Washington, DC 20585

Dear Assistant Secretary Kelly:

Pursuant to 10 CFR 430.27, Sub-Zero respectfully requests expedited attention to this revisedrequest for both an interim and final waiver to modify the DOE test procedure (Test Procedures

for Refrigerators, Refrigerator-Freezers, and Freezers (Final Rule and Interim Final Rule), 75

Fed. Reg. 78,810 (Dec. 16, 2010)) for Sub-Zero refrigerators using two compressors. Withoutthis waiver, we are unable to certify new dual compressor models as compliant with Energy Star

and/or DOE minimum efficiency standards.

Sub-Zero is a family-owned company that has been headquartered in Madison, Wisconsin for

over 60 years. Sub-Zero developed the niche market for customized built-in residential

refrigeration using dual compressors and manufactures all our products in the United States, with

factories in Wisconsin and Arizona. While technically not a “small business” using DOE’sdefinition, Sub-Zero is a small producer of refrigerators striving to compete in an age oflarge,

multi-national manufacturers and is one ofthe few remaining U.S. companies that produce all of

its refrigerator products here in the U.S.In previous comments to the Department, The Association of Home Appliance Manufacturers

and individual manufacturers including Sub-Zero urged DOE to consider the technical

difficulties imposed by the DOE dual compressor test method. DOE’s approach in the final test

procedure is difficult, if not impossible, to apply. In fact, it will require waivers, such as this one,

because many products simply do not work the way DOE’s equation assumes. DOE’s approach

assumes independent, sealed systems. Sub-Zero dual compressor refrigerators do not have

independent, sealed systems—they have shared systems. Thus, DOE’s approach for these

products, at best, requires several added measurements to comply (adding burden), and may evenprovide insurmountable obstacles, leading to test results so misrepresentative as to provide

inaccurate energy consumption data.

CSA International, which is conducting testing for the AHAM Refrigerator-Freezer Verification

Program, has informed us that they also believe that the DOE test procedure is unworkable for

our dual compressor refrigerators. The modified test procedure that we propose for DOE’sconsideration in this waiver request is the product of analysis by CSA International, Sub-Zeroand General Electric Appliances resulting in a practical, accurate and repeatable method. CSA

International also intends to submit this modified procedure for adoption by Natural Resources

Canada.

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SUB-ZERO, INC. WOLF APPLIANCE, INC.
test procedure rule. DOE responded in 75 Fed. Reg. 78,810 (Dec. 16, 2010): 

After analyzing

this alternative proposal for multiple compressors, DOE does not believe that it simplifies testing

ofsystems with two or more compressors. In particular, it does not alleviate the test procedure

burden associated with having to separately measure the energy use for the different systems,which is part ofthe procedure ofthe current dual-compressor product test procedure. DOE

understands that this is a key difficulty in testing such systems since it introduces burden and

that, in some cases, it may be impossible to accomplish, depending on the details of the internalwiring of such products.. .DOE acknowledges that this final rule does not eliminate the difficulty

of obtaining separate energy use measurements required in the test procedure for dualcompressor products. However, as discussed above, neither does the AHAM-proposed

approach.” Thus, DOE acknowledged problems with the current test procedure but did not

believe the AHAM proposal provided an adequate solution. We believe the proposed approach

in this waiver petition, developed by CSA International, GE and Sub-Zero, addresses DOE’sconcerns.

Proposed Modified Dual Compressor Test ProcedureThe DOE test procedure dual compressor calculation requires the system to be divided into two

separate systems— refrigerator and freezer. This is extremely difficult due to the fact that all dual

compressor systems use a single power inlet and almost all, including Sub-Zero units, use a

single electronic control to control both compressors. Energy testing protocols and laboratoryequipment and measurement methods are not capable of evaluating each compressor systemseparately and individually. Also, the current steady state definition may not be achievable in the

dual compressor system due the time required to calculate steady state.We propose a modified procedure to measure dual compressor energy. This method will use a

single electrical data collection system which is same as used in any variable defrost unit energy

test procedure. Sub-Zero proposes simplifying EP1 to provide an accurate method for measuring

energy that is simpler and less burdensome. It will also decrease the testing burden on

manufacturers. To ensure accuracy, dual compressor energy times must be of sufficient length to

reduce synchronization errors. With dual compressors, a short Ti or T2 may result in a

significant error for the system that does not have full compressor cycles represented.

