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3.5 STANDBY MODE AND OFF MODE POWER.
Establish the testing conditions set forth in Section 2 “Testing Conditions” of this appendix. For
clothes dryers that take some time to enter a stable state from a higher power state as discussed in
Section 5, Paragraph 5.1, Note 1 of IEC 62301 (Second Edition ) (incorporated by reference; see
§ 430.3), allow sufficient time for the clothes dryer to reach the lower power state before
proceeding with the test measurement. Follow the test procedure specified in section 5,
paragraph 5.3.2 of IEC 62301 (Second Edition) for testing in each possible mode as described in
sections 3.5.1 and 3.5.2 of this appendix.
3.5.1 If a clothes dryer has an inactive mode, as defined in section 1.13 of this appendix,
measure and record the average inactive mode power of the clothes dryer, P IA, in watts.
3.5.2 If a clothes dryer has an off mode, as defined in section 1.16 of this appendix, measure
and record the average off mode power of the clothes dryer, P OFF, in watts.
4. CALCULATION OF DERIVED RESULTS FROM TEST
MEASUREMENTS
4.1 DOE TEST CALCULATIONS.
Calculation of derived results for measurements gathered during the DOE Test as described in
section 3.3.1.1.
4.1.1 Total per-cycle electric dryer energy consumption for DOE.
Calculate the total electric dryer energy consumption per cycle, E ce, expressed in
kilowatt-hours per cycle and defined as:
E ce= E t,
for automatic termination control dryers, and,
E ce= [55.5/(W w− W d)] × E t× field use,
for timer dryers
Where:
55.5 = an experimentally established value for the percent reduction in the
moisture content of the test load during a laboratory test cycle expressed as a
percent.
E t= the energy recorded in section 3.4.5 of this appendix
field use = 1.18, the field use factor for clothes dryers with time termination
control systems only without any automatic termination control functions.
W w= the moisture content of the wet test load in percent as recorded in section
3.4.2 of this appendix.
W d= the moisture content of the dry test load in percent as recorded in section
3.4.3 of this appendix.
4.1.2 Per-cycle gas dryer electrical energy consumption for DOE.
Calculate the gas dryer electrical energy consumption per cycle, E ge, expressed in
kilowatt-hours per cycle and defined as:
E ge= E te,](https://image.slidesharecdn.com/d9591d3e-6d63-49fd-b6ea-e48f1c3f48ed-141229132233-conversion-gate02/85/PG_E_Dryer_Comment_Letter_EERE-2014-BT-TP-0034-1-31-320.jpg)
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for automatic termination control dryers, and,
E ge= [55.5/(W w−W d)] × E te× field use,
for timer dryers
Where:
E te= the energy recorded in section 3.4.6.1 of this appendix.
field use, 55.5, W w, W d as defined in section 4.1.1 of this appendix.
4.1.3 Per-cycle gas dryer gas energy consumption for DOE.
Calculate the gas dryer gas energy consumption per cycle, E ge, expressed in Btus per
cycle and defined as:
E gg= E tg× GEF
for automatic termination control dryers, and,
E gg= [55.5/(W w−W d)] × E tg× field use × GEF
for timer dryers
Where:
E tg= the energy recorded in section 3.4.6.2 of this appendix.
GEF = corrected gas heat value (Btu per cubic foot) as defined in section 3.4.6.3
of this appendix,
field use, 55.5, W w, W d as defined in section 4.1.1 of this appendix.
4.1.4 Total per-cycle gas dryer energy consumption expressed in kilowatt-hours for DOE.
Calculate the total gas dryer energy consumption per cycle, E cg, expressed in kilowatt-
hours per cycle and defined as:
E cg= E ge+ (E gg/3412 Btu/kWh)
Where:
E ge= the energy calculated in section 4.1.2 of this appendix
E gg= the energy calculated in section 4.1.3 of this appendix
4.1.5 Per-cycle standby mode and off mode energy consumption for DOE.
Calculate the dryer inactive mode and off mode energy consumption per cycle, E TSO,
expressed in kWh per cycle and defined as:
E TSO= [(P IA× S IA) + (P OFF× S OFF)] × K/283
Where:
P IA= dryer inactive mode power, in watts, as measured in section 3.5.1;
P OFF= dryer off mode power, in watts, as measured in section 3.5.2.
If the clothes dryer has both inactive mode and off mode, S IA and S OFF both
equal 8,620 ÷ 2 = 4,310, where 8,620 is the total inactive and off mode annual
hours;
If the clothes dryer has an inactive mode but no off mode, the inactive mode
annual hours, S IA, is equal to 8,620 and the off mode annual hours, S OFF, is equal
to 0;
If the clothes dryer has an off mode but no inactive mode, S IA is equal to 0 and
S OFF is equal to 8,620
Where:
K = 0.001 kWh/Wh conversion factor for watt-hours to kilowatt-hours; and](https://image.slidesharecdn.com/d9591d3e-6d63-49fd-b6ea-e48f1c3f48ed-141229132233-conversion-gate02/85/PG_E_Dryer_Comment_Letter_EERE-2014-BT-TP-0034-1-32-320.jpg)
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T A = [55.5/(W w – W d)] × T D
for timer dryers.
Where:
T D = the duration of the dryer test case in minutes as measured in section 3.4.9
55.5, W w, W d as defined in section 4.1.1 of this appendix.
4.2 SUPPLEMENTAL TEST CALCULATIONS.
Repeat sections 4.2.1 through 4.2.9 a total of four times, once for each supplemental test
(sections 3.3.1.2 through 3.3.1.5).
4.2.1 Total per-cycle electric dryer energy consumption.
Calculate the total electric dryer energy consumption per cycle, E ce, expressed in
kilowatt-hours per cycle and defined as:
E ce = [PD/(W w− W dt)] × E t,
Where:
PD = 58% for tests conducted during sections 3.3.1.2 through 3.3.1.4;
PD = 60% for the test conducted during section 3.3.1.5;
E t = the energy recorded in section 3.4.5 of this appendix;
W w = the moisture content of the wet test load in percent as recorded in section
3.4.2 of this appendix;
W dt = target dry weight of 4% for tests conducted during sections 3.3.1.2 through
3.3.1.4; and
W dt = target dry weight of 2% for the test conducted during section 3.3.1.5
4.2.2 Per-cycle gas dryer electrical energy consumption.
Calculate the gas dryer electrical energy consumption per cycle, E ge, expressed in
kilowatt-hours per cycle and defined as:
E ge= [PD/(W w−W dt)] × E te,
Where:
E te= the energy recorded in section 3.4.6.1 of this appendix.
PD, W w, W dt as defined in section 4.2.1 of this appendix.
4.2.3 Per-cycle gas dryer gas energy consumption.
Calculate the gas dryer gas energy consumption per cycle, E ge, expressed in Btus per
cycle and defined as:
E gg= [PD/(W w−W dt)] × E tg × GEF
Where:
E tg= the energy recorded in section 3.4.6.2 of this appendix.
GEF = corrected gas heat value (Btu per cubic foot) as defined in section 3.4.6.3
of this appendix,
PD, W w, W dt as defined in section 4.2.1 of this appendix.
4.2.4 Total per-cycle gas dryer energy consumption expressed in kilowatt-hours.
Calculate the total gas dryer energy consumption per cycle, E cg, expressed in kilowatt-
hours per cycle and defined as:](https://image.slidesharecdn.com/d9591d3e-6d63-49fd-b6ea-e48f1c3f48ed-141229132233-conversion-gate02/85/PG_E_Dryer_Comment_Letter_EERE-2014-BT-TP-0034-1-34-320.jpg)
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E cg= E ge+ (E gg/3412 Btu/kWh)
Where:
E ge= the energy calculated in section 4.2.2 of this appendix
E gg= the energy calculated in section 4.2.3 of this appendix
4.2.5 Per-cycle standby mode and off mode energy consumption.
Calculate the dryer inactive mode and off mode energy consumption per cycle, E TSO,
expressed in kWh per cycle and defined as:
E TSO= [(P IA× S IA) + (P OFF× S OFF)] × K/283
Where:
P IA= dryer inactive mode power, in watts, as measured in section 3.5.1;
P OFF= dryer off mode power, in watts, as measured in section 3.5.2.
If the clothes dryer has both inactive mode and off mode, S IA and S OFF both
equal 8,620 ÷ 2 = 4,310, where 8,620 is the total inactive and off mode annual
hours;
If the clothes dryer has an inactive mode but no off mode, the inactive mode
annual hours, S IA, is equal to 8,620 and the off mode annual hours, S OFF, is equal
to 0;
If the clothes dryer has an off mode but no inactive mode, S IA is equal to 0 and
S OFF is equal to 8,620
Where:
K = 0.001 kWh/Wh conversion factor for watt-hours to kilowatt-hours; and
283 = representative average number of clothes dryer cycles in a year.
4.2.6 Per-cycle combined total energy consumption expressed in kilowatt-hours.
Calculate the per-cycle combined total energy consumption, E CC, expressed in kilowatt-
hours per cycle and defined for an electric clothes dryer as:
E CC= E ce+ E TSO
Where:
E ce= the energy calculated in section 4.2.1 of this appendix, and
E TSO= the energy calculated in section 4.2.5 of this appendix, and defined for a
gas clothes dryer as:
E CC= E cg+ E TSO
Where:
E cg= the energy calculated in section 4.2.4 of this appendix, and
E TSO= the energy calculated in section 4.2.5 of this appendix.
4.2.7 Per-cycle Energy Factor in pounds per kilowatt-hour.
Calculate the energy factor, EF, expressed in pounds per kilowatt-hour and defined for an
electric clothes dryer as:
EF = W bonedry/E ce
Where:
W bonedry= the bone dry test load weight recorded in section 3.4.1 of this appendix,
and](https://image.slidesharecdn.com/d9591d3e-6d63-49fd-b6ea-e48f1c3f48ed-141229132233-conversion-gate02/85/PG_E_Dryer_Comment_Letter_EERE-2014-BT-TP-0034-1-35-320.jpg)
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E ce= the energy calculated in section 4.2.1 of this appendix, and defined for a gas
clothes dryer as:
EF = W bonedry/E cg
Where:
W bonedry= the bone dry test load weight recorded in section 3.4.1 of this appendix,
and
E cg= the energy calculated in section 4.2.4 of this appendix.
4.2.8 Per-cycle Combined Energy Factor in pounds per kilowatt-hour.
Calculate the combined energy factor, CEF, expressed in pounds per kilowatt-hour and
defined as follows:
CEF = W bonedry/E CC
Where:
W bonedry= the bone dry test load weight recorded in section 3.4.1 of this appendix,
and
E CC= the energy calculated in section 4.2.6 of this appendix.
If the test run was invalid, the CEF shall be given a value of 0.
4.2.9 Per-cycle Test Duration in minutes.
Calculate the per-cycle test duration, T A, expressed in minutes and defined as follows:
T A = [PD/(W w – W dt)] × T D
Where:
T D = the duration of the dryer test case as measured in section 3.4.9
PD, W w, W dt as defined in section 4.2.1 of this appendix.](https://image.slidesharecdn.com/d9591d3e-6d63-49fd-b6ea-e48f1c3f48ed-141229132233-conversion-gate02/85/PG_E_Dryer_Comment_Letter_EERE-2014-BT-TP-0034-1-36-320.jpg)
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4.3 UTILITY COMBINED ENERGY FACTOR (UCEF) IN POUNDS PER
KILOWATT-HOUR.
[NOTE – This section is provided herein for general reference and is not specifically related to
dryer testing. The UCEF value is calculated from the test results of the test protocol. The
weighting factors and UCEF credit values shown here may have changed. ]
Calculate the Utility Combined Energy Factor, UCEF, expressed in pounds per kilowatt-hour
and defined as:
UCEF = α × CEF 1 + β × CEF 2 + γ × CEF 3 + δ × CEF 4 + ε × CEF 5 + UCEF CREDIT
Where:
UCEF = the Utility Combined Energy Factor, a weighted average of the CEF calculated
for the four supplemental tests and DOE D2 CEFs
α = the Supplemental Test One weighting factor, see table below
CEF 1 = the calculated combined energy factor for Supplemental Test One, calculated in
section 4.2.8 for the test case described in section 3.3.1.2
β = the Supplemental Test Two weighting factor, see table below
CEF 2 = the calculated combined energy factor for Supplemental Test Two, calculated in
section 4.2.8 for the test case described in section 3.3.1.3
γ = the Supplemental Test Three weighting factor, see table below
CEF 3 = the calculated combined energy factor for Supplemental Test Three, calculated
in section 4.2.8 for the test case described in section 3.3.1.4
δ = the Supplemental Test Four weighting factor, see table below
CEF 4 = the calculated combined energy factor for Supplemental Test Four, calculated in
section 4.2.8 for the test case described in section 3.3.1.5
ε = the DOE D2 weighting factor, see table below
CEF 5 = the calculated combined energy factor for DOE D2, calculated in 4.1.8 for the
test case described in section 3.3.1.1
UCEF CREDIT = Functionality credits as defined by utility programs
Weighting Factors Table
Weighting factors were set to reflect results most consistent settings used in various field testing. Because no direct
correlation exists between the 5 utility tests and all possible combinations of all possible dryers designs, the
weighting factors are representative, not specific setttings.
Weighting factors are divided into two different product categories, “non-ENERGYSTAR dryers” and “efficient
dryers”. This is done because efficient dryers have settings that are designed provide energy savings, whereas non-
ENERGYSTAR dryers do not typically have such consumer options. Efficient dryers will be more likely used in](https://image.slidesharecdn.com/d9591d3e-6d63-49fd-b6ea-e48f1c3f48ed-141229132233-conversion-gate02/85/PG_E_Dryer_Comment_Letter_EERE-2014-BT-TP-0034-1-37-320.jpg)
PG_E_Dryer_Comment_Letter_EERE-2014-BT-TP-0034 (1)
- 1. 1 December 15, 2014 BrendaEdwards U.S. Department of Energy Building Technologies Program 1000 Independence Avenue, SW Mailstop EE-2J Washington, DC 20585–0121 RE: Notice of public meeting: Test Procedures for Residential Clothes Dryers: Docket Number EERE-2014-BT-TP- 0034 Dear Ms. Edwards: This letter comprises the comments of the Pacific Gas and Electric Company (PG&E) in response to the Department of Energy (DOE, the Department) Notice of Public Meeting: Test Procedures for Residential Clothes Dryers (Docket Number EERE-2014-BT-TP-0034). The signatory of this letter represents one of the largest utility companies in the Western United States, serving over 15 million customers. As an energy company, we understand the potential of appliance efficiency standards to cut costs and reduce energy consumption while maintaining or increasing the consumer utility of products and preserving electrical safety and grid reliability. Indeed, securing cost-effective energy savings from state and federal appliance standards is a cornerstone of our strategy to meet our customers’ energy service needs at the lowest overall cost. Clothes dryers are one of the most common white goods appliances, used in an estimated 80% of U.S. households and representing approximately 6% of total residential electricity use consumption.1 Until very recently, energy efficiency advocates were not promoting clothes dryers as a savings opportunity because of an assumption that currently available products provided similar energy efficiency. As recently as 2009, ENERGY STAR® best practices documentation claimed that dryers could not be awarded a label because there was little difference in energy efficiency between models.2 However, research conducted by the Natural Resources Defense Council (NRDC), the Collaborative Labeling and Appliance Standards Program (CLASP), the Northwest Energy Efficiency Alliance (NEEA), and the California IOUs over the past five years indicates otherwise. Results demonstrate that about 15% to 50% of dryer energy use can be saved cost effectively if manufacturers adopt new technologies like advanced automatic termination and heating element modulation, users accept longer drying times for non-time critical loads, and the test procedure accurately reflects field drying conditions.3 While we believe the DOE Uniform Test Method for Measuring the Energy Consumption of Clothes Dryers, located in 10 CFR 430 Subpart B, Appendix D2 (D2) represents significant progress in developing a robust and realistic test procedure for residential clothes dryers by more accurately measuring the energy impacts of automatic cycle termination, the IOUs still have several areas of concern regarding the representativeness of the test procedure. The 1 Residential Clothes Dryers: An Investigation of Energy Efficiency Test Procedures and Savings Opportunities, Paul Bendt, Chris Calwell and Laura Moorefield, prepared by Ecos for the Natural Resources Defense Council, November 6, 2009. 2 Energy Star (2009): Best practices, Energy Star. Available from: http://www.energy star.gov/index.cfm?c1⁄4clotheswash.clothes_washers_performance_tips. 3 Residential Clothes Dryers: An Investigation of Energy Efficiency Test Procedures and Savings Opportunities, Paul Bendt, Chris Calwell and Laura Moorefield, prepared by Ecos for the Natural Resources Defense Council, November 6, 2009; Residential Clothes Dryers: A Closer Look at Energy Efficiency Test Procedures and Savings Opportunities, David Denkenberger, Serena Mau, Chris Calwell & Eric Wanless, prepared by Ecos for the Natural Resources Defense Council, November 9, 2011. Publication of CLASP, NEEA, and California utilities’ reports is pending.
- 2. 2 ultimate goal ofany DOE test procedure is to fairly and accurately characterize the energy performance of an end- use product in a repeatable manner. Energy efficiency test procedures and their derivative energy use estimates should generally represent the typical or average energy performance of products in real world conditions. Overall, we applaud the DOE for investigating test procedure revisions to more accurately capture the real-world energy use of residential clothes dryers. As a next step, we encourage the DOE to conduct additional investigative testing that will guide and inform the next test procedure revision, with an overarching goal of building a test that is more representative of real-world use and better able to characterize the differences in efficiency. We believe that the additional testing needed to adequately assess the representative energy use of a clothes dryer is quite reasonable, considering the potential national energy savings potential from more energy efficient clothes dryers and given the overall clothes dryer test burden is presently extremely low, relative to other appliances where the remaining efficiency opportunities now appear to be diminishing. We note that including up to four additional tests still involves a lower testing burden than the current DOE clothes washer energy and water test procedure. Additionally, our analysis also suggests that repeatability would be better than the D2 test procedure alone. PG&E and NEEA have committed to using these additional tests to qualify dryers for utility rebates. While not having a direct impact on the test procedure, we also encourage the DOE to consider taking CO2 emissions and time-dependent valuation (TDV) into account for the forthcoming standard. We also suggest that the DOE begin to consider and seek broader stakeholder feedback on building an integrated clothes washer-clothes dryer test procedure. For detailed recommendations on how to improve the DOE’s D2 test procedure, please refer to the IOUs’ March 18, 2013 and NEEA’s December 2014 forthcoming comments. The remainder of this letter will instead focus on the results of the D2 and supplemental dryer testing conducted on behalf of NEEA and the IOUs between May and November, 2014. