Burdened Assembly Labor Wage ($ /h ) 24 24 24 Burdened Fabrication Labor Wage ($ /h ) 24 24 24 Supervisor Span (workers/supervisor) 25 25 25 Supervisor Wage Premium (over fabrication and assembly wage) 30% 30% 30%

*Includes non

- weatherized mobile home fur naces.5

- 23 5.7 MANUFACTURER SELLING PRICE

The output of the cost model is the MPC , whi ch includes all direct costs including production

- related labor, materials, depreciation

, and overhead costs (as defined in section 5.6 )

. To obtain the MSP, DOE multiplies the MPC by the manufacturer markup and adds the cost of shipping. The MSP includes all production and non

- production costs as well as profit . The manufacturer markup is a multiplier that scales MPC to the MSP and covers non

- product ion cost elements, includ ing sales, general and administrative, research and development, other corporate

expenses , and profit. The components of MSP are shown in Figure 5.7.1

. The MPCs are obtained as an output of the cost model, and the manufacturer markup and shipping costs were derived as

described in sections 5.7.1 and 5.7.2 below.

Manufacturer Selling Price

Full Cost of

Product

Manufacturer

Production Cost

Direct

Labor Direct

Material Overhead

Indirect Labor

Indirect Material

Maintenance

Depreciation

Taxes

Insurance related

to assets Non

- Production

Cost

Selling

Market

Research

Advertising

POS Promotion

Salesperson Comp & Travel

Logistics (Warehousing, Delivery, Record

Keeping, Order

Processing) General &

Admin.

Costs of

Service &
Staff Units

General
Corporate

Costs (Comp, etc) R & D

Costs associated with finding new

and improved

products or

processes

Code Compliance

Modernization Interest

Cost of borrowing

funds Profit

Figure 5.7

. 1 Components of Manufacturer Selling Price

5.7.1 Manufacturer Markup

In the final rule analysis, DOE used U.S. Security and Exchange Commission (SEC) 10

- K report s from publicly owned residential cooling and heating product companies to estimate manufacturer markups. The law requires publicly owned companies to disclose financial

inform ation on a regular basis b y filing forms with the SEC . The SEC form 10

- K, filed by5

- 24 companies annually, provides a comprehensive overview of the company’s business and

financial conditions. The 10

- K report includes the company’s revenues and direct and indi rect
costs. The income statement section of the 10

- K often lists the figures necessary for calculating the manufacturer markup

— the net sales, costs of sales, and gross profit. DOE first calculated a five year average markup for each company. After calculat ing the markup for each manufacturer

with 10

- K data, DOE then calculated a single market

- share weighted manufacturer markup to represent the industry. DOE applied this manufacturer markup to the MPC to arrive at a final manufacturer selling price. This ind ustry wide markup was further calibrated based on feedback received during manufacturer interviews. For the final rule analysis, t he manufacturer markup varied by product class and was 1.30 for split system air conditioners and heat pu mps, 1.28 for package d units, 1.32 for SDHV systems, 1.35 for non

- weatherized gas and oil

- fired furnaces, and 1.30 for mobile home gas furnaces.

5.7.2 Shipping Costs

Manufacturers of HVAC products typically pay for freight to the first step in the distribution chain. Freight is not a manufacturing cost, but because it is a substantial cost incurred by the manufacturer, DOE is accounting for shipping costs separately from the non

production costs that comprise the manufacturer markup. To calculate MSP, DOE multipl ied the

MPC determin ed from the cost model by the manufacturer markup and add ed shipping costs. DOE calculated shipping costs based on a typical 53

- foot straight frame trailer with a storage volume of 4,240 cubic feet.

For the final rule , DOE revised its methodology to deve lop shipping costs from the preliminary analysis for central air conditioners and heat pumps and determined a product’s shipping cost as a function of its volume for all analyzed product classes (including furnaces). DOE first calculated the cost per cubic foot of space on a trailer based on a cost of $2,500 per shipping load and the standard dimensions of a 53

- foot trailer. This cost was determined based on a combination of full truck load (FTL) freight quotations and manufacturer feedback. Then,

DOE exami ned the average sizes of products in each product class at each efficiency and capacity combination analyzed. DOE estimated the shipping costs by multiplying the product volume by the cost per cubic foot of space on the trailer. Because product size greatl y depends on efficiency for central air conditioners and heat pumps, DOE calculated a separate volumetric cost for each efficiency level. For furnaces, however, product dimensions typically do not change as a result of increases in efficiency, and DOE’s sh ipping costs show no change across efficiency levels, except for mobile home furnaces. For those products, DOE found that at a legacy design

that is shipped with an evaporator coil cabinet on top of the unit is the most common design at

the baseline , while at t he condensing efficiency levels the size and design of the units were more

in line with non

- weatherized gas furnaces at the condensing level. As a result of the increased size of the baseline unit (to include the coil cabinet) , the shipping cost at th e baseline is higher for mobile home furnaces. In determining volumetric shipping costs, DOE also used manufacturer feedback regarding product mix on each trailer, packing efficiency, and methods and equipment used to load the trailers to revise the shippi ng costs. Table 5.7

. 1 through Table5

- 25 5.7

. 18 show the shipping costs and shipping dimensions for the products analyzed in this rulemaking.

Table 5.7

. 1 Shippin g Costs for Non

- weatherized Gas Furnaces Shipping Cost ($)

AFUE 60 kBtu/h 80 kBtu/h 100 kBtu/h 120 kBtu/h

80 10.06 10.06 11.86 13.67

90 10.06 10.06 11.86 13.67

92 10.06 10.06 11.86 13.67

95 10.06 10.06 11.86 13.67

98 10.06 10.06 11.86 13.67

Table 5.7

. 2 Shipping Costs for Mobile Home Gas Furnaces

AFUE Shipping Cost ($)

80 18.68

90 10.06

92 10.06

96 10.06

Table 5.7

. 3 Shipping Costs for Oil

- Fired Furnace s
AFUE Shipping Cost ($)

82 19.69

83 19.69

84 19.69

85 19.69

97 19.69

Table 5.7

. 4 Shipping Dimensions for Non

- weatherized Gas Furnaces (60 kBtu/h and 80 kBtu/h Input Capacity) Shipping Dimensions

AFUE 60 kBtu/h 80 kBtu/h

Height (in.) Wi dth (in.) Length (in.) Height (in.) Wi dth (in.) Length (in.)

80 42.0 19.5 30.5 42.0 19.5 30.5

90 42.0 19.5 30.5 42.0 19.5 30.5

92 42.0 19.5 30.5 42.0 19.5 30.5

95 42.0 19.5 30.5 42.0 19.5 30.5

98 42.0 19.5 30.5 42 .0 19.5 30.55

- 26 Table 5.7

. 5 Shipping Dimensions for Non

- weatherized Gas Furnaces (100 kBtu/h and 120 kBtu/h) Shipping Dimensions

AFUE 10 0 kBtu/h 120 kBtu/h

Height (in.) Wi dth (in.) Length (in.) Height (in.) Wi dth (in.) Length (in.)

80 42.0 23.0 30.5 42.0 26.5 30.5

90 42.0 23.0 30.5 42.0 26.5 30.5

92 42.0 23.0 30.5 42.0 26.5 30.5

95 42.0 23.0 30.5 42.0 26.5 30.5

98 42.0 23.0 30.5 42.0 26.5 30.5

Table 5.7

. 6 Shipping Dimensions for Mobile Home Furnaces (80 kBtu/h Input Capacity)

AFUE Height (in.) Width (in.) Depth (in.)

80 78.0 19.5 30.5

90 42.0 19.5 30.5

92 42.0 19.5 30.5

96 42.0 19.5 30.5

Table 5.7

. 7 Ship ping Dimensions for Oil

- Fired Furnaces (105 kBtu/h Input Capacity)

AFUE Height (in.) Width (in.) Depth (in.)

82 56.3 25.1 34.6

83 56.3 25.1 34.6

84 56.3 25.1 34.6

85 56.3 25.1 34.6

97 56.3 25.1 34.6

Table 5.7

. 8 Shipping Costs for Split System Central Air Conditioners and Heat Pumps

SEER Split System AC Coil

Only ($) Split System AC Blower

Coil ($) Split System HP ($)

2 Ton 3

Ton 5 Ton 2 Ton 3 Ton 5 Ton 2 Ton 3 Ton 5 Ton

13 16.02 20.51 28.42 19.79 2 4.89 35.60 25.74 28.64 36.80

13.5 18.07 22.62 28.97 21.64 26.95 35.89 25.60 29.58 37.60

14 20.30 24.83 29.50 23.66 29.11 36.16 25.45 30.54 38.42

14.5 20.04 24.16 30.06 23.97 29.55 37.93 28.60 33.50 39.74

15 23.30 25.40 33.08 23.50 28.81 38.20 31.12 35. 40 39.58

15.5 23.91 26.73 33.38 25.19 29.76 39.44 32.09 34.70 40.14

16 24.52 28.10 33.65 27.00 30.75 40.69 33.07 34.09 40.715

- 27 16.5 26.59 28.90 27.38 32.02 40.69 33.97 35.40 41.44

17 28.67 30.74 27.74 33.35 40.69 34.86 36.72 42.17

18 31.41 33.48 35. 23 41.82 36.48 39.52 42.90

19 35.70 37.03 40.27 41.64

20 38.51 38.91 41.15 42. 1 8

21 42.09 42.26 41.59 42. 90

22 45.01 44.71 41.82

23 46.36

24.5 46.75

Table 5.7

. 9 Shi pping Costs for Single Package Central Air Conditioners and Heat Pumps and SDHV Systems

SEER Single Package HP ($) Single Package AC ($) SDHV ($)

13 31.88 30.43 29 .79

13.5 33.38 32.13 32 .76

14 34.91 33.89 34 .93

14.3 35.85 34.97 36 .81

14.5 36.48 35.69

15 38.08 37.55

15.5 39.72 39.47

16 41.39 41.44

16.4 42.75 43.06

16.6 43.88

Table 5.7

. 10 2 Ton Split System Air Conditioner Shipping Dimensions

SEER Outdoor Unit Indoor Unit Box Estimates w/pall et Box Estimates w/pallet Height Width Depth Height Width Depth

13.0 27 37 30 49 19 21

13.5 28 40 31 49 19 21

14.0 29 42 32 49 19 21

14.5 29 41 32 49 21 21

15.0 29 40 32 49 21 21

15.5 30 43 32 49 21 21

16.0 31 45 33 49 21 21

16.5 31 44 33 49 21 2 1

17.0 32 44 34 49 21 215

- 28 18.0 34 46 36 49 26 21

19.0 36 47 37 49 26 21

20.0 37 49 38 49 26 21

21.0 39 50 39 49 26 21

22.0 40 53 40 49 26 21

23.0 41 53 41 49 26 21

24.0 41 52 41 49 26 21

24.5 42 52 42 49 26 21

Table 5.7

. 11 2 Ton Split System Heat Pump Shipping Dimensions

SEER Outdoor Unit Indoor Unit
Box Estimates w/pallet Box Estimates w/pallet
Height Width Depth Height Width Depth

13.0 32 43 33 49 19 21

13.5 32 43 33 49 19 21

14.0 32 43 32 49 19 21

14.5 33 44 35 49 21 21

15.0 33 45 37 49 21 21

15.5 34 45 38 49 21 21

16.0 35 46 38 49 21 21

17.0 35 47 40 49 21 21

18.0 36 49 40 49 21 21

19.0 36 50 41 49 26 21

20.0 36 51 41 49 26 21

21.0 36 51 41 49 26 21

22.0 36 52 41 49 26 21

Table 5.7

. 12 3 Ton Split System Air Conditioner Shipping Dimensions

SEER Outdoor Unit Indoor Unit
Box Estimates w/pallet Box Estimates w/pallet
Height Width Depth Height Width Depth