Lengthening out these times reduces this effect. To further reduce error, Sub-Zero recommendsthat the frequency ofmeasurements taken during the testing should be increased. This willreduce synchronization error and is more consistent with test methods being used inmanufacturer’s and in third party verification company’s labs.Thus, Sub-Zero requests that DOE modify the multiple defrost system equation in 5.2.1.4 ofAppendix Al as follows:

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SUB-ZERO, INC. WOLF APPLIANCE, INC.
• D is the total number of compartments with distinct defrost systems;• EP1 is the dual compressor energy expended during the first part of the test (it is calculated for

a whole number of freezer compressor cycles at least 24 hours in duration and may be thesummation of several running periods that do not include any precool, defrost, or recovery

periods);

• Ti is the length of time for EP1 (minutes);• EP2i is the total energy consumed during the second (defrost) part ofthe test being conducted

for compartment i. (kWh);

• T2i is the length oftime (minutes) for the second (defrost) part ofthe test being conducted for

compartment i.

• CTi is the compressor on time between defrosts for only compartment i. CTi for compartment i

with long time automatic defrost system is calculated as per 10 CFR part 430 subpart B appendix

Al clause 5.2.1.2. CTi for compartment i with variable defrost system is calculated as per 10

CFR part 430 subpart B appendix Al clause 5.2.1.3. (rounded to the nearest tenth of an hour)(hours).

ET = (1440x EPi/T1) + (EP2 1—(EPI x T21/T1))x(i2/C)]

Stabilization:

The test shall start after a minimum 24 hours stabilization run for each temperature control

setting.

Steady State for EP1:

The temperature average for the first and last compressor cycle of the test period must be within

1.0°F (0.6°C) of the test period temperature average for each compartment. Make this

determination for the fresh food compartment for the fresh food compressor cycles closest to the

start and end of the test period. Ifmultiple segments used for test period 1, each segment must

comply with above requirement.

Steady State for EP2i:

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SUB-ZERO, INC. WOLF APPLIANCE, INC.
compressor steady state run cycles to allow T2i to be at least 24 hours. The test period shall start

at the begirming of normal compressor cycle after the previous defrost occurrence (refrigerator orfreezer). The test period includes the target defrost and following normal compressor cycles until

the next defrost occurrence (refrigerator or freezer). Ifthe previous condition does not meet 24hours time, additional EP 1 steady state segment data could be included. Steady state run cycle

data can be utilized in EP1 and EP2i.

Test Measurement Frequency

Measurements shall be taken at regular interval not exceeding 1 minute.

Affected ModelsThe basic models of Sub-Zero dual compressor refrigerators affected are:

700TCI700TR

736TC1

736TC1E

736TR73 6TRE

BI-30U/O

BI-3 OU/S/PH

BI-3OU/S/THBI-3OUA/OBI-3OUAIS/PHBI-3OUA/S/THBI-3OUG/O

BI-3 OUG/S/PH

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SUB-ZERO, INC. WOLF APPLIANCE, INC.
BI-36U/OBI-36U/S/PHBI-3 6U/S/TH

BI-3 6UA/OBI-3 6UA/S/PHBI-3 6UA/S/THBI-3 6TJFD/OB13 6UFD/S/PHB13 6UFD/S/THBI-3 6UG/OBI-3 6UG/S/PHBI-3 6UG/S/TH

BI-42S/OBI-42S/S/PHBI-42S/S/THB1-42 SD/OBI-42SD/S/PHBI-42SD/S/THBI-42S1D/OB1-42 S ID/S/PHBI-42S1D/S/THBI-485/O

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SUB-ZERO, INC. WOLF APPLIANCE, INC.
BI-48SD/S/THBI-48S1D/OBI-48S1D/S/PHBI-48S1D/S/THID-3 6C1IT-27C1IT-30C1IT-3OCIIDIT-36C1IT-36C11D

PR048PRO48GPRO48HAG

In summary, this is a critical issue for our company and we request that DOE expedite thehandling ofthis petition for an interim and final waiver. Sub-Zero would be pleased to discussthis waiver petition with DOE and provide any additional information that the Department mightrequire. We will also notify all manufacturers of domestically marketed refrigerators known tous ofthis waiver petition by letter.

Sincerely,

Paul V. SikirVice President of Design Engineering

Cc: Kathleen Hogan, Deputy Assistant Secretary for Energy Efficiency in the Office of Energy

Efficiency and Renewable Energy (EERE)

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SUB-ZERO, INC. WOLF APPLIANCE, INC.