Side-Mount Refrigerator-Freezers PC7 26 ft3 PC7 26 ft3

 E* PC4 22 ft3 

Fin, Microchannel) 

 Air-side Configuration (wire, plain, 

smooth wavy, herringbone, slit, louver) Wire Wire Wire

 Fan Motor Type (Shaded Pole, ACInput BLDC, DC-Input BLDC) Shaded Pole AC-Input 

BLDC Shaded Pole

 Fan Power (W) 8.5 3.4 9.1

 Air Flow Rate (Liter/s) 26 26 26 

Tube Characteristics 

Airflow Direction (W, L, H) W W H

 Tube OD (mm) 4.8 4.8 4.7

 Tube Wall Thickness (mm) 0.6 0.6 0.63

 Length of Tube in “L” Direction 18.2 18.2 58.0

 # of Tubes in H Direction 9 9 2

 Tube Pitch (cm) 2.3 2.3 2.5

 # of Tubes in W Direction 10 10 10

 Tube Pitch (cm) 2.5 2.5 2.5 

Fin Characteristics 

 Wire OD (mm) 1.1 1.1 1.3

 # of Wires on 1-side 23 23 111

 Wire Mounting (1-side, 2-sides) 2-sides 2-sides 2-sides

 Wire Fin Pitch (mm) 5.6 5.6 5.2

 Wire Length (cm) 24.1 24.1 23.5

 Wire Conductivity (W/m-K) 44.7 44.7 44.7

 Fraction Air through Exchanger (0-1) 1 1 1 

Compressor Data 

Manufacturer Tecumseh Embraco Matsushita

 Model # TSA1374YAS EGX70HLC DC57C84RCU6

 Cycles per Hour 1.12 1.16 0.7 

Interchanger 

Effectiveness (0-1) 0.95 0.95 0.85 

5-A-17
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.2.5: ERA Inputs for Upright Freezers with Automatic Defrost (Product Class 9) 

Upright Freezers 14 ft3

 Baseline 20 ft3 Baseline 20 ft3 E* 

General Data 

 Freezer Volume (ft3

) 13.7 20.1 20.1

 Adjusted Volume (ft3

) 23.7 34.8 34.8

 Rated Energy Use (kWh/yr) 621 745 671

 Calculated Max. Energy Use 

(kWh/yr) 621 758 758

 % Rated Energy Use Below 

Maximum (%) 0.0 1.8 11.5 

Cabinet Dimensions 

Cabinet Height (cm) 130.2 156.2 156.2 

Cabinet Width (cm) 71.3 83.8 83.8 

Depth, from Door Flange (cm) 66.7 64.5 64.5 

Depth, from Door Outer Surface (cm) 72.4 71.1 71.1 

Liner Properties 

Outer Liner Thickness (mm) 0.4 0.9 0.9 

Outer Liner Conductivity (W/m-C) 44.7 44.7 44.7 

Inner Liner Thickness (mm) 0.4 2.2 2.2 

Liner Conductivity (W/m-C) 44.7 0.16 0.16 

Compressor Compartment 

Height (cm) 1.9 27.9 27.9 

Top Depth (cm) 17.8 5.1 5.1 

Bottom Depth (cm) 17.8 30.5 30.5 

Wall (vertical) (cm) 6.2 6.2 6.2 

Wall (horizontal) (cm) 6.2 6.2 6.2 

Insulation 

 Insulation Thickness 

 Top Wall (cm) 6.4 4.8 4.8

 Side Wall (cm) 6.4 5.7 5.7

 Back Wall (cm) 6.4 5.1 5.1

 Bottom Wall (cm) 6.2 6.2 6.2

 Door Average Thickness (cm) 3.8 7.1 7.1

 Insulation Resistivity 

 All Walls (m2-C/W-cm) 0.50 0.50 0.50

 Wedge/Flange Dimensions 

 Wedge Depth (cm) 9.5 8.9 8.9

 Flange Width (cm) 5.9 4.7 4.7

 Heat Paths 

 Gasket Heat Leak (W/m-100C) 12 9 9

 Cabinet Penetration Heat Leak (W) 15 17 17 

Air and Cabinet Temperatures 

 Room Air (°C) 32.2 32.2 32.2

 Air Under Cabinet (°C) 35.0 35.5 35.5 

5-A-18
 

EERE-2008-BT-STD-0012 COMMENT 20
 

Upright Freezers 14 ft3 Baseline 20 ft3 Baseline 20 ft3 E*

 Air Entering Condenser (°C) 32.2 32.2 32.2

 Compressor Compartment ( ̊C) 35.0 35.5 35.5

 Cabinet (°C) -17.8 -17.8 -17.8 

Defrost and Controls Energy 

Defrost Type (Automatic, Manual) Automatic Automatic Automatic

 Timer Interval (Hr) 12.0 9.0 9.0

 Heater On-Time (Min) 5.1 18.0 18.0

 Defrost Power (W) 425 370 370 

Other Cycle-Dependent Loads 

 Outside Cabinet (W) 0 0 0

 Cabinet (W) 1.6 0.3 0.3 

Constant Electrical Loads 

 Outside Cabinet (W) 0 0 0

 Cabinet (W) 0 0 0 

Refrigerant Line Anti-Sweat None None None 

Evaporator Design 

Exit Superheat 5.0 0.0 0.0

 Fin Type (flat, wavy, herringbone) Flat Flat Flat

 Fan Motor Type (Shaded Pole, ACInput BLDC, DC-Input BLDC) Shaded Pole Shaded Pole AC-Input BLDC

 Fan Power (W) 7.4 11.2 4.5

 Air Flow Rate (Liter/s) 26.0 23.7 23.7 

Tube Characteristics 

 Width of Tube Row 55.9k 50.2 50.2

 Tube OD (mm) 7.8 8.6 8.6

 Tube Wall Thickness (mm) 0.8 0.9 0.9

 # of Tubes Deep 4.5k 9 9

 Tube Pitch (cm) 3.8 3.2 3.2

 # of Tubes Normal to Airflow 4 2 2

 Normal Tube Pitch (cm) 1.3 2.5 2.5 

Fin Characteristics 

 Fin Thickness (mm) 0.18 0.24 0.24

 Fin Pitch (mm) 4.6 5.1 5.1

 Fin Conductivity (W/m-K) 190 190 190

 Fraction Finned (0-1) 0.9 0.9 0.9 

Condenser Design 

Exit Subcooling (°C) 3 1 1

 Configuration (Static, Hot-wall, 

Tube & Fin, Microchannel) Hot-wall Hot-wall Hot-wall 

Design Data 

k

 Number of tubes in the air flow direction alternate 4 and 5, averaging 4.5. ERA analysis was conducted by 

selecting 4 rows deep and increasing the tube row width to 62.9 cm to compensate for the missing tubes. 

5-A-19 

EERE-2008-BT-STD-0012 COMMENT 20
Upright Freezers 14 ft3

 Baseline 20 ft3 Baseline 20 ft3 E*

 Total Area (sides) (m2) 2.0 2.1 2.1

 Width, Side Normal to Tubes (cm) 288 333 333

 Number of Legs 26 30 30

 Length of Tubing on Wall (m) 20.3 22.0 22.0

 Tube OD (mm) 4.7 6.4 6.4

 Tube Wall Thickness (mm) 0.8 0.8 0.8

 Thickness of Liner (mm) 0.38 0.9 0.9

 Thermal Conductivity (W/m-K) 44.7 44.7 44.7

 Number of other Hot Walls (0-2) 1 1 1 

Second Hotwall (Top) 

Total Area (m2

) 0.47 0.52 0.52

 Width, Side Normal to Tubes (cm) 71 84 84

 Number of Legs 7 8 8

 Length of Tubing on Wall (m) 5.4 5.8 5.8 

Compressor Data 

Manufacturer Embraco Matsushita Matsushita

 Model # EMY60HER DG73C12RAU6 DG73C12RAU6

 Cycles per Hour 1.4 1.5 1.5 

Interchanger 

 Effectiveness (0-1) 0.7 0.98 0.98 

5-A-20
 

EERE-2008-BT-STD-0012 COMMENT 20
 

Table 5-A.2.6: ERA Inputs for Chest Freezers with Manual Defrost (Product Class 10) 

Chest Freezers 15 ft3

 Baseline 15ft3 E* 20 ft3 Baseline 

General Data 

 Freezer Volume (ft3

) 14.8 14.8 19.9 

 Adjusted Volume (ft3

) 25.6 25.6 34.4 

Rated Energy Use (kWh/yr) 394 354 480

 Calculated Max. Energy Use (kWh/yr) 397 397 484

 Rated Energy Use Below Maximum (%) 0.7 10.8 0.8 

Cabinet Dimensions 

Cabinet Length (cm) 116.8 116.8 155.9 

Cabinet Width (cm) 68.6 68.6 69.9 

Depth, from Door Flange (cm) 81.1 81.1 81.6 

Depth, from Door Outer Surface (cm) 86.8 86.8 87.0 

Liner Properties 

Outer Liner Thickness (mm) 0.5 0.5 0.5 

Outer Liner Conductivity (W/m-C) 44.7 44.7 44.7 

Inner Liner Thickness (mm) 1.3 1.3 0.4 

Liner Conductivity (W/m-C) 44.7 44.7 44.7 

Compressor Compartment Dimensionsl

 Height (cm) 27.9 27.9 22.9

 Depth (cm) 9.1 9.1 22.2

 Fractional width of compartment (cm) 1 1 1

 Top Wall Insulation Thickness (cm) 6.9 6.9 7.7

 Front Wall Insulation Thickness (cm) 5.1 5.1 7.7

 Insulation Thickness 

 Side Wall (cm) 6.6 6.6 6.7

 Bottom (cm) 6.4 6.4 7.0

 Door (cm) 4.8 4.8 5.1

 Insulation Resistivity 

 All Walls (m2-C/W-cm) 0.5 0.5 0.50

 Wedge/Flange Dimensions 

 Wedge Depth (cm) 1.3 1.3 1.0

 Flange Width (cm) 4.6 4.6 5.4

 Heat Paths 

 Gasket Heat Leak (W/m-100C) 9 9 9

 Cabinet Penetration Heat Leak (W) 0.0 0.0 0.0 

Air and Cabinet Temperatures 

 Room Air (°C) 32.2 32.2 32.2

 Air Under Cabinet (°C) 38.0 38.0 36.0

 Air Entering Condenser (°C) 32.2 32.2 33.0

 Compressor Compartment (°C) 38.0 38.0 36.0 

l Windows ERA allows incorporation of the compressor compartment either into the long or the short wall. DOS 

ERA allowed incorporation only into the short wall, so the short wall option should be entered for Windows ERA. 