13.0 29 41 32 54 21 22

13.5 31 40 34 54 21 22

14.0 34 40 36 54 21 22

14.5 33 41 34 54 23 22

15.0 32 42 33 54 23 22

15.5 33 42 34 54 23 22

16.0 34 42 34 54 23 225

- 29 16.5 34 44 35 54 23 22

17.0 34 45 36 54 23 22

18.0 34 46 36 54 26 22

19.0 35 47 37 54 26 22

20.0 36 48 38 54 26 2 2

21.0 37 49 39 54 26 22

22.0 38 50 40 54 26 22

Table 5.7

. 13 3 Ton Split System Heat Pump Shipping Dimensions

SEER Outdoor Unit Indoor Unit
Box Estimates w/pallet Box Estimates w/pallet
Height Width De pth Height Width Depth

13.0 32 42 35 54 21 22

13.5 33 42 35 54 21 22

14.0 33 43 36 54 21 22

14.5 34 44 37 54 23 22

15.0 35 45 38 54 23 22

15.5 35 44 37 54 23 22

16.0 35 44 37 54 23 22

17.0 36 47 38 54 23 22

18.0 37 49 39 54 23 22

19.0 38 50 39 54 26 22

20.0 38 50 39 54 26 22

21.0 38 50 40 54 26 22

Table 5.7

. 14 5 Ton Split System Air Conditioner Shipping Dimensions

SEER Outdoor Unit Indoor Unit
Box Estimates w/pallet Box Estimates w/pallet
Heig ht Width Depth Height Width Depth

13.0 35 44 37 58 23 24

13.5 36 44 36 58 23 24

14.0 36 45 36 58 23 24

14.5 36 45 37 58 26 24

15.0 35 45 38 58 26 24

15.5 35 47 38 58 26 24

16.0 36 48 38 58 26 24

17.0 35 46 40 58 26 245

- 30 18.0 36 47 41 58 26 24

Tabl e 5.7

. 15 5 Ton Split Heat Pump Shipping Dimensions

SEER Outdoor Unit Indoor Unit
Box Estimates w/pallet Box Estimates w/pallet
Height Width Depth Height Width Depth

13.0 35 45 38 58 23 24

13.5 35 47 38 5 8 23 24

14.0 35 48 38 58 23 24

14.5 35 48 38 58 26 24

15.0 35 48 37 58 26 24

15.5 35 48 37 58 26 24

16.0 36 49 38 58 26 24

17.0 36 50 38 58 26 24

18.0 37 52 39 58 26 24

Table 5.7

. 16 Single Package Air Conditioner Shipping Dimensions

SEER Box Estimates w/pallet Height Width Depth

13.0 50 40 39

13.5 50 40 40

14.0 50 41 41

14.5 51 42 42

15.0 51 42 43

15.5 51 43 45

16.0 52 44 46

16.6 52 44 47

Table 5.7

. 17 Single Package Heat Pump Shipping Dimensions

SEER Box Estimates w/pallet

Height Width Depth

13.0 51 39 40

13.5 51 40 41

14.0 51 41 42

14.5 51 41 43

15.0 51 42 44

15.5 51 42 45

16.0 51 43 47

16.4 51 43 475

- 31 Table 5.7

. 18 SDHV Shipping Dimensions *

SEER Box Estimates w/pallet Height Width Depth

ALL 36 33 19

*These dimensions are only for the SDHV portion of the system and do not include the condensing unit.

5.7.3 MSP in the Downstream Analyses

The MSPs derived in the engineering analysis are important inputs to the life

- cycle cost analysis (LCC) and the manufacturer impact analysis (MIA). In the LCC, the MSPs are necessary to calculate the total installed cost of each unit. In the MIA, DOE construct s a number of scenarios that analyze how different pricing schemes impact manufacturers financially. In the MIA, both MSP and the direct production cost components of MSP are important drivers of results. DOE discusses how the engineering analysis is used in the other analyses in chapters 8

and 12 of the TSD.

5.8 CENTRAL AIR CONDITIO NER AND HEAT PUMP NICHE PRODUCTS

For the final rule analysis, DOE conducted a review of the information available regarding products in the niche (small

- duct, high

- velocity and s pace

- constrained) product classes. This consisted of gathering and analyzing publicly available documentation and product specification sheets, as well as interviewing some manufacturers directly. For the final rule analysis

, DOE perform ed a full engineeri ng analysis in including teardowns and cost modeling of units throughout the available efficiency levels, as well as modeling of system designs to develop curves depicting theoretical incremental costs of efficiency increases.

5.8.1 Small Duct High Velocity

Sm all

- duct, high

- velocity (SDHV) systems are intended for applications that require special design constraints, primarily retrofit applications in older homes and residential buildings where the original construction limits the use of conventional ductwork. In these situations, SDHV units often serve as the preferred alternative to operating multiple window units or installing obtrusive conventional ducting systems. SDHV systems are designed with the intent of allowing for simple installation and preserving t he appearances of the existing buildings. These systems are also utilized in new construction applications in building designs that would not be possible if traditional ductwork, and the required space associated with it, were used. 10 CFR

430.2 defines “s mall

- duct high

- velocity system” as:

“...a heating and cooling product that contains a blower and indoor coil combination that (1) Is designed for, and produces, at least 1.2 inches of external static pressure when operated at the certified air volume rate o f 220

- 350 CFM per5

- 32 rated ton of cooling; and (2) When applied in the field, uses high velocity room outlets generally greater than 1000 FPM which have less than 6.0 square inches of

free area.”

5.8.1.1 Identification of the Baseline

Currently, the 13 SEER effic iency level mandated by the 2004 technical amendment (69 FR 50997) to the 2002 final rule applies to all SDHV products. However, all three major domestic manufacturers of SDHV units have been granted exceptions to this standard by the Office of Hearings an d Appeals (OHA), allowing these units to instead adhere to an 11 SEER efficiency level. The decisions applying to these manufacturers went into effect on January 23,

2006

, and remain in effect until DOE establishes an independent standard for SDHV systems. However, EISA 2007 contained an “anti

- backsliding” clause which prevents DOE from setting a

standard lower than the current standard ; therefore, 13 SEER was selected as the baseline

. (US 6925(o)(1)) Due to the ducting constraints mandated by the system si ze requirements, elevation of system performance to high levels is difficult in practice, and manufacturers have stated that they believe the maximum technologically feasible efficiency level to be just over 14 SEER. This is in agreement with the distribut ion of efficiency levels of products in the AHRI Certified Directory c

5.8.1.2 Product Description , as roughly 81 percent of the units listed have rated efficiencies between 11 and 12 SEER, while slightly less than 5 percent of units are rated at 13 SEER or above. The highest

listed e fficiency of a matched unit in the AHRI Directory is 14. 3 SEER.

SDHV air condition ers and heat pumps currently sold in the U.S. are similar to traditional split

- system air conditi oners and heat pumps, incorporating an outdoor unit wi th an indoor

blower

- coil unit. What differentiates SDHV systems from conventional split systems is the use of compact ductwork and specialized diffusers designed to accommodate high air velocities,

combined with a specially designed indoor unit. Since thes e space constraints only affect the indoor portion of the system, the outdoor portion of an SDHV system is a conventional split

system model, selected from a manufacturer based on the desired performance specifications of the system. The inherent system de sign constraints prevent SDHV systems from achieving the same efficiencies as conventional split

- system air conditioners and heat pumps without placing a disproportionate burden on consumers and manufacturers.

Three domestic manufacturers of SDHV systems , SpacePak, Unico, and Energy Saving Products, Ltd. (trade name: Hi

- Velocity), certify their systems in the AHRI Certified Directory. As of June 8, 2010 , the AHRI Certified Directory list ed 732 actively produced mix

- match system

combinations with rated SEE R values ranging from 11 SEER to 14. 3 SEER. As previously mentioned, t he majority of these units are rated between 11 and 12 SEER. The number of distinct

c This refers to the AHRI Certifie d Directory information as of June 8, 2010, for SDHV air conditioning and heat pump units of all residential capacities.5

- 33 SDHV indoor units produced by the three manufacturers is quite small compared to the number

of choices available for the condensing unit, as any conventional condensing unit can be connected to an SDHV indoor unit. Additionally, system performance will be constrained by either the condensing unit or the blower

- coil unit, since the two components are not ma tched by the manufacturer. Based on an examination of the AHRI Certified Directory, for any given SDHV indoor unit, variation of the condensing unit can change the system SEER value by up to

3. 3 points.

SDHV indoor units, along with the return air ducts and supply plenums, are designed to fit into confined spaces ( e.g. , attics, closets, and crawl spaces), within structures that were often not originally built with provisions for central air conditioning systems. The design of the SHDV unit varies by manuf acturer. Spacepak produces packaged blower

- coil combination units, while Energy Saving Products offers the fan mounted in a housing unit with a space to accommodate the evaporator coil, with the coil selectable by the user or installer based on the applica tion. Unico produces a modular system, where the blower, evaporator coil, and optional heating coil are sold separately and are bolted together by the installer in the desired position, allowing for multiple configurations to fit different installation arr angements.

SDHV ducts possess very small cross

- sectional profiles, not more than a few inches in diameter. This allows them to be installed in spaces that could not accommodate larger conventional ductwork. In other cases, the ductwork is concealed in b aseboards or molding, or is simply installed visibly along the edge of a wall when no space for concealment exists. In the case of new construction, SDHV ducts are often routed between studs in walls and through ceilings without requiring the large cleara nces necessitated by conventional ductwork. These systems produce air velocities on the order of four to five times those of conventional systems, and as a result, blower motors must be capable of producing high static pressures. However,

constraints on t he maximum velocity of the air through the ductwork and vents exist, imposed by the onset of undesirable effects at very high air velocities including noise and drafts within rooms. As a result, the maximum volume of air that can be moved per unit time is constrained as well. To partially compensate for this limited flow volume, SDHV systems generally operate with higher temperature differentials across the evaporator coil in order to achieve the desired cooling capacities while moving less air than a conve ntional split

- system air handler. This requires that SHDV units utilize evaporator coils with very high efficiencies; however, this efficiency gain resulting from the more effective coil is more than offset by the increased power consumption of the indoor blower.

5.8.1.3 Design O ptions

Based on interviews with SDHV system manufacturers, evaluation of previous analyses, and an assessment of SDHV systems currently available, DOE developed a list of design options that should be considered in its analysis. This lis t includes technologies considered to be technologically feasible and will serve to establish the maximum technologically feasible (max

tech) design. Due to the aforementioned technological similarities that inherently exist between5

- 34 the SDHV and convention al split

- system product classes, DOE is currently considering the options previously listed for application in split

- system air conditioners and heat pumps as potential methods for increasing SDHV product efficiency.

DOE has concluded that the ability of manufacturers to implement these design options may be limited by the restrictions imposed upon the systems by the higher static pressure and reduced airflow requirements

. The reduced airflow causes the air flowing to the conditioned space to have a lower temperature than that of a conventional system. This in turn results in the refrigerant leaving the evaporator with a lower pressure, which forces the compressor to work harder, thereby decreasing the systems overall efficiency. The higher static pressure within the SDHV ducts increases the work that must be performed by the blower. Because the blower is working harder, it consumes more power, which also reduces the system’s efficiency. Another possibility is to improve the evaporator coil with either impro ved materials and fin designs or the addition of coil rows to increase effective surface area while maintaining the necessary profile. However, increases in coil depth also result in a higher pressure drop across the coil, requiring more fan energy to move the air. Manufacturers have claimed that additional increases in the size of evaporator coils will not prove to be cost effective. Additionally, the overall rating of an SDHV unit is largely dependent upon the condensing unit to which the system is matche d. Certain technologies ( e.g. , high

- efficiency fan motors and compressors) are required in the condensing unit in order for the whole system to achieve the higher efficiency levels. Manufacturers have claimed that a 12 SEER system rating generally requires a two

- speed compressor on the condensing unit, while a 13 SEER system rating can only be attained through

the use of a variable

- speed compressor. Since the design of these condensing units is beyond the control of the SDHV system manufacturer, mandating e fficiency levels which would require consumers to purchase more costly products from other manufacturers could lead to negative

c onsequences for the industry.

