[Federal Register Volume 77, Number 108 (Tuesday, June 5, 2012)]
[Proposed Rules]
[Pages 33106-33120]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-13609]


=======================================================================
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DEPARTMENT OF ENERGY

10 CFR Part 430

[Docket No. EERE-2010-BT-TP-0023]
RIN 1904-AC26


Energy Conservation Program: Test Procedure for Microwave Ovens

AGENCY: Office of Energy Efficiency and Renewable Energy, Department of 
Energy.

ACTION: Notice of data availability; request for comment.

-----------------------------------------------------------------------

SUMMARY: The U.S. Department of Energy (DOE) initiated a test procedure 
rulemaking to develop active mode testing methodologies for residential 
microwave ovens. DOE conducted testing to evaluate potential test 
procedure amendments to provide methods of measuring energy use for 
microwave ovens, including both microwave-only ovens and convection 
microwave cooking ovens. In today's notice, DOE presents the results 
from these testing investigations and requests comment and additional 
information on these results and potential amendments to the microwave 
oven test procedure.

DATES: DOE will accept comments, data, and information regarding this 
notice submitted no later than July 5, 2012.

ADDRESSES: Any comments submitted must identify the Notice of Data 
Availability for Microwave Ovens, and provide docket number EERE-2010-
BT-TP-0023 and/or RIN 1904-AC26. Comments may be submitted using any of 
the following methods:
    1. Federal eRulemaking Portal: www.regulations.gov. Follow the 
instructions for submitting comments.
    2. Email: [email protected]. Include docket EERE-2010-BT-
TP-0023 and/or RIN 1904-AC26 in the subject line of the message.
    3. Mail: Ms. Brenda Edwards, U.S. Department of Energy, Building 
Technologies Program, Mailstop EE-2J, 1000 Independence Avenue SW., 
Washington, DC 20585-0121. If possible, please submit all items on a 
compact disc (CD), in which case it is not necessary to include printed 
copies.
    4. Hand Delivery/Courier: Ms. Brenda Edwards, U.S. Department of 
Energy, Building Technologies Program, 6th Floor, 950 L'Enfant Plaza 
SW., Washington, DC 20024. Telephone: (202) 586-2945. If possible, 
please submit all items on a CD, in which case it is not necessary to 
include printed copies.
    Docket: The docket is available for review at www.regulations.gov, 
including Federal Register notices, public meeting attendee lists and 
transcripts, comments, and other supporting documents/materials. All 
documents in the docket are listed in the www.regulations.gov index. 
However, not all documents listed in the index may be publicly 
available, such as information that is exempt from public disclosure.
    A link to the docket web page can be found at: http://www.regulations.gov/#!docketDetail;dct=FR%252BPR% 
252BN%252BO%252BSR;rpp=10; po=0;D=EERE-2010-BT-TP-0023. This Web page 
contains a link to the docket for this notice on the 
www.regulations.gov site. The www.regulations.gov Web page contains 
simple instructions on how to access all documents, including public 
comments, in the docket.
    For further information on how to submit a comment or review other 
public comments and the docket, contact Ms. Brenda Edwards at (202) 
586-2945 or email: [email protected].

FOR FURTHER INFORMATION CONTACT: 
    Mr. Wes Anderson, U.S. Department of Energy, Office of Energy 
Efficiency and Renewable Energy, Building Technologies Program, EE-2J, 
1000 Independence Avenue SW., Washington, DC 20585-0121. Telephone: 
202-586-7335. Email: [email protected].
    In the Office of the General Counsel, contact Mr. Ari Altman, U.S. 
Department of Energy, 1000 Independence Ave. SW., Room 6B-159, 
Washington, DC 20585. Telephone: 202-287-6307; Email: 
[email protected].

SUPPLEMENTARY INFORMATION: 

Table of Contents

I. Background
II. Discussion
    A. Test Units
    B. Water Load Microwave-Only Testing
    C. Reheat Food Simulation Mixture Testing
    D. Convection Microwave Cooking Testing

[[Page 33107]]

    E. Convection Microwave Oven Convection-Only Cooking Testing
    F. Cooling Down Energy Use
    G. Additional Issues on Which DOE Seeks Comment

I. Background

    On July 22, 2010, DOE published in the Federal Register a final 
rule for the microwave oven test procedure rulemaking (July 2010 TP 
Repeal Final Rule), in which it repealed the regulatory provisions for 
establishing the cooking efficiency test procedure for microwave ovens 
under the Energy Policy and Conservation Act (EPCA). 75 FR 42579. In 
the July 2010 TP Repeal Final Rule, DOE determined that the existing 
microwave oven test procedure to measure the cooking efficiency, which 
was based on the International Electrotechnical Commission (IEC) 
Standard 705-1998 and Amendment 2-1993, ``Methods for Measuring the 
Performance of Microwave Ovens for Households and Similar Purposes'' 
(IEC Standard 705), did not produce representative and repeatable test 
results. DOE stated that it was unaware of any test procedures that had 
been developed that addressed the concerns with the microwave oven 
cooking efficiency test procedure. DOE was also unaware of any research 
or data on consumer usage indicating what a representative food load 
would be, or any data showing the repeatability of test results. 75 FR 
42579, 42581. In addition, in comments received in response to a 
separate test procedure notice of proposed rulemaking (NOPR) published 
in the Federal Register on October 17, 2008, which addressed provisions 
for measuring standby mode and off mode energy use for microwave ovens 
(73 FR 62134), interested parties commented that pure water has 
relatively low specific resistivity, and actual food items that might 
be cooked in a microwave oven would have more salts and thus absorb 
microwave energy more efficiently than pure water. Interested parties 
stated that, as a result, testing with a water load would likely result 
in lower efficiency measurements than would be expected from using 
actual food products.
    On July 22, 2010, DOE also published in the Federal Register a 
notice of public meeting to initiate a separate rulemaking process to 
consider new provisions for measuring microwave oven energy efficiency 
in active (cooking) mode. 75 FR 42611. DOE held the public meeting on 
September 16, 2010 to discuss and receive comments on several issues 
related to active mode test procedures for microwave ovens to consider 
in developing a new test procedure. DOE received no data or comments at 
or after the September 16, 2010 public meeting suggesting potential 
methodologies for test procedures for microwave oven active mode.
    On October 24, 2011, DOE published a Request for Information (RFI) 
notice to announce that it has initiated a test procedure rulemaking to 
develop active mode testing methodologies for microwave ovens. 76 FR 
65631. DOE specifically sought information, data, and comments 
regarding representative and repeatable methods for measuring the 
energy use of microwave ovens, in particular for the microwave-only and 
convection microwave cooking (i.e., microwave plus convection and any 
other means of cooking) functions. In particular, DOE sought comment on 
the following: (1) The characteristics of food loads representative of 
consumer use, (2) the repeatability of energy use measurements using 
different food loads, and (3) consumer usage data on the hours of 
operation in active mode, standby mode, and off mode for the 
development of an integrated energy use metric. In response to the 
August 2011 RFI, DOE received comments from the Association of Home 
Appliance Manufacturers (AHAM) and Whirlpool Corporation (Whirlpool) on 
a number of these test procedure issues. These comments are summarized 
below.
    Food Load Repeatability and Reproducibility. AHAM and Whirlpool 
commented that the repeatability (test-to-test within one laboratory) 
and reproducibility (lab-to-lab) must be considered in developing an 
active mode test procedure for microwave ovens. AHAM and Whirlpool are 
both unaware of any existing test procedures that have successfully 
incorporated actual food loads, noting that the European Committee for 
Electrotechnical Standardization (CENELEC) has conducted testing with 
different food loads, including real and artificial food as well as 
salt water, and concluded that food loads cannot meet CENELEC's 
requirements of repeatability and reproducibility. (AHAM, No. 11 at p. 
2, Whirlpool, No. 10 at pp. 1, 3) According to Whirlpool, the most 
commonly microwaved foods are hot cereal, bacon, pre-made baked goods, 
and frozen vegetables. However, Whirlpool stated the following about 
the lack of reproducibility of various foods:
     The nature and behavior of fresh foods varies over the 
year and by geographical region;
     Prefabricated foods change formulation over time and 
without notice. Various items are routinely added to and removed from 
the market;
     The composition of meats such as chicken, beef, and pork 
vary from not only by region, but also within each meat category, for 
example in the amount of fat or the size of granulation. (Whirlpool, 
No. 10 at p. 3)
    AHAM and Whirlpool also commented that the IEC evaluated gels, but 
they were abandoned due to poor repeatability and excessive preparation 
time. (AHAM, No. 11 at p. 2, Whirlpool, No. 10 at p. 3) Whirlpool added 
that IEC Standard 60705 Edition 4.0, 2010-04, ``Household microwave 
ovens--Methods for measuring performance,'' (IEC Standard 60705 Fourth 
Edition) contains food loads, but that those are used for performance 
testing only and are not reproducible as is stated in the test 
standard. (Whirlpool, No. 10 at p. 2)
    Whirlpool stated that the final temperature of the load must be 
correlated to normal usage (i.e., heating food to ``eating 
temperature''). AHAM and Whirlpool commented that a well-defined final 
temperature of food loads cannot be determined with sufficient accuracy 
to attain an acceptable level of repeatability. According to Whirlpool, 
infrared measurements will only detect surface temperature and 
thermocouples will just measure temperature in a few spots and as a 
result, cold/hot spots inside the food may not be found. (AHAM, No. 11 
at p. 2, Whirlpool, No. 10 at pp. 2, 3)
    Convection Microwave Ovens. Whirlpool noted that convection 
microwave ovens represent less than 4 percent of U.S. shipments and 
that qualitative data suggests that even when consumers own a 
convection microwave oven, the use of the convection microwave cooking 
function is very limited. Whirlpool commented that the European 
Commission established a mandate to define a test method for the 
microwave-only cooking function and that the convection microwave 
cooking function has not been on the agenda. However, Whirlpool noted 
that CENELEC tested convection microwave ovens but was unsuccessful at 
developing repeatable and reproducible test loads and testing 
procedures for the reasons discussed above. (Whirlpool, No. 10 at p. 1, 
2)
    Test Methods for DOE Test Procedure. Whirlpool commented that DOE 
should not attempt to develop a test procedure for both microwave-only 
and convection microwave ovens at this time because the challenge to 
develop just a microwave-only test procedure is significant. 
(Whirlpool, No. 10 at p. 1) AHAM commented that the issues associated 
with the test procedure are not unique to the United States because 
microwave ovens do not vary

