CHAPTER 5. ENGINEERING ANALYSIS

TABLE OF CONTENTS

5.1 INTRODUCTION

................................ ................................ ................................................ 5-1

5.2 EQUIPMENT CLASSES AN ALYZED

................................ ............................................ 5-2

5.3 ENERGY EFFICIENCY ME TRICS

................................ .................................................. 5-5

5.4 EFFICIENCY LEVELS

................................ ................................ ...................................... 5-5

5.4.1 Representative Cooling Capacities

................................ ......................................... 5-5

5.4.2 Baseline Units

................................ ................................ .......................................... 5-6

5.4.3 Incremental Efficiency Levels

................................ ................................................ 5-7

5.5 METHODOLOGY OVERVIEW

................................ ....................................................... 5-9

5.5.1 Manufacturer Interviews

................................ ....................................................... 5- 10

5.5.2 Equipment Teardown

................................ ............................................................ 5- 10

5.5.2.1 Selection of Units

................................ ...................................................... 5- 11

5.5.2.2 Generation of Bills of Materials

............................................................... 5- 11

5.5.2.3 Cost Structure of the Spreadsheet Models

............................................... 5- 12

5.5.3 Shipping Costs

................................ ................................ ....................................... 5- 13

5.5.4 Equipment Testing

................................ ................................ ................................ . 5- 13

5.6 ANALYSIS AND RESULTS

................................ ........................................................... 5- 14

5.6.1 Manufacturer Interviews

................................ ....................................................... 5- 14

5.6.2 Equipment Testing

................................ ................................ ................................ . 5- 14

5.6.3 Equipment Teardown

................................ ............................................................ 5- 18

5.6.4 Cost

- Efficiency Results

................................ ......................................................... 5- 21

LIST OF TABLES

Table 5.2.1 Equipment Classes for PTACs and PTHPs

................................ ................................ 5-3 Table 5.2.2 Equipment Classes Covered by this Rulemaking

...................................................... 5-4 Table 5.4.1 Baseline Efficiency Levels

................................ ........................................................... 5-7 Table 5.4.2 Incremental Efficiency Levels

................................ ..................................................... 5-9

Table 5.5.1 Major Manufacturing Processes

................................ ............................................... 5- 13 Table 5.6.1 PTAC and PTHP Test Units at 9,000 Btu/h Capacity

............................................. 5- 15 Table 5.6.2 PTAC and PTHP Test Units at 15,000 Btu/h Capacity

........................................... 5- 16

Table 5.6.3 Test Results of Selected PTAC and PTHP Units

.................................................... 5- 17

Table 5.6.4. Cost

- Efficiency Relationship for PTACs at 9,000 Btu/h Capacity

....................... 5- 24

Table 5.6.5. Co st

- Efficiency Relationship for PTHPs at 9,000 Btu/h Capacity

........................ 5- 24

Table 5.6.6. Cost

- Efficiency Relationship for PTACs at 15,000 B tu/h Capacity

..................... 5- 25

Table 5.6.7. Cost

- Efficiency Relationship for PTACs at 15,000 Btu/h Capacity

..................... 5- 25

LIST OF FIGURES

Figure 5.4.1 COP versus EER for Standard Size PTHPs with 9,000 Btu/h Cooling Capacity from 2013 AHRI directory

................................ ................................ ................................ 5-8

5-iFigure 5.4.2 COP versus EER for Standard Size PTHPs with 15,000 Btu/h Cooling Capacity from 2013 AHRI directory

................................ ....................................................... 5-8 Figure 5.5.1 Manufacturing Cost Assessment Stages

................................ .................................. 5- 12 Figure 5.6.1 Baseline 9,000 Btu/h PTAC Full Production Cost Distribution

............................. 5- 19 Figure 5.6.2 Baseline 9,000 Btu/h PTAC Materials Cost Distribution

....................................... 5- 19 Figure 5.6.3 Baseline 15,000 Btu/h PTAC Full Production Cost Distribution

.......................... 5- 20 Figure 5.6.4 Baseline 15,000 Btu/h PTAC Materials Cost Distribution

..................................... 5- 20 Figure 5.6.5 Manufacturer Production Cost (2013$) versus Efficien cy for Standard Size PTACs with a Cooling Capacity of 9,000 Btu/h

................................ ................................ 5- 21 Figure 5.6.6 Manufacturer Production Cost (2013$) versus Efficiency for Standard Size PTHPs with a Cooling Capacity of 9,000 Btu/h

................................ ................................ 5- 22 Figure 5.6.7 Manufacturer Production Cost (2013$) versus Efficiency for Standard Size PTACs with a Cooling Capacity of 15,000 Btu/h

.............................................................. 5- 22 Figure 5.6.8 Manufacturer Production Cost (2013$) versus Efficiency for Standard Size PTHPs with a Cooling Capacity of 15,000 Btu/h

.............................................................. 5- 23 Figure 5.6.9 Manufacturer Production Cost (2013$) versus Efficiency for Standard Size PTACs and PTHPs with Cooling Capacities of 9,000 Btu/h and 15,000 Btu/h

............... 5- 23

5- iiCHAPTER 5. ENGINEERING ANALYSIS

5.1 INTRODUCTION

After conducting the screening analysis, the U.S. Department of Energy (DOE) performed an engineering analysis based on the remaining design options. The engineering analysis consists of estimating the energy consumption and costs of products at various levels of increased efficiency. This section provides an overview of the engineering analysis ( section 5.1 ), discusses proposed equipment classes (section 5.2), describes the efficiency metrics used for this equipment (section 5.3 ), establishes baseline unit specifications ( section 5.4.2 ), discusses incremental efficiency levels ( section 5.4.3 ), explains the methodology used during data gathering ( section 5.5 ) and discusses the analysis and results ( section 5.6 )

The primary inputs to the engineering analysis are baseline information from the market and technology assessment (chapter 3 of this technical support document (TSD)) and technology options from the screening analysis (chapter 4)

. Additional inputs include laboratory testing and reverse

- engineering of representative equipment

, and manufacturer interviews. The primary output of the engineering analysis is a set of cost

efficiency curves. In the subsequent markups analysis (chapter 6), DOE determined customer (i.e., equipment purchaser) prices by applying distribution markups, sales tax and contractor markups. Af ter applying these markups and an assumed installation cost

, the customer prices serve as the input to the building energy

- use and end

- use load characterization (chapt er 7) and the life

- cycle cost (LCC) and payback period (PBP) analyses (chapter 8).

DOE typically structures its engineering analysis around one of three methodologies. These are: (1) the design

- option approach, which calculates the

incremental costs of add ing specific design options to a baseline model that will improve its efficiency ( i.e. , lower its energy use) ; (2) the efficiency

- level approach, which calculates the relative costs of achieving increases in energy efficiency levels, without regard to the particular design options used to achieve such increases; and/or (3) the

reverse

- engineering (or cost

- assessment) approach, which provides “bottom

- up” manufacturing cost assessments for achieving various levels of increased efficiency,

based on teardown an alyses (or physical teardowns) providing detailed data on costs for parts and material, labor, shipping/packaging, and investment for models that operate at particular efficiency levels. A supplementary method called a catalog teardown uses published manuf acturer catalogs and supplementary component data to estimate the major physical differences between a piece of equipment that has been physically disassembled and another piece of similar equipment for which catalog data are available

to determine the cos t of the latter equipment. Deciding which methodology to use for the engineering analysis depends on the product, the design options under study, and any historical data upon which DOE can draw.

To establish the industry cost

- efficiency curves for PTAC and PTHP equipment

, the U.S. Department of Energy (DOE) used the efficiency

- level approach and the reverse

5-1engineering approach

. DOE designated a baseline efficiency level equivalent to the minimum efficiency allowed by energy conservation stand ards. a DOE set efficiency levels at incremental steps above the baseline up to the maximum efficiency level that is technologically feasible using current technologies.

To estimate the manufacturing production costs for equipment at each efficiency

level , DOE reverse engineered a set of PTAC and PTHP equipment that was specifically selected to represent the range of efficiency levels. This reverse engineering involved the disassembly of units, analysis of the materials and manufacturing processes, and

dev elopment of a spreadsheet cost model based on a clear and consistent manufacturing cost assessment methodology. DOE built a detailed cost assessment model that accurately estimates the manufacturing production cost (MPC) associated with producing a specifi c piece of equipment. The cost model reports those costs in aggregated form to maintain confidentiality of the data.

5.2 EQUIPMENT CLASSES ANALYZED

Existing Federal energy conservation standards (ECS) , shown in Table 5 of 10 CFR Part 431.97, divide PTACs and PTHPs into twelve equipment classes based on whether the equipment is an air conditioner or heat pump, the cooling capacity

, and the equipment’s wall sleeve dimensions , which fall into two categories:

• Standard size (PTAC or PTHP equipment with wall sleeve dimensions greater than or equal to 16 inches high, or greater than or equal to 42 inches wide)

• Non

- standard size (PTAC or PTHP equipment with wall sleeve dimensions less than 16 inches high and less than 42 inches wide)

The twelve equipment classes for PTACs and PTHPs are listed in Table 5.2 .1 , and correspond to those contained in ANSI/ASHRAE/IES Standard 90.1

- 2013.

a DOE set the baseline level equivalent to the ANSI/ASHRAE/IES Standard 90.1-2013 minimum for PTAC and PTHP equipment, since DOE is required to, at a minimum, adopt the ASHRAE levels as the Federal standard. (42 U.S.C. (a)(6)(A)(ii)(I)).

5-2Table 5.2 .1 Equipment Classes for PTACs and PTHPs Equipment Class Equipment Category Cooling Capacity

PTAC Standard Size * <7,000 Btu/h ≥7,000 Btu/h and ≤15,000 Btu/h >15,000 Btu/h

Non

- Standard Size ** <7,000 Btu/h
≥7,000 Btu/h and ≤15,000 Btu/h >15,000 Btu/h

PTHP Standard Size * <7,000 Btu/h ≥7,000 Btu/h and ≤15,000 Btu/h >15,000 Btu/h

Non

- Standard Size ** <7,000 Btu/h ≥7,000 Btu/h and ≤15,000 Btu/h >15,000 Btu/h

* Standard size refers to PTAC or PTHP equipment with wall sleeve dimensions greater than or equal to 16 inches high, or greater than or equal to 42 inches wide.

** Wall sleeve dimensions less than 16 inches high and less than 42 inches wide.

DOE is not co nsidering amended energy conservation standards for non

- standard size PTAC and PTHP equipment in this rulemaking, because the non

- standard size equipment class es represent a small and declining portion of the market, and because of a lack of adequate information to analyze non

- standard size units. The shipments analysis

conducted for the 2008 final rule projected that shipments of non

- standard size PTACs and PTHPs would decline from about 30,000 units in 2012 (6.6% of the entire PTAC and PTHP market) to abo ut 16,000 units in 2042 (2.4% of the entire PTAC and PTHP market)

. b

For the purposes of this rulemaking , DOE analyzed t he six standard size equipment classes for PTACs and PTHPs , presented in Table 5.2 .2

.

b See DOE’s discussion regarding shipment projections for standard and non-standard PTAC and PTHP

eq uipment and the results of shipment projections in TSD for the 2008 PTAC and PTHP energy conservation standard rulemaking at: http://www.regulations.gov/#!documentDetail;D=EERE-2007- BT

- STD -0012-0032 (Chapter 10, Section 10.5).

5-3Table 5.2 .2 Equipment Classes Covered by this Rulemaking Equipment Class Equipment Category Cooling Capacity

PTAC Standard Size * <7,000 Btu/h ≥7,000 Btu/h and ≤15,000 Btu/h >15,000 Btu/h

PTHP Standard Size * <7,000 Btu/h ≥7,000 Btu/h and ≤15,000 Btu/h >15,000 Btu/h

* Standard size refers to PTAC or PTHP equipment with wall sleeve dimensions greater than or equal to 16 inches high, or greater than or equal to 42 inches wide.

The current Federal energy conservation standards and the efficiency levels specified by ANSI/ ASHRA E/IES Standard 90.1

- 2013 for PTAC and PTHP equipment are a function of the equipment’s cooling capacity. Both standards have equations to calculate the efficiency levels for PTACs and PTHPs in the cooling capacity range between 7,000 Btu/h and 15,000 Btu/h for each equipment class. For equipment with cooling capacities below 7,000 Btu/h and above 15,000 Btu/h, current Federal energy

conservation standards and ANSI/ASHRAE/IES Standar d 90.1

- 2013 maintain a constant efficiency level equal to the value o f the efficiency equation at either 7,000 Btu/h or 15,000 Btu/h cooling capacity (e.g., the efficiency level for 6,000 Btu/h cooling capacity equipment equals the efficiency level for 7,000 Btu/h cooling capacity equipment, and the efficiency level for 16, 000 Btu/h cooling capacity equipment equals the efficiency

level fo r 15,000 Btu/h cooling capacity equipment ).

For the engineering analysis, DOE examined specific cooling capacities for standard size PTACs and PTHPs, which are referred to as “ representat ive cooling capacities. ” Interviews with manufacturers indicated that the majority of PTAC and

PTHP shipments are in the classes with cooling capacity between 7,000 Btu/h to 15,000

Btu/h

. According to the certification data provided by the 2013 AHRI Direct ory of Certified Performance (201 3 AHRI Directory) , over 90 percent of standard

- size PTAC

and PTHP models available on the market are within the 7,000 Btu/h to 15,000 Btu/h cooling capacity range. 1 DOE focused its analysis on equipment with cooling capacities in the range between 7,000 Btu/h and 15,000 Btu/h

.

5-45.3 ENERGY EFFICIENCY ME TRIC S

The current energy conservation standards for PTACs and PTHPs are based on energy efficiency ratio (EER) for cooling efficiency and on coefficient of performance (COP) for PTHP heating efficiency. 10 CFR 431.97(c). The current Federal test procedure for PTACs and PTHPs incorporates by reference ANSI/AHRI/CSA 310/380

- 2004 Standard for Packaged Terminal Air

- Conditioners and Heat Pumps

. c

ANSI/AHRI /CSA 310/380

- 2004 de fines EER as “the ratio of the produced cooling effect of an air conditioner or heat pump to its net work input, expressed in Btu/watt

- hour.” COP is defined by ANSI/AHRI /CSA 310/380

- 2004 as “the ratio of the produced cooling

effect of an air conditioner or heat pump (or its produced heating effect, depending on the mode of operation) to its net work input, when both the cooling (or heating) effect and the net work input are expressed in identical units of measurement.”

In conducting the engineering analysis, DOE only considered technologies and techniques that improve the EER and COP of PTAC and PTHP equipment. As mentioned in the screening analysis (Chapter 4 of this TSD ), there are some technology options and techniques that could reduce the annual energy consumption of the system,

but that have little effect on EER. DOE did not consider technology options that have negligible effects on EER and COP.

5.4 EFFICIENCY LEVELS

5.4.1 Representative Cooling Capacities

Because there are large variations in equipment cooling capacity and performance

in the standard size PTAC and PTHP equipment classes , DOE analyzed some of the cooling capacities individually. DOE selected representative cooling capacities and analyze d specific equipment t o provide information representative of the entire equipment class. The representative cooling capacities allowed DOE to establish baseline units that are used throughout the rulemaking analyses.

For standard

- size PTAC and PTHP equipment classes, DOE id entified two representative cooling capacities : 9,000 Btu/h and 15,000 Btu/h. Both representative cooling capacities fall within the ≥7,000 and ≤15,000 Btu/h cooling capacity range. DOE selected the representative cooling capacity of 9,000 Btu/h because t his capacity had the

c DOE has incorporated by reference ANSI/AHRI/CSA Standard 310/380-2004 as the DOE test procedure

at 10 CFR 431.97.

5-5highest number of standard

- size PTAC and PTHP models listed in the 201 3 AHRI Directory . Chapter 3 of this TSD presents the distribution of models in the 201 3 AHRI Directory at different capacity levels for standard

- size PTAC and PTHP equipment. DOE selected the representative cooling capacity of 15,000 Btu/h because, according to several manufacturers interviewed, the 15,000 Btu/h cooling capacity represents the
greatest technical hurdles for efficiency improvement, considering the si ze constraints of

standard

- size PTACs and PTHPs.

DOE used the analytical results for the two representative cooling capacities to examine the slope of the energy

- efficiency equation (i.e., EER as a function of cooling capacity). Chapter 9 of this TSD co ntains m ore details explaining how DOE extrapolates the proposed amended energy conservation standards for the representative cooling capacities to the entire range of cooling capacities.

5.4.2 Baseline Units

DOE selected baseline units as reference points for e ach equipment class, against which DOE measured changes resulting from potential energy conservation standards. The baseline unit in each equipment class represents the basic characteristics of equipment in that class. Typically, a baseline unit is a unit that just meets current required energy conservation standards and provides basic consumer utility. DOE used the baseline units in the engineering analysis and the life

- cycle

- cost and payback

- period analysis.

The baseline efficiency levels for each equipment class are presented below in

Table 5.4 .1

. These level s represent the ANSI/ASHRAE/IES Standard 90.1

- 2013

minimum s f or PTAC and PTHP equipment. These level s are used as the Baseline s for PTAC and PTHP equipment since DOE is requir ed to, at a minimum, adopt the ASHRAE levels as the Federal standard. (42 U.S.C. (a)(6)(A)(ii)(I)). T he Baseline efficiency level is 1.8% higher than current Federa l standard for PTAC equipment, but is

equ al to current Federal standard for PTHP equipment.

5-6Table 5.4 .1 Baseline Efficiency Levels

Equipment Type Equipment

Class Baseline Efficiency Equation Cooling Capacity Baseline Efficiency

Level

PTAC Standard

Size EER = 14.0 – (0. 300 x Cap † ) 9,000 Btu/h 11.3 EER

15,000 Btu/h 9.5 EER

PTHP Standard

Size EER = 14.0 – (0. 300 x Cap † )

COP = 3.7

– (0.052 x Cap † ) 9,000 Btu/h 11.3 EER

3.2 COP

15,000 Btu/h 9.5 EER

2.9 COP

† Cap means cooling capacity in thousand Btu/h at 95oF outdoor dry-bulb temperature.

5.4.3 Incremental Efficiency Levels

For the equipment classes presented in section 5.2 , DOE analyzed several

effic iency levels and obtained incremental cost data at each of these levels. Table 5.4 .2 presents the efficiency levels for each equipment class.

As part of the NOPR analyses, DOE considered five efficiency levels beyond the baseline efficiency level for each equipment class. DOE selected t hese levels based on a

review of the efficiency levels of available equipment. DOE indicated in the f ramework

documen t for this rulemaking that it planned to consider a maximum efficiency level

20% higher than the current Federal PTAC ECS , because PTAC rating data in the 2013 AHRI Directory of Certified Product Performance showed that this is a level attained by available equipment . 78 FR 12252

. However, DOE ’s testing of PTAC and PTHP equipment as part of this rulemaking shows that the highest efficiency level attained by a

standard size PTAC or PTHP unit on the market is 18% above the current DOE PT AC

standard level . Accordingly, DOE revised the maximum efficiency level for this analysis

from 20% to 18% above the 2012 PTAC standard

.

For the PTHP equipment classes, DOE is proposing heating efficiency levels

based on the variation of COP with EER , as d iscussed in the f rame work document for this rulemaking . 78 FR 12252. DOE evaluated AHRI data for PTHP equipment to develop the relationship between COP and EER and used this relationship to establish the proposed COP efficiency levels

. Figure 5.4 .1 and Figure 5.4 .2 below show the COP and

EER data and best

- fit linear relationships for standard size PTHP units with 9,000 Btu/h

or 1 5 ,000 Btu/h cooling capacity results.

5-7Figure 5.4 .1 COP versus EER for Standard Size PTHPs with 9,000 Btu/h Cooling Capacity from 2013 AH RI directory

Figure 5.4 .2 COP versus EER for Standard Size PTHPs with 15 ,000 Btu/h Cooling

C apacity from 2013 AH RI directory COP = 0.241*(EER) + 0.480

2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0

8 9 10 11 12 13 14COP (no unit)

EER (Btu/Wh)

COP = 0.261*(EER) + 0.374

2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0

8 9 10 11 12 13 14COP (no unit)

EER (Btu/Wh)

5-8DOE established COP efficiency levels for PTHPs at 9,000 and 15,000 Btu/h using the EER values corresponding to the incremental cooling performance efficiency levels and the linear equations developed for the COP/EER relationships that are shown in the figures. The resulting incremental COP efficiency levels are shown for PTHP equipment in Table 5.4 .2

.

Table 5.4 .2 Incremental Efficiency Levels

Equipment
Type Cooling Capacity Efficiency

Metric Efficiency Levels (Percentages relative to 2012 PTAC ECS)

Current

Federal

PTAC

ECS * EL1,
Baseline,

1.8% ** EL2,

4% EL3,

8% EL4,

12% EL5,

16% EL6, 18%
(MaxTech)

PTAC,

Standard Size 7,000

- 15,000

Btu/h EER 13.8

- (0.300 x

Cap † ) 14.0

- (0.300 x

Cap † ) 14.4

- (0.312 x

Cap † ) 14.9

- (0.324 x

Cap † ) 15.5

- (0.336 x

Cap † ) 16.0

- (0.348 x

Cap † ) 16.3

- (0.354 x

Cap † )

9,000

Btu/h EER 11.1 EER 11.3 EER 11.5 EER 12.0 EER 12.4 EER 12.9 EER 13.1 EER

15,000

Btu/h EER 9.3 EER 9.5 EER 9.7 EER 10.0 EER 10.4 EER 10.8 EER 11.0 EER

Equipment
Type Cooling
Capacity Efficiency

Metric Baseline,

1.8% ** EL1,

4% EL2,

8% EL3,

12% EL4,

16% EL5, 18%
( MaxTech)

PTHP,

Standard

Size 7,000

- 15,000

Btu/h EER 14.0

- (0.300 x

Cap † ) 14.4

- (0.312 x

Cap † ) 14.9

- (0.324 x

Cap † ) 15.5

- (0.336 x

Cap † ) 16.0

- (0.348 x

Cap † ) 16.3

- (0.354 x

Cap † )

7,000

- 15,000

Btu/h COP 3.7 - (0.052
x Cap † ) 3.8

- (0.058 x

Cap † ) 4.0 - (0.064
x Cap † ) 4.1 - (0.068
x Cap † ) 4.2

- (0.070 x

Cap † ) 4.3 - (0.073
x Cap † )

9,000

Btu/h EER

COP 11.3 EER

3.2 COP 11.5 EER

3.3 COP 12.0 EER

3.4 COP 12.4 EER

3.5 COP 12.9 EER

3.6 COP 13.1 EER

3.6 COP

15,000

Btu/h EER

COP 9.5 EER

2.9 COP 9.7 EER

2.9 COP 10.0 EER

3.0 COP 10.4 EER

3.1 COP 10.8 EER

3.2 COP 11.0 EER

3.2 COP

* This level represents the current Federal minimum for PTAC equipment.

** This level represents the ANSI/ASHRAE/IES Standard 90.1-2013 minimum for PTAC and PTHP equipment. This level is used as the Baseline for PTAC and PTHP equipment since DOE is required to, at a minimum, adopt the ASHRAE levels as the Federal standard. (42 U. S.C. (a)(6)(A)(ii)(I)) . DOE notes that the Baseline level is 1.8% higher than current Federal ECS for PTAC equipment, but is equivalent to current Federal ECS for PTHP equipment. For PTAC equipment, the Baseline level is also termed EL1.

† Cap means cooling capacity in thousand Btu/h at 95oF outdoor dry-bulb temperature.

5.5 METHODOLOGY OVERVIEW

In order to develop the cost

- efficiency relationships f or PTACs and PTHPs , DOE conducted testing and performed detailed equipment teardowns and reverse

- engineering analyses on a sample of models spanning a range of rated efficiencies

. DOE supplemented these analyses by conducting interviews with equipment manufacturers to

5-9gain a better understanding of the design options and costs associated with achievin g higher efficiency levels.

5.5.1 Manufacturer Interviews

Throughout the rulemaking process, DOE seeks feedback and insight from stakeholders to improve the information used in the analyses. For the engineering analysis, DOE conducted confidential interviews with manufacturers of PTACs and PTHPs to develop a deeper understanding of the various combinations of technologies

used t o increase equipment efficiency and their associated manufacturing costs. DOE considered all the information manufacturers provided w hen refining the cost model. DOE incorporated confidential information ( i.e.

, equipment and manufacturing process figures ) into the analysis in the form of averages to avoid disclosing sensitive information about individual manufacturers’ equipment or man ufacturing processes.

Before th es e interviews, DOE provided manufacturers with an engineering

information package that included a spreadsheet with preliminary assum ptions, estimates,

and cost

- efficiency curves, and a list of possible questions to be asked during the interview. DOE asked manufacturers to provide feedback if the data was representative of the market and to supply any data that could improve DOE’s estimates and assumptions. DOE’s questions included the following:

• Which design features affect ing energy use are generally incorporated into

“baseline” PTACs and PTHPs?

• What are the costs of attaining the individual efficiency levels selected? How do these efficiency levels correspond to the various design options listed? What other design options do you use to attain the various efficiency levels?

• Do the industry manufacturing costs calculated by DOE represent your firm’s

costs for standard and size PTAC and PTHP?

DOE also requested information on a number of other factors that affect

manufactur ing cost and the incremental cost associated with attaining higher efficiency

levels

.

5.5.2 Equipment Teardown

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

- by

- piece and estimate the material and labor cost of

each component using a process commonly called a physical teardown

.

To calculate the manufacturing costs of the different components in PTACs and

PTHP s, DOE disassembled multiple units into their component part s and used cost modeling techniques to estimate the cost of materials, labor, and capital required to fabricate and assemble the components into a complete piece of equipment. The

teardown methodo logy is described in detail in section 5.5.2.1 through section 5.5.2.3

.

5-105.5.2.1 Selection of Units

DOE selected several standard

- size PTAC and PTHP units to represent the market, and used these for teardown in the engineering analysis. The selected equipment exhibited the following five characteristics:

1. The selected equipment, taken together, cover the full range of efficiency levels considered in the analysis.

2. The selected equipment has cooling capacity corresponding to one of the selected representative cooling capacities (9,000 Btu/h or 15,000 Btu/h).

3. When possible, DOE selected on e lower

- efficiency unit and one higher

efficiency unit from the same manufacturer. When possible, those units shared similar characteristics (e.g., both from the same product line).

4. The equipment tended to be from manufacturers with relatively large share s of the PTAC and PTHP markets, and thus was representative of typical design approaches.

5. The selected equipment included base units with few, if any, equipment features or options that add cost without affecting equipment efficiency.

5.5.2.2 Generation of Bills of Materials

The end result of each teardown is a structured bill of materials (BOM)

. Structured BOMs describe each equipment part and its relationship to the other parts, in

the estimated order of assembly. The BOMs describe each fabrication and assembly operation in detail, including the type of equipment needed ( e.g. , stamping presses, injection molding machines, spot

- welders, etc.) and the process cycle times

. The result is a thorough and explicit model of the production process, which includes space, c onveyor, and equipment requirements by planned production level.

The BOMs incorporate all materials, components, and fasteners

, classified as either raw materials or purchased parts and assemblies

. The classification into raw materials or purchased parts i s based on DOE’s previous industry experience, recent information in trade publications, and discussions with high

- and low

- volume original equipment manufacturers (OEMs).

For purchased parts, the purchase price is an estimate based on volume

- variable pri ce quotations and detailed discussions with suppliers

. For fabricated parts, the price of intermediate materials ( e.g. , tube, sheet metal) and the cost of transforming them into finished parts are an estimate based on current industry pricing. DOE shared m ajor assumptions and estimates with manufacturers during the engineering manufacturer interviews to gain feedback on the analysis, its methodology, and preliminary results.

5-11The cost of raw materials is determined using prices for copper, steel and

aluminum from the American Metals Market. 2 Because DOE is using a 5- year average in material prices from 200 9– 20 13 , these price increases are normalized, which better represents long

- term material prices.

5.5.2.3 Cost Structure of the Spreadsheet Models

The manufacturin g cost assessment methodology used is a detailed, component

focused technique for rigorously calculating the manufacturing cost of a product (direct materials, direct labor and some overhead costs. ) Figure 5.5.1 shows the three major steps in generating the manufacturing cost.

Figure 5.5 .1 Manufacturing Cost Assessment Stages

The first step in the man ufacturing cost assessment is the creation of a complete and structured BOM from the disassembly of the units selected for teardown . The units are dismantled, and each part is characterized according to weight, manufacturing processes used, dimensions, material, and quantity. The BOM incorporates all materials, components, and fasteners with estimates of raw material costs and purchased part costs. Assumptions on the sourcing of parts and in

- house fabrication are based on industry experience, information in trade publications, and discussions with manufacturers. Interviews and plant visits are also conducted with manufacturers to ensure accuracy on methodology and pricing.

Following the development of a detailed BOM, the major manufacturing processes are identified and developed for the spreadsheet model. These processes are

listed in Table 5.5.1

.

5-12Table 5.5 .1 Major Manufacturing Processes

Fabrication Finishing Assembly/Joining Quality Control Injection Molding Washing Adhesive Bonding Inspecting & Testing Stamping/Pressing Powder Coating Spot Welding Turret Punching De

- burring Seam Welding Brake Forming Polishing Brazing Cutting and Shearing Tube Forming

Fabrication process cycle times are estimated and entered into the BOM. For this analysis, $ 9.1 0 per hour was used as the average fully

- burdened labor rate based on typical annual wages and benefits of industry employees. Labor rates for manufacturers

of s tandard size PTACs and PTHPs are based on the weighted averages of foreign and domestic manufacturers. Certain large manufacturers of PTACs and PTHPs make their equipment in foreign factories, where labor rates are significantly less than domestic

rates. Foreign labor rates are based on engineering manufacturer interviews, internal expertise, and industry literature research. In the final step of the cost assessment, assembly times and associated direct labor costs are estimated. Once the cost estimate f or each teardown unit is finalized, a detailed summary is prepared for relevant components, subassemblies and processes. The BOM thus details all aspects of unit costs.

Design options used in units subject to teardown are noted in the summary sheet

of eac h cost model and are cost

- estimated individually. Thus, various implementations of design options can be accommodated, ranging from assemblies that are entirely purchased to units that are made entirely from raw materials. Hybrid assemblies, consisting of purchased parts and parts made on site are thus also accommodated.

5.5.3 Shipping Costs

In addition to the MPC, DOE also considered the cost to ship the unit from the manufacturing facility to the first point on the distribution chain. In calculating the shipping costs, DOE first gathered estimates of the cost to ship a standard

- size shipping

container of manufactured equipment from China to the United States, and the cost to ship the equipment an average distance in the United States. The bulk of PTAC an d PTHP shipments originate from factories in China, but one major manufacturer of standard size PTACs and PTHPs produces units in the United States. Using the relative market shares for standard size equipment manufacturers, DOE constructed a weighted average shipping cost to account for units produced domestically and overseas. DOE then used the representative unit sizes to calculate a volume for eac h unit. Along with the dimensions of a shipping container , DOE used this cost and volume information to develop an average shipping cost for each equipment class directly analyzed.

5.5.4 Equipment Testing

DOE conducted equipment testing to verify the energy use of equipment and to develop a better understanding of the potential efficiency improvements associated with

5-13various design options and to develop disaggregated efficiency data. DOE contracted with qualified thi rd- party test laboratories to test the capac ity, EER, and COP of the equipment using the DOE test procedures for PTACs and PTHPs (see 10 CFR 431.96).

5.6 ANALYSIS AND RESULTS

DOE conducted the engineering analysis using the efficiency

- level approach and

the reverse

- engineering approach, analyzing two specific cooling capacities to represent the range of standard

- size PTACs and PTHPs available on the market. As discussed in

section 5.6.1

, DOE selected representat ive capacities of 9,000 Btu/h and 15,000 Btu/h

, ,

5.6.1 Manufacturer Interviews

As previously discussed in section 5.5.1 , DOE conducted confidential int erviews

with PTAC and PTHP manufacturers . F rom the manufacturers interviewed, DOE collected a general impression of PTAC and PTHP equipment on the market. Interviewed manufacturers indicated that all of the equipment covered in this rulemaking currently
use rotary compressors, round

- tube

- and

- fin heat exchangers, and R

- 410A refrigerant.

Manufacturers employ different de sign strategies in terms of compressor selection, indoor and outdoor fan motor selection, and heat exchanger design. Manufacturers interviewed noted that selecting higher efficiency motors and compressors can increase system efficiency . Manufacturers also commented that increasing the size of the heat exchangers in a unit increases efficiency, though this use of this option is limited in larger capacity models (such as 15,000 Btu/h models) because of size constraints.

M anufacturers noted that standard

- size PTACs and PTHPs are limited in terms of case size because the units are typically installed in wall openings of 16 inches high by 42

inches wide . These wall opening dimensions were standardized in buildings over the past 25 years. DOE understood from manuf acturers that altering existing wall sleeve opening s could include extensive structural changes to a building, could b e very costly, and is

therefore rarely done.

5.6.2 Equipment Testing

DOE conducted a market survey of PTAC and PTHP models and their features

. DOE selected six 9,000 Btu/h and five 15,000 Btu/h PTAC models for testing and reverse engineering. The models were selected to develop a representative sample of the market at different efficiency levels. DOE select ed the units based on the efficiency d ata available in the AHRI certification database. Where feasible, DOE selected models for reverse engineering with low and high capacities from a given manufacturer that are built on the same platform (i.e., with the same basic design and construction). D OE also

selected five 9,000 Btu/h and four 15,000 Btu/h PTHP models to evaluate the differences between PTAC and PTHP units. Details about the key features of the tested units are presented in Table 5.6 .1 and Table 5.6 .2

.

5-14Table 5.6 .1 PTAC and PTHP Test Units at 9,000 Btu/h Capacity

Feature Test Unit Description

PTAC PTHP

Test
Unit 1 Test
Unit 2 Test
Unit 3 Test
Unit 4 Test
Unit 5 Test
Unit 6 Test
Unit 7 Test
Unit 8 Test
Unit 9 Test
Unit 10 Test
Unit 11 Rated Cooling Capacity (Btu/h) 9,000 9,000 9,000 9,700 9,500 9,700 9,500 9,400 9,000 9,000 9,000

Rated EER (Btu/Wh) 11.3 11.5 11.3 12.1 12.7 12.1 12.9 12.7 11.3 11.3 11.5

Rated COP (unitless)

- - - - - - 3.6 3.8 3.3 3.3 3.4

Outdoor

Coil Face Area (ft^2) 2.67 2.67 1.85 2.67 2.48 2.67 2.50 2.55 1.85 2.67 2.67

Fin Pitch 19 23 21 19 21 19 20 19 21 19 23

Tube Rows 3 2 2 2 3 2 3 3 2 3 2

Tube OD (in.) 0.200 0.200 0.250 0.250 0.200 0.250 0.250 0.250 0.250 0.200 0.200

Outdoor

Fan

Motor Type PSC PSC PSC PSC BLDC PSC BLDC BLDC PSC PSC PSC

Power (hp) 0.054 0.040 0.028 0.037 0.067 0.037 0.067 0.060 0.028 0.054 0.040

Indoor

Coil Face Area (ft^2) 2.08 1.93 2.34 1.87 1.88 1.87 1.88 1.87 2.34 2.08 1.93

Fin Pitch 18 18 18 19 19 19 19 21 18 18 18

Tube Rows 2 2 3 2 2 2 2 2 3 2 2

Tube OD (in.) 0.313 0.375 0.313 0.250 0.375 0.250 0.375 0.250 0.313 0.313 0.375

Indoor

Fan

Motor Type PSC PSC PSC PSC BLDC PSC BLDC BLDC PSC PSC PSC

Power (hp) 0.028 0.020 0.054 0.042 0.040 0.042 0.040 0.048 0.028 0.028 0.020

5-15Table 5.6 .2 PTAC and PTHP Test Units at 15,000 Btu/h Capacity

Feature Test Unit Description

PTAC PTHP

Test
Unit 12 Test
Unit 13 Test
Unit 14 Test
Unit 15 Test Unit

16 Test
Unit 17 Test
Unit 18 Test
Unit 19 Test
Unit 20

Rated Cooling Capacity (Btu/h) 15,000 14,400 15,000 15,000 14,200 15,100 14,400 15,000 14,200

Rated EER (Btu/Wh) 10.0 10.5 9.8 10.0 9.7 11.2 10.8 9.8 9.7

Rated COP (unitless)

- - - - 3.0 3.1 3.3 2.9 3.0

Outdoor

Coil Face Area (ft^2) 2.53 2.44 2.41 2.53 2.56 2.48 2.55 2.41 2.56

Fin Pitch 24 19 18 24 20 20 19 18 20

Tube Rows 2 3 3 2 2 3 3 3 2 Tube OD (in.) 0.200 0.250 0.325 0.200 0.375 0.250 0.250 0.325 0.375

Outdoor

Fan

Motor Type PSC PSC PSC PSC PSC BLDC BLDC PSC PSC

Power (hp) 0.094 0.060 0.088 0.094 0.094 0.067 0.060 0.088 0.094

Indoor

Coil Face Area (ft^2) 2.08 1.87 1.85 2.08 1.79 1.83 1.87 1.85 1.79

Fin Pitch 18 19 19 18 18 19 21 19 18

Tube Rows 2 2 3 2 3 2 3 3 3 Tube OD (in.) 0.375 0.250 0.313 0.375 0.313 0.375 0.250 0.313 0.313

Indoor

Fan

Motor Type PSC PSC PSC PSC PSC BLDC BLDC PSC PSC

Power (hp) 0.034 0.042 0.030 0.034 0.034 0.040 0.048 0.031 0.034

5-16D OE conducted testing on each unit according to the current Federal test procedure for PTACs and PTHPs

. Table 5.6.3 shows the test results of selected PTAC

and PTHP units. DOE observed t h at the maximum deviation of tested and rated cooling capacity was + 8.9 percent , and the maximum deviation of tested EER and rated EER wa s

- 7.1 percent.

Table 5.6 .3 Test Results of Selected PTAC and PTHP Units

Parameter

Test
Unit Type Rated Cooling Capacity

(Btu/h) Rated

EER (Btu/Wh) Rated

COP (unitless) Tested Cooling Capacity

(Btu/h) Tested

EER (Btu/Wh) Tested

COP (unitless)

1 PTAC 9,000 11.3

- 8,280 10.7

- 2 PTAC 9,000 11.5

- 8,849 10.9

- 3 PTAC 9,000 11.3

- 8,831 11.1

- 4 PTAC 9,700 12.1

- 9,537 12.0

- 5 PTAC 9,500 12.7

- 9,654 12.4

- 6 PTAC 9,700 12.1

- 9,737 12.3

- 7 PTHP 9,500 12.9 3.6 9,691 12.4 3.5

8 PTHP 9,400 12.7 3. 8 9,673 12.9 3.6

9 PTHP 9,000 11.3 3.3 9,798 11.6 3.5

10 PTHP 9,000 11.3 3.3 9,298 11.5 3.3

11 PTHP 9,000 11.5 3.4 9,54 1 11.7 3.5

12 PTAC 15,000 10.0

- 15,037 10.0

- 13 PTAC 14,400 10.5

- 14,450 10.5

- 14 PTAC 15,000 9.8

- 15,635 10.3

- 15 PTAC 15,000 10.0

- 15,088 10.0

- 16 PTAC 15,100 11.2 3.1 14,871 10.4

- 17 PTHP 14,200 9.7 3.0 14,785 9.9 3.0

18 PTHP 14,400 10.8 3.3 14,590 11.0 3.3

19 PTHP 15,000 9.8 2.9 15,394 10.3 2.9

20 PTHP 15,100 11.2 3.1 * * *

* T esting on Test Unit 20 failed repeatedly due to frosting on the outdoor heat exchanger.

No test data is available for this unit.

5-175.6.3 Equipment Teardown

As part of the reverse engineering analyses, DOE conducted physical teardowns

on each test unit d to develop a manufacturing cost model and to evaluate and identify design details of key components ( e.g. , heat exchangers, compressors, fans and fan motors, control strategies, etc.) and the corresponding manufacturing cost of each unit.

Based upon product teardowns, DOE developed the following baseline production cost distributions and materials cost distributions for typical PTACs, shown in Figure

5.6 .1 through Figure 5.6 .4 . Production cost distributions include raw material, purchased parts, labor (asse mbly, fabrication, supervision, and indirect labor), depreciation (equipment, tooling, and building depreciation), and other overhead (indirect process, maintenance, utility, property tax, and insurance) costs.

d For test units #6, 9, 11, 12, 15, 17, and 20, DOE conducted a partial teardown, examining key components (heat exchangers, compressors, fans/motors, controls, etc.) and basic design construction without fully disassembling the unit.

5-18Figure 5.6 .1 Baseline 9,000 Btu/h PTAC Full Production Cost Distribution

Figure 5.6 .2 Baseline 9,000 Btu/h PTAC Materials Cost Distribution Labor

6% Depreciation

5% Other Overhead

7% Raw Materials

34%

Purchased Parts

48% Total Estimated MPC for Baseline 9,000 Btu/h PTAC: $359.62

Packaging

5%

Final Assembly

21%

Outdoor HX

8%

Outdoor Fan Assy

5%

Indoor HX

12% Indoor Fan Assy

5% Controls

22% Sealed System

22%

5-19Figure 5.6 .3 Baseline 15,000 Btu/h PTAC Full Production Cost Distribution

Figure 5.6 .4 Baseline 15,000 Btu/h PTAC Materials Cost Distribution Labor

5% Depreciation

5%

Other Overhead

6% Raw Materials

29%

Purchased Parts

55% Total Estimated MPC for Baseline 15,000 Btu/h PTAC: $428.99

Packaging

5%

Final Assembly

22%

Outdoor HX

8%

Outdoor Fan
Assy

7% Indoor HX

9% Indoor Fan Assy

6% Controls

14% Sealed System

29%

5-205.6.4 Cost

- Efficiency Results

The reverse engineering analysis provides MPC data and tested efficiency data for the selected set of PTAC and PTHP units. DOE assembled this data into four groups, organized by cooling capacity (9,000 Btu/h and 15,000 Btu/h) and equipment type (PTAC and PTHP). DOE used the least square s method to fit second

- order polynomial

curves to the cost

- efficiency data for each group. Figure 5.6.5 through Figure 5.6 .8 show

the four cost

- efficiency curv es in the form of EER versus MPC

. These four cost curves are pictured together in Figure 5.6 .9

.

Figure 5.6 .5 Manufacturer Production Cost (2013$) versus Efficiency for Standard Size PTACs with a Cooling Capacity of 9,000 Btu/h MPC = 1.78*(EER) 2

- 22.40*(EER) + 389.15

$300 $325 $350 $375 $400 $425 $450 $475 $500

9 10 11 12 13 14Manufacturer Production Cost (2013$)

System EER (Btu/Wh)

Standard Size PTAC, 9,000 Btu/h

5-21Figure 5.6 .6 Manufacturer Production Cost (2013$) versus Efficiency for Standard

Size PTHP s with a Cooling Capacity of 9,000 Btu/h

Figure 5.6 .7 Manufacturer Production Cost (20 13$) versus Efficiency for Standard

Size PT AC s with a Cooling Capacity of 15 ,000 Btu/h MPC = 1.78*(EER) 2

- 22.40*(EER) + 427.62

$300 $325 $350 $375 $400 $425 $450 $475 $500

9 10 11 12 13 14Manufacturer Production Cost (2013$)

System EER (Btu/Wh)

Standard Size PTHP, 9,000 Btu/h

MPC = 12.19*(EER) 2

- 208.96*(EER) + 1280.9

$300 $325 $350 $375 $400 $425 $450 $475 $500

9 10 11 12 13 14Manufacturer Production Cost (2013$)

System EER (Btu/Wh) Standard Size PTAC, 15,000 Btu/h

5-22Figure 5.6 .8 Manufacturer Production Cost (2013$) versus Efficiency for Standard

Size PTHP s with a Cooling Capacity of 15,000 Btu/ h

Figure 5.6 .9 Manufacturer Production Cost (2013$) versus Efficiency for Standard

Size PTACs and PTHP s with Cooling Capacities of 9,000 Btu/h and 15,000 Btu/h MPC = 12.19*(EER) 2

- 208.96*(EER) + 1318.1

$300 $325 $350 $375 $400 $425 $450 $475 $500

9 10 11 12 13 14Manufacturer Production Cost (2013$)

System EER (Btu/Wh)
Standard Size PTHP, 15,000 Btu/h

$300 $320 $340 $360 $380 $400 $420 $440 $460 $480 $500

9 10 11 12 13 14Manufacturer Production Cost (2013$)

EER (Btu/Wh) Standard Size PTAC, 15,000 Btu/h Standard Size PTAC, 9,000 Btu/h Standard Size PTHP, 9,000 Btu/h Standard Size PTHP, 15,000 Btu/h

5-23The results show that the cost

- efficiency curves are nonlinear. As efficiency increases, manufacturing becomes more difficult and more costly for manufacturers. A faster increase in the curve (i.e., a steep er slope) is evident for the standard size PTAC s and PTHPs with 15, 000 Btu/h cooling capacity compared to the standard size PTAC s and

PTHPs with 9,000 Btu/h cooling capacity

. T he increase in capacity between 9,000 Btu/h

and 1 5 ,000 Btu/h causes an i ncrease in the baseline unit MPC

. Comparing otherwise

identical PTAC and PTHP models ( i.e. , models with similar casing, controls, and fans, but where the PTHP has reverse cycle capability), DOE estimates that the typical PTHP
unit has an additional $37

- $38 of production costs compared with an otherwise

- identi cal

PTAC unit.

As stated above, the cost efficiency results from the engineering analysis are an inp ut to subsequent LCC analyses that determine the customer price of PTACs and PTHPs (see chapter 8, life

- cycle cost and payback period analyses). For these i nputs,
DOE used the cost

- efficiency curves above to calculate the MPCs at each efficiency level

considered. DOE used the curve

- fit equations presented in Figure 5.6 .5 through Figure

5.6 .8 to calculate the estimated MPC for each of the efficiency levels for PTACs and

PTHPs. These results are shown in Table 5.6.4 through Table 5.6.7

.

Table 5.6 .4

. Cost

- Efficiency Relationship for PTAC s at 9,000 Btu/h Capacity
Efficiency Level (Percentages relative to 2012 PTAC ECS) Manufacturer

Production Cost (2013$) Incremental Manufacturer

Production Cost (2013$) Incremental Shipping

Cost (2013$)

Baseline , EL1, 1.8% $359.62

- -

E L2, 4% $363.50 $3.88

-
EL3, 8% $367.55 $7.93

-
EL4, 12% $376.19 $16.57

-
EL5, 16% $385.52 $25.91

- EL6, 18% (Max

- Tech) $395.56 $35.94

-

Table 5.6 .5

. Cost

- Efficiency Relationship for PTHPs at 9,000 Btu/h Capacity
Efficiency Level (Percentages relative to 2012 PTAC ECS) Manufacturer

Production Cost (2013$) Incremental Manufacturer

Production Cost (2013$) Incremental Shipping

Cost (2013$)

Baseline , 1.8% $398.09

- -

EL1 , 4% $401.97 $3.88

-

EL2 , 8% $406.02 $7.93

-

EL3 , 12% $414.66 $16.57

-

EL4 , 16% $423.99 $25.91

-

EL5 , 18% (Max

- Tech) $434.03 $35.94

-

5-24Table 5.6 .6

. Cost

- Efficiency Relationship for PT AC s at 15,000 Btu/h Capacity
Efficiency Level (Percentages relative to 2012 PTAC ECS) Manufacturer

Production Cost (2013$) Incremental Manufacturer

Production Cost (2013$) Incremental Shipping

Cost (2013$)

Baseline

, EL1, 1.8% $391.78

- -

E L2, 4% $395.51 $3.73

- EL3, 8% $400.08 $8.29

- EL4, 12% $411.75 $19.96

- EL5, 16% $426.79 $35.00

- EL6, 18% (Max

- Tech) $445.20 $53.42

-

Table 5.6 .7 . Cost -Efficiency Relationship for PT HP s at 15,000 Btu/h Capacity
Efficiency Level (Percentages relative to 2012 PTAC ECS) Manufacturer

Production Cost (2013$) Incremental Manufacturer

Production Cost (2013$) Incremental Shipping

Cost (2013$)

Baseline $428.99

- -

EL1

, 4% $432.72 $3.73

-

EL2 , 8% $437.29 $8.29

-
EL3 , 12% $448.96 $19.96

-

EL4 , 16% $464.00 $35.00

-

EL5 , 18% (Max

- Tech) $482.41 $53.42

-

5-25REFERENCES

1 Air

- Conditioning, Heating, and Refrigeration Institute. Directory of Certified Product

Performance . Available online at: https://www.ahridirectory.org/ahridirectory/pages/home.aspx (Last accessed July 2014)

2 American Metals Market. Available online at http://www.amm.com/ . (Last accessed December 2012)

5-26