5.8.1.4 Cost of Efficiency Improvements

Due to constraints on the implementation of the design options av ailable to manufacturers, increases in system efficiency would come at a high cost, and improvements would meet with diminishing returns beyond a certain point. Increases in coil size would likely incur corresponding increases in coil cost, as material cos ts are the biggest contributor to the pricing of coils. Additionally, improved fin designs or other design features would come at a high cost as well. Moreover, since overall system performance is highly dependent upon the efficiency of the outdoor unit, w hich is produced by a different manufacturer altogether, costs passed on to the consumer in upgrading to a higher

- efficiency system would be greater than those encountered by the SDHV system manufacturers.

5.8.2 Space

- Constrained Products

Certain types of cent ral air conditioners and heat pumps are manufactured for applications with space constraints and, therefore, have features that distinguish them from the majority of products available. Sometimes these products are not able to meet5

- 35 standards designed for c onventional split

- system air conditioners and heat pumps, or are able to, but, in doing so, place a disproportionate burden on manufacturers and consumers. This product class covers the products that DOE has determined to fit the definition of space constr ained. 10 CFR 430.2 defines “space

- constrained product” as:

“...a central air conditioner or heat pump:

(1) That has rated cooling capacities no greater than 30,000 BTU /h ;

(2) That has an outdoor or indoor unit having at least two overall exterior

dimensio ns or an overall displacement that: (i) Is substantially smaller than those of other units that are: (A) Currently usually installed in site

- built single family homes;

and (B) Of a similar cooling, and, if a heat pump, heating capacity; and

(ii) If increased, would certainly result in a considerable increase in the usual cost of installation or would certainly result in a significant loss in the utility of the product to the consumer; and

(3) Of a product type that was available for purchase in t he United States as of December 1, 2000.”

5.8.2.1 Identification of the Baseline

In the 1999 SANOPR, DOE first suggested separate product classes as a way to set standards for these niche products. 64 FR at 66310. Originally, these products were believed to

inc lude through

- the

- wall (TTW) split systems, single

- package vertical units (SPVU), ductless split systems, and SDHV systems. As of the 2000 NOPR, TTW single

- package and non

weatherized single

- package systems were also added to this product class. In the 2004 Technical Amendment, DOE established a separate product class for space

- constrained systems, requiring them to meet a 12 SEER standard. TTW systems were made their own product class and were required to meet a 10.9 SEER standard; however, this expired on January 23, 2010. Within the scope of this rulemaking, SDHV units have been granted consideration as a separate product class, and also ductless split systems are being considered as part of the conventional split

system air conditioner and heat pump produ ct classes. SPVU’s are considered to be commercial equipment, and thus do not fall under the scope of this rulemaking. Additionally, there currently appears to be no major manufacturer of domestically

- sold single

- package non

- weatherized units.

As a result of these changes since the last rulemaking, DOE is currently unaware of any products which would fall within the classification of space

- constrained products aside from TTW units. For this reason, DOE considered TTW products as the basis for its study of t his product class.

5.8.2.2 Product Description5

- 36 T here are two main types of TTW products: (1) TTW split systems and (2) TTW single

package systems. TTW products were popular in new multi

- story residential construction in the 1960s and 1970s. Major OEMs have since abandoned the replacement market, providing an opportunity for lower

- volume manufacturers, such as First Company, National Comfort Products, and EnviroMaster International .The replacement market is now dominated by these

lower

- volume manufacturers. Most T TW products are in the 1

- 1/2 to 2

- 1/2 ton (18,000 Btu/h to 30,000 Btu/h) capacity range. Residents and building owners are particularly sensitive to any increase in price, especially the cost of enlarging the wall opening to accommodate a larger product. A s a result, new TTW products for retrofit applications must fit within the same wall opening as the original units. Since repair is the only other cost

- effective alternative to replacement, a new standard that increases cabinet size or results in a signifi cant price increase

could be counter

- productive, preventing the turnover of old, inefficient products and instead encouraging users to repair those existing units.

TTW equipment also is used in new construction where the same physical constraints do

not apply because there is no pre

- existing hole in the wall that the unit must fit into. Consequently, the significant cost to enlarge the wall opening to accommodate a larger unit does not apply. DOE believes that TTW products sold into new construction mark ets are not

- space constrained and therefore are not included in the class.

5.8.2.3 Design Options

DOE uses information about existing and past technology options and prototype designs as input in identifying technologies manufacturers could use to meet and/or exc eed energy conservation standards. In consultation with interested parties, DOE developed a list of technologies that should be considered in the analysis. This list consists of all those technologies considered to be technologically feasible and will serv e to establish the max

- tech design. Due to the technological similarities that inherently exist between the space

- constrained and conventional split

- system product classes, DOE is currently considering the options previously listed for application in split

- system air conditioners and heat pumps as potential methods for increasing space

- constrained product efficiency.

DOE conducted MIA interviews and various engineering evaluations to investigate the technology options available to space

- constrained produc t manufacturers to increase the energy efficiency of their units. Based on this investigation, DOE has concluded that unique factors may prevent TTW products from realizing the full potential of many energy saving design options. Typically, increased cond enser coil surface area is the most cost

- effective energy saving measure. However, manufacturers of these products are limited in their ability to implement this option by the apparent constraints upon coil size inherently present in this product class, a nd

some manufactur ers have expressed concern that the available condenser coil surface area may have already been maximized in order to reach the 10.9 SEER standard. Similarly, DOE

believes that the number of coil rows has also been maximized to the point at which the addition of further rows would provide insignificant returns. Other coil improvements, such as micro

-5

- 37 channel tubing, have not yet proven effective during research and development testing. Specifically, manufacturers have been unable to solv e defrosting issues for heat pumps , calling into question the technological feasibility of this desig n option. If coil improvements are insufficient to increase product efficiency, TTW manufacturers must explore more costly design options, such as high

- ef ficiency compressors and fan motors and controls. According to certain manufacturers, higher

- efficiency compressors are already in products on the market, having been implemented to meet the 10.9 SEER standard ; and higher efficiency fan motors and advanced

controls were implemented to meet the 12 SEER standard

. The implementation of this technology to meet 12 SEER suggests that manufacturers have few, if any, technology options to improve efficiency level beyond 12 SEER.

DOE conducted teardowns and furthe r market research to confirm this information and

found the space

- constrained max

- tech efficiency level to be 12 SEER for both the space

constrained air conditioner and heat pump product classes. This level ma tches the baseline ; therefore

, DOE would be una ble to raise the energy conser vation standards. For this reason, DOE is not conducting further analysis on the space

- constrained product classes for active mode

, and the standard will remain unchanged at 12 SEER. However, as a part of this rulemaking,

DOE is adopting off mode standards for central air conditioners and heat pumps. During its investigation of the space constrained product classes, DOE found that these products have the potential for off mode energy savings and included them in the off mode an alysis, which is

discussed in section 5.11

.

5.9 I NDUSTRY COST

- EFFICIENCY RELATIONSHIPS

5.9.1 Furnaces

For residential furnaces, DOE used the cost model to estimate the MPC of various products across the full range of efficiencies an d for each manufacturer with significant market

share. DOE used these results as the basis for its cost

- efficiency relationship for all furnace product classes.

DOE first developed an industry cost

- efficiency relationship for non

- weatherized gas

furnaces

. These products are the highest

- selling of all furnace product classes

. For non

weatherized gas furnaces, DOE began its construction of the cost efficiency relationship at the baseline efficiency level. To create an industry average cost at the baseline eff iciency, DOE

calculated a market share

- weighted average of the cost modeling results for each product that was torn down at the baseline efficiency level. Above the baseline DOE examined the cost differential to reach the next highest efficiency level exam ined for each manufacturer. For each individual manufacturer, DOE calculated the incremental cost of achieving the next higher efficiency level ( i.e

. , the estimated cost to go from 80 percent AFUE to 90 percent AFUE, then from 90 percent AFUE to 92 percent AFUE, and so on). For each efficiency level above the baseline, DOE then calculated the market

- share weighted incremental increase in cost to achieve

that efficiency level for each level analyzed up to max

- tech.5

- 38 Because mobile home furnace designs are typ ically similar to non

- weatherized gas furnace designs, the cost

- efficiency relationship for mobile home furnaces was developed based

on six mobile home gas furnace teardowns in conjunction with the cost

- efficiency relationship that was developed for non

- we atherized gas furnaces. DOE performed teardowns of mobile home furnaces from major mobile home furnace manufacturers at each efficiency level. DOE

used those teardowns to examine the differences between mobile home gas furnaces and non

weatherized gas furn ace s made by e ach manufacturer of mobile home furnaces . DOE calculated

the cost differential between each manufacturer’s non

- weatherized gas furnace and mobile home gas furnace at each efficiency level analyzed . DOE used these cost differentials on a marke t
share

- weighted basis to determine the industry average differential cost of mobile home furnaces

versus non

- weatherized gas furnaces. The manufacturer production costs developed using this method were validated based on the results of DOE’s cost modeling for each individual mobile

home furnace torn down and verified by manufacturer feedback during manufacturer interviews.

For oil

- fired furnaces, DOE performed eight teardowns to develop the industry cost

efficiency relationship. DOE performed teardowns of units from several different manufacturers across the full range of efficiencies . For each manufacturer, DOE developed an incremental cost efficiency relationship based on the teardowns performed for that manufacturer. DOE then developed a weighted

- averag e of the incremental increase in manufacturing cost at each efficiency level above the baseline to determine the industry average cost efficiency relationship

for oil

- fired furnaces.

5.9.1.1 Furnaces with ECM Blower Motors

DOE’s analysis focused on furnace produc ts utilizing a standard PSC blower motor in the furnace fan because switching to an ECM motor does not impact AFUE. However, DOE

believes that a significant segment of consumers choose to buy a product with an ECM blower

motor because of benefits to comfor t and reduced electrical consumption. Therefore, DOE also determined the additional cost of changing from a PSC to an ECM motor in the engineering analysis. DOE estimated the cost differential of the ECM motor and its additional wiring and

controls based o n observations during teardowns and discussions with manufacturers. Because

DOE assumed that the blower motor is a purchased part, the difference in price for that component is based largely on DOE’s component estimates which were adjusted based on

manufac turer feedback regarding DOE’s estimates for purchased parts . DOE estimated the cost

of switching from a PSC motor to an ECM motor separately for gas and oil

- fired furnaces

because oil

- fired furnace manufacturers typically produce a lower volume of product s and would not have as much bulk purchasing power. Further, DOE estimated the cost of switching to an ECM motor separately for each input capacity analyzed based on the most common blower motor characteristics observed at each input capacity. Table 5.9

. 1 shows DOE’s estimates of the cost to change from a PSC to an ECM blower motor.5

- 39 Table 5.9

. 1 Additional Cost to Switch from PSC to ECM Blower Motor for Furnaces

Product Class Input Capa city (kBtu/h) Additional MPC (includes motor, controls, and wiring) ($)

Non

- weatherized Gas 60 66.43

80 67.46

100 83.05

120 83.05

Mobile Home Gas 80 67.46

Non

- weatherized Oil

- Fired 105 89.49

5.9.1.2 Two

- Stage Furnaces

The market for non

- weatherized gas f urnaces also contains a significant number of two

stage products rated at the same efficiency as single

- stage products. DOE believes consumers choose to purchase these products for the additional comfort of two stage operation. During the teardowns, DOE ex amined two

- s tage furnace designs to analyze the production cost differential for manufacturers to switch from single

- stage to two

- stage (with no impact on the rated AFUE ).

DOE determined a market sh are weighted

- average cost of $31.69 to change from a singl e stage to a two stage design. The additional cost to change to a two

- stage furnace includes the added

cost of a two

- stage gas valve, two

- speed inducer assembly, upgraded pressure switch, and additional controls and wiring.

