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APPENDIX 5-D. ROOM AIR CONDITIONER ENGINEERING DATA

TABLE OF CONTENTS

5-D.1 INTRODUCTION

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

5-D.2 MANUFACTURING COST MODELING DETAILS

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

5-D.3 ENERGY MODELING DETAILS

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

5-D.4 DESCRIPTION OF SUPPORTING ANALYSES

................................................ 5-D- 20

5-D.4.1 Room Air Conditioner Airflow Modeling

.............................................................. 5-D- 20

5-D.4.2 Room Air Conditioner Motor Analysis

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

LIST OF TABLES

Table 5-D.2.1 Incremental Cost Detail for 5,000 Btu/h Louvered, No Reverse Cycle

Room Air Conditioner (Product Class 1) – Final Rule Analysis

............... 5-D-3

Table 5-D.2.2 Incremental Cost Detail for 8,000 Btu/h Louvered, No Reverse Cycle

Room Air Conditioner (Product Class 3) – Final Rule Analysis

............... 5-D-5

Table 5-D.2.3 Incremental Cost Detail for 12000 Btu/h Louvered, No Reverse Cycle

Room Air Conditioner (Product Class 3) – Final Rule Analysis

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

Table 5-D.2.4 Incremental Cost Detail for 24000 Btu/h Louvered, No Reverse Cycle

Room Air Conditioner (Product Class 5A) – Final Rule Analysis

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

Table 5-D.2.5 Incremental Cost Detail for 28000 Btu/h Louvered, No Reverse Cycle

Room Air Conditioner (Product Class 5B) – Final Rule Analysis

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

Table 5-D.2.6 Incremental Cost Detail for 8000 Btu/h Non-Louvered, No Reverse

Cycle Room Air Conditioner (Product Class 8A) – Final Rule Analysis 5-D- 10

Table 5-D.2.7 Incremental Cost Detail for 12000 Btu/h Non-Louvered, No Reverse

Cycle Room Air Conditioner (Product Class 8B) – Final Rule Analysis 5-D- 11

Table 5-D.3.1 MarkN Results for 5000 Btu/h Louvered, No Reverse Cycle Room Air

Conditioner (Product Class 1) – Final Rule Analysis

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

Table 5-D.3.2 MarkN Results for 8000 Btu/h Louvered, No Reverse Cycle Room Air

Conditioner (Product Class 3) – Final Rule Analysis

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

Table 5-D.3.3 MarkN Results for 12000 Btu/h Louvered, No Reverse Cycle Room

Air Conditioner (Product Class 3) – Final Rule Analysis

......................... 5-D- 15

Table 5-D.3.4 MarkN Results for 24000 Btu/h Louvered, No Reverse Cycle Room

Air Conditioner (Product Class 5A) – Final Rule Analysis

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

Table 5-D.3.5 MarkN Results for 28000 Btu/h Louvered, No Reverse Cycle Room

Air Conditioner (Product Class 5B) – Final Rule Analysis

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

Table 5-D.3.6 MarkN Results for 8000 Btu/h Non-Louvered, No Reverse Cycle

Room Air Conditioner (Product Class 8A) – Final Rule Analysis

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

Table 5-D.3.7 MarkN Results for 12000 Btu/h Non-Louvered, No Reverse Cycle

Room Air Conditioner (Product Class 8B) – Final Rule Analysis

........... 5-D- 19

Table 5-D.4.1 Components Modeled to Calculate Room Air Conditioner Airflow

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

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- ii LIST OF FIGURES

Figure 5-D.4.1 Motor Incremental Cost Steps

.................................................................... 5-D- 22

Figure 5-D.4 .2 Motor Shaft Output Ratings by Capacity for Different Product Classes . 5-D- 23

Figure 5-D.4.3 Motor Pricing Increase with Weight Increase

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

Figure 5-D.4.4 Weight-Current Curves for room air conditioner PSC motors, grouped

by shaft output

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

Figure 5-D.4.5 Cost of Increased Efficiency for Different Motor Output Ratings

........... 5-D- 26

Figure 5-D.4.6 Brushless DC Motor Cost Curve by Shaft Output Rating

........................ 5-D- 27

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- 1 APPENDIX 5-D. ENGINEERING DATA

5-D.1 INTRODUCTION

Chapter 5 presents incremental cost curves describing costs to attain each analyzed

efficiency level for the six products analyzed in detail. The U.S. Department of Energy (DOE)

developed the curves using design option analysis based on energy use modeling using the

MarkN program and manufacturing cost modeling

.

The tables in section 5-D.2 show the costs associated which each of the design

configurations analyzed. The tables identify the design options associated with each design

configuration and show the key elements comprising the cost impacts, including materials, labor,

overhead, and depreciation. The tables also present total manufacturing production cost (MPC)

, total manufacturer sales price (MSP), and shipping cost associated with each design

configuration. These costs represent the costs from the final rule analysis.

Details of the energy modeling are presented in section 5-D.3 . Tables in this section

identify for each analyzed design configuration the MarkN input file name, the compressor data

file name, the MarkN key program output (energy efficiency ratio (EER) and capacity), standby

energy use, and integrated efficiency (combined energy efficiency ratio (CEER) ). These tables

represent the analysis from the final rule analysis.

Details of two aspects of the engineering analysis are presented in section 5-D.4

. Section

5-D.4.1 describes the airflow analysis that DOE used to account for changes in the airflow

system, including changes to fans and heat exchangers. Section 5-D.4.2 describes the data

collection and analysis used to develop the incremental cost estimates associated with increasing

motor efficiency, both with higher-efficiency permanent split capacitor (PSC) motors and with

brushless direct current (BLDC) motors.

5-D.2 MANUFACTURING COST MODELING DETAILS

The tables in this section itemize the results of the manufacturing cost analysis. The

tables identify for each of the analyzed products the analyzed design configurations and their

associated EER and C EER . The successive design configurations represent baseline designs with

increasing numbers of design options. The total and incremental costs associated with each of the

design configurations are presented in the tables as well, with separate identification of the key

cost elements: materials, labor, overhead, depreciation, and shipping cost. The incremental

manufacturing costs represent increases in MPC. The tables also show total MPC and MSC

calculated for each design configuration. Chapter 5 describes the conversion of this data into

incremental costs for specified efficiency levels (rather than by design configuration). T he

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efficiency level format of the data is used in the downstream analyses ( i.e. , life-cycle cost (LCC)

, national impact analysis (NIA), etc.)

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Table 5-D.2.1 Incremental Cost Detail for 5,000 Btu/h Louvered, No Reverse Cycle Room Air Conditioner (Product Class

1) – Final Rule Analysis

Design Configuration

Description EER IEER Incremental Costs (MPC) Total Cost

Material Labor OH Depre

ciation Increase Cumulative

Increase MPC MSP * Shipping

R

- 410A Baseline 8.94 8.79

- - - - - - $ 146.63 $ 184.76 $3.86

1 Add Subcooler 9.18 9.02 $0.57 $0.25 $0.10 $0.02 $ 0.80 $ 0.80 $ 147.43 $ 185.77 $3.86

2 Increase Evap Circuits 9.37 9.20 $0.75

- - - $ 0.75 $ 1.55 $ 148.18 $ 186.71 $3.86

3 Increase Compressor

Efficiency 9.72 9.54 $1.80

- - - $ 1.80 $ 3.35 $ 149.98 $ 188.98 $3.86

4 Stand

- by Reduction 9.72 9.63 $0.75

- - - $ 0.75 $ 4.10 $ 150.73 $ 189.92 $3.86

5 Increase Evap Width 9.89 9.80 $0.65 $0.21 $1.31 $0.00 $ 2.17 $ 6.27 $ 152.90 $ 192.66 $3.86

6 Increase Chassis to

Medium Size 10.59 10.48 $6.74 $1.06

- $0.3 1 $0.01 $ 7.50 $ 13.77 $ 160.40 $ 202.10 $5.72

7 Increase Chassis to

Large Size 10.80 10.69 $2.67

- $0.46 $3.14 $0.01 $ 5.36 $ 19.13 $ 165.76 $ 208.86 $8.39

8 Increase Condenser

Tube Rows 11.23 11.12 $5.58 $1.17 $0.09 $0.00 $ 6.85 $ 25.98 $ 172.61 $ 217.49 $8.39

9 Increase PSC

Efficiency 11.49 11.37 $8.11

- - - $ 8.11 $ 34.09 $ 180.72 $ 227.71 $8.39

10 Increase Fin

Thickness 11.51 11.38 $1.49

- - - $ 1.49 $ 35.58 $ 182.21 $ 229.59 $8.39

11 DC Brushless Motor 11.80 11.67 $43.50

- - - $ 43.50 $ 79.08 $ 225.71 $ 284.40 $8.39

*MSP is equal to MPC times the manufacturer markup of 1.26.

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- 4 (1) Add subcooler with 0.25 inches (in) outer diameter ( OD ), 24.25 in. length, and condensate temperature of 95o F

(2) Increase total refrigerant circuits in evaporator from 1 circuit to 2 circuits

(3) Improve rotary R-410A compressor efficiency to 10.0 EER

(4 ) Change Main Control Board to a Switching Power Supply.

(5 ) Increase evaporator width by 2 in. by redesigning the unit’s user interface placement.

(6) Increase Baseline Chassis Size by: Width 3 in., Height 0.75 in., Depth 2 in.

(7) Increase Baseline Chassis Size by: Width 4.2 in., Height 1.9 in., Depth 5.7 in.

(8) Convert Condenser to 3-tube row heat exchangers from 2-tube rows

(9 ) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor

(10) Increase evaporator fin thickness from 0.005 in to 0.006 in.

(11) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Table 5-D.2.2 Incremental Cost Detail for 8,000 Btu/h Louvered, No Reverse Cycle Room Air Conditioner (Product Class

3) – Final Rule Analysis

Design Option Step EER IEER Incremental Costs Total Cost

Material Labor OH Depre

ciation Increase Cumulative

Increase MPC MSP Shipping

R

- 410A Baseline 9.30 9.19

- - - - - - $ 179.60 $ 226.30 $6.32

1 Add Subcooler 9.60 9.50 $0.81 $0.00 $0.00 $0.00 $ 0.81 $ 0.81 $ 180.41 $ 227.32 $6.32

2 Increase Evap

Width 9.76 9.65 $0.88 $0.31 $0.00 $0.00 $ 1.20 $ 2.01 $ 181.61 $ 228.83 $6.32

3 Increase Compre.

Efficiency 10.17 10.05 $3.60

- - - $ 3.60 $ 5.61 $ 185.21 $ 233.36 $6.32

4 Stand

- by Reduction 10.17 10.11 $11.36

- - - $ 0.75 $ 6.36 $ 185.96 $ 234.31 $6.32

5 Increase Chassis to

Medium Size 10.87 10.80 $8.27 $1.00 $0.46 $0.00 $ 9.73 $ 16.09 $ 195.69 $ 246.57 $9.58

6 Increase PSC

Efficiency 11.49 11.41 $13.70

- - - $ 13.70 $ 29.79 $ 209.39 $ 263.83 $9.58

7 Increase Chassis to

Large Size 11.84 11.76 $10.74 $0.97 $1.56 $0.04 $ 13.32 $ 43.11 $ 222.71 $ 280.61 $14.63

8 DC Brushless Motor 12.05 11.96 $63.1 4

- - - $ 63.14 $ 106.25 $ 285.85 $ 360.17 $14.63

(1 ) Add subcooler with 0.25 in. OD, 24.25 in. length, and condensate temperature of 95o F

(2) Increase evaporator width by 3 in

. by redesigning the unit’s user interface placement

(3) Improve rotary R-410A compressor efficiency to 10.0 EER

(4 ) Change Main Control Board to a Switching Power Supply.

(5) Increase baseline chassis size by: Width 0.81 in., Height 3.13 in., Depth 2.5 in.

(6) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(7) Increase baseline chassis size by: Width 4 in., Height 3.13 in., Depth 8.1 in.

(8) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Table 5-D.2.3 Incremental Cost Detail for 12000 Btu/h Louvered, No Reverse Cycle Room Air Conditioner (Product Class

3) – Final Rule Analysis

Design Option Step EER IEER Incremental Costs Total Cost

Material Labor OH Depre

ciation Increase Cumulative

Increase MPC MSP Shipping

R

- 410A Baseline 9.76 9.68

- - - - - - $ 211.36 $ 266.31 $10.33

1 Add Subcooler 10.20 10.12 $0.75 $0.36 $0.14 $0.00 $ 1.25 $ 1.25 $ 212.61 $ 267.89 $10.33

2 Increase Compressor

Efficiency 11.05 10.95 $9.03

- - - $ 9.03 $ 10.28 $ 221.64 $ 279.27 $10.33

3 Standby Reduction 11.05 11.00 $0

. 75 $ 0.75 $ 11.03 $ 222.39 $ 280.21 $10.33

4 Increase PSC Efficiency 11.54 11.49 $1 8 .00

- - - $ 18.00 $ 29.03 $ 240.39 $ 302.89 $10.33

5 Increase Evaporator Tube

Rows 11.66 11.60 $3.37 $0.92 $0.11 $0.00 $ 4.40 $ 33.43 $ 244.79 $ 308.43 $10.33

6 Increase Chassis Size to

Medium Size 11.97 11.92 $9.49 $1.11 $1.79 $0.01 $ 12.41 $ 45.83 $ 257.19 $ 324.06 $15.30

7 Increase Chassis Size to

Large Size 12.27 12.21 $1 0.65 $0.73 $2.27 $0.73 $ 13.65 $ 59.49 $ 270.85 $ 341.27 $20.37

8 DC Brushless Motor 12.44 12.38 $ 73

. 26

- - - $ 73.26 $132.75 $ 344.11 $ 433.58 $20.37

(1) Add subcooler with 0.315 in. OD, 32 in. length, and condensate temperature of 95o F

(2) Improve rotary R-410A compressor efficiency to 10.0 EER

(3) Change Main Control Board to a Switching Power Supply.

(4) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(5) Increase number of evaporator tube rows from 3 rows to 4 rows

(6) Increase baseline chassis size by: Width 4.5 in., Height 1.125 in., Depth 2.3 in.

(7) Increase baseline chassis size by: Width 7 in., Height 1.125 in., Depth 7.2 in.

(8) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Table 5-D.2.4 Incremental Cost Detail for 24000 Btu/h Louvered, No Reverse Cycle Room Air Conditioner (Product Class

5A) – Final Rule Analysis

Design Option Step EER IEER Incremental Costs Total Cost

Material Labor OH Depre

ciation Increase Cumulative

Increase MPC MSP Shipping

R

- 410A Baseline 7.87 7.84

- - - - - - $ 336.81 $ 424.38 $23.10

1 Add Subcooler 8.17 8.14 $1.61 $0.00 $0.00 $0.00 $ 1.61 $ 1.61 $ 338.42 $ 426.41 $23.10

2 Increase Chassis size

to Medium Size 8.98 8.95 $11.31 $0.57 $0.81 $0.01 $ 12.70 $ 14.31 $ 351.13 $ 442.42 $27.22

3 Increase Condenser

Tube Rows 9.42 9.38 $8.28 $1.57 $0.94 $0.01 $ 10.80 $ 25.12 $ 361.93 $ 456.03 $27.22

4 Stand

- by Reduction 9.42 9.40 $0.75

- - - $ 0.75 $ 25.87 $ 362.68 $ 456.98 $27.22

5 Increase Compressor

Efficiency 9.68 9.66 $15.00

- - - $ 15.00 $ 40.87 $ 377.68 $ 475.88 $27.22

6 Increase PSC

Efficiency 10.05 10.03 $44.25

- - - $ 44.25 $ 85.12 $ 421.93 $ 531.63 $27.22

7 DC Brushless Motor 10.18 10.15 $126.33

- - - $ 126.33 $ 211.45 $ 548.26 $ 690.81 $27.22

(1) Add subcooler with 0.282 in OD, 63 in. length, and condensate temperature of 95o F

(2) Increase baseline chassis size by: Width 1.75 in., Height 0.25 in., Depth 2.53 in.

(3) Increase number of condenser tube rows from 3 rows to 4 rows

(4) Change Main Control Board to a Switching Power Supply.

(5 ) Improve rotary R-410A compressor efficiency to 10.3 EER

(6) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(7) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Table 5-D.2.5 Incremental Cost Detail for 28000 Btu/h Louvered, No Reverse Cycle Room Air Conditioner (Product Class

5B ) – Final Rule Analysis

Design Option Step EER IEER Incremental Costs Total Cost

Material Labor OH Depre

ciation Increase Cumulative

Increase MPC MSP Shipping

R

- 410A Baseline 7.48 7.46

- - - - - - $ 366.81 $ 462.18 $23.10

1 Add Subcooler 7.74 7.72 $1.61 $0.00 $0.00 $0.00 $ 1.61 $ 1.61 $ 368.42 $ 464.21 $23.10

2 Increase Chassis size

to Medium Size 8.29 8.26 $11.31 $0.57 $0.81 $0.01 $ 12.70 $ 14.31 $ 381.13 $ 480.22 $27.22

3 Increase Chassis size

to Large Size 9.05 9.03 $24.51 $2.85 $6.81 $0.02 $ 34.18 $ 48.50 $ 415.31 $ 523.29 $36.46

4 Stand

- by Reduction 9.05 9.04 $0.75

- - - $ 0.75 $ 49.25 $ 416.06 $ 524.24 $36.46

5 Increase Compressor

Efficiency 9.37 9.36 $16.50

- - - $ 16.50 $ 65.75 $ 432.56 $ 545.03 $36.46

6 Increase Condenser

Tube Rows 9.46 9.44 $14.48 $2.04 $0.00 $0.01 $ 16.53 $ 82.28 $ 449.09 $ 565.86 $36.46

7 Increase PSC

Efficiency 9.73 9.71 $44.25

- - - $ 44.25 $ 126.53 $ 493.34 $ 621.61 $36.46

8 DC Brushless Motor 9.81 9.80 $126.33

- - - $ 126.33 $ 252.86 $ 619.67 $ 780.79 $36.46

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- 9 (1) Add subcooler with 0.282 in OD, 63 in. length, and condensate temperature of 95o F

(2) Increase baseline chassis size by: Width 1.75 in., Height 0.25 in., Depth 2.53 in.

(3 ) Increase baseline chassis size by: Width 3.81 in., Height 4.69 in., Depth 2.53 in.

(4 ) Change Main Control Board to a Switching Power Supply.

(5) Improve rotary R-410A compressor efficiency to 10.3 EER

(6 ) Increase number of condenser tube rows from 3 rows to 4 rows

(7) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(8 ) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Table 5-D.2.6 Incremental Cost Detail for 8000 Btu/h Non-Louvered, No Reverse Cycle Room Air Conditioner (Product

Class 8A) – Final Rule Analysis

Design Option Step EER IEER Incremental Costs Total Cost

Material Labor OH Depre

ciation Increase Cumulative

Increase MPC MSP Shipping

R

- 410A Baseline 8.43 8.34

- - - - - - $ 210.70 $ 265.49 $12.26

1 Increase Evap Width 9.44 9.34 $4.74 $0.43 $0.00 $0.01 $ 5.17 $ 5.17 $ 215.88 $ 272.01 $12.26

2 Add Subcooler 9.59 9.48 $0.80 $0.00 $0.00 $0.00 $ 0.80 $ 5.97 $ 216.68 $ 273.01 $12.26

3 Improve Compressor

Efficiency 9.78 9.66 $1 .65

- - - $ 1.65 $ 7.62 $ 218.33 $ 275.09 $12.26

4 Stand

- by Reduction 9.78 9.72 $0.75

- - - $ 0.75 $ 8.37 $ 219.08 $ 276.04 $12.26

5 Increase PSC

Efficiency 10.26 10.20 $14.68

- - - $ 14.68 $ 23.05 $ 233.76 $ 294.53 $12.26

6 DC Brushless Motor 10.42 10.35 $ 65.77

- - - $ 65.77 $ 88.82 $ 299.53 $ 377.40 $12.26

(1) Increase evaporator width by 4 inches by redesigning the unit’s user interface placement.

(2) Add subcooler with 0.25 in. OD, 24.25 in. length, and condensate temperature of 95o F

(3) Improve rotary R-410A compressor efficiency to 10.0 EER

(4) Change Main Control Board to a Switching Power Supply

(5) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(6) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Incremental Cost Detail for 12000 Btu/h Non-Louvered, No Reverse Cycle Room Air Conditioner (Product Class 8B) – Final

Rule Analysis

Design Option Step EER IEER Incremental Costs Total C ost

Material Labor OH Depre

ciation Increase Cumulative

Increase MPC MSP Shipping

R

- 410A Baseline 8.37 8.32

- - - - - - $ 236.54 $ 298.04 $12.26

1 Add Subcooler 8.57 8.51 $0.68 $0.36 $0.14 $0.00 $ 1.18 $ 1.18 $ 237.72 $ 299.53 $12.26

2 Improve Compressor

Efficiency 9.09 9.03 $6.30

- - - $ 6.30 $ 7.48 $ 244.02 $ 307.47 $12.26

3 Increase Evap width 9.59 9.52 $7.61 $1.14 $0.20 $0.01 $ 8.95 $ 16.43 $ 252.97 $ 318.74 $12.26

4 Stand

- by Reduction 9.59 9.55 $0.75

- - - $ 0.75 $ 17.18 $ 253.72 $ 319.69 $12.26

5 Increase PSC

Efficiency 9.94 9.90 $13.70

- - - $ 13.70 $ 30.88 $ 267.42 $ 336.95 $12.26

6 DC Brushless Motor 10.06 10.02 $63.23

- - - $ 63.23 $ 94.11 $ 330.65 $ 416.62 $12.26

(1) Add subcooler with 0.315 in. OD, 32 in. length, and condensate temperature of 95o F

(2) Improve rotary R-410A compressor efficiency to 10.0 EER

(3) Increase evaporator width by 6 inches by redesigning the unit’s user interface placement.

(4) Change Main Control Board to a Switching Power Supply

(5) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(6 ) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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5-D.3 ENERGY MODELING DETAILS

The tables in this section identify the analyzed design configurations for the analyzed

products. For each design configuration, the tables present the key MarkN outputs (capacity and

EER), the standby energy use, the IEER, and the MarkN input and compressor files used in the

analysis. The MarkN program, a MarkN user manual, and the input and compressor files will be

made available on the website for this rulemaking.

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Table 5-D.3.1 MarkN Results for 5000 Btu/h Louvered, No Reverse Cycle Room Air Conditioner (Product Class 1) – Final

Rule Analysis

Design Configuration

Description MarkN Input Filename Compressor Map

(EER, Capacity) MarkN Outputs Stand

- by

Power IEER

EER Capacity

R

- 410A Baseline In_PC1_Baseline_R410A.dat 9.7 EER 4.6 kBtu/h 8.94 4,624 1.4 8.79

1 Add Subcooler In_PC1_Step1.dat 9.7 EER 4.6 kBtu/h 9.18 4,689 1.4 9.02

2 Increase Evap Circuits In_PC1_Step2.dat 9.7 EER 4.6 kBtu/h 9.37 4,834 1.4 9.20

3 Increase Compressor

Efficiency In_PC1_Step3.dat 10 EER 4.6 kBtu/h 9.72 4,842 1.4 9.54

4 Stand

- by Reduction In_PC1_Step4.dat 10 EER 4.6 kBtu/h

- - 0.7 9.63

5 Increase Evap Width In_PC1_Step5.dat 10 EER 4.6 kBtu/h 9.89 4,934 0.7 9.80

6 Increase Chassis to

Medium Size In_PC1_Step6.dat 10 EER 4.6 kBtu/h 10.59 5,066 0.7 10.48

7 Increase Chassis to

Large Size In_PC1_Step7.dat 10 EER 4.6 kBtu/h 10.80 5,215 0.7 10.69

8 Increase Condenser

Tube Rows In_PC1_Step8.dat 10 EER 4.6 kBtu/h 11.23 5,324 0.7 11.12

9 Increase PSC

Efficiency In_PC1_Step9.dat 10 EER 4.6 kBtu/h 11.49 5,325 0.7 11.37

10 Increase Fin

Thickness In_PC1_Step10 .dat 10 EER 4.6 kBtu/h 11.51 5,338 0.7 11.38

11 DC Brushless Motor In_PC1_Step11 .dat 10 EER 4.6 kBtu/h 11.80 5,339 0.7 11.67

(1) Add subcooler with 0.25 inches (in) outer diameter ( OD ), 24.25 in. length, and condensate temperature of 95o F

(2) Increase total refrigerant circuits in evaporator from 1 circuit to 2 circuits

(3) Improve rotary R-410A compressor efficiency to 10.0 EER

(4 ) Change Main Control Board to a Switching Power Supply.

(5 ) Increase evaporator width by 2 in. by redesigning the unit’s user interface placement.

(6) Increase Baseline Chassis Size by: Width 3 in., Height 0.75 in., Depth 2 in.

(7) Increase Baseline Chassis Size by: Width 4.2 in., Height 1.9 in., Depth 5.7 in.

(8) Convert Condenser to 3-tube row heat exchangers from 2-tube rows

(9 ) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor

(10) Increase evaporator fin thickness from 0.005 in to 0.006 in.

(11) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Table 5-D.3.2 MarkN Results for 8000 Btu/h Louvered, No Reverse Cycle Room Air Conditioner (Product Class 3) – Final

Rule Analysis

Design Option Step MarkN Filename Compressor Map

(EER, Capacity) MarkN Outputs Stand

- by

Power IEER

EER Capacity

R

- 410A Baseline In_PC3_12k_Baseline_R410A.dat 9.39 EER 7.6 kBtu/h 9.30 7,688 1.4 9.19

1 Add Subcooler In_PC3_8k_Step1.dat 9.39 EER 7.6 kBtu/h 9.60 7,816 1.4 9.50

2 Increase Evap

Width In_PC3_8k_Step2.dat 9.39 EER 7.6 kBtu/h 9.76 8,001 1.4 9.65

3 Increase Compre.

Efficiency In_PC3_8k_Step3.dat 10 EER 7.6 kBtu/h 10.17 8,005 1.4 10.05

4 Stand

- by Reduction In_PC3_8k_Step4.dat 10 EER 7.6 kBtu/h

- - 0.7 10.11

5 Increase Chassis to

Medium Size In_PC3_8k_Step5.dat 10 EER 7.6 kBtu/h 10.87 8,425 0.7 10.80

6 Increase PSC

Efficiency In_PC3_8k_Step6.dat 10 EER 7.6 kBtu/h 11.49 8,431 0.7 11.41

7 Increase Chassis to

Large Size In_PC3_8k_Step7.dat 10 EER 7.6 kBtu/h 11.84 8,633 0.7 11.76

8 DC Brushless Motor In_PC3_8k_Step8.dat 10 EER 7.6 kBtu/h 12.05 8,635 0.7 11.96

(1 ) Add subcooler with 0.25 in. OD, 24.25 in. length, and condensate temperature of 95o F

(2) Increase evaporator width by 3 in

. by redesigning the unit’s user interface placement

(3) Improve rotary R-410A compressor efficiency to 10.0 EER

(4 ) Change Main Control Board to a Switching Power Supply.

(5) Increase baseline chassis size by: Width 0.81 in., Height 3.13 in., Depth 2.5 in.

(6) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(7) Increase baseline chassis size by: Width 4 in., Height 3.13 in., Depth 8.1 in.

(8) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Table 5-D.3.3 MarkN Results for 12000 Btu/h Louvered, No Reverse Cycle Room Air Conditioner (Product Class 3) –

Final Rule Analysis

Design Option Step MarkN Filename Compressor Map

(EER, Capacity) MarkN Outputs Stand

- by

Power IEER

EER Capacity

R

- 410A Baseline In_PC3_12k_Baseline_R410A.dat 9.14 EER 11.3 kBtu/h 9.76 12,607 1.4 9.68

1 Add Subcooler In_PC3_12k_Step1.dat 9.14 EER 11.3 kBtu/h 10.20 12,913 1.4 10.12

2 Increase Compressor

Efficiency In_PC3_12k_Step2.dat 10 EER 10.9 kBtu/h 11.05 12,928 1.4 10.95

3 Standby Reduction In_PC3_12k_Step3.dat 10 EER 10.9 kBtu/h 11.05

- 0.7 11.00

4 Increase PSC Efficiency In_PC3_12k_Step4.dat 10 EER 10.9 kBtu/h 11.54 12,935 0.7 11.49

5 Increase Evaporator Tube

Rows In_PC3_12k_Step5.dat 10 EER 10.9 kBtu/h 11.66 13,206 0.7 11.60

6 Increase Chassis Size to

Medium Size In_PC3_12k_Step6.dat 10 EER 10.9 kBtu/h 11.97 13,607 0.7 11.92

7 Increase Chassis Size to

Large Size In_PC3_12k_Step7.dat 10 EER 10.9 kBtu/h 12.27 13,850 0.7 12.21

8 DC Brushless Motor In_PC3_12k_Step8 .dat 10 EER 10.9 kBtu/h 12.44 13,854 0.7 12.38

(1) Add subcooler with 0.315 in. OD, 32 in. length, and condensate temperature of 95o F

(2) Improve rotary R-410A compressor efficiency to 10.0 EER

(3) Change Main Control Board to a Switching Power Supply.

(4) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(5) Increase number of evaporator tube rows from 3 rows to 4 rows

(6) Increase baseline chassis size by: Width 4.5 in., Height 1.125 in., Depth 2.3 in.

(7) Increase baseline chassis size by: Width 7 in., Height 1.125 in., Depth 7.2 in.

(8) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Table 5-D.3.4 MarkN Results for 24000 Btu/h Louvered, No Reverse Cycle Room Air Conditioner (Product Class 5A) –

Final Rule Analysis

Design Option Step MarkN Filename Compressor Map

(EER, Capacity) MarkN Outputs Stand

- by

Power IEER

EER Capacity

R

- 410A Baseline In_PC5 A _Baseline_R410A.dat 9.79 EER 24.1 kBtu/h 7.87 22,477 1.4 7.84

1 Add Subcooler In_PC5 A _Step1.dat 9.79 EER 24.1 kBtu/h 8.17 23,007 1.4 8.14

2 Increase Chassis size to

Medium Size In_PC5 A _Step2.dat 10.0 EER 23.1 kBtu/h 8.98 22,998 1.4 8.95

3 Increase Condenser

Tube Rows In_PC5 A _Step3.dat 10.0 EER 23.1 kBtu/h 9.42 23,725 1.4 9.38

4 Stand

- by Reduction In_PC5 A _Step4.dat 10.0 EER 23.1 kBtu/h

- - 0.7 9.40

5 Increase Compressor

Efficiency In_PC5 A _Step5.dat 10.3 EER 23.1 kBtu/h 9.68 23,740 0.7 9.66

6 Increase PSC Efficiency In_PC5 A _Step6.dat 10.3 EER 23.1 kBtu/h 10.05 23,766 0.7 10.03

7 DC Brushless Motor In_PC5 A _Step7.dat 10.3 EER 23.1 kBtu/h 10.18 23,775 0.7 10.15

(1) Add subcooler with 0.282 in OD, 63 in. length, and condensate temperature of 95o F

(2) Increase baseline chassis size by: Width 1.75 in., Height 0.25 in., Depth 2.53 in.

(3) Increase number of condenser tube rows from 3 rows to 4 rows

(4) Change Main Control Board to a Switching Power Supply.

(5 ) Improve rotary R-410A compressor efficiency to 10.3 EER

(6) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(7) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Table 5-D.3.5 MarkN Results for 28000 Btu/h Louvered, No Reverse Cycle Room Air Conditioner (Product Class 5B) –

Final Rule Analysis

Design Option Step MarkN Filename Compressor Map

(EER, Capacity) MarkN Outputs Stand

- by

Power IEER

EER Capacity

R

- 410A Baseline In_PC5 B

_Baseline_R410A.dat 9.79 EER 27 .1 kBtu/h 7.48 27,326 1.4 7.46

1 Add Subcooler In_PC5 B _Step1.dat 9.79 EER 27 .1 kBtu/h 7.74 27,963 1.4 7.72

2 Increase Chassis size to

Medium Size In_PC5 B _Step2.dat 10.0 EER 27 .1 kBtu/h 8.29 28,024 1.4 8.26

3 Increase Chassis size to Large

Size In_PC5 B _Step3.dat 10.0 EER 27 .1 kBtu/h 9.05 27,400 1.4 9.03

4 Stand

- by Reduction In_PC5 B _Step4.dat 10.0 EER 27 .1 kBtu/h

- - 0.7 9.04

5 Increase Compressor

Efficiency In_PC5 B _Step5.dat 10.3 EER 27 .1 kBtu/h 9.37 27,424 0.7 9.36

6 Increase Condenser Tube

Rows In_PC5 B _Step6.dat 10.3 EER 27 .1 kBtu/h 9.46 27,647 0.7 9.44

7 Increase PSC Efficiency In_PC5 B _Step7.dat 10.3 EER 27 .1 kBtu/h 9.73 27,662 0.7 9.71

8 DC Brushless Motor In_PC5B_ Step7.dat 10.3 EER 27 .1 kBtu/h 9.81 27,666 0.7 9.80

(1) Add subcooler with 0.282 in OD, 63 in. length, and condensate temperature of 95o F

(2) Increase baseline chassis size by: Width 1.75 in., Height 0.25 in., Depth 2.53 in.

(3 ) Increase baseline chassis size by: Width 3.81 in., Height 4.69 in., Depth 2.53 in.

(4 ) Change Main Control Board to a Switching Power Supply.

(5) Improve rotary R-410A compressor efficiency to 10.3 EER

(6) Increase number of condenser tube rows from 3 rows to 4 rows

(7) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(8 ) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Table 5-D.3.6 MarkN Results for 8000 Btu/h Non-Louvered, No Reverse Cycle Room Air Conditioner (Product Class 8A) –

Final Rule Analysis

Design Option Step MarkN Filename Compressor Map

(EER, Capacity) MarkN Outputs Stand

- by

Power IEER

EER Capacity

R

- 410A Baseline In_PC8 A _8k_Baseline_R410A.dat 9.78 EER 7.2 kBtu/h 8.43 7,968 1.4 8.34

1 Increase Evap Width In_PC8 A _8k_Step1.dat 9.78 EER 7.2 kBtu/h 9.44 8,275 1.4 9.34

2 Add Subcooler In_PC8 A _8k_Step2.dat 9.78 EER 7.2 kBtu/h 9.59 8,348 1.4 9.48

3 Improve Compressor

Efficiency In_PC8 A _8k_Step3.dat 10 EER 7.2 kBtu/h 9.78 8,352 0.7 9.66

4 Stand

- by Reduction In_PC8 A _8k_Step4.dat 10 EER 7.2 kBtu/h

- - 0.7 9.72

5 Increase PSC Efficiency In_PC8 A _8k_Step5.dat 10 EER 7.2 kBtu/h 10.26 8,360 0.7 10.20

6 DC Brushless Motor In_PC8 A _8k_Step6.dat 10 EER 7.2 kBtu/h 10.42 8,362 0.7 10.35

(1) Increase evaporator width by 4 inches by redesigning the unit’s user interface placement.

(2) Add subcooler with 0.25 in. OD, 24.25 in. length, and condensate temperature of 95o F

(3) Improve rotary R-410A compressor efficiency to 10.0 EER

(4) Change Main Control Board to a Switching Power Supply

(5) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(6) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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Table 5-D.3.7 MarkN Results for 12000 Btu/h Non-Louvered, No Reverse Cycle Room Air Conditioner (Product Class 8B)

– Final Rule Analysis

Design Option Step MarkN Filename Compressor Map

(EER, Capacity) MarkN Outputs Stand

- by

Power IEER

EER Capacity

R

- 410A Baseline In_PC8 B _Baseline_R410A.dat 9.03 EER 11.5 kBtu/h 8.37 11,869 1.4 8.32

1 Add Subcooler In_PC8 B _Step1.dat 9.03 EER 11.5 kBtu/h 8.57 12,037 1.4 8.51

2 Improve Compressor

Efficiency In_PC8 B _Step2.dat 10 EER 11.5 kBtu/h 9.09 12,068 1.4 9.03

3 Increase Evap width In_PC8 B _Step3.dat 10 EER 11.1 kBtu/h 9.59 12,233 1.4 9.52

4 Stand

- by Reduction In_PC8 B _Step4.dat 10 EER 11.1 kBtu/h

- - 0.7 9.55

5 Increase PSC Efficiency In_PC8 B _Step5.dat 10 EER 11.1 kBtu/h 9.94 12,247 0.7 9.90

6 DC Brushless Motor In_PC8 B _Step6.dat 10 EER 11.1 kBtu/h 10.06 12,252 0.7 10.02

(1) Add subcooler with 0.315 in. OD, 32 in. length, and condensate temperature of 95o F

(2) Improve rotary R-410A compressor efficiency to 10.0 EER

(3) Increase evaporator width by 6 inches by redesigning the unit’s user interface placement.

(4) Change Main Control Board to a Switching Power Supply

(5) Replace 50 percent efficiency PSC Motor with 70 percent efficiency PSC Motor.

(6 ) Replace PSC Motor with an 80 percent efficiency Brushless DC Motor

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5-D.4 DESCRIPTION OF SUPPORTING ANALYSES

This section present s additional description of two aspects of the engineering analysis for room

air conditioner s:

Airflow modeling

Motor pricing analysis

5-D.4.1 Room Air Conditioner Airflow Modeling

DOE introduced the room air conditioner airflow modelling analysis during the

preliminary analysi phase of the rulemaking, and continued the use of this analysis (developed

during the preliminary analysis phase) to support the energy modelling analysis performed

during the final rule analysis. DOE did not receive comments on the airflow modeling analysis

from stakeholders during the stakeholder comment period.

Many factors influence the airflow characteristics of a room air conditioner. The flow

passages, heat exchangers, motor and fans all influence the airflow behavior within the room air

conditioner. The MarkN model treats the heat exchanger dimensions, airflows, and motor powe r

as separate, decoupled inputs, so the effect of physical changes in the airflow system on the

airflow and motor power must be calculated separately from the model

. DOE conducted an

airflow calculation for each distinct airside design configuration

.

DOE calculated the system airflow using an iterative approach with the following steps.

1. Select an airflow rate

2. Calculate fan or blower pressure rise

3. Calculate heat exchanger pressure drops using MarkN

4. Calculate other system pressure drops using spreadsheet calculation.

5. Add pressure drops and compare to fan or blower pressure rise.

a. If fan pressure rise is higher than total pressure drop, increase is airflow rate and

return to step 2

b. If fan pressure rise is lower than total pressure drop, reduce airflow rate and return

to step 2

c. If fan pressure rise and total pressure drop are equal within reasonable tolerance,

airflow calculation is complete.

The airflow modeling was based on calculating the pressure drops for the separate

components of the room air conditioner and the pressure rise associated with the condenser fan

or the evaporator blower. The approaches for calculating the pressure characteristics of the key

component are listed in Table 5-D.4.1 below.

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Table 5-D.4.1 Components Modeled to Calculate Room Air Conditioner Airflow

Component Pressure Drop Value or Calculation

Method Source s

Evaporator Blower Total Pressure Curve , adjusted using Fan

Laws to match observed baseline unit

performance. Comair Rotron Fan Company Ltd

2008 ASHRAE Handbook:

HVAC Systems and Equipment

Condenser Fan Static Pressure Curve , adjusted using Fan

Laws to match observed baseline unit

performance. Sofasco International

2008 ASHRAE Handbook:

HVAC Systems and Equipment

Filter 0.25 inches of water Filter vendors

Grilles and Louvers Loss c oefficient times velocity pressure 2005 ASHRAE Handbook: Fundamentals

Duct s and Transitions Loss c oefficient times velocity pressure 2005 ASHRAE Handbook: Fundamentals

Inflow to Condenser

(transition from fan

outlet to condenser) 50 percent of Condenser Pressure Drop Estimate

Heat Exchangers MarkN Outputs MarkN Model



### Fan performance curves provided a relationship between fan static pressure rise and

airflow delivered by the fan. DOE obtained fan performance curves for fans similar in size and

geometry to those used in the teardown units

. The fan performance curves were adjusted as

needed to match the sizes, rotational speed, and performance of the modeled room air

conditioner fans using the fan laws.

On the evaporator side, DOE accounted for the airside pressure losses of the evaporator,

the entry and exit grilles, the filter, and the impeller exit transition

. On the condenser side, DOE

accounted for the pressure losses of the condenser, the airflow path from the louvers to the fan

inlet, and the fan exit plenum geometry

.

The evaporator and condenser pressure drops were calculated by the MarkN model based on

assumed airflow rate.

5-D.4.2 Room Air Conditioner Motor Analysis

DOE introduced the room air conditioner motor analysis during the preliminary analysi

phase of the rulemaking, and continued the use of the analysis (developed during the preliminary

analysis phase) to support the manufacturing cost modelling analysis performed during the final

rule analysis. DOE did not receive comments on the motoranalysis from stakeholders during the

stakeholder comment period.

Through examination of the teardown units and interviews with room air conditioner

manufacturers, DOE determined that PSC motors are the primary motor technology used in room

### 5

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air conditioners to power the fan and blower assemblies

. DOE examined improvement in motor

efficiency, including higher efficiency PSC motors and brushless DC motors as design options

for improving the energy-efficiency of the room air conditioners.

For all of the teardown units, DOE measured the power consumption of the motor at the

available fan speeds. In accordance with the current test procedure, DOE used the data for the

highest fan setting in its energy models, by using the energy consumption of each fan as a model

input. Changes in the technology of the fan motor from design options are expressed in the

model through changes in the fan motor energy consumption.

Figure 5-D.4.1 below shows the steps taken to develop the incremental costs for the PSC

motor efficiency increases. DOE research ed motor characteristics and prices and established a room air conditioner motor database. DOE develop ed separate correlations for price and

efficiency as functions of motor weight and extended this analysis to develop a relationship for

incremental costs for increases in efficiency for PSC motors.

Figure 5-D.4.1 Motor Incremental Cost Steps

Teardown Unit Motor Sizes

The costs associated with increasing efficiency varied by motor shaft output rating. DOE

examined the motor shaft output ratings associated with each of the different product classes, and

used the baseline PSC shaft output rating as the basis of its efficiency analysis. Figure 5-D.4.2

shows the shaft output power of the motors that were examined during the reverse engineering

work, identified by product class and room air conditioner efficiency level (baseline or high).

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- 23 Figure 5-D.4.2 Motor Shaft Output Ratings by Capacity for

Different Product Classes

Motor Efficiencies

DOE obtained PSC motor efficiency data from discussions with motor vendors, review of

motor catalogs, and discussions with room air conditioner manufacturers. Most PSC motors

found in room air conditioners have a full-load efficiency between 45 percent and 60 percent.

High efficiency PSC motors can reach up to 70 percent efficiency. DOE selected an efficiency of

50 percent as the baseline for the room air conditioner PSC motors, and an efficiency of 70

percent for high efficiency PSC motors.

Cost as a Function of Weight

The DOE examined motor prices for a range of power ratings from a variety of motor

vendors. DOE examined the correlation of motor prices with weights, incoming electrical

current, incoming electrical voltage and shaft power for both single-shaft ed and double-shaft ed

HVAC PSC motors.

DOE noted that, across motors of similar shaft output, motor frame size, and voltage,

motor weight consistently increases as the efficiency increases

. DOE found a strong correlation

between motor pricing and motor weight across all motor data, and used a subset of this data to

establish a basis for pricing PSC efficiency improvements. DOE established a statistically

significant correlation between motor price and motor weight using data from two motor

### 5

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- 24

vendors, for motors with rated shaft output up to 0.25 horsepower (186.5 Watts (W)). Figure 5-

D.4.3 below shows the motor data used to establish this relationship.

The correlation establishes the increased cost of a motor per increase in weight, for PSC

motors within the range of established room air conditioner motors. It was established as

statistically significant through statistical t-tests and DOE used the ratio of cost per weight

increase to help calculate the cost of increasing the motor efficiency by a given amount.

Figure 5-D.4.3 Motor Pricing Increase with Weight Increase

Efficiency as a Function of Weight

Available motor data did not generally included efficienc y. However, full-load current

data was available for most motor entries. Current is an indicator of efficiency, assuming that

power factor does not change significantly among motors that are compared. The relationships

between current and motor weight for a range of applicable motor sizes is illustrated in Figure 5-

D.4.4 below. These relationships were developed from the available motor data.

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- 25 Figure 5-D.4.4 Weight-Current Curves for room air conditioner

PSC motors, grouped by shaft output

Cost as Function of Efficiency

DOE combined the cost/weight and the current/weight relationships to develop a

relationship for the cost of increasing motor efficiency from 50 percent to 70 percent as a

function of shaft output power. DOE determined the incremental cost for this efficiency increase

for the shaft output power levels of interest using the equation below.

The curve shown in Figure 5-D.4.5 below illustrates the resulting cost increase as a

function of shaft power. This relationship was developed for shaft power up to roughly 100W.

The high end of the relationship was extrapolated linearly to 200W to represent the cost of a high

efficiency PSC motor for a product class 5 product. DOE expects that the linear extrapolation is

conservative, since the curve’s slope decreases as shaft power increases.

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- 26 Figure 5-D.4.5 Cost of Increased Efficiency for Different Motor

Output Ratings

Brushless DC Motors

BLDC motors are a more efficient alternative to PSC motors, and are already in use in

products such as in PTACs. BLDC motors provide the same output power as PSC motors at

higher efficiencies. DOE obtained BLDC motor efficiency data from discussions with motor

vendors, review of motor catalogs, and discussions with room air conditioner manufacturers.

Typical BLDC motors have efficiencies between 70 percent and 90 percent. However, in

searching for replacement motors for room air conditioners, DOE found that the average

efficiency of these motors is approximately 80 percent; motors with 90 percent efficiency are not

very common. DOE selected a BLDC motor efficiency of 80 percent for the analysis.

DOE search ed motor catalogs and contacted motor vendors to develop a database of

BLDC motor characteristics. Using this data, DOE developed a representative relationship for

the cost premium of BLDC motors as a function of shaft power. This is shown in Figure 5-D.4.6.

### 5

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- 27 Figure 5-D.4.6 Brushless DC Motor Cost Curve by Shaft Output

Rating