[[Page 33108]]

significantly across countries. AHAM noted that microwave ovens do not 
represent a large amount of energy consumption as compared to other 
products, and that DOE should not direct its limited resources to 
duplicate what another group has adequately done. (AHAM, No. 11 at p. 
2)
    AHAM and Whirlpool commented that if DOE proceeds with a test 
procedure, it should develop a test procedure for microwave-only ovens 
that is harmonized with IEC Standard 60705, which is currently being 
updated based on extensive testing. AHAM and Whirlpool noted that the 
draft revised IEC Standard 60705, which uses varying water loads (1000 
grams (g), 350 g, and 275 g), was evaluated in a round robin testing 
program completed in July 2011 and the results verified that the 
testing procedures have acceptable repeatability and reproducibility. 
Whirlpool also commented that the three amounts of water defined in the 
test procedure give good correlation to ``normal usage'' and the water 
temperature rise of 50 degrees Celsius ([deg]C) achieves eating 
temperature. (AHAM, No. 11 at p. 2, Whirlpool, No. 10 at pp. 3-4)
    Based on DOE's determination to initiate a microwave oven active 
mode test procedure rulemaking and comments received on the October 
2011 RFI discussed above, DOE conducted testing to evaluate potential 
amendments to its microwave oven test procedure to provide methods for 
measuring the active mode energy use for these products. The sections 
below present DOE's tests results and the analytical approaches that it 
is considering for potential amendments to the microwave oven test 
procedure to measure active mode energy use.

II. Discussion

A. Test Units

    In order to evaluate potential amendments to the microwave oven 
test procedure, DOE selected a number of test units representative of 
products currently available on the U.S. market. DOE considered 
features such as installation configuration, cooking functions (i.e., 
microwave cooking, convection microwave cooking), rated output power, 
and rated cavity volume. The test units and key features are presented 
below in Table 1. Unless otherwise noted, the test unit numbers 
presented in Table 1 correspond to the test units in the tables 
presenting test results in today's notice.

                                 Table 1--Microwave Oven Test Units and Features
----------------------------------------------------------------------------------------------------------------
                                                                               Rated microwave    Rated cavity
                       Product type                             Test unit     power output (W)   volume (ft\3\)
----------------------------------------------------------------------------------------------------------------
Microwave-Only, Countertop................................                 1               700               0.7
                                                                           2              1200               2.0
                                                                           3              1000               1.5
                                                                           4              1200               1.2
                                                                           5              1200               1.5
Microwave-Only, Over-the-Range............................                 6              1000               1.7
                                                                           7               950               1.5
                                                                           8              1000               2.0
                                                                           9              1200               2.0
                                                                          10              1100               2.0
Convection Microwave, Countertop..........................                11              1000               1.2
                                                                          12              1100               1.5
                                                                          13              1000               1.0
                                                                          14               900               1.5
Convection Microwave, Over-the-Range......................                15              1050               1.7
                                                                          16              1100               1.8
                                                                          17               950               1.7
                                                                          18               950               1.7
----------------------------------------------------------------------------------------------------------------

B. Water Load Microwave-Only Testing

    As discussed in section 0, DOE's previous active mode test 
procedure incorporated portions of IEC Standard 705. These test methods 
measured the amount of energy required to raise the temperature of 1 
kilogram of water by 10 [deg]C under controlled conditions. The ratio 
of usable output power over input power described the energy factor 
(EF), a measure of the cooking efficiency.\1\ DOE noted that IEC is in 
the process of revising its current test standard for microwave ovens, 
IEC Standard 60705 Fourth Edition. In addition to the 10 [deg]C 
temperature rise water load test from IEC Standard 705, the draft 
revised IEC Standard 60705 includes a new test method that continues to 
use water as the cooking load. The draft revised test method involves 
measuring the energy consumption required to heat water loads of 275 g, 
350 g, and 1000 g, in 400 milliliter (ml), 900 ml, and 2000 ml 
borosilicate glass test containers, respectively, by 45-50 [deg]C and 
50-55 [deg]C. The results from the two different temperature rise tests 
are used to linearly interpolate the energy consumption required to 
heat each load by 50 [deg]C. The cooking cycle energy consumption for 
each water load size is then weighted based on consumer usage to 
calculate the weighted per-cycle cooking energy consumption. In 
addition to the cooking cycle energy consumption, the low power energy 
consumption while the microwave is cooling down after the completion of 
the cooking cycle is also measured for a 15-minute period. This energy 
consumption is then added to the cooking energy consumption to 
calculate an overall weighted per-cycle energy consumption. DOE 
recognizes that these draft revised IEC Standard 60705 testing methods 
may be subject to changes during the IEC review process, however DOE 
decided to consider this latest available draft revised test method for 
potential amendments to the DOE test procedure. Table 2 presents the 
key differences between IEC Standard 705 and the draft revised IEC 
Standard 60705.
---------------------------------------------------------------------------

    \1\ The previous DOE microwave oven test procedure also provided 
for the calculation of several other measures of energy consumption, 
including cooking efficiency and annual energy consumption.

[[Page 33109]]



 Table 2--Key Differences Between IEC Standard 705 and Draft Revised IEC
                             Standard 60705
------------------------------------------------------------------------
                                                      Draft revised IEC
       Test condition           IEC standard 705       standard 60705
------------------------------------------------------------------------
Test Load Type..............  Water...............  Water.
Test Load Size..............  1000 g..............  275 g, 375 g, 1000
                                                     g.
Test Container Size.........  2000 ml.............  400 ml, 900 ml, 2000
                                                     ml.
Temperature Requirements....  Ambient Temp.,T0 =    Ambient Temp.,T0 =
                               20  2     23  2
                               [deg]C.               [deg]C.
                              Starting Water        Starting Water
                               Temp., T1 = T0-(10    Temp., T1 = 10
                                1         0.5
                               [deg]C).              [deg]C.
                              Final Water Temp.,    Final Water Temp.,
                               T2 = T0  1 [deg]C.      60-65 [deg]C
Test Load Preparation.......  Prior to the test,    Prior to the test,
                               water load and test   water load and test
                               container are not     container are
                               allowed to            allowed to
                               equilibrate.          equilibrate.
Time Limit to Measure Final   60 seconds..........  20 seconds.
 Temperature.
Measurement Equipment         Mass  1   Mass  1
 Accuracy.                     g.                    g.
                              Watt-hour  1.5 percent.   minus> 1.0 percent.
                              Temperature  0.25 [deg]C     1
                               over the range of 7-  Kelvin (K).
                               23 [deg]C for all    Water temperature
                               temperature            1.5 K.
                               measurements. Also
                               specifies linearity
                               of better than 1
                               percent.
                              Time      Time  1
                               0.25 seconds.         seconds.
Number of Repeat Tests......  Test is carried out   No additional repeat
                               three times unless    tests specified.
                               the power output
                               value resulting
                               from second
                               measurement is
                               within 1.5 percent
                               of the value
                               obtained from the
                               first measurement.
Cooling Down Energy Use       No..................  Yes.
 Measured?
------------------------------------------------------------------------

    For over-the-range microwave ovens, DOE reviewed installation 
instructions for products available on the market. All products 
equipped with a venting fan offer two installation conditions for the 
venting fan: (1) Exhaust air to the outside and (2) recirculating air 
back into the room. DOE noted that for the majority of products, the 
default installation configuration for the venting fan was for air 
recirculation. As a result, DOE conducted testing with the venting fan 
installed in the air recirculation configuration and did not conduct 
testing using the exhaust configuration with additional requirements 
for venting.
    DOE selected 15 microwave ovens in its test sample and conducted 
testing according to the draft revised IEC Standard 60705 to evaluate 
the repeatability of test results and the suitability for incorporating 
such methods into the DOE microwave oven test procedure.\2\ For each 
test unit, DOE conducted two to three identical repeat tests. Table 3 
through Table 5 present the cooking cycle energy consumption test 
results for each water load size. DOE noted that for the 275 g and 350 
g water load sizes, the test-to-test variation expressed in terms of 
standard error ranged from roughly 0.1 percent to 2.5 percent, with 
averages of approximately 1.1 percent. For the 1000 g water load size, 
the test-to-test variation ranged from approximately 0.1 percent to 0.8 
percent, with an average of 0.44 percent.
---------------------------------------------------------------------------

    \2\ Although the draft revised IEC Standard 60705 specifies that 
the accuracy of ambient temperature and water temperature 
measurements to be  1 K and  1.5 K, 
respectively, testing conducted by DOE used thermocouples for 
temperature measurements with an accuracy of  0.2 
[deg]C, which meets the requirements of IEC Standard 705.