5.9.2 Central Air Conditioners and Hea t Pumps

5.9.2.1 Split

- System Air Conditioners: Blower

- Coil

In new construction applications, a complete central air conditioner or heat pump system is always installed. In replacement applications for split

- system air conditioners, consumers are presented with two options: (1) replace a portion of their system, or (2) replace the entire system. For the first option, if a consumer has a furnace installed and a portion of the air conditioning system ( i.e. , condensing unit or evaporator coil) fails, the consumer may c hoose to only replace the air conditioning portion of the system. This scenario involves the replacement of a condensing unit and an evaporator coil used with the existing fan blower in the furnace. In these applications, manufacturers are constrained by t he fan blower in the installed furnace; they only have the ability to modify the condensing unit or evaporator coil to achieve the desired efficiency. These systems are referred to as coil

- only systems, and are tested and rated using the

combination of a s pecific condensing unit and evaporator coil with default fan specifications identified in the test procedure.

For the second option, if the entire system is replaced, the consumer has the ability to

select a combination of indoor and outdoor units that ca n achieve any efficiency within the commercially available range of efficiencies for split

- system air conditioners. Since the systems are sold as specific combinations of indoor and outdoor units, manufacturers have the ability to5

- 40 modify all portions of th e system ( i.e. , condensing unit, evaporator coil, and evaporator fan blower) to achieve the desired efficiency. These systems are referred to as blower

- coil systems and are tested and rated using the combination of a specific condensing unit, evaporator co il, and evaporator fan blower. Since manufacturers have more options to improve the efficiency of a

blower

- coil system, the cost

- efficiency relationship is inherently different than for coil

- only systems. Both types of systems are prevalent in the marketpl ace, and DOE characterized split

system air conditioners with a separate cost

- efficiency curve for blower

- coil and coil

- only

systems.

DOE first developed an industry cost

- efficiency curve for blower

- coil, split

- system air conditioners using the process lis ted below. These products span the largest efficiency range and are the highest

- selling product class of all central air conditioners and heat pumps. Creating the industry cost

- efficiency curve for split

- system air conditioners was a four

- step process that consisted of: (1) plotting the raw data points as absolute system cost versus efficiency, (2) translating the absolute system costs by manufacturer to common normalized system costs, (3) trending system and subsystem costs, and (4) aggregating the cost da ta to develop a cost

efficiency curve representative of the industry. The details of these steps are described in this

section.

Plo tting Absolute System Cost Versu s Efficiency

. The cost model analysis developed cost estimates for each of the teardowns, as detailed in section 5.6 . The output from the model includes all manufacturing costs, which includes corporate overhead expenses. DOE developed system costs for blower

- coil, split

- system air conditioners by summ ing the costs of specific matched pairs of condensing units and air handlers. DOE selected matched pairs from manufacturer specification sheets and the AHRI database to span the entire efficiency range for split

- system products. The combined cost, called “ absolute system cost” for purposes of this analysis, is the cost to manufacture each system

— it is not the final cost to the end

- user, because it does not include the manufacturing and distribution channel markups.

The absolute system cost from the model is plotted as a function of each product’s efficiency

— given as SEER. Manufacturers publish SEER values for each of their products, according to AHRI specifications. DOE does not present any absolute costs for individual

manufacturers in this document, becaus e doing so could expose sensitive financial information about individual manufacturers’ products. Figure 5.9.1 illustrates how DOE plotted absolute system cost versus efficiency5

- 41 Figure 5.9

. 1 Illustration of Four Manufacturers’ Absolute Cost versus SEER Relationship

Translating Absolute System Cost to Normalized System Cost

. For the next step in the process of creating the industry cost

- efficiency curves, DOE normal ized the absolute system costs from each manufacturer. DOE shifted system costs for products made by the same manufacturer equally, but shifted system costs for products made by different manufacturers independently.

As illustrated in Figure 5.9.2 , the cost translation process shifted the absolute system costs of each manufacturer’s products so that the cost of the baseline system ( i.e ., 13 SEER) is consistent across all manufacturers. By ensuring that all manufactu rers shared a common baseline system cost, DOE was able to compare manufacturers’ data points directly while maintaining each manufacturer’s incremental costs as efficiency increases, allowing for a direct analysis of the cost of efficiency improvements re gardless of baseline costs. To do this, DOE

first identified the average 13 SEER system cost for each manufacturer and the n calculated an industry average 13 SEER system cost based on each manufacturer’s market share. DOE then

shifted manufacturers’ absolu te system cost data points up or down until each manufacturer’s

lowest

- cost 13 SEER system matched the overall market share weighted average 13 SEER system. DOE realizes that other methods of normalizing the data are available, such as shifting

the cost va lues to center the curves at the lowest cost rather than a t a market

- weighted average

, but believes that a market

- weight average gives a better representation of the industry average.5

- 42 Figure 5.9

. 2 Illustration of System Cost Translation Process

In analyses downstream of the engineering analysis, DOE accounted for the fact that in replacement applications, some consumers will not replace their entire air conditioning system.

For this scenari o, DOE assumed that the consumer will only replace the condensing unit and the evaporator coil. For more detail on these replacement scenarios, see chapter 8 of the final rule TSD. In order to model these scenarios, DOE estimated costs for different porti ons of the central air conditioning system. Therefore, DOE simplified the output from the cost model into five subsystems for each split

- system air conditioner analyzed. The five subsystems were: (1) condensing unit, (2) indoor unit casing (sheet metal and insulation), (3) evaporator coil, (4) evaporator fan blower, and (5) balance of indoor unit.

In addition to normalizing system costs, DOE also normalized the subsystem costs that were estimated from cost model data. This step was necessary in order to e nsure that the sum of the subsystem costs equated to the normalized overall system costs developed previously. To do this, for each absolute system cost, DOE calculated the percentage that each absolute subsystem

cost accounted for in the total. DOE then a pplied these same percentages, specific to each system cost, to the normalized system cost to estimate the normalized subsystem costs. As a result, the normalized subsystem costs were scaled proportionally to the normalized system costs.

Trending System and Subsystem Costs

. It is rare that a single manufacturer produces a system at every efficiency level throughout the entire operating efficiency range of central air conditioners and heat pumps. In addition, some manufacturers produce multiple systems in different product lines that achieve the same rated efficiency. These variations in product offerings across different manufacturers introduce complications to the analysis which must be addressed through trending of the data. Trending by manufacturer ensu res that there is data at every efficiency level for each manufacturer studied, allowing for aggregation across all manufacturers at every data point. If the data were not trended, certain efficiency levels would

contain more models from some manufacturers than others, or perhaps no models at all from some manufacturers. This would introduce an undesired weighting effect into the data once the aggregated curves were developed, with some manufacturers’ products at certain efficiency levels essentially being represented more than others. Therefore, DOE developed trends to estimate each manufacturer’s production costs at all efficiency levels. Figure 5.9.3 illustrates the5

- 43 type of trends that DOE developed, first showing trend lines produced from normalized data for each manufacturer, then showing an overall trend line created using aggregated normalized data.

Figure 5.9

. 3 Illustration of Cost Trends

After interviewing manufacturers, examin ing manufacturer specification sheets, and conducting physical teardowns, DOE found that system costs generally increase linearly with respect to efficiency from 13

- 14 SEER. At these lower efficiencies, the most cost

- effe ctive method for manufacturers to achieve efficiency gains is to increase the surface area of the heat exchangers. Without strict constraints on the size of the heat exchangers, the efficiency gains resulting from their increased size are relatively propor tional to the additional material, and thus cost. As air conditioners become more efficient, it becomes increasingly difficult and costly to increase efficiency to the next higher level. This is partly because traditional lower

- cost design changes, such as increasing heat exchanger surface area, may not suffice. This relationship becomes increasingly evident at efficiencies greater than 14 SEER. Therefore, DOE derived the

system cost

- efficiency curve for each manufacturer using a linear line

- fit from 13

- 14 SEER, and an exponential curve

- fit for efficiencies greater than 14 SEER.

DOE also developed trends for the five subsystems described above. When examining the normalized subsystem costs, DOE found that each manufacturer used different methods to

increas e system efficiency. While each manufacturer’s system costs exhibited a similar trend as efficiency increased, the differences in the subsystem trends between different manufacturers were masked since all of the subsystem costs summed to the system cost. T herefore, DOE analyzed every subsystem from each manufacturer on an individual basis when developing trends to estimate subsystem costs for the operating efficiency range of split

- system air

conditioners.

Aggregating System and Subsystem Costs

. To develop the industry cost

- efficiency curve for split

- system air conditioners, DOE aggregated the manufacturer cost

- efficiency curves at both the system and subsystem level. Because DOE only developed curves for four manufacturers, it adjusted market shares of tho se four manufacturers to represent the entire5

- 44 industry. DOE then used those adjusted market shares to weight each manufacturer’s cost

efficiency data. The result was a cost

- efficiency curve that represented the MPC at each efficiency level for the industry , as well as five subsystem cost

- efficiency curves.

Because DOE evaluated the subsystems individually for each manufacturer, there were small discrepancies between the sum of the aggregated subsystem cost

- efficiency curves and the aggregated system cost

- e fficiency curve. Therefore, DOE calibrated the subsystem costs such that their sum at each efficiency level was consistent with the system cost at each level.

5.9.2.2 Split

- System Air Conditioners: Coil

- Only

Because coil

- only, split

- system air conditioners rely on a default evaporator fan power to achieve their SEER rating, DOE’s cost

- efficiency curve consisted of only two subsystems, a condensing unit and an evaporator coil. Because a coil

- only system is constrained by the default evaporator fan power in the test procedure, the system faces additional limitations in the maximum achievable ( i.e. , max

- tech) SEER level compared to blower

- coil systems. Referring to the AHRI Certified Directory, DOE determined that the max

- tech for a 3 ton coil

- only system was roughly 17 SEER. Upon review of these systems, DOE found that this max

- tech level was achieved using a condensing unit similar to a condensing unit used in a 20

- 21 SEER blower

- coil system. DOE also found that at lower efficiencies ( i.e. , 13

- 14 SEER), the condensin g units and evaporator coils were very similar to blower

- coil systems of the same SEER level. Due to the parallels between coil

- only and blower

- coil systems, DOE used its estimated blower

- coil cost

efficiency curve as the basis for the coil

- only cost

- effic iency curve.

As a starting point for the coil

- only cost

- efficiency curve, DOE eliminated the indoor unit casing, evaporator fan blower, and balance of indoor unit subsystems from the blower

- coil cost

efficiency curve. Using manufacturer specification sheet s and the AHRI Certified Directory, DOE then compared the SEER ratings of the same condensing unit when rated as a blower

- coil

and a coil

- only system. DOE found that through 14 SEER, the condensing units were generally

consistent between blower

- coil and co il

- only systems. Above 14 SEER, higher

- efficiency condensing units were typically required in coil

- only systems to achieve the same SEER levels

as blower

- coil systems.

When assessing the differences between the evaporator coils in coil

- only and blower

- coi l systems, DOE found that above the baseline, higher

- efficiency evaporator coils were typically required for coil

- only systems to achieve the same SEER levels as blower

- coil systems. As the system efficiencies increase, the disparity between the complexity and cost of evaporator coils

used in blower

- coil and coil

- only systems also increases.

5.9.2.3 Split

- System Heat Pumps

To develop a split

- system heat pump cost

- efficiency curve, DOE used manufacturer specification sheets and limited heat pump teardowns to modify the blower

- coil, split

- system air

conditioner cost

- efficiency curve. DOE maintained the breakdown of system costs into the five5

- 45 subsystems used for blower

- coil, split

- system air conditioners. DOE first examined manufacturer specification sheets to identify any differences in the indoor units used in air conditioners and heat pumps. DOE found that the indoor units used in 13 SEER split

- system heat pumps are generally the same indoor units that are used in 13.5 SEER split

- system air conditioners. This 0.5

SEE R offset between the indoor units used with heat pumps and air conditioners existed throughout the entire efficiency range. Therefore, DOE shifted all split

- system air conditioner subsystem costs relating to the indoor unit ( i.e. , indoor unit casing, evapo rator coil, evaporator fan blower, and balance of indoor unit) d

Next, DOE compared the condensing units ( i.e. , outdoor units) used in split

- system air

conditi oners and heat pumps. To do this, DOE compared the estimated system cost (based on teardowns) of a 13 SEER heat pump with a 13 SEER air conditioner from the same manufacturer. DOE calculated the percentage increase in cost of the system for that

manufactur er. DOE then applied this percentage increase to the estimated industry cost of a 13 SEER split

- system air conditioner to estimate the industry cost of a 13 SEER split

- system heat pump. From this, DOE used the estimated industry cost of the indoor unit of a 13 SEER heat pump to back out the industry cost of an outdoor unit for a 13 SEER heat pump. DOE then calculated the percentage increase in the industry cost of an outdoor unit for a 13 SEER heat pump compared to a 13 SEER air conditioner. DOE applied thi s percentage increase to the industry costs of outdoor units for split

- system air conditioners to estimate the costs of outdoor units for split

- system heat pumps throughout the entire efficiency range. down by 0.5 SEER to modify the cost

- efficiency curve to be applicable to split

- system heat pumps.