5-A-21 

EERE-2008-BT-STD-0012 COMMENT 20
Chest Freezers 15 ft3

 Baseline 15ft3 E* 20 ft3 Baseline 

Cabinet (°C) -17.8 -17.8 -17.8 

Defrost and Controls Energy 

Defrost Type (Automatic, Manual) Manual Manual Manual 

Other Cycle-Dependent Loads 

 Outside Cabinet (W) 0 0 0

 Inside Cabinet (W) 0 0 0 

Constant Electrical Loads 

 Outside Cabinet (W) 0.4 0.4 0.1

 Inside Cabinet (W) 0 0 0 

Refrigerant Line Anti-Sweat None None None 

Evaporator Design (Cold Wall) 

Exit Superheat 0.5 0.5 0.5

 Tube OD (mm) 6.4 6.4 7.9

 Tube Wall Thickness (mm) 0.8 0.8 0.8 

Side Walls (perimeter) 

Total Area of Side Walls (m2

) 1.57 1.57 2.73

 Number of Tube Legs 9 9 9

 Width Normal to Tubes 49.1 49.1 73

 Liner Thickness (mm) 1.3 1.3 0.4

 Liner Conductivity (W/mK) 44.7 44.7 44.7 

Bottom Surface 

 Area of Bottom Surface (m2

) 0.17 0.17 0.3

 Number of Tube Legs 3 3 2

 Width Normal to Tubes 16.4 16.4 15 

Condenser Design 

Exit Subcooling (°C) 0.5 0.5 0.5

 Configuration Hot-wall Hot-wall Hot-wall

 Total Area (m2

) 2.0 2.0 2.4

 Width of Side Normal to Tubes (cm) 53.3 53.3 53.7

 Number of Legs 6 6 7

 Length of Tubing on Wall (m) 22.3 22.3 29.5

 Tube OD (mm) 4.8 4.8 4.8

 Tube Wall Thickness (mm) 0.8 0.8 0.8

 Thickness of Liner (mm) 0.5 0.5 0.5

 Thermal Conductivity (W/m-K) 44.7 44.7 44.7

 Number of other Hot Walls (0-2) 0 0 0 

Second Hotwall None None None 

Compressor Data 

Manufacturer Matsushita Matsushita Matsushita

 Model # SF51C97RAU6 DG57C84RAU6 DGH66C94RAU

 Cycles per Hour 1.0 1.0 1.0 

Interchanger 

Effectiveness (0-1) 0.9 0.9 0.7 

5-A-22
 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

Table 5-A.2.7: ERA Inputs for Compact Refrigerators (Product Class 11) 

Compact Refrigerators 4 ft3

 Baseline 4 ft3 E* 1.7 ft3 

General Data 

 Fresh Food Volume (ft3) 3.3 3.65 1.5

 Freezer Volume (ft3

) 0.7m 0.44 0.2

 Total Volume (ft3) 4.0 4.1 1.7

 Adjusted Volume (ft3) 4.3 4.3 1.7n

 Rated Energy Use (kWh/yr) 340 270 296

 Calculated Max. Energy Use (kWh/yr) 345 345 317

 Rated Energy Use Below Maximum (%) 1.5 22 6.8 

Cabinet Dimensions 

 Cabinet Height (cm) 83.5 83.8 47.0

 Cabinet Width (cm) 47.3 49.5 44.5

 Depth, from Door Flange (cm) 40.4 45.6 40.6

 Depth, from Door Outer Surface (cm) 44.5 50.2 44.8 

Liner Properties 

 Outer Liner Thickness (mm) 0.8 0.5 0.4

 Outer Liner Conductivity (W/m-C) 44.7 44.7 44.7

 Inner Liner Thickness (mm) 1.3 1.1 1.3

 Liner Conductivity (W/m-C) 0.16 0.16 0.16 

Compressor Compartment Dimensions 

 Height (cm) 21.6 20.3 19.1

 Horizontal Wall Thickness (cm) 3.4 4.3 3.8

 Top Depth (cm) 16.2 12.7 13.0

 Vertical Wall Thickness (cm) 3.3 3.0 2.8

 Bottom Depth (cm) 16.2 12.7 13.0 

Insulation Thickness – Fresh Food 

 Top Wall (cm) 2.5 4.1 3.4

 Side Wall (cm) 2.7 4.1 3.4

 Back Wall (cm) 3.3 5.8 3.5

 Bottom (cm) 2.5 4.8 3.1

 Door (cm) 2.8 4.3 3.3 

Insulation Resistivity – Fresh Food 

 All Walls (m2-C/W-cm) 0.50 0.50 0.50 

Wedge/Flange Dimensions 

 Fresh Food Flange Width (cm) 2.3 3.3 2.5 

m The rated freezer volume is 0.7 ft3

 as indicated, but the volume based on observed freezer dimensions is 0.4 ft3 

n

 This product is classified as an all-refrigerator for testing and rating purposes, since its freezer compartment is less 

than 0.5 ft3

 in volume. It is not clear wheter the 4 ft3 E* product was also rated as an all-refrigerator based on 

available data. DOE analyzed both 4 ft3

 products as basic refrigerators and the 1.7 ft3 product as an all-refrigerator. 

5-A-23 

EERE-2008-BT-STD-0012 COMMENT 20
 

Compact Refrigerators 4 ft3 Baseline 4 ft3 E* 1.7 ft3

 Fresh Food Wedge Depth (cm) 0 0 0.6

 Heat Paths 

 Gasket Heat Leak (W/m-100C) 12.0 9.0 12.0

 Cabinet Penetration Heat Leak (W) 0 0 0 

Air and Cabinet Temperatures 

 Room Air (°C) 32.2 32.2 32.2

 Freezer Section (°C) -9.4 -9.4 -3.9

 Fresh Food Section (°C) 7.2 7.2 3.3

 Air Under Cabinet (°C) 35.0 36.6 35.0

 Compressor Compartment (°C) 35.0 36.6 35.0

 Air Entering Condenser (°C) 32.2 32.2 32.2 

Defrost and Controls Energy 

Defrost Type (Manual, Cycle) Manual Manual Manual 

Cycle-Dependent Loads 

 Inside Cabinet (W) 0 0 0

 Outside Cabinet (W) 0 0 0 

Constant Electrical Loads 

 Inside Cabinet (W) 0 0 0

 Outside Cabinet (W) 0 0 0 

Anti-Sweat Heat None None None 

Evaporator Design 

Exit Superheat (°C) 0.0 0.1 2.0

 Tube Height (mm)

 Width (mm) 

 Hydraulic Diameter (mm) 

4.4 

9.5 

6.1 

4.7 

9.5 

6.3 

4.3 

9.5 

5.9

 Refrigerant Tube Length (m) 6.7 6.1 3.1

 Number of Legs 11 10 8 

Freezer Surfaces: Present (Y/N), Spacing to 

Cabinet Wall (cm)

 Top N N N

 Left Y 1.4 Y 1.6 Y 15

 Right Y 1.4 Y 1.6 Y 1.3 

Freezer Box Dimensions 

 Width (cm) 38.7 38.4 21.0

 Height (cm) 11.4 12.7 8.9

 Depth (cm) 25.4 24.8 21.0

 Inner Door (Y or N) Y Y Y 

Condenser Design 

Exit Subcooling (°C) 1.0 1.0 0.0 

Heat Transfer Type (Static, Hot-wall, Tube 

& Fin, Microchannel) Static Static Hot-wall 

Static Condenser Details 

Fin Type Wire Wire NA 

5-A-24
 

EERE-2008-BT-STD-0012 COMMENT 20
Compact Refrigerators 4 ft3

 Baseline 4 ft3 E* 1.7 ft3

 Tube OD (mm) 4.8 4.8 NA

 Tube Wall Thickness (mm) 0.6 0.6 NA

 Number of Tube Rows 9 9 NA

 Tube Pitch (mm) 6.0 6.0 NA

 Width of Tube Row (cm) 43.2 43.2 NA

 Wire OD (mm) 1.5 1.5 NA

 Wire Length (cm) 60.3 60.3 NA

 # of Wires 98 98 NA

 Wire Conductivity (W/m-K) 44.7 44.7 NA 

Hot Wall Condenser Details 

 First Hot Wall (sides)

 Total Area of Side Panels (m2) NA NA 0.33

 Width of Side Normal to Tubes (cm) NA NA 94.0

 Number of Legs NA NA 16

 Length of Tubing on Wall (m) NA NA 6.0

 Tube OD (cm) NA NA 3.9

 Tube Wall (mm) NA NA 0.76

 Liner Thickness (mm) NA NA 0.38

 Thermal Conductivity (W/mK) NA NA 44.7

 Second Hot Wall (top) 

 Total Area (m2) NA NA 0.10

 Width Normal to Tubes (cm) NA NA 23.5

 Number of Legs NA NA 4

 Length of Tubing on Wall (m) NA NA 1.7 

Compressor Data 

Manufacturer ZEL LG Huayi 

Model # GVT44AD NSA36LACG AES25DS

 Cycles per Hour 4.0 5.0 3.0 

Interchanger 

Effectiveness (0-1) 0.8 0.98 0.7 

5-A-25
 

EERE-2008-BT-STD-0012 COMMENT 20
 

Table 5-A.2.8: ERA Inputs for Compact Chest Freezers (Product Class 18) 

Compact Chest Freezers 3.4 ft3 7.0 ft3

, #1 7.0 ft3, #2 

General Data 

 Freezer Volume (ft3

) 3.4 7.0 7.0

 Adjusted Volume (ft3

) 5.9 12.1 12.1

 Rated Energy Use (kWh/yr) 213 277 276

 Calculated Max. Energy Use (kWh/yr) 213 279 279

 Rated Energy Use Below Maximum (%) 0 0.6 0.9 

Cabinet Dimensions 

 Cabinet Length (cm) 53.3 92.7 94.0

 Cabinet Width (cm) 58.4 51.8 58.4

 Depth, from Door Flange (cm) 76.2 74.6 73.3

 Depth, from Door Outer Surface (cm) 81.3 80.0 78.7 

Liner Properties 

 Outer Liner Thickness (mm) 0.5 0.6 0.9

 Outer Liner Conductivity (W/m-C) 44.7 44.7 44.7

 Inner Liner Thickness (mm) 0.4 0.4 1.0

 Liner Conductivity (W/m-C) 190 190 190 

Compressor Compartment Dimensionso

 Height (cm) 21.0 28.6 22.9

 Depth (cm) 19.7 18.1 22.9

 Fractional width of compartment (0-1) 1 1 1

 Top Wall Insulation Thickness (cm) 6.6 7.0 6.4

 Front Wall Insulation Thickness (cm) 6.4 7.0 7.3 

Insulation Thickness – Freezer 

 Side Wall (cm) 6.7 6.0 6.4

 Bottom Wall (cm) 6.3 5.1 7.3

 Door (cm) 5.8 6.4 5.5 

Insulation Resistivity – Freezer 

 All Walls (m2-C/W-cm) 0.5 0.5 0.53 

Wedge/Flange Dimensions 

 Wedge Depth (cm) 1.0 1.0 1.9

 Flange Width (cm) 3.8 4.0 4.4

 Heat Paths 

 Gasket Heat Leak (W/m-100C) 7.5 7.5 7.5

 Cabinet Penetration Heat Leak (W) 0 0 0 

Air and Cabinet Temperatures 

 Room Air (°C) 32.2 32.2 32.2

 Air Under Cabinet (°C) 35.0 35.0 35.0

 Air Entering Condenser (°C) 32.2 32.2 32.2

 Compressor Compartment (°C) 35.0 35.0 35.0 

o Windows ERA allows incorporation of the compressor compartment either into the long or the short wall. DOS 

ERA allowed incorporation only into the short wall, so the short wall option should be entered for Windows ERA. 