                     Table 3--Draft Revised IEC Standard 60705 275 g Water Load Test Results
----------------------------------------------------------------------------------------------------------------
                                                        Cooking cycle energy use (Wh)            Test-to-test
            Product type              Test unit -------------------------------------------- variation--standard
                                                   Test 1     Test 2     Test 3    Average        error (%)
----------------------------------------------------------------------------------------------------------------
Microwave-Only, Countertop..........          1      34.27      34.28      34.47      34.34               0.34
                                              2      36.13      36.76      36.58      36.49               0.88
                                              3      37.97      36.95  .........      37.46               1.93
                                              4      33.03      32.05  .........      32.54               2.12
                                              5      34.52      35.66  .........      35.09               2.31
Microwave-Only, Over-the-Range......          6      35.27      34.92  .........      35.09               0.71
                                              7      35.18      36.00  .........      35.59               1.63
                                              9      40.14      39.19  .........      39.67               1.70
                                             10      33.96      34.63      34.54      34.38               1.05
Convection Microwave, Countertop....         11      46.53      46.69  .........      46.61               0.25
                                             12      45.50      46.14      45.94      45.86               0.70
                                             13      41.75      41.47  .........      41.61               0.48
Convection Microwave, Over-the-Range         15      36.07      36.15  .........      36.11               0.17
                                             16      38.29      37.41      38.86      38.18               1.91
                                             17      40.83      40.80      40.83      40.82               0.05
                                     ---------------------------------------------------------------------------
    Average.........................  .........  .........  .........  .........      37.99               1.08
----------------------------------------------------------------------------------------------------------------


[[Page 33110]]


                     Table 4--Draft Revised IEC Standard 60705 350 g Water Load Test Results
----------------------------------------------------------------------------------------------------------------
                                                        Cooking cycle energy use (Wh)            Test-to-test
            Product type              Test unit -------------------------------------------- variation--standard
                                                   Test 1     Test 2     Test 3    Average        error (%)
----------------------------------------------------------------------------------------------------------------
Microwave-Only, Countertop..........          1      39.50      39.50      39.43      39.48               0.10
                                              2      42.81      42.87      41.26      42.31               2.16
                                              3      44.46      42.86  .........      43.66               2.59
                                              4      39.65      39.29  .........      39.47               0.65
                                              5      39.11      39.17  .........      39.14               0.11
Microwave-Only, Over-the-Range......          6      43.35      43.63  .........      43.49               0.46
                                              7      42.74      43.76  .........      43.25               1.68
                                              9      43.96      44.35  .........      44.15               0.62
                                             10      40.25      39.64      40.60      40.16               1.20
Convection Microwave, Countertop....         11      55.05      54.31  .........      54.68               0.95
                                             12      53.85      52.36      53.07      53.10               1.41
                                             13      47.43      47.64  .........      47.54               0.31
Convection Microwave, Over-the-Range         15      42.71      42.91  .........      42.81               0.32
                                             16      45.21      43.89      45.19      44.77               1.69
                                             17      47.59      46.28      47.63      47.17               1.62
                                     ---------------------------------------------------------------------------
    Average.........................  .........  .........  .........  .........      44.34               1.06
----------------------------------------------------------------------------------------------------------------


                    Table 5--Draft Revised IEC Standard 60705 1000 g Water Load Test Results
----------------------------------------------------------------------------------------------------------------
                                                        Cooking cycle energy use (Wh)            Test-to-test
            Product type              Test unit -------------------------------------------- variation--standard
                                                   Test 1     Test 2     Test 3    Average        error (%)
----------------------------------------------------------------------------------------------------------------
Microwave-Only, Countertop..........          1     116.06     115.08     115.42     115.52               0.43
                                              2     106.02     105.48     105.38     105.63               0.33
                                              3     107.59     108.72  .........     108.16               0.74
                                              4     104.93      104.8  .........     104.86               0.09
                                              5     106.54     106.18  .........     106.36               0.24
Microwave-Only, Over-the-Range......          6     115.69     116.74  .........     116.22               0.64
                                              7     113.91     114.53  .........     114.22               0.38
                                              9     117.14     117.80  .........     117.47               0.40
                                             10     107.44     107.85     107.04     107.44               0.38
Convection Microwave, Countertop....         11     128.77     127.35  .........     128.06               0.78
                                             12     131.95     130.17      130.5     130.87               0.72
                                             13     114.97     115.11  .........     115.04               0.09
Convection Microwave, Over-the-Range         15     112.54     111.69  .........     112.12               0.54
                                             16     120.83     120.18     119.56     120.19               0.53
                                             17     121.71     120.95      121.2     121.29               0.32
                                     ---------------------------------------------------------------------------
    Average.........................  .........  .........  .........  .........     114.90               0.44
----------------------------------------------------------------------------------------------------------------

    Table 6 presents the calculated overall weighted average cooking 
cycle energy consumption results for each test unit. The following 
weighting factors provided in the draft revised IEC Standard 60705 are 
applied to the measured energy use for each test load size to calculate 
the weighted energy consumption: 1000 g = 2/11; 350 g = 6/11; 275 g = 
3/11. DOE noted that values for the overall weighted average cooking 
cycle energy consumption ranged from approximately 50.4 Watt-hours (Wh) 
to 66.5 Wh (a 32.2 percent difference). DOE compared the range of 
values from testing according to the draft revised IEC Standard 60705 
to the testing conducted for the most recent energy conservation 
standards rulemaking for microwave ovens. For that testing, DOE 
conducted testing on 32 microwave ovens and AHAM conducted tests on 21 
separate microwave ovens according to the previous DOE microwave oven 
test procedure that was based on IEC Standard 705, with the results 
expressed in EF (i.e., the ratio of usable output power over input 
power). The DOE test units for the most recent energy conservation 
standards rulemaking testing are different from the test units tested 
for today's notice listed in Table 1. The results from this testing, 
presented in Table 7, showed a much smaller range in the efficiency 
metric, with EF values ranging from 54.8 percent to 61.8 percent (12.8 
percent difference). Based on these results, DOE believes that the 
draft revised IEC Standard 60705 may provide the opportunity to better 
differentiate products available on the market based on efficiency and 
their associated design options for the purposes of energy conservation 
standards rulemakings.

[[Page 33111]]



           Table 6--Draft Revised IEC Standard 60705 Overall Weighted Energy Consumption Test Results
----------------------------------------------------------------------------------------------------------------
                                                      Overall weighted energy use (Wh)           Test-to-test
            Product type              Test unit -------------------------------------------- variation--standard
                                                   Test 1     Test 2     Test 3    Average        error (%)
----------------------------------------------------------------------------------------------------------------
Microwave-Only, Countertop..........          1      51.99      51.82      51.90      51.90               0.17
                                              2      53.27      53.37      51.60      52.75               0.98
                                              3      54.41      53.46  .........      53.93               1.25
                                              4      50.60      50.11  .........      50.35               0.68
                                              5      50.51      50.79  .........      50.65               0.39
Microwave-Only, Over-the-Range......          6      55.11      55.36  .........      55.23               0.32
                                              7      54.04      54.93  .........      54.48               1.16
                                              9      57.31      57.38  .........      57.34               0.09
                                             10      51.50      51.44      51.79      51.57               0.36
Convection Microwave, Countertop....         11      66.85      66.24  .........      66.54               0.65
                                             12      66.72      65.75      66.14      66.20               0.74
                                             13      58.47      58.54  .........      58.51               0.08
Convection Microwave, Over-the-Range         15      54.58      54.55  .........      54.57               0.03
                                             16      58.15      57.07      58.06      57.76               1.04
                                             17      59.89      59.03      59.82      59.58               0.80
ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½
    Average.........................  .........  .........  .........  .........      56.11               0.58
----------------------------------------------------------------------------------------------------------------


         Table 7--DOE and AHAM IEC Standard 705 Testing Results
------------------------------------------------------------------------
                     DOE Testing                         AHAM Testing
------------------------------------------------------------------------
                                                        Test
               Test unit \1\                 EF (%)   unit \1\   EF (%)
------------------------------------------------------------------------
1.........................................      57.5        33      57.6
2.........................................      58.0        34      61.1
3.........................................      55.9        35      58.9
4.........................................      59.6        36      57.4
5.........................................      59.5        37      60.7
6.........................................      58.4        38      61.8
7.........................................      57.6        39      55.2
8.........................................      57.3        40      59.1
9.........................................      60.2        41      57.2
10........................................      56.9        42      57.8
11........................................      59.4        43      58.7
12........................................      59.2        44      61.4
13........................................      59.0        45      56.4
14........................................      60.8        46      61.4
15........................................      58.9        47      57.3
16........................................      60.6        48      55.7
17........................................      57.2        49      54.8
18........................................      59.2        50      55.8
19........................................      58.2        51      59.1
20........................................      60.4        52      56.8
21........................................      61.2        53      58.1
22........................................      56.9  ........  ........
23........................................      59.4  ........  ........
24........................................      58.7  ........  ........
25........................................      61.3  ........  ........
26........................................      58.0  ........  ........
27........................................      61.5  ........  ........
28........................................      60.4  ........  ........
29........................................      59.7  ........  ........
30........................................      57.6  ........  ........
31........................................      58.5  ........  ........
32........................................      58.0  ........  ........
------------------------------------------------------------------------
                       Minimum Efficiency = 54.8%
                       Maximum Efficiency = 61.8%
------------------------------------------------------------------------
\1\ Test units listed in this table are different models than the models
  from DOE's latest testing.

    DOE also noted that CENELEC conducted a round-robin testing program 
to evaluate the repeatability and reproducibility of the draft revised 
IEC Standard 60705. A total of 5 manufacturer test labs and 5 
independent test labs in Europe conducted testing according to the 
draft revised IEC Standard 60705 on 4 microwave oven models. In terms 
of repeatability of the measured weighted cooking cycle energy 
consumption, the results showed that the test-to-test variation 
expressed as standard error within each laboratory was on average 0.56 
percent. The lab-to-lab reproducibility of the measured weighted 
cooking cycle energy consumption showed a variation of 2.30 percent on 
average. CENELEC determined these to be acceptable levels of 
repeatability and reproducibility.
    DOE also conducted testing to evaluate the testing methodology for 
measuring the low power energy consumption of the cooling down period. 
The draft revised IEC Standard 60705 requires that the cooking cycle 
test be run to achieve a 50 [deg]C temperature rise. When the cooking 
cycle has finished, the load is removed from the microwave oven and the 
door is closed, at which point the cooling down energy consumption is 
measured for a period of 15 minutes. This test is conducted for each of 
the three test load sizes, and the weighted cooling down energy 
consumption is calculated using the same weighting factors used for the 
cooking cycle weighted energy consumption. The weighted cooling down 
energy consumption is then added to the weighted cooking cycle energy 
consumption to calculate the overall weighted energy consumption. For 
the 1000 g load size, DOE conducted two identical repeat tests. For the 
275 g and 350 g load sizes, DOE conducted one test each. The results of 
this testing are presented below in Table 8.

             Table 8--Draft Revised IEC Standard 60705 Cooling Down Energy Consumption Test Results
----------------------------------------------------------------------------------------------------------------
                                                                             Cooling down energy use (Wh)
                                                                     -------------------------------------------
                       Product type                        Test unit    1000 g     1000 g     350 g      275 g
                                                                        Test 1     Test 2      Test       Test
----------------------------------------------------------------------------------------------------------------
Microwave-Only, Countertop...............................          1       0.00       0.00       0.00       0.00
                                                                   2       0.81       0.80       0.79       0.78
                                                                   3       0.23  .........       0.23       0.25
                                                                   4       0.88       0.89       0.88       0.88
                                                                   5       0.39       0.39       0.40       0.39

[[Page 33112]]

 
Microwave-Only, Over-the-Range...........................          6       0.80  .........       0.81       0.81
                                                                   7       0.41       0.41       0.43       0.41
                                                                   9       1.09       1.10       1.08       1.09
                                                                  10       0.72       0.78       0.77       0.72
Convection Microwave, Countertop.........................         11       0.72       0.72       0.73       0.73
                                                                  12       0.92       0.89       0.89       1.07
                                                                  13       0.31       0.32       0.32       0.31
Convection Microwave, Over-the-Range.....................         15       0.99       0.99       0.97       1.00
                                                                  16       1.08       1.07       1.07       1.07
                                                                  17       0.69       0.67       0.67       0.66
----------------------------------------------------------------------------------------------------------------

    DOE observed minimal variation in the measured cooling down energy 
consumption from test to test and also between the different load 
sizes. DOE noted that for all of the units in its test sample, none 
contained a fan that operated at the end of the microwave-only cooking 
cycle to cool the appliance down. DOE also noted that when the door was 
closed after the load was removed at the end of the cooking cycle, the 
microwave ovens reverted back to the standby mode. Table 9 presents the 
average measured power for the cooling down mode as compared to the 
average measured standby mode power for each test unit.

                        Table 9--Draft Revised IEC Standard 60705 Cooling Down Mode Power
----------------------------------------------------------------------------------------------------------------
                                                                  Average cooling down power (W)
                                                                ---------------------------------     Average
                    Product type                      Test unit    1000 g     350 g      275 g     standby power
                                                                   Tests       Test       Test          (W)
----------------------------------------------------------------------------------------------------------------
Microwave-Only, Countertop..........................          1       0.00       0.00       0.00        \1\ 0.00
                                                              2       3.24       3.15       3.10            3.18
                                                              3       0.90       0.92       1.00            1.06
                                                              4       3.55       3.54       3.54            3.52
                                                              5       1.56       1.59       1.55            1.63
Microwave-Only, Over-the-Range......................          6       3.23       3.25       3.25            3.24
                                                              7       1.64       1.72       1.64            1.71
                                                              9       4.41       4.40       4.38            4.29
                                                             10       3.00       3.11       2.90            3.16
Convection Microwave, Countertop....................         11       2.88       2.91       2.91            2.93
                                                             12       3.66       3.58       4.29            3.54
                                                             13       1.26       1.26       1.27            1.19
Convection Microwave, Over-the-Range................         15       3.98       3.90       3.99            3.98
                                                             16       4.29       4.30       4.29            4.32
                                                             17       2.72       2.69       2.66            2.73
----------------------------------------------------------------------------------------------------------------
\1\ Test unit 1 had electromechanical controls and operated in off mode, consuming 0 W. This unit was not
  capable of operating in standby mode.

    The repeatability and reproducibility of the cooling down energy 
consumption measurement method from the draft revised IEC Standard 
60705 was also evaluated as part of the CENELEC round-robin testing 
program. In terms of repeatability of the measured weighted cooling 
down energy consumption, the results showed that the test-to-test 
variation expressed as standard error within each laboratory was on 
average 0.24 percent. The lab-to-lab reproducibility of the measured 
weighted cooling down energy consumption showed a variation of 6.14 
percent on average. CENELEC determined these to be acceptable levels of 
repeatability and reproducibility.
    DOE may consider incorporating the draft revised IEC Standard 60705 
test method into the DOE microwave oven test procedure for measuring 
the energy consumption of the microwave-only cooking function. As a 
result DOE is seeking comment on the following issues:
    1. DOE seeks comment on the suitability of the testing 
methodologies provided in the draft revised IEC Standard 60705 for 
incorporation into the DOE microwave oven test procedure. In 
particular, DOE requests comment on the repeatability and 
reproducibility of the test results from both DOE and CENELEC testing. 
DOE also welcomes comment on whether the test procedure should require 
multiple test runs with the results averaged.
    2. DOE requests comment on the accuracy requirements for measuring 
equipment specified in the draft revised IEC Standard 60705. In 
particular, DOE requests comment on the less stringent requirements for 
the accuracy of the temperature measurements as compared to IEC 
Standard 705.
    3. DOE welcomes comment on the testing burden associated with 
testing according to the draft revised IEC Standard 60705. When 
providing comments, please quantify and describe the associated testing 
burdens.
    4. DOE requests consumer usage data on the number of annual active 
mode cooking cycles and annual hours spent in active mode for 
microwave-only ovens.
    5. DOE welcomes comment on the determination to conduct testing for 
over-the-range microwave ovens with

[[Page 33113]]

the airflow exhaust/recirculation fan installed in the default air 
recirculation configuration. DOE welcomes comment on whether there are 
any other installation conditions for over-the-range or built-in 
microwave ovens that it should consider for the DOE microwave oven test 
procedure.

C. Reheat Food Simulation Mixture Testing

    DOE notes that water may not be representative of actual food loads 
cooked by consumers in microwave ovens. As a result, DOE conducted 
testing on 7 microwave ovens using the microwave-only cooking function 
to evaluate mixtures that would simulate food load that may be reheated 
in a microwave. The mixtures were composed of water and basic food 
ingredients (i.e., fats, sugars, salt, fiber, proteins, etc.) with a 
total combined mass of 350 g. DOE selected the 350 g load size (using 
the 900 ml borosilicate glass container) based on the draft revised IEC 
Standard 60705 weighting factors for the load size with the highest 
frequency of use. DOE also conducted testing on an actual food load, 
chicken noodle soup, to serve as a comparison to the food simulations. 
The mixtures and food load were tested using the same basic testing 
methodology as the draft revised IEC Standard 60705 (i.e., microwave-
only cooking function, temperature rise from 10 [deg]C to 60 [deg]C). 
The measured cooking cycle energy consumption was then used to 
calculate the energy consumption required to heat one gram of the 
mixture by one degree Celsius, an effective heat capacity. For each 
test unit, three identical tests were conducted for each mixture to 
evaluate the repeatability of such a testing procedure.
    The results from this testing, presented in Table 10 and Table 11, 
show a higher range and average test-to-test variation, expressed as a 
standard error, compared to the water-only load and compared to the 
results using the draft revised IEC Standard 60705 test method 
presented in 0.0. DOE also noted that the same brands were used for 
each ingredient in the mixtures. Therefore, additional variation in 
test results may be observed from lab to lab due to the use of 
different brands of the ingredients.

                                                                     Table 10--Food Simulation Mixture Test Results--Part 1
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Water                       Water + fat                  Water + glucose             Water + fat + glucose
                                                          ---------------------------------------------------------------------------------------------------------------------------
                                                                               Test-to-                       Test-to-                       Test-to-                       Test-to-
                        Test unit                            Average heat        test       Average heat        test       Average heat        test       Average heat        test
                                                             capacity (J/     variation     capacity (J/     variation     capacity (J/     variation     capacity (J/     variation
                                                           g[middot][deg]C)      (%)      g[middot][deg]C)      (%)      g[middot][deg]C)      (%)      g[middot][deg]C)      (%)
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1........................................................           8.570           0.39           8.284           3.57           7.514           1.50           7.672           1.54
2........................................................           8.635           0.99           8.759           7.20           7.259           1.85           7.416           5.95
8........................................................               *              *           8.952           1.67           8.332           1.06           8.241           4.04
9........................................................           8.363           0.64           8.561           2.39           7.559           2.61           7.293           2.16
11.......................................................          11.419           1.42          10.941           0.87          10.203           1.65           9.704           3.00
15.......................................................           9.356           0.68           8.922           0.11           8.152           0.49           8.028           2.55
16.......................................................           9.833           0.27           9.774           0.41           8.769           1.55           8.790           2.35
                                                          --------------------------------------------------------------------------------------------------------------------------------------
    Average..............................................           9.363           0.73           9.170           2.32           8.255           1.53           8.163           3.08
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Not tested.


                                                 Table 11--Food Simulation Mixture Test Results--Part 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Pizza simulation             Chicken noodle soup            Chicken noodle soup
                                                            -------------------------------           simulation          ------------------------------
                                                                                           -------------------------------
                         Test unit                             Average heat      Test-to-                       Test-to-     Average heat      Test-to-
                                                               capacity (J/        test       Average heat        test       capacity (J/        test
                                                             g[middot][deg]C)   variation     capacity (J/     variation   g[middot][deg]C)   variation
                                                                                   (%)      g[middot][deg]C)      (%)                            (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
1..........................................................           6.975           2.42           8.618           1.09           8.941           2.01
2..........................................................           6.486           1.24           8.811           3.77           9.210           1.26
8..........................................................           7.715           1.93           8.952           0.69           9.754           2.67
9..........................................................           6.453           0.61           8.406           0.73           8.995           3.29
11.........................................................           9.036           0.90          11.108           0.81          11.662           1.39
15.........................................................           7.164           1.28           8.909           0.56           9.236           1.04
16.........................................................           7.715           1.15           9.624           0.88          10.012           1.43
                                                            --------------------------------------------------------------------------------------------
    Average................................................           7.363           1.36           9.204           1.22           9.687           1.87
--------------------------------------------------------------------------------------------------------------------------------------------------------

    6. DOE welcomes comment on suitability of using food simulation 
mixtures for the microwave oven test procedure for microwave-only 
cooking. In particular, DOE requests comment on the repeatability and 
reproducibility of the food simulation mixture tests results presented 
in Table 10 and Table 11.

D. Convection Microwave Cooking Testing

    As discussed above in section 0, according to Whirlpool, convection 
microwave ovens (i.e., microwave ovens that incorporate convection 
features and any other means of cooking in a single compartment) 
represent less than 4 percent of U.S. shipments. Based on shipments 
data from Appliance Magazine showing 11.340 million microwave oven 
shipments in 2008,\3\ convection microwave ovens represent 
approximately 450,000 annual shipments.
---------------------------------------------------------------------------

    \3\ ``U.S. Appliance Industry: Market Share, Life Expectancy & 
Replacement Market, and Saturation Levels.'' Appliance Market 
Research Report, Appliance Magazine, January 2010.

---------------------------------------------------------------------------

[[Page 33114]]

    DOE's review of product literature indicated that convection 
microwave ovens can be operated using the microwave-only cooking 
function, convection-only cooking function, and convection microwave 
cooking function. DOE also noted based on a review of the cooking 
manuals and recipe books supplied with convection microwave ovens that 
a significant portion of the recipes included cooking procedures that 
used the convection microwave cooking function. As a result, DOE first 
investigated whether testing procedures could be developed to evaluate 
the convection microwave cooking function of convection microwave 
ovens. As discussed in section 0, AHAM and Whirlpool both noted a 
number of concerns with the repeatability and reproducibility of test 
results using actual food loads. DOE therefore decided to conduct 
limited testing to evaluate the repeatability of real food loads when 
heated using the convection microwave cooking function. DOE tested 
three different food loads: shortening, potatoes, and chicken. For each 
food load, the same brand of products was used for all tests to 
specifically evaluate repeatability of test results. DOE then conducted 
testing to assess food simulation cooking loads to determine whether 
such loads are representative of actual food loads and improve the 
repeatability of test results.
    As part of this testing DOE noted that for the majority of 
microwave ovens in its test sample, the default program setting for 
convection microwave cooking allowed the user to set the overall 
cooking time and cycled between microwave-only cooking and convection-
only cooking, where microwave-only cooking accounted for 30 percent of 
the cooking time and convection-only cooking accounted for the 
remaining 70 percent of total cooking time. DOE used this default 
convection microwave cooking program setting that used 30 percent 
microwave-only cooking and 70 percent convection-only cooking for 
testing. DOE also noted that for the majority of the convection 
microwave ovens in its test sample, the user is required to program the 
temperature setting for the convection portion of the convection 
microwave cooking cycle. Based on a review of the cooking manuals and 
recipe books supplied with convection microwave ovens, DOE noted that a 
majority of the recipes that used convection microwave cooking 
specified convection temperature settings between 300 degrees 
Fahrenheit ([deg]F) and 375 [deg]F. DOE also noted that its current 
test procedure for conventional ovens found in 10 Code of Federal 
Regulations (CFR) part 430, subpart B, appendix I specifies a 
convection temperature setting 325  5 [deg]F higher than 
the room ambient air temperature, which would result in a temperature 
setting close to 400 [deg]F. However, based on DOE's survey of 
convection microwave ovens available on the market, not all products 
are equipped with a 400 [deg]F temperature setting, but all convection 
microwave ovens DOE surveyed had a 375 [deg]F setting. As a result, DOE 
selected a convection temperature setting of 375 [deg]F for the 
convection microwave cooking function for its testing of convection 
microwave ovens.
    For convection microwave cooking testing, DOE noted that the 
temperatures of the test loads had to be measured before and after the 
cooking cycle, as is done for IEC Standard 60705, due to safety 
concerns with arcing inside the microwave oven cavity from the metal 
thermocouples and the microwave energy. The following sections discuss 
these testing investigations to evaluate the convection microwave 
cooking function.

Food Load Testing

    For shortening, DOE conducted limited testing on two convection 
microwave oven models. For each test, DOE prepared a 350 g load of 
shortening in the 900 ml borosilicate glass container with a starting 
load temperature of 10  1 [deg]C. DOE used three 
thermocouples to measure the average temperature of the load, with one 
thermocouple placed in the center of the load, and the other two placed 
approximately one inch from the edge of the container on either side. 
All of the thermocouples were placed at an equal distance from the top 
and bottom of the load. The shortening load was then heated using the 
default convection microwave cooking function to achieve a target 
average final temperature of 60  5 [deg]C. As for the 
reheat food simulation mixture testing, the measured cooking cycle 
energy consumption was then used to calculate the effective heat 
capacity. For each test unit, DOE conducted three identical tests to 
evaluate repeatability. DOE also conducted an additional set of testing 
with target average final temperatures of 70  5 [deg]C for 
one test unit and 80  5 [deg]C for the other test unit. DOE 
was unable to establish a target final average temperature range 
tighter than  5 [deg]C due to the test-to-test variation in 
the final average temperature of the test load even when using the same 
cooking time. DOE noted that using tighter ranges such as  
2 [deg]C or  1 [deg]C for this food load would require a 
significant number of retests to achieve the specified final average 
temperatures.
    The test results for the shortening tests are presented below in 
Table 12. For the tests using an average final temperature of 60  5 [deg]C, the test-to-test variation ranged from 5.18 percent to 
7.42 percent. DOE observed that the shortening, which was all solid at 
the starting temperature of 10  1 [deg]C, was only partly 
liquefied at the final temperature of approximately 60 [deg]C, with the 
middle still being partly solid, and the outer portion being liquid. 
Unlike the tests using an average final temperature of 60 [deg]C, DOE 
observed that the shortening was all liquid at the end of the cooking 
cycle for the 70 [deg]C and 80 [deg]C average final temperature tests. 
However, the test results for these tests continued to show significant 
test-to-test variation.
    For all shortening tests, DOE noted that when it measured the final 
temperature of the load after the completion of the cooking cycle, the 
temperature continued to rise for 30-90 seconds before finally leveling 
off. DOE believes that this may be attributable to continued heat 
transfer from the hotter outer edges of the test container and/or food 
load after the completion of the cycle. DOE waited until the 
temperature leveled off and used that measurement for the calculation 
of the effective heat capacity. DOE recognizes that this may contribute 
to additional test-to-test variation depending on the time needed for 
the temperature of the load to stabilize for each test. DOE also noted 
that it had to conduct a number of additional retests in cases where 
the final temperature was not within the specified range. DOE 
recognizes that specifying a tighter final temperature range than 
 5 [deg]C may represent a testing burden due to the 
difficulties of achieving a consistent final load temperature from test 
to test.

[[Page 33115]]



                                                      Table 12--Food Load Test Results: Shortening
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                             Target               Test 1                       Test 2                       Test 3
                                           final avg. ---------------------------------------------------------------------------------------  Test-to-
         Product type           Test unit  temp range     Avg. heat     Avg. final     Avg. heat     Avg. final     Avg. heat     Avg. final     test
                                             of load    capacity  (J/g     temp      capacity  (J/g     temp      capacity  (J/g     temp      variation
                                            ([deg]C)   [middot][deg]C)   ([deg]C)   [middot][deg]C)   ([deg]C)   [middot][deg]C)   ([deg]C)       (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Combination, Countertop......          14   60  5         33.115          83.7         35.924          79.1         31.932          75.9        6.09
                                            80  5
Combination, Over-the-Range..          17   60  5         25.688          69.1         25.081          68.0         26.199          67.5        2.18
                                            70  5
--------------------------------------------------------------------------------------------------------------------------------------------------------

    DOE next conducted testing to evaluate the repeatability of Russet 
Burbank potatoes as a test food load using the convection microwave 
cooking function. DOE selected potatoes as a test load based on a 
review of commonly found foods contained in the cooking manuals and 
recipe books supplied with convection microwave ovens. Based on 
discussions with a food scientist specializing in potato production and 
storage management as well as potato seed quality and performance, DOE 
specifically selected Russet Burbank potatoes based on their consistent 
water content. In addition, Russet potatoes were identified to be the 
most likely to be available year round and are grown with standardized 
approaches. For each test DOE selected 3 potatoes with similar weights, 
with no greater than an 80 g difference between the largest and 
smallest potato for a batch of 3 potatoes. The potatoes were then 
placed in an equidistant triangle pattern directly on the turntable 
dish at approximately 7 centimeters from the center of the dish. DOE 
noted that it was unable to keep a tight tolerance on the total 
combined mass due to the variability in size and shape of the potatoes. 
The temperature of each potato was measured using single thermocouples 
placed approximately at the center of each potato. The potato loads 
were heated from 10  1 [deg]C to about 60  5 
[deg]C using the convection microwave cooking function. DOE selected 
the target final temperature of 60 [deg]C based on a review of the 
cooking instructions for potatoes found in the cooking manuals and 
recipe books. As was done for the shortening tests, the measured 
cooking cycle energy consumption was then used to calculate the 
effective heat capacity. For each test unit, DOE conducted three 
identical tests to evaluate repeatability. DOE noted that Russet 
Burbank potatoes are grown in multiple geographical regions in North 
America, the majority of which are grown in Idaho and Canada. DOE 
decided to conduct testing to determine whether Russet Burbank potatoes 
grown in certain regions produce more repeatable test results. As a 
result, DOE tested batches of potatoes from the two areas where the 
majority of Russet Burbank potatoes are grown, Idaho and Canada.
    The Russet Burbank potato testing results are presented below in 
Table 13 and Table 14. The results showed test-to-test variation for 
the calculated effective heat capacity ranging from 2.89 percent to 
8.50 percent for both types of Russet Burbank potatoes. DOE noted that, 
in addition to the varying masses of each of the three test potatoes, 
the varying shape of each potato may also affect the time required to 
heat the center of each potato to the target final temperature. DOE 
also noted that it was difficult to achieve a consistent final average 
temperature from test to test due to the different masses and shapes of 
the potatoes. DOE observed, similar to the tests for shortening, that 
when it measured the final temperature of the load after the completion 
of the cooking cycle, the temperature continued to rise for 80-160 
seconds in some cases before finally leveling off. DOE waited until the 
temperature leveled off and used that measurement for the calculation 
of the effective heat capacity. DOE recognizes that this may contribute 
to additional test-to-test variation depending on the time needed for 
the temperature of the load to stabilize for each test. As with the 
shortening tests, DOE noted that it had to conduct a number of 
additional retests in cases in which the final temperature was not 
within the specified range. DOE similarly recognizes that specifying a 
tighter final temperature range than  5 [deg]C for potatoes 
may represent a testing burden due to the difficulties of achieving a 
consistent final load temperature from test to test.
    DOE recognizes that in addition to issues with test-to-test 
repeatability, the lab-to-lab reproducibility will also be difficult to 
maintain if the potatoes are grown under different conditions, 
including climate and growing conditions (i.e., soil conditions, 
watering frequency, harvesting time, etc.) that may vary throughout the 
growing seasons even within specific geographical regions.

                              Table 13--Food Load Test Results: Idaho Russet Potato
----------------------------------------------------------------------------------------------------------------
                                                 Average heat capacity (J/g [middot][deg]C)      Test-to-test
            Product type              Test unit -------------------------------------------- variation--standard
                                                   Test 1     Test 2     Test 3    Average        error (%)
----------------------------------------------------------------------------------------------------------------
Convection Microwave, Countertop....         12     29.541     32.359     31.366     31.089               4.60
                                             14     33.972     39.277     39.732     37.660               8.50
                                     ---------------------------------------------------------------------------
    Average.........................  .........  .........  .........  .........     34.375               6.55
----------------------------------------------------------------------------------------------------------------


[[Page 33116]]


                            Table 14--Food Load Test Results: Canadian Russet Potato
----------------------------------------------------------------------------------------------------------------
                                                 Average heat capacity (J/g [middot][deg]C)      Test-to-test
            Product type              Test unit -------------------------------------------- variation--standard
                                                   Test 1     Test 2     Test 3    Average        error (%)
----------------------------------------------------------------------------------------------------------------
Convection Microwave, Countertop....         13     20.230     22.081     19.741     20.684               5.97
Convection Microwave, Over-the-Range         17     29.145     29.722     30.845     29.904               2.89
                                             18     29.155     27.766     27.300     28.074               3.44
                                     ---------------------------------------------------------------------------
    Average.........................  .........  .........  .........  .........     26.220               4.10
----------------------------------------------------------------------------------------------------------------

    DOE also conducted testing with USDA grade A boneless chicken 
breasts using the same basic procedure described for the testing with 
potatoes, but with the different starting and final test load 
temperatures. DOE noted that chicken is generally stored frozen, and 
then allowed to thaw before cooking. To determine an appropriate 
starting temperature, DOE used the programmed defrost cycle settings 
for chicken on a microwave oven in its test sample and measured the 
temperature of the chicken breasts after the defrost cycle. The 
temperature of the thawed chicken after the defrost cycle ranged 
between 2 to 5 [deg]C. However, at 2 [deg]C, DOE noted that the chicken 
breast still had some localized frozen sections not found at 5 [deg]C. 
Therefore, DOE used a starting temperature of 5  1 [deg]C. 
A target final temperature of 90  5 [deg]C was used based 
on review of cooking instructions for chicken found in cooking manuals 
and recipe books supplied with convection microwave ovens. For this 
testing, DOE selected 3 chicken breasts for each test with similar 
weights with no greater than a 170 g difference between the largest and 
smallest chicken breast. For each test unit, DOE conducted up to four 
identical tests to evaluate repeatability.
    The results from testing, presented below in Table 15, showed test-
to-test variation for the calculated effective heat capacity ranging 
from 1.09 percent to 12.57 percent, with an average of 7.20 percent. 
DOE noted that this variability may be due to the varying masses and 
shapes of each chicken breast. DOE also observed, similar to the tests 
for shortening and potatoes, that when it measured the final 
temperature of the load after the completion of the cooking cycle, the 
temperature continued to rise for 60-150 seconds in some cases before 
finally leveling off. DOE waited until the temperature leveled off and 
used that measurement for the calculation of the effective heat 
capacity. DOE recognizes that this may contribute to additional test-
to-test variation depending on the time needed for the temperature of 
the load to stabilize for each test. As with the other food load tests, 
DOE noted that it had to conduct a number of additional retests in 
cases in which the final temperature was not within the specified 
range. DOE similarly recognizes that specifying a tighter final 
temperature range than  5 [deg]C for chicken may represent 
a testing burden due to the difficulties of achieving a consistent 
final load temperature from test to test.
    DOE recognizes that the following factors may contribute to 
variation from chicken to chicken, and thus test to test, as well as 
contribute to variation in reproducibility for chicken breasts from 
different suppliers:
     Individual chicken's diet;
     Individual chicken's physical activity;
     Genetics; and
     Methods of breeding and raising chickens from farm to farm

                                         Table 15--Food Load Test Results: USDA Grade A Boneless Chicken Breast
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Range of        Average heat capacity (J/g [middot][deg]C)
                                                                     total   -------------------------------------------------------     Test-to-test
                     Product type                       Test unit    masses                                                          variation--standard
                                                                      (g)       Test 1     Test 2     Test 3     Test 4    Average        error  (%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Convection Microwave, Countertop......................         12    700-781     37.449     37.533     36.867      (\1\)     37.283               0.97
                                                               14    687-804     34.674     32.619     35.469                34.254               4.29
Convection Microwave, Over-the-Range..................         17    708-794     32.751     44.727     39.019     39.373     38.967              12.57
                                                       -------------------------------------------------------------------------------------------------
    Average...........................................  .........  .........  .........  .........  .........  .........     36.835               5.95
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ For test units 12 and 14, DOE conducted only 3 repeat tests.

    7. DOE requests comment on the suitability of real food loads for 
incorporation into the DOE microwave oven test procedure for testing 
convection microwave ovens. DOE also welcomes comments specifically on 
the test methodologies (i.e., load temperature measurement methods, 
starting and final temperatures, mass of test load) described in this 
section and the repeatability of test results using shortening, Russet 
Burbank potatoes, and USDA grade A boneless chicken breasts as well as 
the reproducibility of such food loads.
Food Load Simulation Testing
    As part of the convection microwave cooking testing, DOE also 
evaluated loads that would simulate actual foods. As discussed in the 
October 2011 RFI, DOE noted that one consumer product review 
organization in the UK uses the solidifying powder TX-151, which when 
combined with water creates a gel, to simulate a food load (in their 
case lasagna).\4\ DOE decided to conduct testing using the TX-151 
solidifying powder to evaluate the repeatability of test results using 
the convection microwave cooking function. DOE prepared three different 
water-solidifying powder mixtures using ratios recommended by the 
manufacturer of TX-151 to create medium, medium-hard, and hard firmness 
gels, using ratios of powder to water of 1:10, 1:7,

[[Page 33117]]

and 1:5, respectively. DOE noted that when mixing each powder-to-water 
ratio, the temperature of the water and mixing speed/time directly 
influenced the mixture's homogeneity. As a result, DOE determined, 
based on experimentation, the water temperatures and mixing speeds/
times for each powder-to-water ratio that produced the most homogenous 
mixtures. DOE also covered the mixtures and allowed them to set for two 
different lengths of time (2 hours and 6 hours) and at two different 
temperatures (20-25 [deg]C and 7-10 [deg]C) to evaluate whether setting 
time and temperature affected the consistency of the gel. DOE observed 
that the allowing the gels to set for 6 hours did not noticeably change 
the hardness or consistency as compared to the gels that were allowed 
to set for 2 hours. In addition, DOE observed in most cases a 0.1 g to 
0.3 g loss in water prior to the cooking cycle for both the 2 hour and 
6 hour setting times due to evaporation, and that the water loss was 
not noticeably higher for the 6 hour setting time. DOE noted that this 
was likely because the mixtures were covered while being allowed to 
set. Based on these observations, DOE selected the 2 hour setting time 
for testing. In addition, DOE noted that the two different setting 
temperatures did not result in a noticeably different hardness or 
consistency after a given setting time. As a result, DOE selected the 
7-10 [deg]C setting temperature so that the temperature of the test 
load at the start of the test cycle would be more representative of 
food load temperatures at the start of cooking.
---------------------------------------------------------------------------

    \4\ For more information, visit http://www.which.co.uk/home-and-garden/kitchen/guides/how-we-test-microwaves/.
---------------------------------------------------------------------------

    DOE tested each convection microwave oven in its test sample using 
each of the three power-to-water ratio gels (i.e., 1:10, 1:7, and 1:5) 
prepared as described above. For each test, DOE prepared 350 g of the 
gel mixtures in the 900 ml borosilicate glass containers. Similar to 
the method discussed above for shortening, DOE used three thermocouples 
to measure the temperature of the load, with one thermocouple placed in 
the center of the load, and the other two placed approximately one inch 
from the edge of the container on either side, and each thermocouple 
placed at an equal distance from the top and bottom of the load. The 
test loads were heated from 10  1 [deg]C until the center 
temperature was 60  5 [deg]C using the convection microwave 
cooking function. DOE chose to use a target final temperature for the 
center thermocouple probe because it noted that the temperatures of two 
outer thermocouple probes were much more variable and difficult to 
repeat. In addition, the temperature at the center of the food load is 
generally used to determine whether food is cooked completely. DOE 
noted that the target final temperature of 60  5 [deg]C 
resulted in an overall average final temperature of approximately 70 
 5 [deg]C for all three thermocouple probes in most cases.
    The results from this testing are presented below in Table 16 
through Table 18. For the 1:10 powder-to-water ratio gel, the test-to-
test variation ranged from 1.89 percent to 5.89 percent, with an 
average of 4.02 percent. For the 1:7 and 1:5 powder-to-water ratio gel 
tests the range in test-to-test variation was greater than the 1:10 
powder-to-water ratio gel tests. DOE noted that this may be due to the 
1:10 powder-to-water ratio gel being the most homogenous mixture. DOE 
also observed that the outer edge on the surface of the gel was 
slightly evaporated at the completion of the cooking cycle. In 
particular, the gels with a powder-to-water ratio of 1:10 had more 
evaporation on the edges than the 1:7 and 1:5 ratio gels, which was 
likely due to the larger amount of water making up the 1:10 ratio gels.
    DOE also observed, similar to the tests for real food loads, that 
when it measured the final temperature of the load after the completion 
of the cooking cycle, the temperature continued to rise for 30-90 
seconds in most cases before finally leveling off. DOE waited until the 
temperature leveled off and used that measurement for the calculation 
of the effective heat capacity. DOE recognizes that this may contribute 
to additional test-to-test variation depending on the time needed for 
the temperature of the load to stabilize for each test. As with the 
real food load tests, DOE also noted that it had to conduct a number of 
additional retests in cases in which the final temperature was not 
within the specified range. DOE similarly recognizes that specifying a 
tighter final temperature range than  5 [deg]C for the TX-
151 gels may represent a testing burden due to the difficulties of 
achieving a consistent final load temperature from test to test.

                                      Table 16--TX-151 1:10 Ratio Gel Tests
----------------------------------------------------------------------------------------------------------------
                                                 Average heat capacity (J/g [middot][deg]C)      Test-to-test
            Product type              Test unit -------------------------------------------- variation--standard
                                                   Test 1     Test 2     Test 3    Average        error (%)
----------------------------------------------------------------------------------------------------------------
Convection Microwave, Countertop....         11     33.828     32.448     36.422     34.233               5.89
                                             12     43.748     40.932     39.665     41.448               5.04
                                             13     27.655     29.565     28.127     28.449               3.50
                                             14     54.402     51.997     53.212     53.203               2.26
Convection Microwave, Over-the-Range         15     31.301     32.376     29.910     31.196               3.96
                                             17     34.785     33.503     34.035     34.108               1.89
                                             18     49.865     45.797     44.999     46.887               5.57
                                     ---------------------------------------------------------------------------
    Average.........................  .........  .........  .........  .........     38.503               4.02
----------------------------------------------------------------------------------------------------------------


                                      Table 17--TX-151 1:7 Ratio Gel Tests
----------------------------------------------------------------------------------------------------------------
                                                 Average heat capacity (J/g [middot][deg]C)      Test-to-test
            Product type              Test unit -------------------------------------------- variation--standard
                                                   Test 1     Test 2     Test 3    Average        error (%)
----------------------------------------------------------------------------------------------------------------
Convection Microwave, Countertop....         11     34.378     34.588     32.836     33.934               2.82
                                             12     44.150     43.724     42.968     43.614               1.37
                                             13     28.102     28.068     28.381     28.183               0.61
                                             14     48.668     57.097     56.416     54.060               8.66
Convection Microwave, Over-the-Range         15     34.109     27.204     33.126     31.480              11.87

[[Page 33118]]

 
                                             17     34.850     34.699     34.307     34.618               0.81
                                             18     44.813     43.801     44.559     44.391               1.19
                                     ---------------------------------------------------------------------------
    Average.........................  .........  .........  .........  .........     38.612               3.90
----------------------------------------------------------------------------------------------------------------


                                      Table 18--TX-151 1:5 Ratio Gel Tests
----------------------------------------------------------------------------------------------------------------
                                                 Average heat capacity (J/g [middot][deg]C)      Test-to-test
            Product type              Test unit -------------------------------------------- variation--standard
                                                   Test 1     Test 2     Test 3    Average        error (%)
----------------------------------------------------------------------------------------------------------------
Convection Microwave, Countertop....         11     32.798     34.219     31.778     32.932               3.72
                                             12     45.869     45.375     44.995     45.413               0.97
                                             13     30.061     28.882     28.484     29.142               2.81
                                             14     55.433     59.854     48.900     54.729              10.07
Convection Microwave, Over-the-Range         15     27.940     33.899     32.653     31.497               9.98
                                             17     35.116     36.735     36.633     36.162               2.51
                                             18     54.040     46.450     47.023     49.171               8.60
                                     ---------------------------------------------------------------------------
    Average.........................  .........  .........  .........  .........     39.864               5.52
----------------------------------------------------------------------------------------------------------------

    DOE may consider amendments to the microwave oven test procedure 
for measuring the convection microwave cooking function for convection 
microwave ovens. If DOE determines such test procedure amendments are 
warranted, it may consider developing an integrated metric that 
incorporates the convection microwave cooking function energy use along 
with other active mode and standby mode energy use. As a result, DOE 
would require consumer usage data on the number of annual convection 
microwave cooking cycles and annual hours spent in convection microwave 
cooking mode for convection microwave ovens. However, DOE is currently 
unaware of any such data. DOE is seeking comment on the following 
issues related to convection microwave cooking.
    8. DOE requests comment on the suitability of the various powder-
to-water ratio gels and testing methods (i.e., load temperature 
measurement methods, starting and final temperatures, and mass of test 
load) described in this section for incorporation into the DOE 
microwave oven test procedure for testing convection microwave ovens. 
DOE also welcomes comments specifically on the repeatability of test 
results presented in this section as well as comments on the 
reproducibility of test measurements. In addition, DOE requests comment 
on the testing burden associated with these testing methods. When 
providing comments, please quantify and describe the associated testing 
burdens.
    9. DOE requests comment on whether there are any other food load 
simulations and testing methods that it should consider for measuring 
the energy use of convection microwave ovens. In particular, DOE 
requests data and information on the repeatability of such loads and 
testing methods.
    10. DOE requests consumer usage data on the number of annual active 
mode cycles and annual hours spent in microwave-only cooking mode and 
convection microwave cooking mode for convection microwave ovens.

E. Convection Microwave Oven Convection-Only Cooking Testing

    As discussed above, DOE noted that convection microwave ovens can 
also be operated using the convection-only cooking function. DOE 
investigated whether a testing procedure could be developed to evaluate 
the convection-only cooking function of a convection microwave oven. 
DOE developed a testing method based on the DOE conventional cooking 
products test procedure for conventional ovens at 10 CFR part 430, 
subpart B, appendix I, to measure the energy consumption of the 
convection cooking function for convection microwave ovens. The DOE 
conventional oven test procedure involves setting the convection 
cooking cycle such that the temperature inside the oven is 325  5[emsp14][deg]F higher than the room ambient air temperature. An 
8.5  0.1 pound cylindrical aluminum test block is then 
heated from ambient room air temperature  4[emsp14][deg]F 
until the test block temperature has increased 234[emsp14][deg]F above 
its initial temperature. The temperature of the aluminum test block is 
measured using a single thermocouple placed at the center of the block 
in a 0.08 inch diameter hole 0.8 inches from the top of the block. 
Because this test uses only convection heating and is not subject to 
safety concerns with arcing from microwave energy, thermocouples can be 
used to measure the test load temperature inside the microwave oven 
cavity during the test cycle. The measured energy consumption is used 
to calculate the cooking efficiency and energy factor.
    As discussed above, DOE noted that the convection temperature 
setting requirement of 325  5[emsp14][deg]F higher than the 
room ambient air temperature would result in a temperature setting 
close to 400[emsp14][deg]F. Based on DOE's review of products currently 
available on the U.S. market, a number of convection microwave ovens 
did not have a 400[emsp14][deg]F temperature setting, but all 
convection microwave ovens that DOE surveyed had a 375[emsp14][deg]F 
temperature setting. As a result, DOE modified the test method to 
conduct this testing using a temperature control setting of 
375[emsp14][deg]F to heat the aluminum test block to 234[emsp14][deg]F 
above its initial temperature. In addition, DOE also specified that the 
aluminum test block be placed on the metal cooking rack provided by the 
manufacturer. For each convection microwave oven, DOE conducted three 
identical tests to evaluate repeatability of results. The results from 
testing, presented in Table 19, showed test-to-test variation ranging

[[Page 33119]]

from 0.68 percent to 2.11 percent, with an average of 1.30 percent.

                                 Table 19--Convection-Only Cooking Test Results
----------------------------------------------------------------------------------------------------------------
                                                           Cooking efficiency (%)                Test-to-test
            Product type              Test unit -------------------------------------------- variation--standard
                                                   Test 1     Test 2     Test 3    Average        error (%)
----------------------------------------------------------------------------------------------------------------
Convection Microwave, Countertop....         11       7.37       7.24       7.07       7.23               2.11
                                             12      12.48      12.53      12.25      12.42               1.19
                                             13       8.29       8.49       8.32       8.37               1.28
                                             14      10.12      10.06      10.31      10.16               1.32
Convection Microwave, Over-the-Range         15       6.62       6.49       6.43       6.51               1.51
                                             17      11.19      11.05      11.08      11.11               0.68
                                             18       7.60       7.66       7.51       7.59               1.00
                                     ---------------------------------------------------------------------------
    Average.........................  .........  .........  .........  .........       9.06               1.30
----------------------------------------------------------------------------------------------------------------

    If DOE determines that actual and simulation food loads do not 
produce repeatable results using the convection microwave cooking 
function, DOE may consider developing a test procedure using a single 
metric that accounts for the energy use of the different cooking 
functions (i.e., microwave-only, convection-only, and convection 
microwave cooking) using the microwave-only cooking test method and the 
convection-only cooking test method. As discussed above, DOE noted that 
the convection microwave cooking cycle for microwave ovens in DOE's 
test sample consisted of cycling between microwave-only cooking for 30 
percent of the time and convection-only cooking for the remaining 70 
percent of the time. DOE may use this mix of microwave and convection 
cooking to apportion the energy use measured using the individual test 
procedures for microwave-only and convection-only cooking to calculate 
the per-cycle energy use for a convection microwave cooking cycle. 
However, DOE is not aware of consumer usage data regarding 
representative cooking cycle lengths, number of annual cooking cycles, 
or annual usage hours for each of the cooking functions for convection 
microwave ovens.
    11. DOE requests comment on the suitability of incorporating the 
convection-only cooking method presented above into the DOE test 
procedure for convection microwave ovens. DOE also requests comment on 
the potential approach of using the microwave-only and convection-only 
cooking tests to calculate the energy use for the convection microwave 
cooking function. DOE seeks comment on the repeatability of the 
convection microwave oven convection-only cooking function test results 
presented in this section. DOE welcomes additional data and inputs on 
the repeatability and reproducibility of this convection-only cooking 
test method.
    12. DOE requests comment on the testing burden associated with 
these testing methods. When providing comments, please quantify and 
describe the associated testing burdens.
    13. DOE seeks comment on the temperature setting of 
375[emsp14][deg]F and target final temperature of 234[emsp14][deg]F 
above the initial test block temperature and whether such settings 
would be appropriate for the DOE test procedure for convection 
microwave ovens.
    14. DOE seeks consumer usage data on the representative cooking 
cycle lengths, number of annual cooking cycles, and annual usage hours 
for each of the cooking functions for convection microwave ovens (i.e., 
microwave-only, convection-only, and convection microwave cooking). DOE 
also welcomes comment on whether a split of 30 percent microwave and 70 
percent convection would be appropriate for apportioning energy use for 
the convection microwave cooking function.

F. Cooling Down Energy Use

    As discussed above in section 0.0, DOE noted that for all of the 
units in its test sample, none contained a fan that operated at the end 
of the microwave-only cooking cycle to cool the appliance down. 
However, DOE noted that a number of the convection microwave ovens in 
its sample had a fan that operated after the completion of the 
convection microwave cooking cycle and convection-only cooking cycle in 
order to cool the microwave oven. DOE observed during testing that the 
cooling down power ranged from approximately 19 watts (W) to 63 W. 
Table 20 shows the measured cooling down energy consumption and amount 
of time the cooling fan ran after the completion of the convection-only 
cooking cycle for the convection microwave ovens in DOE's test sample 
that operated a cooling fan after the cooking cycle. These measurements 
showed that the convection microwave ovens in DOE's test sample that 
operated a cooling fan after the completion of the cooking cycle 
consumed between 1.0 Wh and 7.2 Wh. DOE also noted that the amount of 
time that the cooling fan operated varied from product to product, and 
also from test to test.

                                                    Table 20--Convection-Only Cooling Down Energy Use
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Test 1                    Test 2                    Test 3
                                                                           -----------------------------------------------------------------------------
                         Product type                           Test unit    Cool down    Cool down    Cool down    Cool down    Cool down    Cool down
                                                                             energy use    duration    energy use    duration    energy use    duration
                                                                                (Wh)        (min)         (Wh)        (min)         (Wh)        (min)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Convection Microwave, Countertop.............................           11  ...........  ...........  ...........  ...........  ...........  ...........
                                                                        12          1.2         3.22          1.1         2.95          1.0         2.80
                                                                        13  ...........  ...........  ...........  ...........  ...........  ...........
                                                                        14          1.2         3.68          1.3         3.83          1.1         3.48
Convection Microwave, Over-the-Range.........................           15  ...........  ...........  ...........  ...........  ...........  ...........

[[Page 33120]]

 
                                                                        17          6.7         6.52          6.6         6.28          7.2         6.90
                                                                        18          2.5         3.13          2.6         3.25          2.6         3.27
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Test units for which no values are listed indicate that no cooling fan ran after the completion of the combination or convection-only cooking
  cycles.

    DOE may consider test procedure amendments to include the cooling 
fan energy consumption as part of the energy efficiency metric for 
convection microwave ovens. If DOE determines that such amendments are 
appropriate, it may also consider adjustments to the annual standby 
mode hours to account for the additional time that the product operates 
the cooling fan at the end of the cooking cycle. The total annual 
cooling fan hours would be calculated by multiplying the amount of time 
that the cooling fan operates per cycle by the number of total annual 
convection microwave cooking and convection-only cooking cycles. These 
hours would then be subtracted from the total number of standby mode 
hours. However, DOE is unaware of consumer usage data regarding the 
total annual convection microwave and convection-only cooking cycles 
for convection microwave ovens.
    15. DOE welcomes comment on whether the cooling fan energy 
consumption should be included in the efficiency metric for convection 
microwave ovens.

G. Additional Issues on Which DOE Seeks Comment

    DOE may consider amendments to the microwave oven test procedure 
for both microwave-only and convection microwave ovens based on the 
testing discussed in the sections above. In addition to the specific 
issues for each testing method on which DOE is seeking comment, DOE is 
seeking comment on the following:
    16. DOE welcomes general comments about the potential testing 
methodologies to measure microwave oven active mode energy use 
presented in this notice. DOE also welcomes comment on any alternative 
testing methodologies appropriate for inclusion in the DOE microwave 
oven test procedure. DOE requests data on the repeatability and 
reproducibility of such testing methods. DOE also welcomes additional 
data on the repeatability and reproducibility of testing results using 
the test methods presented in this notice.
    The purpose of this NODA is to solicit feedback from industry, 
manufacturers, academia, consumer groups, efficiency advocates, 
government agencies, and other stakeholders on issues related to the 
DOE microwave oven test procedure. DOE is specifically interested in 
information and additional data on the potential amendments to the 
microwave oven test procedure for measuring active mode energy use 
presented in today's notice. Respondents are advised that DOE is under 
no obligation to acknowledge receipt of the information received or 
provide feedback to respondents with respect to any information 
submitted under this NODA. Responses to this NODA do not bind DOE to 
any further actions related to this topic.

    Issued in Washington, DC, on May 29, 2012.
Kathleen B. Hogan,
Deputy Assistant Secretary for Energy, Energy Efficiency and Renewable 
Energy.
[FR Doc. 2012-13609 Filed 6-4-12; 8:45 am]
BILLING CODE 6450-01-P