DOE determined that the max

- tech level for 3

- ton split

- system heat pumps was 21 SEER using the AHRI Certified Directory. DOE then examined manufacturer specification sheets for high

- efficiency systems to validate the costs estimated using the blower

- coil, split

- system air

conditioner cost

- efficiency curve. DO E did not develop a separate coil

- only cost

- efficiency curve for split

- system heat pumps as it did for air conditioners. DOE believes that the majority of split

system heat pumps are sold as a matched set of indoor and outdoor units for both the new

constr uction and replacement markets. However, DOE recognize d during the preliminary analysis that in some instances heat pumps are used in conjunction with gas

- or oil

- fired furnaces today providing a “dual

- fuel” heating capability. DOE s ought input on the char acterization of the heat pump replacement market and whether installations of matched sets of indoor and outdoor products should be the basis for DOE’s analysis for all heat pumps. After reviewing feedback on this issue, DOE decided that installation of ma tched sets should be the basis for analysis and applied this assumption to the final rule analyses.

5.9.2.4 Single

- Package Air Conditioners

d For heat pump products (split

- system and single

- package), DOE refers to the heat exchangers and associated system components with res pect to their functionality while the system is in cooling mode. For example, in a split

system heat pump, the outdoor heat exchanger is referred to as the condenser coil and the indoor heat exchanger is referred to as the evaporator coil.5

- 46 The basic system components of a single

- package air conditioner are very similar to a split

- system air conditioner. However , the system configurations differ enough that incremental costs cannot be estimated based simply on the incremental costs of a split

- system air conditioner, as was done for split

- system heat pumps. Rather, DOE used manufacturer specification sheets

and in formation from manufacturer interviews to determine the sizes and complexity of components in the baseline system. DOE relied on the cost estimates from split

- system air conditioners to estimate the costs for various single

- package air conditioner componen ts for the baseline system. To estimate component costs for single

- package air conditioners, DOE separated the condensing unit costs for split

- system air conditioners into individual component costs ( i.e. , unit casing, condensing coil, condensing fan, comp ressor, sealed system components, and a balance of the condensing unit). DOE then considered the costs of individual components at each efficiency level when developing cost estimates for a baseline single

- package air

conditioner.

To estimate the cost of t he baseline casing, DOE used the sum of the indoor unit and outdoor unit casings for a 13 SEER split

- system air conditioner. DOE found that the baseline condensing coils in single

- package air conditioners are typically about 10

- percent larger than

those us ed in 13 SEER split

- system air conditioners. Therefore, DOE estimated the baseline cost for the condensing coil as 1.1 times the cost of a 13 SEER split

- system air conditioner condensing coil. DOE also found that variable

- speed evaporator fan blowers are t ypically implemented in single

- package air conditioners at 13.5 SEER, compared to 14.5 SEER in split

system air conditioners. So, DOE estimated that the baseline cost of the evaporator fan blower was approximately the same as a 14 SEER split

- system air con ditioner evaporator fan blower. DOE assumed that the baseline costs of the remaining system components were identical to those

estimated for a 13 SEER blower

- coil, split

- system air conditioner.

Once DOE established the component costs for a baseline single

- package air conditioner,

DOE examined the AHRI Certified Database to determine that the max

- tech level was 16.6 SEER. Using information from discussions with manufacturers and product specification sheets, DOE estimated the incremental costs of each compo nent from 13

- 16 SEER in 0.5 SEER

increments , except for the 0.1 increment from 16.5 to the max

- tech level at 16.6 SEER . For simplicity, DOE then grouped the component costs into two subsystems: (1) evaporating, and (2) condensing. The evaporating subsystem consisted of the evaporator coil and the evaporator fan blower. The condensing subsystem consisted of all the remaining components in the system. The sum of these two subsystems at each efficiency level provides the system MPC for that level.

5.9.2.5 Single

- Packa ge Heat Pumps

DOE derived the single

- package heat pump cost

- efficiency curve using a similar methodology as was used to develop the split

- system heat pump cost

- efficiency curve. However, DOE used the single

- package air conditioner cost

- efficiency curve as the basis rather than the split

- system air conditioner cost

- efficiency curve. DOE retained the two subsystems used for single

- package air conditioners. To develop the cost

- efficiency curve for single

- package heat pumps, DOE first examined manufacturer spec ification sheets to identify any differences in the5

- 47 evaporator coils and evaporator fan blowers used in air conditioners and heat pumps. DOE found

that the baseline packaged heat pumps typically used a variable

- speed evaporator fan blower.

DOE also found t hat the evaporator coils used in 13 SEER heat pumps were about the same size

as those used 13.5 SEER air conditioners. This 0.5 SEER offset between the indoor units used with heat pumps and air conditioners existed throughout the entire efficiency range. T herefore, DOE shifted the evaporating subsystem costs for the single package air conditioners down by 0.5 SEER to modify the cost

- efficiency curve to be applicable to single

- package heat pumps. Next, DOE increased the condensing subsystem cost for single

- p ackage air conditioners by the same percentage used to estimate the cost of the outdoor unit for split

- system heat pumps. This was

done for all efficiencies.

DOE determined that the max

- tech level for split

- system heat pumps was 16.4 SEER using the AHRI Ce rtified Directory. For the condensing subsystem, this max

- tech level fell between two single

- package air conditioner SEER levels that were used to estimate its cost. So, DOE interpolated between the two SEER levels to estimate a corresponding cost for 16.4 SEER. For the evaporating subsystem, the air conditioner costs were shifted down by 0.5 SEER, but the

max

- tech level for heat pumps was only 0.2 SEER less than air conditioners. Therefore, DOE trended the evaporating subsystem costs using a line of best f it to estimate the subsystem cost at 16.4 SEER. The sum of these two subsystems at each efficiency level provides the system MPC

for that level.

5.9.2.6 Small Duct High Velocity Systems

As discussed in section 5.8.1.2 , an SDHV system consi sts of the indoor unit produced by the SDHV manufacturer and a matched condensing unit. DOE derived the SDHV cost

- efficiency curve using a similar methodology as was used to develop the split

- system air conditioner cost

efficiency curve. Manufacturer feedb ack indicated that the overall system SEER rating is improved by matching with a more efficient condensing unit. To determine the overall system cost, DOE first determined a typical condensing unit SEER rating for each SDHV system SEER

level in the AHRI Ce rtified Directory. Based on findings in the Directory and manufacturer specification sheets, DOE found that a 13 SEER condensing unit was generally matched with an indoor SDHV unit to produce an 11 SEER system

. Therefore, a 15 SEER condensing unit was

matc hed with an indoor SDHV unit to produce a baseline 13 SEER unit. T o arrive at a total

system cost, DOE added the cost of this condensing unit from the split

- system curve to the cost of an indoor SDHV unit, which was based on teardowns.

DOE determined t hat the max

- tech level for SDHV units was 14.3 SEER using the AHRI Certified Directory. For the condensing subsystem, this max

- tech level fell between two SDHV SEER levels that were used to estimate its cost. So, DOE interpolated between the two SEER

level s to esti mate a corresponding cost for 14.3 SEER.5

- 48 5.10 EXPANSION OF ANALYSE S TO ADDITIONAL CAPA CITIES

5.10.1 Furnaces

To dev elop the MPC s for the analysis of capacities other than the representative input capacity ( i.e., at 60 kBtu/h, 100 kBtu/h, and 120 kBtu/h) , DOE performed one teardown of a furnace below the representative capacity and one teardown of a furnace above the representative capacity

, in addition to performing multiple virtual teardowns. DOE used the physical teardowns

to estimate the changes in material and labor costs that occur at capacities higher and lower than the representative capacities based on observations made during teardowns and professional experience. Performing physical teardowns of models outside of the representative capacities

allowed DOE to accurately model certain characteristics that are not identifiable in manufacturer

literature. DOE modified the cost model for the representative capacity ( i.e., 80 kBtu/h ) to account for changes in the size of furnace components that would scale wit h input capacity ( e.g., heat exchanger size ). DOE accurately modeled certain other characteristics ( e.g., gas valves ) using information contained in manufacturer literature

. Whenever possible, DOE maintained the same product line that was used for the tear down at the representative products to allow for a

dire ct comparison between representative products and the products at the additional input capacities that were analyzed

. To avoid the publication of sensitive material, DOE aggregated

and normalized the c osts for the additional input capacities in the same manner as wa s done for the representative input capacity

.

5.10.2 Central Air Conditioners and Heat Pumps

To dev elop the MPC s for the analysis of two ton and five ton cooling capacities for

residential central a ir conditioners and heat pumps

, DOE conducted one teardown of a two ton condensing unit and one teardown of a five ton condensing unit. DOE modified the cost model for the representative capacity ( i.e., three

- tons) to account for changes in the size of cen tral air conditioner and heat pump components that would scale with cooling capacity ( e.g., evaporator and condenser coils, outer cabinet, packaging). DOE accurately modeled certain other characteristics ( e.g., compressor, fan motor, fan blades) using info rmation contained in

manufacturer literature

. Whenever possible, DOE maintained the same product line that was used for the teardown at the representative products to allow for a dire ct comparison between

three tons models and two and five ton models

. To a void the publication of sensitive material, DOE aggregated and normalized the costs for two and five ton models in the same manner as was done for the three tons models. For the analysis, units with a nominal cooling capacity of between 18,000 Btu/h and 30 ,000 Btu/h were considered two ton units and five ton units were considered to have a cooling capacity greater than 54,000 Btu/h.

5.11 STAN D BY MODE AND OFF MODE

For the standby mode and off mode analyse s , DOE adopted a design

- option approach

, which allowed for the calculation of incremental costs through the addition specific design5

- 49 options to a baseline model. DOE decided on this approach because it did not have sufficient data to execute an efficiency

- level analysis, as no manufacturers currently rate or publi sh data on

the standby mode and/or off mode energy consumption of their products. Because standby mode

and off mode electricity consumption is not currently regulated, DOE believes manufacturers generally do not invest in reducing the off mode electrical e nergy consumption of their products because the production cost cannot be passed onto the consumer because consumers currently do not value this feature highly enough to pay extra for it . Therefore, DOE determined that there is no basis for comparison of e fficiency levels between products. The design

- option approach , by contrast, allowed DOE to examine potential designs for improving the off mode energy consumption.

5.11.1 Electric Furnaces

DOE analyzed the expected standby mode and off mode power consumption of an electric

furnace by comparing it to the standby mode and off mode power consumption of a non

weatherized gas furnaces. In an electric furnace , DOE found that for the same components primarily contribute to standby mode and off mode power consumption in the baseline design (i.e., the control transformer, an ECM fan motor (which was assumed present for the baseline standby and off mode design), and the control board power supply)

.

To estimate the standby mode and off mode power consumption of electric fu rnaces, DOE compared wiring diagrams, control schematics, and images of control boards of gas and electric furnaces. DOE found that electric furnaces commonly use a 40VA transformer that is very

similar to those found in non

- weatherized gas furnaces. For t he final rule analysis of standby mode and off mode for electric furnaces, DOE assumed that the power consumption associated

with these transformers would be the same. Further, a DOE review of electric furnaces found

that other c omponents are also the same as or very similar to those used in non

- weatherized gas

furna ces (such as ECM blower motors). Therefore, DOE also assumed the standby consumption for these components would be the same in electric furnaces as in non

- weatherized gas furnaces

. Finally, DOE examined the control boards, their power supplies, and the electrical systems of both electric and gas furnaces to examine potential differences in standby mode and off mode power consumption in the rest of the electrical system. The control boards for bot h electric and

non

- weatherized gas furnaces typically share many common features, such as linear and/or

zener

- style power supplies, relays, and microchip controllers. Additionally both furnace types need a wiring harness and s ensors for safety and control. A key diffe rence between electric furnace and gas furnace control systems is that electric furnace control boards tend to be less complex because they do not require functions such as flame ignition and supervision or other

co mbustion safety controls. How ever, electric furnace control boards must use relays and/or sequencers that have higher capacity ratings than the relays typically found in gas furnaces to turn the electric furnace heating elements on incrementally . The elements must be activated

individ ually to limit inrush currents and prevent trips of circuit breakers. DOE estimates that the additional standby mode and off mode power consumption associated with the use of larger5

- 50 relays and/or sequencers in electric furnaces is offset by need for combus tion controls in gas

furnaces

.

As a result, DOE assumed that an electric furnace has a standby mode and off mode electrical consumption that is similar that of non

- weatherized gas furnaces in similar models.

DOE also believes that the design options that were identified for reducing the standby mode and off mode power consumption of gas furnaces (i.e., a switching mode power supply and a toroidal transformer) will have the same impact on the standby mode and off mode power consumption

of electric furnaces

. Therefore, DOE analyzed standby mode and off mode standards that were identical to those analyzed for non

- weatherized gas furnaces.

5.11.2 Identification and Characterization of Standby Mode and Off Mode Components

Using the design

- option approach, DOE identif ied components that contribute to off mode energy consumption in the teardown

- generated B OMs used for the SEER standards and the components that contribute to the standby mode and off mode energy consumption in the BOMs of the furnaces that were analyzed. DOE performed measurements of standby mode off mode electrical energy consumption on each of these components in accordance with the test procedures specified in DOE central air conditioners and heat pumps test procedure NOPR

. DOE aggregated these measure ments, in conjunction with nominal power ratings and feedback from manufacturer regarding individual component’s power draw , to characterize the electrical energy use of each component operating in standby mode or off mode for furnaces and in off

mode for central air conditioners and heat pumps

. DOE also estimated the costs of individual components based on volume

- variable price quotations and detailed discussions with manufacturers and component suppliers

.

5.11.3 Baseline Model

The design

- option approach calcul ates the incremental costs for products with standby or off mode energy consumption levels above a baseline model in each off mode product class covered in this rulemaking

. In most rulemakings, the baseline is determined by the current

Federal minimum ener gy conservation standard. However, because this is the first rulemaking to regulate the off mode electrical energy consumption of residential furnaces and central air conditioners and heat pumps, DOE instead established the baseline model for the standby m ode

and off mode analysis as the most energy

- consumptive product from the representative teardown

selection. DOE defined and identified baseline components as those that consumed the most electricity during standby mode and off mode operation. The most con sumptive b aseline components were then “assembled” to model the electrical system of a furnace or central air conditioner or heat pump with the maximum system off mode electrical energy consumption from DOE’s representative test data. For central air condi tioners and heat pumps t he baseline

model contains the following components: 40W crankcase heater, 40VA control transformer

.5

- 51 Additionally, in the baseline model, the crankcase heater comes on whenever the compressor

shuts off.

For furnaces, DOE’s testing of over 40 models of residential furnaces showed standby mode power consumption from 4 to 10 watts. However, because this represented only a fraction of the residential furnace market, DOE took a conservative approach and summed the most energy consumptiv e components in each individual furnace tested to create the baseline model.

T he baseline furnace model contains a 40VA control transformer, ECM blower motor (and associated controls), and linear power supply. For oil

- fired furnaces only, th e baseline mode l also

included an oil

- fired burner that contains an additional transformer that consumes additional standby power. For furnaces, DOE examined and tested the standby power consumption of a variety of products, including those with “premium” features that a re related to consumer utility, but unrelated to product efficiency. In order to prevent a reduction in consumer utility, DOE did not consider any design options that would reduce the feature set of these units. The results of the testing for individual co mponents are shown in Table 5.11

. 1 below.

Table 5.11

. 1 Baseline Standby Mode and Off Mode Power Consumption by Component for

Furnaces Component Non

- weatherized Gas, Mobile Home Gas, and

Electric Furnace Baseline Power Consumption (W) Oil

- Fired Furnace

Baseline Power Consumption (W)

Transformer 4 4 ECM Blower Motor (includes controls) 3 3

Controls/Other 4 2

Oil Burner N/A 3

Total 11 12

5.11.4 Cost

- Power Consumption Results

The results of the engineering analysis are reported as cost

- power consumption data in the

form of power (in watts ) versus M PC (in dollars). For each design option that passed the screening analysis (chapter 4 of this TSD), DOE estimated the power consumption reducti on of the design option based on the applicable DOE test procedure. For furnaces, DOE used the test procedures promulgated in the October 2010 test procedure. For central air conditioners and heat

pumps, t he power consumption of each system design was calc ulated based on the off mode test procedure for central air conditioners and heat pumps that was proposed in the test procedure

S NOPR, and is also contained in the direct final rule

. 76 FR 18105

. For residential furnaces, DOE developed two sets of standby and off mode data

– one for non

- weatherized gas furnaces and mobile home furnaces, and one for oil

- fired furnaces. DOE assumed that furnaces do not5

- 52 have a seasonal off switch and, therefore

, assumed that standby mode and off mode power consumption are equa l. For furnaces, the efficiency levels listed are based on units with ECM motors because ECM motors use a higher amount of off mode power, specifically 3 watts more than units with PSC motors (including additional controls). For central air conditioners an d heat

pumps, DOE developed six off mode data sets

, four for air conditioners and two for heat pumps. As with furnaces, t he efficiency levels listed are based on units with ECM motors because ECM

motor s use a higher amount of off mode power , specifically 3 watts more than units with PSC

motors

. For both furnaces and central air conditioners and heat pumps , the costs for each design option are the same regardless of motor type , and therefore the results are given only for units

with ECM motors

. Coil

- only air conditioners have a separate data set because there is no indoor fan nor is there a transformer because this component is assumed to be included in the existing

furnace that the coil

- only unit is installed with. The inclusion of this off mode power

consum ption from the transformer for coil only units would lead to double counting of the energy consumption because the furnace has a separate off mode metric.

The methodology for developing the curves started with determining the energy use of

baseline produc ts . Above the baseline, DOE implemented design options , which were discussed in Chapter 3, based on cost

- effectiveness until all availa ble technologies were employed ( i.e., at a

max

- tech level). T he design options considered are not all mutually exclusive ; therefore, systems could incorporate multiple design options simu ltaneously, which allowed for three different system designs, in addition to the baseline for air conditioners , and two different system designs

in addition to the baseline for furnaces

. For central air conditioners and heat pumps,

t hermostatically controlling the crankcase heater based on compressor shell temperature is the first design improvement, followed by the addition of a compressor cover. Lastly, the 40VA control transformer is repla ced with a more efficient toroidal transformer. For furnaces, changing from a linear power supply to a switching mode power supply is the first design option

, and adding a toroidal transformer in addition to the switching mode power supply is the second

de sign option. Table 5.11

. 2 and Table 5.11

. 3 list the standby and off mode power consumption

and associated MPC increase for residential furnaces. Table 5.11

. 4 and Table 5.11

. 5 list the MPC

and off mode power consumption for air conditioners:

Table 5.11

. 2 Non

- weatherized Gas, Mobile Home Gas , and Electric Furnace Standby Mode and Off Mode Power Consumption an d Cost Description Standby Mode and

Off Mode Power Consumption (W) MPC ($)

Baseline 11 0 Efficiency Level 1 Switching Mode Power Supply 10 7.25

Efficiency Level 2 Switching Mode Power Supply and

Toroidal Transformer 9 18.205

- 53 Table 5 .11

. 3 Oil

- fired Furnace Stand b y Mode and Off Mode Power Consumption and Cost Description Standby Mode and

Off Mode Power Consumption (W) MPC ($)

Baseline 12 Efficiency Level 1 Switching Mode Power Supply 11 7.25

Efficie ncy Level 2 Switching Mode Power Supply and

Toroidal Transformer 10 18.20

Table 5.11

. 4 Split System Blower Coil

, Packaged , and Space Constrained Air Conditioner Off Mode Power Consumption and Cost

MPC with a n ECM Motor

and Crankcase

Heater

($) Power Consumption

with a n ECM Motor

and Crankcase

Heater

(W) MPC with a n ECM Motor and

No Crankcase

Heater

($) Power Consumption with

a n ECM Motor and

No Crankcase

Heater

(W)

Baseline 8.0 6 48 .0 6.56 11 .0 Efficiency

Level 1 11.82 35

. 5 17.58 10 .2

Efficiency

Level 2 46.20 30

. 3

Efficiency

Level 3 57.22 29.5

Table 5.11

. 5 Coil Only Split System Air Conditioner Off Mode Power Consumption and

Cost

MPC with a

Crankcase

Heater

($) Power Consumption with

a Crankcase

Heater

(W) MPC with No

Crankcase

Heater

($) Power Consumption with

No Crankcase

Heater

(W)

Baseline 3.64 37 .0 0 0 Efficiency

Level 1 7.40 24.5

Efficiency

Level 2 24.24 19.3

For heat pumps, there were only two design options, thermostatica lly controlled

crankcase heater and toroidal transformer, in addition to the baseline. During testing of different crankcase heater control strategies, DOE found that heat pumps had a lower power draw5

- 54 according to the test June 2010 central air conditioner test procedure NOPR (75 FR 21224) when the crankcase heater was thermostatically controlled based on outdoor ambient than when it was controlled based on compressor shell temperature. Therefore, the addition of a comp ressor cover will not provide any benefit with this control strategy because the crankcase heater on time is

unaffected ; t herefore, it was not included as a design option. The other off mode heat pump design option was replacing the 40VA control transforme r with a toroidal transformer.

Table 5.11

. 6 Split System

, Packaged and Space Constrained Heat Pump Off Mode Power Consumption and Cost

MPC with a n ECM Motor

and Crankcase

Heater

($) Power Consumption

with a n ECM

Motor and

Crankcase

Heater

(W) MPC with an ECM Motor and

No Crankcase

Heater

($) Power Consumption

with a n ECM Motor

and No Crankcase

Heater

(W)

Baseline 8.06 51.0 6.56 14.0 Efficiency

Level 1 11.82 32 .5 17.58 13.2

Efficiency

Level 2 22.84 31 .7

5.12 M ISCELLANEOUS CENTRAL AIR CONDITIO NER AND HEAT PUMP

SYSTEM CHARACTERISTI CS

5.12.1 Investigation of the Relationship Between SEER and HSPF

Energy efficiency standards for heat pumps must establish minimum values for HSPF as well as SEER. However, this analysis thus far has only been performed in terms of rated SEER values, with no trending or aggregat ion of data with regard to HSPF . As part of this analysis, DOE investigated whether the relationship between HSPF and SEER is substantial enough to

allow a SEER sta ndard to serve as a basis for an HSPF standard as well.

5.12.1.1 Split

- System Heat Pumps

To set energy efficiency standards for heat pumps, DOE must determine both an HSPF level and a SEER level. This complicates the analysis since each SEER level corresponds to a range of varied HSPF ratings. To provide a rationale for selecting SEER

- HSPF pairs, DOE examined plots based on Table 5.11.2 that showed the number of models possessing each HSPF at each SEER level. A minimum HSPF requirement was determined based on the d istribution of the products currently available throughout the range of efficiency levels. Median (50 th
percentile) HSPFs are generally well above the minimum HSPF level

. This is due to the5

- 55 perceived ability of high

- SEER products to attain higher HSPF val ues as well, and follows relationships used in past CAC rulemakings

.

After examining the distribution data, DOE plotted the relationship between HSPF and

SEER for all three

- ton split

- system heat pumps currently listed as active in the AHRI Certified

Dire ctory. At the baseline efficiency of 13 SEER, the difference between the minimum HSPF (6.7) and the median (8 .0 ) is 1.3 HSPF. However, the existing standard is 7.7 HSPF, and for this reason, DOE chose not to include any units below this level in its analys is . DOE realizes that a number of different methodologies could be utilized in setting the relationship between SEER and the required corresponding HSPF. However, DOE believes that a line fitted to the median HSPF values is the most accurate representation of the market because a mean value could be skewed based on a small number of outliers, which would have a disproportionate effect. Using the median ensures that each model is accounted for equally. From this trending based on median HSPF values, DOE prod uc ed the foll owing relation for the analyses :

HSPF = 0.223 × SEER + 4.998 Equation 5.12

. 1

The minimum HSPF requirements are derived by inserting the minimum SEER requirements into the formula . Even though DOE does not have information on the distribution of heat pump sales by HSPF at each SEER level, it is apparent that the market currently favors products that exceed the minimum allowable HSPF level. This is due both to the correlation

betwee n HSPF and SEER and the pref erence in the market for higher HSPF heat pumps in cooler

climates. However, DOE believes that establishing an HSPF standard well above the current median at a given SEER level would impose an undue design constraint on manufact urers, adding to the cost and burden of designing, producing, testing, and qualifying the product without resulting in a significant increase in the average HSPF of products sold. Table 5.12

. 1

summarizes the selection of HSPF stan dard levels for three ton units :

Table 5.12

. 1 Comparison of Three Ton HSPF Standard Levels with Available Products

Efficiency/Standard Level (SEER) 13 14 15 16 17 18 19 20 21

Recommended

Minim um (HSPF) 8 8.3 8.5 8.7 9 9.2 9.4 9.7 9.9

Median HSPF in

Available Products 8 8.2 8.5 9 9.25 9.25 9.5 N/A 9.55

- 56 Offset from Median (HSPF) 0 0.1 0

- 0.3

- 0.2 0.05

- 0.1 N/A 0.4

Source: 20 10 AHRI Directory of Certified Product Performance

Table 5.12

. 2 provides a more detailed breakdown of the models available at each efficiency level as well as the total number of models at each efficiency level.

Table 5.12

. 2 Prevalence of HSPF Ratings by SEER Level for Three Ton Split System Heat Pumps with Impacts of Suggested HSPF Standards

Decile Efficiency Level (SEER)

13 14 15 16 17 18 19 20 21

Selected HSPF

8.0 8.3 8.5 8. 7 9 .0 9.2 9.4 9.7 9.9

0% 6.7 6.7 6.7 6.7 7.1 7.4 9 N/A 9.6

10% 7.7 7.8 8 8.5 8.7 8.9 9 N/A 9.6

20% 7.8 8 8.2 8.7 9 9 9.2 N/A 9.6

30% 7.8 8.2 8.5 8.9 9.1 9.2 9.5 N/A 9.6

40% 8 8.2 8.5 9 9.2 9.2 9.5 N/A 9.6

50% 8 8.2 8.5 9 9.25 9.25 9.5 N/A 9.6

60% 8 8.2 8.6 9 9.3 9.25 9.6 N/A 9.6

70% 8.1 8 .4 8.7 9.1 9.6 9.5 9.6 N/A 9.6

80% 8.2 8.5 9 9.3 9.7 9.5 9.6 N/A 9.6

90% 8.4 8.5 9 9.5 9.9 9.95 9.6 N/A 9.6

100% 9.3 10 10 10.4 10.7 10.6 10.05 N/A 9.6

No. Listings 14547 22976 11860 3858 3011 1025 143 0 8

Source: 20 10 AHRI Directory of Certified Prod uct Performance

Because DOE conducted separate analyses for two and five ton heat pumps, SEER/HSPF

r elationships were needed for these capacities as well. Initially, DOE considered applying the three ton SEER/HSPF relationship to the other capacities. Ho wever, after conducting further research and receiving feedback during manufacturer interviews, DOE determined that the differences between the capacities were enough to justify separate curves. DOE produced the following relationships for the two and five ton products by utilizing the same approach used for the 3 ton products:

Table 5.12

. 3 SEER/HSPF Relationship for Two and Five Ton Split Heat Pumps

SEER 13 14 15 16 17 18 19 20 21 225

- 57 2 Ton HSPF 8.0 8.2 8.5 8.7 8.9 9.1 9.4 9.6 9.8 10.1

5 Ton HSPF 7.9 8.1 8.4 8.7 8.9 9.0

5.12.1.2 Single

- Package Heat Pumps

The study of the relation between HSPF and SEER for single

- package heat pumps, performed as part of th e final rule analysis, is based off of the fit of an e quation directly to the AHRI Certified Directory data for this product class. DOE also investigated the applicability of the results obtained for split

- system heat pumps to the single

- package heat pump product class. The single

- package heat pump product cl ass contained a much lower number of product models ( 2354 ) than the split

- system heat pump product class, constituting only 0. 9 percent of the total heat pump listings in the AHRI Certified Directory. When the products were categorized by SEER rating, it b ecame evident that the variation present within the HSPF values at each SEER level was much smaller than was the case with split

- system heat pumps. Whereas the HSPF values for a given SEER could vary by as much as 3. 2 5 HSPF within the split

- system products

, the largest variation observed for the single

- package products at a specific SEER was 1 HSPF. This suggests that there is a strong er correlation for these products between SEER and HSPF, and that an HSPF standard would likely have a similar effect on all manufacturers.

Following the preliminary analysis

, DOE proposed using the split system SEER/HSPF relationship for single package systems as well because the general, median trend in the

SEER/HSPF relationship exhibited for split

- system products is also followed by single

- package products

. However, further analysis for the final rule based on 2010 databases submitted by

AHRI instead of the 2008 databases, which were used for the preliminary analysis and manufacturer feedback on the accuracy of this approa ch

, led DOE to believe that the differences between split

- system and single package heat pumps are enough to justify a separate SEER/HSPF relationship for single package heat pumps:

Table 5.12

. 4 HSPF Standa rd Levels for Single Package Heat Pumps

SEER 13 14 15 16 16.4
Standard ( HSPF ) 7.7 8.1 8.4 8.8 9

5.12.1.3 Small Duct High Velocity Heat Pumps

Manufacturers indicated that the physical differences and different operating characteristics of SDHV unit as compared to conventional systems justified an independent analysis of the SEER/HSPF relationship for SDHV heat pumps. After investigating this assertion, DOE believes that the differences between SDHV and the other product classes were enough to warrant a separate re lationship as well. DOE initially considered basing the SEER/HSPF relationship for the SDHV product class based on the median based approach using ratings in the AHRI Directory as of June 8, 2010

. Using the median based approach produces the results displa yed below in Table 5.12

. 5 . However, as part of this investigation DOE f ound that5

- 58 only 28 of the 235 product listings exceeded the current standard of 7.7 HSPF and that there were only 3 products listed with a SEER rating greater than 13.5. DOE is concerned about basing standards and analysis on such limited data and instead has decided to use the current standard level of 7.7 HSPF at 13 SEER as opposed to the median value of 8.1 HSPF.

Table 5.12

. 5 Median HSPF Levels for SDHV Heat Pumps

SEER 13 14 14.3

Median HSPF 8.1 8.5 8.6

5.12.2 Calculation of System Weights

Representative system weights for units at all SEER levels were required as an input to downstream analyses, including the life

- cycl e cost calculations. The basis for this calculation of typical system weight was operating weight information obtained from manufacturer specification sheets. For each of the four conventional product classes (split

- system air conditioners, split

- system he at pumps, single

- package air conditioners, single

- package heat pumps) and the SDHV product class , data were collected across a number of manufacturers and across the entirety of the range of applicable rated SEER levels

. Separate calculations were performe d for the indoor units and outdoor units for the split

- system product classes and the single

- package product class. SDHV system weights were determined based on an indoor SDHV unit weight and the split system condensing unit from conventional manufacturers

. For all of these units, the data across the various manufacturers were consistent enough to allow for direct trending of unit weight. Therefore, system weights as listed by the manufacturers were plotted against rated SEER for all manufacturers and SEER levels, and a best fit curve was fit to the data. From this curve fit, typical unit weights were estimated for each applicable SEER level. This trending and calculation allowed for a single typical unit weight corresponding to a given

SEER value to be used for the systems in each product class. Table 5.12.6 through 5.11.10 give the calculated typical weights by SEER level for each product class examined

.

Table 5.12

. 6 Calculated Typical Split

- System Air Conditioner Unit Weights Split AC ( lbs )

SEER Outdoor Unit Weight Indoor Unit Weight

2 Ton 3 Ton 5 Ton 2 Ton 3 Ton 5 Ton

13 157 188 262 115 135 180

13.5 164 196 278 117 139 184

14 172 204 293 119 142 187

14.5 180 211 307 120 145 190

15 188 218 321 122 149 194

15.5 195 225 334 124 152 197

16 203 232 347 125 155 200

16.5 211 238 360 127 158 203

17 218 244 372 128 161 2055

- 59 18 234 256 396 131 166 211

19 249 268 134 171

20 265 279 136 176

21 280 289 139 18 1

22 296 299 142 186

23 311 144

24.5 334 148

Table 5.12

. 7 Calculated Typical Split

- System Heat Pump Unit Weights Split HP ( lbs )

SEER Outdoor Unit Weight Indoor Unit Weight

2 Ton 3 Ton 5 To n 2 Ton 3 Ton 5 Ton

13 165 223 293 115 135 180

13.5 183 237 306 117 139 184

14 201 251 318 119 142 187

14.5 218 264 330 120 145 190

15 235 277 342 122 149 194

15.5 251 289 354 124 152 197

16 266 301 365 125 155 200

16.5 281 313 375 127 158 203

17 296 324 386 128 161 205

18 324 346 405 131 166 212

19 350 366 134 171

20 375 388 136 17 9

21 399 415 139 1 85

22 422 142

Table 5.12

. 8 Calculated Typical Packaged Air Conditioner Unit Weights

S EER Packaged AC ( lbs )

13 341

13.5 351

14 361

14.5 371

15 382

15.5 392

16 402

16.6 4145

- 60 Table 5.12

. 9 Calculated Typical Packaged Heat Pump Unit Weights

SEER Packaged HP (lbs)

13 379

13.5 395

14 411

14.5 427

15 443

15.5 460

16 476

16.4 489

Table 5.12

. 10 Calculated Typical SDHV Unit Weights *

SEER SDHV (lbs)

13 394

13.5 412

14 430

14.3 441

* These weights are for the combined weight of the SDHV unit and the outdoor unit.

5.13 RESULTS

The final result of the engineering analysis is a set of cost

- efficiency relationship s. DOE developed relationship s for the four conventional product classes of central air conditioners and heat pumps, the SDHV product class , and the three furnace product classes using the reverse

engineering and cost modeling methodology described above. The c ost

- efficiency results are shown in tabular form in Table 5.13

. 1 through Table 5.13

. 15 in the form of efficiency versus MPC.

As stated above, DOE used the cost

- efficiency curves from the engineering analysis as an input to the life

- cycle cost (LCC) analysis to determine the price of central air conditioning and heat pump units to the custo mer (see chapter 8 of the TSD).

5.13.1 Furnaces

Table 5.13

. 1 Cost

- Efficiency Data for Non

- weatherized Gas Furnaces with a PSC Blower

Motor

AFUE MPC [$]

60 kBtu/h 80 kBtu/h 100 kBtu/h 120 kBtu/h5

- 61 80 259 26 6 282 305

90 367 379 403 435

92 397 412 441 473

95 453 482 528 568

98 582 595 630 686

Table 5.13

. 2 Cost

- Efficiency Data for Mobile Home Gas Furnaces (80 kBtu/h Input Capacity) with a PSC Blower Motor

AF UE MPC [$]

80 297

90 414

92 448

96 520

Table 5.13

. 3 Cost

- Efficiency Data for Oil

- Fired Furnaces (105 kBtu/h Input Capacity) with

a PSC Blower Motor

AFUE MPC [$]

82 809

83 817

84 826

85 835

97 1,089

5.13.2 Central Air Conditioners and Heat Pumps

Table 5.13

. 4 Cost

- Efficiency Data for Two Ton Split

- System Air Conditioners: Blower

- Coil

Efficiency

Level Outdoor

Unit Indoor Unit System

SEER Condensing

Unit [$] Indoor

Unit Casing [$] Evaporator

Coil [$] Evaporator

Fan Blower [$] Balance

of Indoor

Unit [$] MPC [$]5

- 62 13 455.42 50.11 120.51 93.10 18.51 737.66

13.5 470.60 51.70 126.23 98.52 19.48 766.53

14 486.01 53.29 131.90 104.03 20.45 795.67

14.5 501.65 54. 87 137.53 109.64 21.42 825.11

15 517.54 56.44 143.12 115.36 22.40 854.86

15.5 533.69 58.01 148.67 121.19 23.38 884.94

16 550.12 59.58 154.19 127.13 24.36 915.38

16.5 566.82 61.15 159.67 133.19 25.35 946.19

17 583.83 62.71 165.13 139.37 26.34 977.38

1 8 618.79 65.82 175.95 152.11 28.33 1

, 041.00

19 655.11 68.91 186.67 165.37 30.34 1

, 106.39

20 692.89 72.00 197.29 179.17 32.36 1

, 173.71

21 732.27 75.07 207.83 193.54 34.39 1

, 243.10

22 773.36 78.14 218.29 208.49 36.45 1

, 314.72

23 816.32 81.19 228.67 224. 05 38.52 1

, 388.75

24.5 884.56 85.76 244.14 248.55 41.66 1

, 504.665

- 63 Table 5.13

. 5 Cost

- Efficiency Data for Three Ton Split

- System Air Conditioners: Blower

Coil Efficiency

Level Outdoor

Unit Indoor Unit System

SEER Condensing

Unit [$] Indoor

Unit Casing [$] Evaporator

Coil [$] Evaporator

Fan Blower [$] Balance

of Indoor

Unit [$] MPC [$]

13 521.83 50.92 123.73 108.10 19.44 824.03

13.5 539.01 52.81 130.34 115.21 20.55 857.91

14 556.47 54.65 137.15 122.62 21.64 892.52

14.5 574.23 56.44 144.16 130.34 22.72 927.89

15 592.31 58.19 151.38 138.39 23.79 964.05

15.5 610.72 59.90 158.81 146.77 24.85 1

, 001.05

16 629.48 61.58 166.45 155.51 25.90 1

, 038.93

16.5 648.62 63.22 174.31 164.62 26.95 1

, 077.71

17 668.14 64.83 182.39 174.10 27.99 1

, 117.45

18 708.42 67.95 199.23 194.25 30.08 1

, 199.93

19 750.47 70.97 217.00 216.10 32.18 1

, 286.71

20 794.47 73.88 235.72 239.78 34.29 1

, 378.14

21 840.59 76.71 255.41 265.43 36.45 1

, 474.59

22 889.00 79.45 276.12 293.23 38.65 1

, 576. 45

Table 5.13

. 6 Cost

- Efficiency Data for Five Ton Split

- System Air Conditioners: Blower

- Coil

Efficiency

Level Outdoor

Unit Indoor Unit System

SEER Condensing

Unit [$] Indoor

Unit Casing [$] Evaporator

Coi l [$] Evaporator

Fan Blower [$] Balance

of Indoor

Unit [$] MPC [$]

13 724.24 61.70 172.82 116.94 24.04 1

, 099.74

13.5 748.01 63.28 179.89 127.30 25.31 1

, 143.79

14 772.69 64.96 187.43 138.13 26.62 1

, 189.83

14.5 798.30 66.74 195.47 149.46 27.97 1

, 237.94

15 824.90 68.62 204.01 161.32 29.34 1

, 288.19

15.5 852.51 70.60 213.09 173.73 30.76 1

, 340.68

16 881.18 72.68 222.70 186.71 32.21 1

, 395.48

16.5 910.95 74.87 232.88 200.30 33.70 1

, 452.69

17 941.87 77.16 243.63 214.52 35.22 1

, 512.40

18 1

, 007.37 82.04 266. 95 244.93 38.38 1

, 639.685

- 64 Table 5.13

. 7 Cost

- Efficiency Data for Two Ton Split

- System Air Conditioners: Coil

- Only

Efficiency

Level Outdoor Unit Indoor Unit System

SEER Condensing Unit [$] Evaporator Coil [$] MPC [$]

13 451.51 122.36 573.87

13.5 472.78 129.63 602.41

14 496.63 137.33 633.96

14.5 523.08 145.49 668.56

15 552.10 154.13 706.23

15.5 583.71 163.28 747.00

16 617.91 172.98 790.89

16.5 654.69 183.25 837.94

17 694.05 194.14 888.19

18 780.54 217 .89 998.42

Table 5.13

. 8 Cost

- Efficiency Data for Three Ton Split

- System Air Conditioners: Coil

- Only

Efficiency

Level Outdoor Unit Indoor Unit System

SEER Condensing Unit [$] Evaporator Coil [$] MPC [$]

13 522.62 119.50 642.12

13.5 539.69 130.46 670.15

14 563.33 142.43 705.76

14.5 593.53 155.49 749.02

15 630.30 169.75 800.05

15.5 673.63 185.32 858.95

16 723.52 202.32 925.84

16.5 779.98 220.87 1

, 000.85

17 843.00 241.13 1

, 084.135

- 65 Table 5.13

. 9 Cost

- Efficiency Data for Five Ton Split

- System Air Conditioners: Coil

- Only

Efficiency Level Outdoor Unit Indoor Unit System

SEER Condensing Unit [$] Evaporator Coil [$] MPC [$]

13 719.78 174.84 894.62

13.5 75 0.80 184.43 935.23

14 788.63 196.22 984.85

14.5 833.28 210.20 1,043.48

15 884.75 226.37 1,111.12

15.5 943.04 244.73 1,187.77

16 1,008.15 265.28 1,273.42

Table 5.13

. 10 Cost

- Efficiency Data for Two Ton S plit

- System Heat Pumps

Efficiency

Level Outdoor

Unit Indoor Unit System

SEER HSPF Condensing

Unit [$] Indoor

Unit Casing [$] Evaporator

Coil [$] Evaporator

Fan Blower [$] Balance

of Indoor

Unit [$] MPC [$]

13 8.0 540.69 51.70 126.23 98.52 19.48 836.62

1 3.5 8.1 558.72 53.29 131.90 104.03 20.45 868.38

14 8.2 577.01 54.87 137.53 109.64 21.42 900.47

14.5 8.3 595.58 56.44 143.12 115.36 22.40 932.90

15 8.5 614.44 58.01 148.67 121.19 23.38 965.70

15.5 8.6 633.62 59.58 154.19 127.13 24.36 998.89

16 8.7 653. 12 62.71 165.13 139.37 26.34 1,046.67

16.5 8.8 673.14 64.26 170.54 145.74 27.34 1,081.01

17 8.9 693.15 65.82 175.95 152.11 28.33 1,115.36

18 9.1 734.66 68.91 186.67 165.37 30.34 1,185.94

19 9.4 777.77 72.00 197.29 179.17 32.36 1,258.59

20 9.6 822.63 7 5.07 207.83 193.54 34.39 1,333.46

21 9.8 869.38 78.14 218.29 208.49 36.45 1,410.74

22 10.1 918.17 81.19 228.67 224.05 38.52 1,490.605

- 66 Table 5.13

. 11 Cost

- Efficiency Data for Three Ton Split

- System Heat Pump s

Efficiency

Level Outdoor

Unit Indoor Unit System

SEER HSPF Condensing

Unit [$] Indoor

Unit Casing [$] Evaporator

Coil [$] Evaporator

Fan Blower [$] Balance

of Indoor

Unit [$] MPC [$]

13 8.0 664.76 53.60 130.26 114.80 20.86 984.28

13.5 8.1 692.99 55.47 137.50 122.17 21.97 1,030.09

14 8.3 720.52 57.29 144.84 129.84 23.06 1,075.56

14.5 8.4 747.42 59.07 152.29 137.84 24.15 1,120.77

15 8.5 773.72 60.81 159.86 146.17 25.22 1,165.78

15.5 8.6 799.47 62.51 167.56 154.84 26.29 1,210.67

16 8.7 824.69 65.80 1 83.38 173.26 28.41 1,275.56

16.5 8.8 849.19 67.39 191.60 183.24 29.47 1,320.90

17 9.0 873.69 68.98 199.82 193.22 30.53 1,366.24

18 9.2 920.95 72.04 216.92 214.82 32.66 1,457.39

19 9.4 966.66 74.99 234.73 238.19 34.81 1,549.39

20 9.7 1023.88 76.71 255. 41 265.43 36.45 1,657.88

21 9.9 1074.36 81.90 276.96 291.46 39.39 1764.08

Table 5.13

. 12 Cost

- Efficiency Data for Five Ton Split

- System Heat Pumps

Efficiency

Level Outdoor

Unit Indoor Unit System

SEER HSPF Condensing

Unit [$] Indoor

Unit Casing [$] Evaporator

Coil [$] Evaporator

Fan Blower [$] Balance

of Indoor

Unit [$] MPC [$]

13 7.9 855.81 63.28 179.89 127.30 25.31 1,251.59

13.5 8.0 883.90 64.96 187.43 138.13 26.62 1,301.05

14 8.1 913.06 66.74 195.47 1 49.46 27.97 1,352.70

14.5 8.3 943.33 68.62 204.01 161.32 29.34 1,406.62

15 8.4 974.75 70.60 213.09 173.73 30.76 1,462.92

15.5 8.5 1,007.38 72.68 222.70 186.71 32.21 1,521.69

16 8.7 1,041.26 77.16 243.63 214.52 35.22 1,611.79

17 8.9 1,077.12 79.60 255. 29 229.72 36.80 1,678.54

18 9.0 1,112.98 82.04 266.95 244.93 38.38 1,745.295

- 67 Table 5.13

. 13 Cost

- Efficiency Data for Single

- Package Air Conditioners

Efficiency

Level Subsystems System

SEER Condensing [$] Ev aporating [$] MPC [$]

13 712.12 249.31 961.44

13.5 745.62 277.41 1,023.03

14 793.30 276.97 1,070.27

14.5 857.63 293.11 1,150.74

15 921.26 309.68 1,230.94

15.5 994.99 326.69 1,321.68

16 1,070.44 344.15 1,414.59

16.6 1,177.24 397.99 1,575.22

Table 5.13

. 14 Cost

- Efficiency Data for Single

- Package Heat Pumps

Efficiency

Level Subsystems System

SEER HSPF Condensing [$] Evaporating [$] MPC [$]

13 7.7 907.30 277.41 1

, 184.71

13.5 7.9 949.97 276.97 1

, 226.94

14 8.1 1

, 010.73 293.11 1

, 303.84

14.5 8.3 1

, 092.68 309.68 1

, 402.36

15 8.4 1

, 173.75 326.69 1

, 500.44

15.5 8.6 1

, 267.69 344.15 1

, 611.84

16 8.8 1

, 363.82 397.99 1

, 761.80

16.4 9.0 1

, 454.53 460.25 1

, 914.77

Table 5.13

. 15 Cost Efficiency Data for SDHV Systems

SEER SDHV [$]

13 1

, 325.48

13.5 1

, 395.25

14 1

, 468.70

14.3 1

, 546.015

- 68 REFERENCES

1 AHRI. Directory of Certified Product Performance , Performance Data Updated June 7, 2010. Last accessed June 7, 2010. <http://www.ahridirectory.org/ahridirectory/pages/home.aspx >

2 American Metals Market, (Last accessed December 8, 2010.) < http://www.amm.com/ .>

3 U.S. Department of Labor, Bureau of Labor Statistics, Producer Price Indices . (Last accessed December 8, 2010.) < http://www.bls.gov/ppi/ >

4 U.S. Department of Commerce, Bureau of Economic Analysis, Gross Domestic Product Implicit Price Deflator . (Last accessed December 8, 2010.)

< http://www.bea.gov/national/nipaweb/TableView.asp?SelectedTable=13&Freq=Qtr&FirstYear=2008

&LastYear=2010 >