5-A-26 

EERE-2008-BT-STD-0012 COMMENT 20
Compact Chest Freezers 3.4 ft3 7.0 ft3

, #1 7.0 ft3, #2

 Cabinet Setpoint (°C) -17.8 -17.8 -17.8 

Defrost and Controls Energy 

Defrost Type (Manual, Auto) Manual Manual Manual 

Cycle-Dependent Loads 

 Inside Cabinet (W) 0 0 0

 Outside Cabinet (W) 0 0 0 

Constant Electrical Loads 

 Inside Cabinet (W) 0 0 0

 Outside Cabinet (W) 0.4 0.2 0.1 

Anti-Sweat Heat None None None 

Evaporator Design 

Exit Superheat (°C) 0.5 0.5 0.0

 Tube OD (mm) 8.0 7.6 6.4

 Tube Wall Thickness (mm) 0.6 0.6 0.6

 Liner Thickness (mm) 0.4 0.4 1.0

 Liner Conductivity (W/m-K) 190 190 190

 Total Area of Side Walls (m2) 1.1 1.43 1.5

 Number of Legs 10 9 12

 Width Normal to Tubes (cm) 68.3 72 64.8 

Condenser Design 

Exit Subcooling (°C) 0.5 0.5 0.0 

Heat Transfer Type (Static, Hot-wall, Tube 

& Fin, Microchannel) Static Hot-wall Hot-wall 

Static Condenser Details 

Fin Type Wire NA NA

 Tube OD (mm) 6.0 NA NA

 Tube Wall Thickness (mm) 0.64 NA NA

 Number of Tube Rows 14 NA NA

 Tube Pitch (mm) 4.6 NA NA

 Width of Tube Row (cm) 47.0 NA NA

 Wire OD (mm) 1.4 NA NA

 Wire Length (cm) 64.5 NA NA

 # of Wires 110 NA NA

 Wire Conductivity (W/m-K) 44.7 NA NA 

Hot Wall Condenser Details 

 Total Area of Side Panels (m2) NA 1.5 1.72

 Width of Side Normal to Tubes (cm) NA 53.3 241

 Number of Legs NA 7 32

 Length of Tubing on Wall (m) NA 20.2 19.6

 Tube OD (mm) NA 4.6 3.9

 Tube Wall Thickness (mm) NA 0.6 0.5

 Liner Thickness (mm) NA 0.64 0.9

 Thermal Conductivity (W/mK) NA 44.7 44.7 

5-A-27
 

EERE-2008-BT-STD-0012 COMMENT 20
 

Compact Chest Freezers 3.4 ft3 7.0 ft3, #1 7.0 ft3, #2 

Compressor Data 

Manufacturer Jiangsu Baixuep Danfoss ZEL

 Model # QDH3511G TTE4.6GFK GVY44AD

 Cycles per Hour 2.25 1.3 2.0 

Interchanger 

Effectiveness (0-1) 0.95 0.95 0.95 

p

 Jiangsu Baixue Electric Appliances Co. Ltd. 

5-A-28 

EERE-2008-BT-STD-0012 COMMENT 20
5-A.3 INCREMENTAL COST DETAIL 

The tables in this section identify the groups of design options and their associated costs 

for all analyzed efficiency levels for the reverse-engineering units for which the full incremental 

cost analysis was conducted. 

5-A-29
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.1: Incremental Cost Detail for 16 ft3 Top-Mount Refrigerator-Freezer (Product Class 3) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

10% 

Increase compressor EER from 5.55 to 5.74 $1.43 $0.00 $0.00 $0.00 $0.37 $1.80 

Brushless DC Condenser Fan Motor $3.75 $0.00 $0.00 $0.00 $0.98 $4.73 

Increase Evaporator Size by 20% $1.20 $0.00 $0.00 $0.00 $0.31 $1.51 

15% Increase Condenser Size by 20% $1.69 $0.00 $0.00 $0.00 $0.44 $2.13 

Increase compressor EER from 5.74 to 5.85 $0.83 $0.00 $0.00 $0.00 $0.21 $1.04 

20% Increase compressor EER from 5.85 to 6.26 $8.15 $0.00 $0.00 $0.00 $2.12 $10.26 

25% Adaptive Defrost $8.00 $0.00 $0.00 $0.00 $2.08 $10.08 

3.5 sqft VIP in FZR Cabinet $11.49 $1.20 $1.48 $3.68 $17.86 

30% 8.7 sqft more VIP in FZR Cabinet $28.43 $2.97 $3.67 $9.12 $44.19 

35% 6.9 sqft VIP in FF Cabinet $22.62 $1.22 $2.79 $6.92 $33.55 

40% 8.4 sqft more VIP in FF Cabinet $27.34 $1.47 $3.37 $8.37 $40.55 

45% 8.4 sqft more VIP in FF Cabinet $27.34 $1.47 $3.37 $8.37 $40.55 

5-A-30
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.2: Incremental Cost Detail for 21 ft3 Top-Mount Refrigerator-Freezer (Product Class 3) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

10% Increase compressor EER from 4.92 to 5.55 $0.37 $0.00 $0.00 $0.00 $0.10 $0.47 

15% Increase compressor EER from 5.55 to 5.94 $2.93 $0.00 $0.00 $0.00 $0.76 $3.69 

Increase compressor EER from 5.94 to 6.08 $2.61 $0.00 $0.00 $0.00 $0.68 $3.29 

20% Increase Evaporator Size by 

20% $1.61 $0.00 $0.00 $0.00 $0.42 $2.03 

Increase Condenser Size by 20% $1.45 $0.00 $0.00 $0.00 $0.38 $1.83 

25% 

Brushless DC Evaporator Fan Motor $3.50 $0.00 $0.00 $0.00 $0.91 $4.41 

Brushless DC Condenser Fan Motor $3.75 $0.00 $0.00 $0.00 $0.98 $4.73 

30% Adaptive Defrost $8.00 $0.00 $0.00 $0.00 $2.08 $10.08 

35% 10.5 sqft VIP in FF Cabinet $34.22 $1.42 $4.17 $10.35 $50.16 

40% 13.4 sqft more VIP in FF Cabinet $43.68 $1.82 $5.32 $13.21 $64.03 

45% 6.8 sqft more VIP in FF Cabinet $22.26 $0.93 $2.71 $6.73 $32.63 

6.2 sqft VIP in FZR Cabinet $20.21 $1.60 $2.55 $6.33 $30.70 

5-A-31
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.3: Incremental Cost Detail for 18.5 ft3 Bottom-Mount Refrigerator-Freezer (Product Class 5) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

10% 

Increase compressor EER from 5.72 to 6.06 $3.72 $0.00 $0.00 $0.00 $0.97 $4.69 

Increase Evaporator Size by 20% $2.00 $0.00 $0.00 $0.00 $0.52 $2.52 

15% 

Brushless DC Evaporator Fan Motor $3.50 $0.00 $0.00 $0.00 $0.91 $4.41 

Brushless DC Condenser Fan Motor $3.75 $0.00 $0.00 $0.00 $0.98 $4.73 

20% Adaptive Defrost $8.00 $0.00 $0.00 $0.00 $2.08 $10.08 

25% 

Increase compressor efficiency from 6.06 to 6.26 $5.40 $0.00 $0.00 $0.00 $1.40 $6.80 

Increase Condenser Size by 20% $2.00 $0.00 $0.00 $0.00 $0.52 $2.52 

30% 

Variable Anti-Sweat Heater Control $17.48 $0.00 $0.00 $0.00 $4.54 $22.02 

35% 12.6 sqft VIP in FF Cabinet $41.09 $2.12 $5.06 $12.55 $60.82 

40% 

12.1 sqft more VIP in FF Cabinet $39.59 $2.04 $4.87 $12.09 $58.60 

45% 

13.3 sqft more VIP in FZR Cabinet $43.44 $3.00 $5.43 $13.49 $65.37 

5-A-32
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.4: Incremental Cost Detail for 25 ft3 Bottom-Mount Refrigerator-Freezer (Product Class 5) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

10% 

Increase compressor EER from 4.79 to 5.42 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 

15% 

Increase compressor EER from 5.42 to 5.74 $1.80 $0.00 $0.00 $0.00 $0.47 $2.27 

20% 

Increase compressor EER from 5.74 to 6.14 $5.73 $0.00 $0.00 $0.00 $1.49 $7.22 

Increase compressor EER from 6.14 to 6.26 $3.24 $0.00 $0.00 $0.00 $0.84 $4.08 

25% 

Brushless DC Evaporator Fan Motor $3.50 $0.00 $0.00 $0.00 $0.91 $4.41 

Variable Anti-Sweat Heater Control $9.48 $0.00 $0.00 $0.00 $2.46 $11.94 

Increase Condenser Size by 20% $4.90 $0.00 $0.00 $0.00 $1.27 $6.17 

30% Brushless DC Condenser Fan 

Motor $3.75 $0.00 $0.00 $0.00 $0.98 $4.73 

35% 

Increase Evaporator Size by 20% $2.60 $0.00 $0.00 $0.00 $0.68 $3.27 

13.2 sqft VIP in FF Cabinet $42.98 $1.86 $5.25 $13.02 $63.11 

40% 

16.3 sqft more VIP in FF Cabinet $53.24 $2.31 $6.50 $16.13 $78.18 

45% 14.1 sqft VIP in FZR Cabinet $46.03 $2.83 $5.72 $14.19 $68.77 

5-A-33
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.5: Incremental Cost Detail for 22 ft3 Side-Mount Refrigerator-Freezer with TTD Ice (Product 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

10% 

Increase compressor EER from 5.51 to 5.89 $2.85 $0.00 $0.00 $0.00 $0.74 $3.59 

Brushless DC Condenser Fan Motor $3.75 $0.00 $0.00 $0.00 $0.98 $4.73 Increase Evaporator Size by 20% $1.27 $0.00 $0.00 $0.00 $0.33 $1.60 

15% 

Increase compressor EER from 5.89 to 6.26 $7.85 $0.00 $0.00 $0.00 $2.04 $9.88 

Increase Condenser Size by 20% $2.89 $0.00 $0.00 $0.00 $0.75 $3.65 

20% 11 sqft VIP in FF Cabinet $35.92 $1.77 $4.4.1 $10.95 $53.05 

25% 13 sqft more VIP in FF Cabinet $42.58 $2.10 $5.23 $12.98 $62.89 30% 1.8 sqft more VIP in FF Cabinet $5.85 $0.29 $0.72 $1.78 $8.64 

11.3 sqft VIP in FZR Cabinet $36.90 $2.30 $4.59 $11.38 $55.17 

35% 

9.2 sqft more VIP in FZR Cabinet $30.01 $1.87 $3.73 $9.26 $44.86 

3.4 sqft VIP in FZR Door $10.97 $0.27 $1.32 $3.27 $15.82 

40% 

1.8 sqft more VIP in FZR Door $5.75 $0.14 $0.69 $1.71 $8.29 

8 sqft VIP in FF Door $26.28 $0.42 $3.12 $7.75 $37.75 

Variable Speed Compressor $39.31 $0.00 $0.00 $0.00 $10.22 $49.52 

5-A-34
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.6: Incremental Cost Detail for 26 ft3 Side-Mount Refrigerator-Freezer with TTD Ice (Product 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

10% 

Increase compressor EER from 5.58 to 5.93 $2.63 $0.00 $0.00 $0.00 $0.68 $3.31 

Brushless DC Evaporator Fan Motor $3.50 $0.00 $0.00 $0.00 $0.91 $4.41 Brushless DC Condenser Fan Motor $3.75 $0.00 $0.00 $0.00 $0.98 $4.73 

15% Increase compressor EER from 5.93 to 6.04 $1.61 $0.00 $0.00 $0.00 $0.42 $2.02 20% 

Increase compressor EER from 6.04 to 6.26 $5.94 $0.00 $0.00 $0.00 $1.54 $7.48 

Adaptive Defrost $8.00 $0.00 $0.00 $0.00 $2.08 $10.08 

25% 

Increase Evaporator Size by 20% $1.16 $0.00 $0.00 $0.00 $0.30 $1.46 

Increase Condenser Size by 20% $2.42 $0.00 $0.00 $0.00 $0.63 $3.05 

7.5 sqft VIP in FF Cabinet $24.47 $1.16 $3.00 $7.44 $36.08 

30% 12.2 sqft more VIP in FF Cabinet $39.86 $1.89 $4.88 $12.13 $58.76 

35% 7.2 sqft more VIP in FF Cabinet $23.44 $1.11 $2.87 $7.13 $34.56 

5.8 sqft VIP in FZR Cabinet $18.93 $1.04 $2.34 $5.80 $28.10 

40% 14.1 sqft VIP in FZR Cabinet $45.96 $2.53 $5.67 $14.08 $68.23 45% 

3.3 sqft more VIP in FZR Cabinet $10.91 $0.60 $1.35 $3.34 $16.20 

6.2 sqft VIP in FZR Door $20.14 $0.42 $2.41 $5.97 $28.93 

8.0 sqft VIP in FF Door $26.65 $0.42 $3.17 $7.86 $38.09 

5-A-35
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.7: Incremental Cost Detail for 14 ft3 Upright Freezer with Auto Defrost (Product Class 9) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

10% 

Brushless DC Evaporator Fan Motor $3.50 $0.00 $0.00 $0.00 $0.91 $4.41 

Add 1" Insulation to Door $0.65 $0.00 $0.00 $0.91 $0.41 $1.97 

15% Increase Compressor EER from 5.04 to 5.43 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 20% Increase Compressor EER from 5.43 to 5.95 $3.38 $0.00 $0.00 $0.00 $0.88 $4.25 

Increase Compressor EER from 5.95 to 6.08 $2.54 $0.00 $0.00 $0.00 $0.66 $3.19 

25% 

Increase Evaporator Size by 20% $1.47 $0.00 $0.00 $0.00 $0.38 $1.85 

Convert condenser to forced convection with BLDC fan motor 

$6.75 $0.00 $0.00 $0.00 $1.76 $8.51 

Adaptive Defrost $8.00 $0.00 $0.00 $0.00 $2.08 $10.08 

30% Add 0.36" Insulation to Cabinet $4.54 $0.00 $0.00 $17.35 $5.69 $27.58 

35% 

Add another 0.64" Insulation to Cabinet $7.87 $0.00 $0.00 $0.00 $2.05 $9.91 

3.7 sqft VIP in Cabinet $12.05 $0.41 $1.77 $3.70 $17.93 

40% 17.6 sqft more VIP in Cabinet $57.37 $1.94 $8.42 $17.61 $85.35 

45% 16.4 sqft more VIP in Cabinet $53.75 $1.82 $7.89 $16.50 $79.95 0.8 sqft VIP in Door $2.70 $0.03 $0.39 $0.81 $3.94 

5-A-36
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.8: Incremental Cost Detail for 20 ft3 Upright Freezer with Auto Defrost (Product Class 9) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

10% 

Brushless DC Evaporator Fan Motor $3.50 $0.00 $0.00 $0.00 $0.91 $4.41 

Add 1" Insulation to Door $0.69 $0.00 $0.00 $0.91 $0.42 $2.02 

15% Adaptive Defrost $8.00 $0.00 $0.00 $0.00 $2.08 $10.08 

20% N/A $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 25% 

Increase compressor EER from 5.73 to 6.00 $2.03 $0.00 $0.00 $0.00 $0.53 $2.55 

Increase Evaporator Size by 20% $1.34 $0.00 $0.00 $0.00 $0.35 $1.69 Increase compressor EER from 6.01 to 6.24 $6.21 $0.00 $0.00 $0.00 $1.61 $7.82 

30% 

Increase Evaporator Size by Additional 30% $2.01 $0.00 $0.00 $0.00 $0.52 $2.53 

Increase Door Insulation Thickness 1/4" $0.17 $0.00 $0.00 $0.00 $0.04 $0.22 Remove 1/4" Door Insulation -$0.17 $0.00 $0.00 $0.00 -$0.04 -$0.22 

35% 

Forced Convection Condenser with BLDC Cond Fan $6.75 $0.00 $0.00 $0.00 $1.76 $8.51 

Add 0.15" Insulation to Cabinet $1.97 $0.00 $0.00 $17.35 $5.02 $24.34 

40% Add Additional 0.55" Insulation to Cabinet $7.26 $0.00 $0.00 $0.00 $1.89 $9.15 45% 

11.7 sqft VIP in FZR Cabinet $38.31 $1.06 $5.59 $11.69 $56.65 

Add Additional 0.3" Insulation to Cabinet $3.88 $0.00 $0.00 $0.00 $1.01 $4.89 

5-A-37
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.9: Incremental Cost Detail for 15 ft3 Chest Freezer (Product Class 10) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

10% Increase compressor EER from 4.92 to 5.48 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 15% Increase compressor EER from 5.48 to 5.81 $2.33 $0.00 $0.00 $0.00 $0.60 $2.93 20% 

Increase compressor EER from 5.81 to 6.08 $3.59 $0.00 $0.00 $0.00 $0.93 $4.52 

Add 0.5" Insulation to Door $0.24 $0.00 $0.91 $0.00 $0.30 $1.45 

25% 

Add another 0.5" Insulation to Door $0.23 $0.00 $0.00 $0.00 $0.06 $0.29 

Increase Condenser Size by 45% $3.48 $0.00 $0.00 $0.00 $0.90 $4.38 

30% 

Increase Evaporator Size by 30% $3.11 $0.00 $0.00 $0.00 $0.81 $3.91 

Add another 0.5" Insulation to Door $0.24 $0.00 $0.00 $0.00 $0.06 $0.30 

35% 

Remove 0.5" Insulation from Door -$0.24 $0.00 $0.00 $0.00 -$0.06 -$0.30 

Add 0.5" Insulation to Cabinet $4.54 $0.00 $0.00 $17.35 $5.69 $27.58 

40% Add another 0.5" Insulation to Cabinet $4.40 $0.00 $0.00 $0.00 $1.14 $5.54 45% Variable Speed Compressor $44.09 $0.00 $0.00 $0.00 $11.46 $55.55 

5-A-38
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.10: Incremental Cost Detail for 20 ft3 Chest Freezer (Product Class 10) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

Increase Condenser Size by 29% $1.68 $0.00 $0.00 $0.00 $0.44 $2.12 

10% 

Add 1" Insulation to Door $0.62 $0.00 $0.00 $0.91 $0.40 $1.93 Increase compressor EER from 

5.71 to 5.78 $0.53 $0.00 $0.00 $0.00 $0.14 $0.66 

15% Increase compressor EER from 5.78 to 6.07 $3.54 $0.00 $0.00 $0.00 $0.92 $4.46 20% 

Increase compressor EER from 6.07 to 6.25 $4.86 $0.00 $0.00 $0.00 $1.26 $6.12 

Add 0.14 in Insulation to Cabinet $1.67 $0.00 $0.00 $17.35 $4.95 $23.97 

25% Add another 0.38 in Insulation to Cabinet $4.52 $0.00 $0.00 $0.00 $1.17 $5.69 30% Add another 0.48 in Insulation to Cabinet $5.50 $0.00 $0.00 $0.00 $1.43 $6.94 35% Variable Speed Compressor $41.08 $0.00 $0.00 $0.00 $10.68 $51.75 

40% N/A $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 45% 10.2 sqft VIP in Bottom Wall $33.46 $1.39 $4.95 $10.35 $50.14 

2.9 sqft VIP in Door $9.53 $0.10 $1.37 $2.86 $13.86 

5-A-39
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.11: Incremental Cost Detail for 1.7 ft3 Compact Refrigerator (Product Class 11) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

Increase evaporator size by 20% $0.27 $0.00 $0.00 $0.00 $0.07 $0.34 

Increase condenser size by 20% $0.39 $0.00 $0.00 $0.00 $0.10 $0.49 

10% Add 0.75" Insulation to Door $0.13 $0.00 $0.00 $0.45 $0.15 $0.72 

Increase compressor EER from 3.02 to 3.09 $0.70 $0.00 $0.00 $0.00 $0.18 $0.88 

15% Increase compressor EER from 3.09 to 3.27 $1.80 $0.00 $0.00 $0.00 $0.47 $2.27 20% Increase compressor EER from 3.27 to 3.46 $1.90 $0.00 $0.00 $0.00 $0.49 $2.39 25% 

Increase compressor EER from 3.46 to 3.47 $0.10 $0.00 $0.00 $0.03 $0.13 

Add 0.23" Insulation to Cabinet $0.72 $0.00 $0.00 $8.53 $2.40 $11.65 

30% Add 0.31" Insulation to Cabinet $0.98 $0.00 $0.00 $0.00 $0.25 $1.23 

35% Add 0.21" Insulation to Cabinet $0.68 $0.00 $0.00 $0.00 $0.18 $0.85 

Add 1.6 sqft VIP in Door $5.15 $0.29 $1.07 $1.69 $8.20 

40% 

Add Another 0.7 sqft VIP in Door $2.14 $0.12 $0.44 $0.70 $3.40 

Add 2.3 sqft VIP in Cabinet $7.53 $1.02 $1.68 $2.66 $12.89 

45% Add Another 2.9 sqft VIP in Cabinet $9.38 $1.27 $2.09 $3.31 $16.06 

5-A-40
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.12: Incremental Cost Detail for 4.0 ft3 Compact Refrigerator (Product Class 11) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

Add 0.75" Insulation to Door $0.15 $0.00 $0.00 $0.45 $0.16 $0.75 

10% Increase compressor EER from 

4.57 to 4.85 $2.80 $0.00 $0.00 $0.00 $0.73 $3.53 

15% Increase compressor EER from 4.85 to 5.14 $2.90 $0.00 $0.00 $0.00 $0.75 $3.65 20% 

Increase compressor EER from 5.14 to 5.33 $1.90 $0.00 $0.00 $0.00 $0.49 $2.39 

Increase Condenser Size by 8% $0.22 $0.00 $0.00 $0.00 $0.06 $0.28 

25% 

Increase Condenser Size to 20% more than initial size $0.32 $0.00 $0.00 $0.00 $0.08 $0.40 

Add 0.10" Insulation to Cabinet $0.39 $0.00 $0.00 $8.53 $2.32 $11.23 

30% Add another 0.19" Insulation to Cabinet $0.72 $0.00 $0.00 $0.00 $0.19 $0.91 35% Add another 0.26" Insulation to Cabinet $0.99 $0.00 $0.00 $0.00 $0.26 $1.24 40% 

Add another 0.20" Insulation to Cabinet $0.74 $0.00 $0.00 $0.00 $0.19 $0.93 

Add 1.4 sqft VIP in Cabinet $4.71 $0.42 $1.01 $1.60 $7.73 

45% Add Another 3.8 sqft VIP in Cabinet $12.46 $1.10 $2.66 $4.22 $20.44 

5-A-41
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.13: Incremental Cost Detail for 3.4 ft3 Compact Chest Freezer (Product Class 18) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

10% Increase compressor EER from 3.74 to 4.17 $4.30 $0.00 $0.00 $0.00 $1.12 $5.42 

15% 

Increase compressor EER from 4.17 to 4.29 $1.23 $0.00 $0.00 $0.00 $0.32 $1.55 

Add 1" Insulation to Door $0.20 $0.00 $0.00 $0.91 $0.29 $1.41 

20% 

Remove 1/4" Insulation from Door -$0.05 $0.00 $0.00 $0.00 -$0.01 -$0.06 

Add 0.48" Insulation to Cabinet $1.88 $0.00 $0.00 $17.35 $5.00 $24.23 

25% 

Add another 0.27" Insulation to Cabinet $1.03 $0.00 $0.00 $0.00 $0.27 $1.30 

2.1 sqft VIP in Bottom Wall $6.85 $1.39 $1.62 $2.56 $12.42 

Add 1/4" Insulation to Door $0.05 $0.00 $0.00 $0.00 $0.01 $0.06 

30% 

Remove all design options through 25% Level -$15.50 -$1.39 -$19.88 -$9.56 -$46.33 

Variable Speed Compressor $50.00 $0.00 $0.00 $0.00 $13.00 

35% N/A $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 

40% N/A $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 

Add 0.75" Insulation to Door $0.15 $0.00 $0.00 $0.91 $0.28 $1.34 

45% Add 0.21" Insulation to 

Cabinet $0.83 $0.00 $0.00 $17.35 $4.73 $22.91 

5-A-42
 

EERE-2008-BT-STD-0012 COMMENT 20
Table 5-A.3.14: Incremental Cost Detail for 7.0 ft3 Compact Chest Freezer (Product Class 18) 

Efficiency 

Level 

Design Options Added Design Option Costs 

Material Labor Overhead Depreciation G&A, Profit Total 

10% Increase compressor EER from 4.50 to 5.03 $5.30 $0.00 $0.00 $0.00 $1.38 $6.68 15% 

Increase compressor EER from 5.03 to 5.27 $2.40 $0.00 $0.00 $0.00 $0.62 $3.02 

Add 0.15" Insulation to Door $0.06 $0.00 $0.00 $0.91 $0.25 $1.23 

20% Add 0.60" Insulation to Door $0.25 $0.00 $0.00 $0.00 $0.07 $0.32 

Add 0.24" Insulation to Cabinet $1.92 $0.00 $0.00 $17.35 $5.01 $24.28 

25% Add another 0.34" Insulation to Cabinet $2.68 $0.00 $0.00 $0.00 $0.70 $3.38 30% 

Add another 0.17" Insulation to Cabinet $1.36 $0.00 $0.00 $0.00 $0.35 $1.71 

Add 3.1 sqft VIP in Bottom Wall $10.09 $1.04 $2.18 $3.46 $16.77 

35% 

Remove all design options through 30% Level -$24.06 -$1.04 -$20.44 -$11.84 -$57.38 

Variable Speed Compressor $50.00 $0.00 $0.00 $0.00 $13.00 $63.00 

40% Add 0.26" Insulation to Cabinet $2.05 $0.00 $0.00 $17.35 $5.04 $24.43 

45% Add another 0.47" Insulation to Cabinet $3.74 $0.00 $0.00 $0.00 $0.97 $4.71 

5-A-43
 

EERE-2008-BT-STD-0012 COMMENT 20
5-A.4 ENGINEERING QUESTIONNAIRE 

The engineering questionnaire used as a guide for engineering discussions during 

manufacturer interviews is shown in this section. Some of the information provided in the 

questionnaire has been redacted to protect vendor information. 

5-A-44
 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

 

 

 

 

 

 

 

 

 

 

 

 

DESIGN FOR ENERGY IMPROVEMENT INFORMATION REQUEST 

DOE would like to confirm information on the incremental costs of increasing product efficiency 

by understanding the design options involved in the efficiency improvement. 

1. Market Share of products you sell 

To help DOE discover manufacturer sub-groups and the relative importance of various product 

classes to specific manufacturers, please disaggregate your annual unit shipments for each 

product category as shown below. Please also indicate whether you purchase these products 

from other manufacturers (i.e. private label), and whether the factory that supplies the product 

is located in the USA. 

Product Class (response for PC1 through PC20 not 

including built-in products) 

% Private 

Label? 

% Made 

in USA? 

Yearly Unit 

Shipments 

1. Refrigerators and refrigerator-freezers with 

manual defrost. 

2. Refrigerator-freezer—partial automatic defrost. 

3a. Refrigerator-freezer—automatic defrost with topmounted freezer without through-the-door ice 

service 

3b. All-refrigerator—automatic defrost. 

4. Refrigerator-freezers—automatic defrost with 

side-mounted freezer without through-the-door 

ice service. 

5. Refrigerator-freezers—automatic defrost with 

bottom-mounted freezer without through-the-door 

ice service. 

6. Refrigerator-freezers—automatic defrost with 

top-mounted freezer with through-the-door ice 

service. 

7. Refrigerator-freezers—automatic defrost with 

side-mounted freezer with through-the-door ice 

service. 

8. Upright freezers with manual defrost. 

9. Upright freezers with automatic defrost. 

10. Chest freezers and all other freezers except 

compact freezers. 

11. Compact refrigerators and refrigerator-freezers 

with manual defrost. 

12. Compact refrigerator-freezer—partial automatic 

defrost. 

13a. Compact refrigerator-freezers—automatic 

defrost with top-mounted freezer compact all5-A-45
 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

 

 

 

 

 

 

 

 

refrigerator—automatic defrost. 

13b. Compact all-refrigerator—automatic defrost. 

14. Compact refrigerator-freezers—automatic defrost 

with side-mounted freezer. 

15. Compact refrigerator-freezers—automatic defrost 

with bottom-mounted freezer. 

16. Compact upright freezers with manual defrost. 

17. Compact upright freezers with automatic defrost. 

18. Compact chest freezers. 

19. Refrigerator-freezer—automatic defrost with 

bottom-mounted freezer with through-the-door 

ice service. 

20. Chest freezers with automatic defrost. 

21. Wine Coolers 

22. Built-in Refrigerators, Refrigerator-Freezers, and 

Freezers 

(please provide percentage breakdown by Product 

Class for units presenting at least 5% of unit 

sales) 

a.	 What percentage of products classified as product class 4 or 7 (side-by-sides) have convertible 

bottom drawers? 

b.	 What percentage of product class 5 and what percentage of product class 19 products are 

French-door?
 

2. Product Technical Descriptions 

The following series of exhibits and questions address technical characteristics of key 

refrigerator and freezer components for both baseline and improved-efficiency products. 

Compressors 

Please comment on the typical capacities of compressors used in the indicated products. 

5-A-46
 

EERE-2008-BT-STD-0012 COMMENT 20
 

•	 Should there be differences in capacity levels for auto-defrost and manual defrost freezers? 

•	 What capacity/volume relationship is representative for standard-sized manual-defrost 

refrigerators? 

Please comment on the indicated typical EER of compressors used in standard and Energy Star 

products. 

•	 Should there be differences between compressor EER used in auto-defrost and manual defrost 

freezers? 

Typical EER trend for compressors used in compact refrigerators and freezers: 

5-A-47
 

EERE-2008-BT-STD-0012 COMMENT 20
•	 Is variation in compressor EER in compact products dependent primarily on capacity, as 

illustrated in the line in the plot below? 

•	 Note that while a range of EER is offered by compressor vendors, it is not clear that the range of 

EER’s actually being used in products is as broad--Is this driven by cost pressures for compact 

products? 

5-A-48
 

EERE-2008-BT-STD-0012 COMMENT 20
Is the Illustrated Typical Cost vs. Capacity for Baseline Product compressors accurate? 

Is the Illustrated Curve for incremental cost for higher EER compressors for standard-sized 

refrigerator-freezers accurate? 

5-A-49
 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

•	 What percentage of your baseline unit shipments use variable-speed compressors, and what 

percentage of Energy Star-rated products do? 

•	 If you use variable-speed compressors in your products, do you run them at two or three 

speeds, or do you modulate the speed based on demand? 

•	 Is $30 an appropriate cost increase for a variable-speed compressor as compared to a baseline 

efficiency single-speed compressor purchased from the vendor for standard-sized 

refrigerator-freezers? What other costs need to be considered? 

Evaporator Heat Exchanger Characteristics 

In the following table, please comment on the typical key details of evaporator heat exchangers. 

Product Type Type Core 

Volume 

(cuft) 

Tube 

Outer Dia 

(inch) 

Tube 

Length 

(ft) 

Fin Surface 

or cold 

plate 

surface 

(sqft) 

Standard-Sized 

RefrigeratorFreezers 

Forced 

Convection 

0.21 0.33 

(0.008 wall) 

37 18 

Standard-Sized 

Upright Freezers 

Forced 

Convection 

0.18 0.33 

(0.008 wall) 

32 18 

Product Type Type Tube 

Outer Dia 

(inch) 

Specific 

Tube 

Length 

(inch per 

Btu/hr 

compressor 

capacity) 

Fin Surface 

(sqin per 

Btu/hr 

compressor 

capacity) 

Standard-Sized 

Chest Freezers 

Cold Wall 0.3 1.7 

Compact Basic 

Refrigerators 

Roll Bond Channels 

0.18 high 

x 0.38 

wide 

0.55 0.6 

Compact Chest 

Freezers 

Cold Wall 0.3 2.0 

•	 All forced-convention evaporators use aluminum tubes? 

•	 Typical forced-convection evaporator fin style is flat aluminum with oval gaps to slide over 

tube serpentine? 

•	 Any use of internally-enhanced tubes? 

•	 Any use of enhanced fins? 

•	 What percentage of refrigerator/freezers use more than one evaporator? 

•	 What percentage of refrigerator/freezers use other than forced-convection evaporators? 

•	 Do you employ wide fin spacing and lack of fin surface enhancements for frost tolerance and 

quick melt runoff? 

5-A-50
 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

 

•	 Is there a typical evaporator air flow rate vs. compressor capacity relationship? If so, can you 

detail it? 

•	 Are you aware of any further significant system improvements that may be possible through 

evaporator heat exchanger changes? (for example, via eggcrate evaporators, spine-fin?) 

•	 If you use spine-fin heat exchangers, is their performance for volume/fan power better than 

for flat-fin heat exchangers? Or was your decision driven by cost? What about frost 

tolerance and internal enhancements? 

Condenser Heat Exchanger Characteristics 

In the following table, please comment on the typical key details of evaporator heat exchangers. 

Product Type Type Tube 

Outer 

Dia 

(inch) 

Tube 

Length 

(ft) 

Wire Fin 

Diameter 

(inch) 

Wire Fin 

Total Length 

(ft) 

Standard-Sized 

RefrigeratorFreezers 

Forced 

Convection 

Steel Tube 

Wire Fin 

0.19 

(0.025 

wall) 

50 0.05 300 

Product Type Type Tube 

Outer 

Dia 

(inch) 

Tube 

Wall 

(inch) 

Specific 

Tube Length 

(inch per 

Btu/hr 

compressor 

capacity) 

Specific Wire 

Fin Length 

(foot per 

Btu/hr 

compressor 

capacity) 

Standard-Sized 

Upright Freezers 

Hot Wall 0.19 0.03 1.0 N/A 

Standard-Sized 

Chest Freezers 

Hot Wall 0.19 0.03 1.3 N/A 

Compact Basic 

Refrigerators 

Static or 

Hot Wall 

0.19 0.025 Hot Wall 1.5 

Static 0.4 

0.4 

Compact Chest 

Freezers 

Hot Wall 

or Static 

0.19 0.025 Hot Wall 1.7 

Static 0.9 

0.7 

•	 Any use of internally-enhanced tubes? 

•	 Most external condenser heat exchangers designs appear to be based on steel wire fins. What 

are the key drivers leading to this design choice? 

o	 Is in-field dust-covered performance a consideration? 

o	 Are enhanced-surface designs too expensive? 

o	 Or perhaps not worthwhile because there is enough space for lower-cost wire fin 

design? 

o	 Performance degradation when dirty? 

o	 Or can’t do better than wire fin for a given volume and the typically low fan power? 

•	 Is there a relationship between typical condenser air flow rate vs. the compressor capacity? If 

so, can you detail it? 

5-A-51
 

EERE-2008-BT-STD-0012 COMMENT 20
•	 During teardowns we noted that some manufacturers use “rolled up” heat exchangers vs. the 

typical flat external condenser heat exchangers. What are the benefits and drawbacks of such 

heat exchangers? 

Evaporator and Condenser Fans 

• Are the indicated characteristics for fan motors typical for refrigerator-freezers? 

•	 Is there any room for further, significant energy efficiency improvement via fan blade/air 

flow path design improvements (i.e. PAX fan)? 

•	 Do you consider PSC fan motors a viable intermediary step between SP and BLDC fan 

motors? 

•	 Do any of your fans run at multiple speeds, for example to match the output of a variablespeed compressor? 

•	 What are the benefits or drawbacks associated with using BLDC motors that are based on 

DC-power input vs. AC-power input? What is the cost difference between such motors? 

Cabinet Insulation Characteristics (as applicable) 

In the following table, please comment on the typical average insulation thicknesses. 

Product Type Insulation Thickess (inches) 

Standard-Sized Refrigerator-Freezers with 

Automatic Defrost—Fresh Food 

Compartment 

1.9 

Standard-Sized Refrigerator-Freezers with 

Automatic Defrost—Freezer Compartment 

2.7 

Standard-Sized Upright Freezers 2.3 

Standard-Sized Chest Freezers 2.5 

Compact Basic Refrigerators 1.2 

Compact Chest Freezers 2.5 

What typical insulation thickness would be used for the following product types? 

•	 Standard-sized refrigerator with manual or partial automatic defrost? 

•	 Compact refrigerator-freezers? 

5-A-52 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

 

•	 Standard-sized all-refrigerators? 

•	 Compact all-refrigerators? 

•	 Differences in typical average insulation thicknesses for built-in products? 

•	 Is the state-of-the-art current insulation system based on HFC-245fa blowing agent with 

cabinet preheating and high pressure injection? Is the conductivity typically achieved for this 

system 0.13 Btu-in/hr-ft2

-oF at room temperature? Do you use any other insulation systems? 

•	 Is there any significant further cabinet load reduction possible through lower conductivity 

foam? 

•	 Have you considered switching to low Global-Warming-Potential (GWP) blowing agents? If 

so, what are the drivers for these changes? What are the conductivity, cost impacts? 

•	 Are you using any vacuum-insulated panels (VIPs) in any products? 

•	 If you have or were considering the adoption of VIPs can you detail how you would 

incorporate them into your products, what the capital costs, and what the marginal product 

costs of such a step would be? 

•	 Have you considered gas-filled panels? If so, what drove you to adopt, or not to adopt them? 

Door Frame: 

•	 What are the key aspects of good state-of-the-art door frame/gasket area design? To what 

extent does a typical product adhere to this? What is the range of load impact of poor door 

frame region designs (i.e. in Btu/hr-ft)? 

•	 Is there any value to using double-gaskets? 

•	 Some refrigerators have extra-strong magnets requiring special handle designs to assist with 

door-opening. How much load reduction is possible with such an approach? 

Through-the-Door Dispensers: 

•	 Today’s TTD systems don’t appear to represent thermal loads as high as suggested by the 

energy allowance associated with this feature, based for example on max energy difference 

between product classes 7 and 4. Is there more to the energy impact than the thermal load 

difference? How much anti-sweat heating wattage is typically used around your TTDs? 

Anti-sweat Heaters: 

•	 Most anti-sweat heaters appear to use hot liquid. Is this correct? Is there any continued use 

of hot gas anti-sweat systems? 

•	 Is there data available indicating average duty cycle of such heaters for typical in-home 

installation? Does this depend on use of anti-sweat heater for freezer door frame, mullion 

door frame, ducts, etc.? 

•	 For example, do your products use resistance heaters within the fresh food return air duct to 

prevent frost accumulation? If so, is it always on or controlled based on humidity? 

Defrost: 

•	 What are your thoughts about benefits and drawbacks of precool prior to the defrost cycle? 

5-A-53
 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

•	 The DOE energy test energy impact of defrost is small, particularly with variable defrost. Is 

this a good reflection of in-field defrost impacts? 

•	 Are dedicated controllers available to allow variable defrost to be used in products which 

otherwise use non-electronic controls? 

Expansion Devices: 

•	 Is there any performance improvement potential with expansion devices other than capillary 

tube? What about for variable-speed compressor systems? 

•	 Do you use any expansion device besides capillary tubes? 

Energy Efficiency Conversion Costs 

•	 What design changes are typically associated with converting baseline products mentioned 

above in Question 1 to Energy Star? 

•	 What are the marginal costs of the individual design options selected? 

•	 When considering energy efficiency improvements to achieve or exceed Energy Star, do 

different product classes take different pathways or are pathways similar? 

•	 Are the cost increments higher for some classes than others for a given performance 

improvement over baseline? (think 10%, 15%, 20%, 25%, 30%, 35%, 35+ improvement over 

today’s baseline) 

Thoughts/feedback on alternative refrigeration cycles/implementations: 

•	 Dual-evaporator systems attempting to cool fresh food compartment at higher evaporator 

temperatures. 

•	 Ejector system. 

•	 Stirling. 

•	 Thermoacoustic. 

•	 Thermoelectric. 

5-A-54
 

EERE-2008-BT-STD-0012 COMMENT 20
APPENDIX 5-B. ERA MODEL DEVELOPMENT AND WINERA USERS 

MANUAL 

TABLE OF CONTENTS 

5-B.1 INTRODUCTION ................................................................................................. 5-B-1 

5-B.2 HISTORY OF ERA MODEL................................................................................ 5-B-1 

5-B.2.1 DOE Refrigeration Appliance Efficiency Standards ............................................. 5-B-1 

5-B.2.2 Thailand Refrigeration Appliance Efficiency Standards ....................................... 5-B-2 

5-B.2.3 ERA Training Workshop in China ........................................................................ 5-B-2 

5-B.3 CHARACTERISTICS OF THE DOS VERSION OF ERA.................................. 5-B-3 

5-B.3.1 Modifications to ERA Since its Public Release..................................................... 5-B-3 

5-B.4 OBJECTIVES OF THE CURRENT PROJECT.................................................... 5-B-5 

5-B.4.1 Evaporator Analysis Program – ERAEVAP.......................................................... 5-B-6 

5-B.4.2 Condenser Analysis Program – ERACOND ......................................................... 5-B-9 

5-B.4.3 Windows Version of ERA ................................................................................... 5-B-12 

5-B-i 

EERE-2008-BT-STD-0012 COMMENT 20
APPENDIX 5-B. ERA MODEL DEVELOPMENT AND WINERA USERS MANUAL 

5-B.1 INTRODUCTION 

The Energy-efficient Refrigerator Analysis Program (ERA), formerly called the EPA 

Refrigerator Analysis Program, serves as an important tool in the engineering analysis, described 

in Chapter 5 of the TSD. This appendix provides background description of the evolution of the 

program since its creation in the late 1980s, provides details regarding changes made to the 

program as part of this rulemaking, and provides program operation guidance for the user. ERA 

has undergone extensive analytical upgrades and has also been converted to a Window-based 

program. The program has its own internal help utility to provide additional assistance to the user 

beyond the information provided in this appendix. 

5-B.2 HISTORY OF ERA MODEL 

ERA has seen several major improvements since its creation. This section describes the 

characteristics of the initial version of ERA and the subsequent modifications to the model prior 

to the current DOE rulemaking, including involvement in the Thailand refrigeration appliance 

efficiency standards analysis and in refrigerator energy use analysis training workshops in China 

in the 1990s. 

5-B.2.1 DOE Refrigeration Appliance Efficiency Standards 

Preparation of the current DOS version of ERA (EPA Refrigerator Analysis Program) 

was initiated under EPA-sponsorship during the late 1980s. This was undertaken by the EPA as 

part its involvement in the establishment of energy standards for refrigerators, refrigeratorfreezers, and freezers under the National Appliance Energy Conservation Act of 1987 (NAECA). 

A developmental version of the program was used by the DOE (Lawrence Berkeley Laboratory) 

as a partial basis for the energy standard established in 1989 (effective in 1993). The LBL work 

also involved an extensive testing of the model against manufacturer-supplied refrigeration 

appliance design and test data. Based on these comparisons and manufacturer review comments 

through its industry organization (AHAM), development of the model continued until its release 

in 1997 [1]. 

ERA combined an analysis of the refrigeration load requirements of the cabinet with a 

simulation of the capacity and efficiency of the refrigeration cycle. The cabinet loads module 

was a modest enhancement of a program developed for the DOE during the late 1970s [2], 

including the consideration of door-opening effects on the load and an ability to deal with 

complex insulation systems. The cycle module was a derivative of the NIST CYCLE 7 program 

[3] which used the CSD equation of state to represent the thermodynamic properties of pure and 

mixed refrigerants [4], adapting routines for calculating refrigerant properties from REFPROP3 

[5]. Using this new program, EPA carried out an extensive investigation of the potential for 

energy efficiency improvements [6]. 

5-B-1
 

EERE-2008-BT-STD-0012 COMMENT 20
 

The program, and its User’s Manual, were first released to the public in 1993, and for a few 

years were downloadable from the EPA website [7]. 

Subsequent to the 1993 final rule, DOE published updated standards for refrigerators, 

refrigerator-freezers and freezers in 1997, becoming effective in 2001. This involved use of the 

final released EPA version of ERA [1]. 

5-B.2.2 Thailand Refrigeration Appliance Efficiency Standards 

Under three separate contracts from the Thai National Energy Policy Office, a modified 

version of the program was used by the program authora

 to establish minimum efficiency 

performance standards (MEPS) for residential refrigerators and refrigerator-freezers used in 

Thailand [8, 9, 10]. The first study established goals for two categories of appliances: a one-door 

manual defrost refrigerator, and a two-door automatic-defrost refrigerator-freezer. Three levels 

of MEPS were proposed, a “long-term goal” (assumed to be achievable within 10 years, and 

tier1 and tier 2 standards which allowed 30% and 15% energy use over the long-term goal. 

As in the earlier DOE work, the local manufacturing industry was involved in the review 

and assessment of the proposed standard. 

In response to highly negative comments on the achievability of any of the proposed 

efficiency levels, a second contract was awarded to prepare and test refrigerators that would meet 

or exceed the long-term energy target. Working with Sano Electric Company of Thailand, four 

prototype units were designed and tested: 31-liter and 41.5-liter one-door refrigerators, and 78.5-

liter and 126.5-liter two-door refrigerator-freezers. Using available technology, the achieved 

energy reductions were over 20% for the one-door units, and over 34% for the two-door units, 

meeting the long-term target levels. Within several years, the proposed standards became law. 

5-B.2.3 ERA Training Workshop in China 

In response to a request from China’s State Bureau of Technical Supervision (SBTS), 

LBNL hosted a training seminar on the use of ERA for three research engineers. The results of 

this training provided an increased understanding of approaches to achieve improved standards, 

leading to a more substantial series of cost-effective cooperative efforts towards creating China’s 

standards program [11]. 

As part of a subsequent large program sponsored by the UN Global Environmental Fund (GEF), 

ThermoSoft carried out a one-week training workshop in Beijing [12]. The participants included 

40 engineers from 20 manufacturers located throughout China. Although focused on the use of 

ERA as a design tool, the workshop covered the then-current component technologies available 

a

 A consultant, established under the name ThermoSoft. This work was subcontracted through ERM-Siam. 

5-B-2
 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

 

 

worldwide, providing an opportunity for a lively exchange of ideas. Each of the participants 

utilized ERA to perform analyses of their proprietary appliance models. 

5-B.3 CHARACTERISTICS OF THE DOS VERSION OF ERA 

ERA was developed employing then-current computer technology of the 1980s. The 

cabinet loads module was a minor upgrade of an earlier program used for efficiency standards, 

and an existing simplified heat pump cycle model was adapted to represent the refrigerator cycle. 

Written in FORTRAN, with a very extensive set of assembly language routines to provide a 

smooth user-interface, the program was hosted in DOS. 

Because of the complexities of the program, and the limitations of DOS, it was broken 

into three modules, linked by data files and a batch file that managed the information and 

program execution flow. Both the MENU module (which provided the user-input interface) and 

the cycle execution module used nearly all of the available 600+ Kbytes of DOS accessible 

memory.b

 This memory limitation, inherent in DOS (which can address only 655,360 bytes of 

conventional memory, 10 x 216), imposed a fundamental limitation on the design of the program 

and the details that could be considered in any analysis. 

ERA was constructed to take maximum advantage of the available capabilities provided 

by DOS, leading to somewhat complicated coding and sharing of memory spaces for certain 

functions. Because of the limitations imposed by DOS, ERA was designed to fit within the 

capabilities of a specific compiler, Microsoft FORTRAN 5.0, which was discontinued in the 

early 1990s. As a result, ERA is not compliable with any other version FORTRAN compiler. 

Further, the program requires access to the specially-developed assembly language user-interface 

module. As a consequence, although the source code has been made available upon request, no 

entity other than ThermoSoft has been able to compile it. 

Because of these restrictions, the thermophysical property routines within the DOS 

version cannot be upgraded beyond Refprop 4.0, nor can additional fluids be considered.c 

Hence, no changes to the refrigerant properties capabilities of ERA have been made since the 

mid-1990s. 

5-B.3.1 Modifications to ERA Since its Public Release 

Given the DOS-imposed restrictions, options for upgrades to the model have been limited 

within this environment. However, during on the work in Thailand, several minor enhancements 

were made: 

b

 Of course, the program executable object had to load within this space, limiting the available memory space for 

data objects. 

c

 Later versions of Refprop use a different structure. 

5-B-3
 

EERE-2008-BT-STD-0012 COMMENT 20
 

•	 Calculation of the hot-wall effective heat transfer area. This involved specification of the 

tubing routing and additional details about the wall area. The outer shell, to which the 

tubing is pressed by the expanded foam, was treated as a thermal fin to estimate the 

effective heat transfer area. This capability was used during the development of the 

prototype models in Thailand while investigating the effects of improved hot wall design 

of the energy use. 

•	 Addition of a similar analysis sub-model to calculate the effective heat transfer area for a 

cold-wall evaporator. 

•	 Added multiple-speed capability to the compressor model. The efficiency-based model, 

which was valid only for R-12, was removed to provide this capability. 

•	 Improved evaporator analysis in the single-door refrigerator to more correctly incorporate 

the radiative heat transfer effects. This led to an improvement between the model 

predictions and test results for the compact-refrigerator category. 

Although no changes to the model were made in the model’s use of compressor maps, 

experience working with Thai manufacturers highlighted the importance of high-quality 

calorimeter data.d

 As a result, each of the manufacturer-supplied maps was analyzed for 

consistency by examining the corresponding volumetric and isentropic efficiencies. An ability to 

qualify a compressor map on the basis of the underlying volumetric and isentropic efficiencies is 

built into the current revision of the model (see below). 

d

 Similar experience with poorly constructed manufacturer-supplied compressor maps was encountered during the 

EPA Multiple Pathways project [6]. 

5-B-4
 

EERE-2008-BT-STD-0012 COMMENT 20
5-B.4 OBJECTIVES OF THE CURRENT PROJECT 

A thorough revision of the ERA program, now entitled the “Energy-Efficient 

Refrigerator Analysis” program, is being undertaken for the current rulemaking to meet the 

following objectives: 

•	 Enhancement of the user-interface to a Windows environment 

•	 Employment of the most current refrigerant property routines 

•	 Incorporation of a broad range of evaporator and condenser algorithms that correspond to 

the technologies now found in modern refrigerators 

•	 Improved compressor modeling, with built-in procedures for validating supplied 

compressor maps 

•	 Improvements where desirable in the cabinet loads analysis and cycle performance 

algorithms. 

•	 Preparation of internal documentation of the program through extensive context-sensitive 

Help files. 

In addition to these objectives, support has been provided in the use of the DOS-version 

of ERA for the current standards development work. To assist this effort, a small suite of standalone programs has been prepared to calculate the required input values to ERA. This suite 

consists of: 

ERAEVAP – for the calculation of the net heat transfer capabilities of a variety of 

evaporator designs; 

ERACOND – for the calculation of the net heat transfer capabilities of a variety of 

condenser designs; and 

COMPMAP – a program to validate compressor maps by the calculation and display of 

isentropic and volumetric efficiencies, and the construction of new maps based on 

methods for smoothing the efficiencies as a function of compression ratio. 

Each of these models contains algorithms that will be incorporated into the final 

Windows version of ERA, including the refrigerant algorithms. They are stand-alone programs, 

designed only for interim use. However, since they provide a technical basis for the new version 

of ERA and have been used in the ongoing engineering analyses, they are described next. 

5-B-5
 

EERE-2008-BT-STD-0012 COMMENT 20
 

5-B.4.1 Evaporator Analysis Program – ERAEVAP 

User Interface 

ERAEVAP is a data-wizard based 

Windows program that guides the user 

through several steps in the specification 

of the evaporator design parameters. 

Step1 requires selection of the heat 

exchanger type (roll-bond freezer 

compartment, tube and fin fan-forced 

evaporator, or a chest freezer cold-wall). 

Three options are represented for a tube 

and fin configuration: plain fin, smooth 

wavy fin, and herringbone fin. 

Refrigerant choices are: R134a, R152a, R290 (propane), R404A, R507A, R600a (isobutane), and 

R744 (carbon dioxide). Refrigerant properties are calculated using the NIST Refprop 8.0 

routines, supplied as a linkable dll. 

Other typical value operating parameters are user-specified: refrigerant mass-flow, refrigerant 

saturation temperature, refrigerant inlet quality, return or cabinet air temperature, and the airflow 

rate and corresponding fan efficiency (fan-forced analyses only).e 

Step 2 depends on the heat exchanger 

configuration selected above. The 

illustration shows the input dialog for a 

tube and wavy fin design. In this 

instance, the tube dimensions, vertical 

pitch (normal to the air flow) and 

horizontal pitch (along the direction of 

the air flow) are specified. 

Each data dialog contains a simple 

illustration of the component under 

consideration. 

e

 These data must be user-defined since the program is not integrated into an overall cycle analysis. 

5-B-6
 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

 

Step 3, in this example, presents a dialog 

that requests information on the design of 

the fin. For the example of a wavy fin, 

the requested data are: fin thickness and 

pitch, fin thermal conductivity, fraction 

of the tube row that is finned, and fin 

pattern depth. 

The number of steps required to define 

the evaporator depends on the design. 

For example, roll-bond and chest freezer 

evaporators only require two steps. 

Results displayed depend on the type of 

evaporator modeled. In the case of a tube 

and fin design, the output includes the fin 

heat transfer area and effectiveness, the 

total effective heat transfer area, air-side 

pressure drop and fan energy, and the 

refrigerant-side pressure drop. In 

addition, the display lists the overall Uvalues that are to be used as input to 

ERA. These are shown specific to the 

input requirements of the DOS version of 

ERA.f 

Roll-bond Evaporator 

ERAEVAP uses the Dittus-Bolter equation [13] to determine the heat transfer coefficients for the 

air and the vapor phase of the refrigerant. A radiative component is added on the air-side. 

Liquid phase heat transfer is calculated using the Bo Pierre correlation [14]. The overall heat 

transfer rate is dominated by the air-side resistance. Heat transfer resistance across the roll-bond 

surface is assumed to be negligible. 

The pressure drop in the evaporating heat transfer regime is calculated by marching stepwise 

downstream, calculating the local pressure gradient, and summing the local pressure drops to 

determine the total pressure drop. The local pressure drop is calculated using the LockhartMartinelli correlation [15]. 

f

 As noted earlier, the stand-alone programs are intended only as an assist towards preparing input values needed by 

DOS ERA. Hence, they are considered an interim step in the development of the final Windows version of the 

updated ERA program. 

5-B-7
 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

Chest Freezer Cold Wall 

Both air-side and refrigerant-side heat transfer rates are determined in the same manner as with a 

roll-bond. Calculation of the refrigerant pressure drop also uses the Lockhart-Martinelli 

correlation. 

The refrigerant tubes are pressed on the inside surface of the chest freezer liner, which because 

of its small thickness acts like a thermal fin. With adjustment made for the end tubes, each 

parallel tube is represented as having a fin of width: 

Wf = Width of plate normal to the tube / (2 * number of tubes), 

The effectiveness for this equivalent fin is: 

η = (k δ / h) 0.5 tanh [Wf * ( h / k δ) 0.5] / Wf 

For typical designs the effectiveness should be close to unity. 

Tube and Fin Evaporator 

Three fin options are modeled for the tube and fin design: plain fin, wavy fin, and herringbone 

fin. Refrigerant-side heat transfer and pressure drop are calculated in the same manner as 

described above. The air-side heat transfer rate depends on the type of fin and its design. 

Equations for representing plain fin and herringbone fin designs were based on studies by Wang 

[16]. The wavy fin configuration was represented by correlations published by Mirth and 

Ramadhyani [17].g Because the correlations are quite complex, they are not reproduced here. 

However, both references are readily available. 

The modeling and calculation approaches used in ERAEVAP will be employed in the final 

Windows version of ERA where analyses of the heat transfer and pressure drop characteristics of 

the evaporator will be built into the program. ERAEVAP will not be part of the Windows ERA 

package. 

g

 Reference [16] is a summary of many studies performed and published by Wang and his colleagues for a wide 

variety of fin configurations, including louver fins, and slit-fins. It includes a summary of the work done on wavy 

fins by Mirth and Ramadhyani, but incorrectly reproduces their correlation. 

5-B-8
 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

 

5-B.4.2 Condenser Analysis Program – ERACOND 

Condenser Design Options 

Four generic classes of condensers are 

modeled: 1) static condenser, 2) various 

tube and fin designs, 3) microchannel 

design, and 4) a hot wall condenser. For 

each of these, the user defines the 

refrigerant mass flow rate, the saturation 

temperature, and the temperature of the 

environment (room or under-cabinet). 

The air flow rate and fan efficiency are 

also specified for the fan-forced designs. 

Static Condenser 

The static condenser model uses 

correlations developed by Bansal and 

Chin [18], who relied heavily on the 

work by Tagliafico and Tamda [19]. 

Design data include tube spacing and 

length, wire diameter, conductivity, and 

length, and the number of wires on both 

sides of the tubing. Heat transfer from 

the connecting bare tube is included in 

the analysis. 

Refrigerant-side heat transfer is calculated according to the Shah correlation [20, 21]. Pressure 

drop is calculated according to the Lockhart-Martinelli correlation, assuming for the purposes of 

analysis that 15% of the tube is in the superheated vapor phase regime, 80% in two-phase 

condensation, and 5% in the subcooled regime.h 

All of the condenser models to be described use the same approach to determining refrigerantside heat transfer and pressure drop. 

Wire Fin Condensers 

h

 This assumption will be replaced by the cycle model for the condenser in the Windows version of ERA, which will 

model the entire cycle system. 

5-B-9
 

EERE-2008-BT-STD-0012 COMMENT 20
Wire fin condensers are found in many 

domestic refrigerators. ERACOND 

provides three options for air flow across 

the unit, listed in the data dialog as along 

the W-, L- or H-directions. Since the heat 

exchanger is normally located under the 

cabinet in the compressor space, not all 

of the air flow will cross the unit. Hence, 

a required input is the fraction of the total 

air flow through the condenser. 

Calculation of the air-side heat transfer rate employs the Lee, et al correlation [22], which 

accounts for the orientation of the heat exchanger relative to the air flow. 

Tube and Extended Fins 

Calculation of the fin heat transfer uses 

the Wang correlations [16] for the plain 

fin, the herringbone fin, and the slit fin 

configurations. Representation of a wavy 

fin heat transfer uses the Mirth and 

Ramadhyani correlation [17]. 

Both sets of correlations also estimate the 

air flow pressure drop thought the fins. 

Although calculated and displayed in the 

output, they do not consider other air 

flow restrictions, and therefore represent 

low values for the fan energy. 

5-B-10
 

EERE-2008-BT-STD-0012 COMMENT 20
Hotwall Condenser 

A hotwall condenser can be modeled as a 

single wall, as in a chest freezer, or by 

multiple walls, as in an upright freezer or 

refrigerator. The heat transfer 

effectiveness of each wall is determined. 

As with the evaporator cold wall, the 

major heat flow resistance is on the airside. An overall pressure drop is 

calculated for the connected tubing using 

the Lockhart-Martinelli algorithm, with 

the Shah correlation used for the 

refrigerant condensing regime. 

Microchannel and Louver Design 

A microchannel condenser is assumed to 

use a louver-type fin. The refrigerantside design determines the refrigerant 

flow rates and corresponding heat 

transfer coefficients and pressure drop. 

Design parameters for the louver 

determine the air-side heat transfer and 

air flow pressure drop. They are 

calculated using correlations developed 

by Wang [16]. 

These same correlations, adopted by ERA, are used in the current (Mark VI) on-line version of 

the Oak Ridge heat pump model [23]. 

Compressor Model – COMPMAP 

COMPMAP is an auxiliary program to the Windows version of ERA. The program graphically 

displays the isentropic and volumetric efficiencies implied by a compressor map, as a function of 

pressure ratio, providing a visual indication of whether the map is well formed. If desired, the 

map can be rebuilt based on various options for smoothing these underlying efficiencies. 

5-B-11
 

EERE-2008-BT-STD-0012 COMMENT 20
COMPMAP may also be used to scale an 

existing map to a different COP and/or 

capacity. The program can import maps 

previously used with the DOS version of 

ERA or prepare new maps for use with 

the DOS version 

COMPMAP can be used in stand-alone 

mode or can be directly called by ERA. 

This provides a built-in tool to validate 

and prepare maps for use in a simulation. 

No assumption is made about the specific dependence of isentropic or volumetric efficiency on 

pressure ratio, other than that some correlation should exit. Using the efficiency values 

calculated for the particular map, the user is offered a choice of using the map as-is, or using a 

linear or quadratic smoothing of the efficiencies against the pressure ratio. This can be done for 

individual condenser temperatures if desired, preserving much of the original map while 

removing apparent randomness of performance as a function of the evaporator temperature. 

5-B.4.3 Windows Version of ERA 

User Interface 

ERA uses a highly-graphical interface, providing multiple options for selecting from the various 

cabinet and component choices. It is designed to guide the user carefully through the data input 

and editing process to ensure data consistency. Prior to an actual simulation of the refrigeration 

appliance performance, the user is presented a summary of the selected design variables. 

5-B-12
 

EERE-2008-BT-STD-0012 COMMENT 20
Cabinet Mode 

ERA operates in one of four view modes: 

1) cabinet design mode (shown in the 

image), 2) cycle design mode, 3) 

simulation mode, and 4) reports mode. 

Each is characterized by its own sidebar, 

containing hotspots for selecting 

component or report options. The color 

of the sidebar provides an additional 

visual clue to highlight the particular 

mode that is current. 

To define a new analysis, the user may either begin with a default set of design parameters and 

proceed through the editing process, or may read in an existing data file to be used as-is or 

edited. 

Each analysis must begin with a selection of the basic cabinet design parameters: cabinet 

category (shown on the desktop) and the overall dimensions of the unit. Once these basic choices 

have been made, the remaining categories of cabinet design data may be specified in any order. 

Data wizards, similar to those illustrated above for the stand-alone programs, guide the user at 

each stage. 

As each category of data is processed, a check mark is drawn on the sidebar to indicate the 

completeness of the editing progress. 

In some instances, special-function dialogs may be 

summoned to assist in the preparation of an input value. 

For example, the image to the right shows a dialog used to 

calculate the effective resistivity of a cabinet wall that 

contains a vacuum panel or some equivalent high thermal 

resistance element. 

5-B-13
 

EERE-2008-BT-STD-0012 COMMENT 20
Cycle Mode 

Once the basic cabinet type has been 

selected, the user may specify the cycle 

parameters. This would begin with a 

selection of the basic cycle type (single 

evaporator, dual loop, dual evaporator, or 

Lorenz cycle). Once this choice has been 

made, a simple schematic of the chosen 

cycle category is displayed on the 

desktop. The user may then continue to 

define the cycle parameters by clicking 

on the desktop to select the component of 

interest, or may use the sidebar or the 

the drop-down menu to select the next component to be defined. 

The displayed desktop image and its associated hotspots depend on the specific cycle category 

selected. 

Simulation Mode 

Prior to simulation of the cabinet loads 

and cycle behavior, the user is presented 

with a summary of the defined input. A 

data item can be selected for further 

editing by double-clicking on the 

summary line displaying the item in the 

data review dialog. 

Once the data has been reviewed and 

accepted, the user selects the Continue 

button to start the simulation. 

5-B-14
 

EERE-2008-BT-STD-0012 COMMENT 20
Reports Mode 

At the completion of the simulation (which 

is instantaneous for the cabinet loads), the 

program automatically switches to reports 

mode and displays the results on the 

desktop. The example here shows the 

calculated cabinet loads. Results for the 

cycle analysis, overall performance 

parameters, or a more detailed summary, 

can be selected using the side-bar or the 

drop-down menu for reports. 

Cabinet Loads 

As of this preliminary documentation, only the cabinet loads have been modeled. 

Each of the cabinet walls has at least one beveled edge where it joins another wall. Hence, some 

adjustment needs to be made for the difference between the inside and outside surfaces of the 

wall – that is, the conduction is not strictly one-dimensional. Detailed finite difference 

calculations carried out for a flat wall with adiabatic beveled edges (where the walls connect) 

show that a very good approximation can be obtained by representing the beveled wall as an 

equivalent wall of one dimensional heat transfer, where the equivalent wall area is: 

Areaequiv = 0.25 Areaoutside + 0.75 Areainside 

This is nearly identical to the method adopted in the DOS version of ERA, which also made 

adjustments for corner effects where three walls join. Hence, the previous methodology was 

retained, with minor corrections made as needed. 

The loads analysis does not yet consider cycle-dependent interactions such as hot- or cold-walls, 

fan energies, defrost, or other cycle-dependent heat terms. These will be incorporated during the 

cycle portion of the simulation. 

Refrigerant Properties 

The fluid choices for the refrigeration cycle are: R134a, R152a, R290, R404A, R507A, or 

R600a. Thermodynamic properties are based on Refprop 8.0 [24]. To speed the computations, 

an approach to using the Helmholtz equation of state outlined by one of the authors of Refprop 

[25] has been adopted as the primary simulation option for ERA. This reference contains 

required property data for R-404A and R-507A. Data for the other refrigerants represented by 

ERA have been obtained from the Refprop fluid database. 

5-B-15
 

EERE-2008-BT-STD-0012 COMMENT 20
 

 

A secondary option to use the full set of the more comprehensive, but considerably slower,i 

Refprop routines will be offered for those instances when the user might wish to confirm the 

simulated performance. 

Because Refprop does not supply a complete set of thermophysical properties for all of the 

refrigerants over the full set of temperatures and pressures, correlations for the thermal 

conductivity and viscosity were developed from refrigerant manufacturer literature. In general, 

uncertainties in these properties are less important than uncertainties in the thermodynamic 

properties since the net heat transfer resistance is normally dominated by the air-side. 

Cycle Analysis 

The cycle model, currently under development, will adopt the general approach employed in the 

DOS version of ERA. An iterative solution procedure will be required to simultaneously satisfy 

the heat transfer and mass flow equations throughout the loop. Where the cycle components 

affect the cabinet loads, adjustments to the loads will be calculated. 

Several major differences will appear between the Windows and DOS versions of ERA: 

•	 Only a map-based compressor model will be used. This decision is based on experience 

gained using ERA with actual equipment, where compressor information for the actual 

unit was needed to accurately reflect the energy consumption. The accompanying 

compressor module, COMPMAP, can be employed to create or modify map data. 

•	 The heat exchanger performance routines will be integrated into the overall cycle 

simulation. Hence, the effects of parameters such as refrigerant mass flow, and entering 

temperature and pressure on the heat exchanger performance will be automatically taken 

into account at each stage of the simulation. 

•	 An improved iteration approach will be used to ensure rapid and proper convergence. 

The solution method used in the ORNL Mark series heat pump looks promising [26]. 

Tools 

The new version of ERA provides several tools to assist in preparing the program inputs and in 

interpreting the results: 

Compressor Map program. COMPMAP may be run directly from ERA by selecting this option 

from the Tools menu. It provides a means of viewing and/or adjusting a map that is to be used in 

i

 Both Lemmon [25] and ThermoSoft experience obtained with a heat pump model confirm that the Helmholtz 

method can result in computation time reductions of a factor of 30 to 40 over the full set of Refprop routines. 

5-B-16
 

EERE-2008-BT-STD-0012 COMMENT 20
the cycle simulation. When selected, ERA is minimized until the compressor map program is 

dismissed, 

Refrigerant Properties. A calculation of the refrigerant properties for the selected refrigerant 

can be made given certain specified state points. The calculations are carried out using the 

Helmholtz method. 

Unit Conversion. This tool can be used to convert to different units values of length, flow rate, 

temperature, thermal conductivity, volume, energy, or power. 

5-B-17
 

EERE-2008-BT-STD-0012 COMMENT 20
REFERENCES 

1.	 “ERA 1.2E, EPA Refrigerator Analysis Program, User’s Manual, Report to the 

Environmental Protection Agency Atmospheric Pollution Prevention Division,” Arthur D. 

Little, Inc., February 1997 

2.	 "Engineering Computer Models for Refrigerators, Freezers, Furnaces, Water Heaters, Room 

and Central Air Conditioners," Report to U.S. DOE, by Arthur D. Little, Inc., November 

1982. 

3.	 McLinden, M., "Theoretical Vapor Compression Cycle, CYCLE7," unpublished. 

4.	 Morrison, G., and McLinden, M., "Application of a Hard Sphere Equation of State to 

Refrigerants and Refrigerant Mixtures," National Bureau of Standards Technical Note 1218, 

1986. 

5.	 "NIST Standard Reference Database 23: NIST Thermodynamic Properties of Refrigerants 

and Refrigerant Mixtures Database, Version 3.0," NIST, December 1991. 

6.	 “Multiple Pathways to Super Efficient Refrigerators," U.S. EPA, Global Change Division, 

Office of Atmospheric Programs, 1993. 

7.	 EPA Refrigerator Analysis (ERA) Program: User’s Manual, Version 1.0. United States 

Environmental Protection Agency. EPA-430-R-93-007. June 1993. with Version 1.2 Update, 

November 1994. 

8.	 Energy Efficiency Standards Regime Study: Refrigerator Manufacturer Workshop, ERMSiam Co Ltd, May 1999. 

9.	 Energy Efficient Refrigerator Prototype Development, ERM-Siam Co. Ltd, September 2001. 

10. Draft Standard: Household Refrigerators, ThermoSoft, June 2002. 

11. State Bur. Tech. Superv. China. 1999. Maximum Allowable Values of Energy Consumption 

and Evaluating Values of Energy Consumption for Household Refrigerators, GB12021.2-

1999. Beijing: China Stand. Publ. House 

12. “ERA Training Workshop Module, The Use of Computer Modeling and Design Tools for 

Energy-Efficient Refrigerators,” ThermoSoft, September 2000. 

13. Dittus, F. W., and Boelter, L. M. K., "Heat Transfer in Automobile Radiators of the Tubular 

type", Publications in Engineering, University of California, Berkeley, 2, pp. 443-461, 1930. 

5-B-18
 

EERE-2008-BT-STD-0012 COMMENT 20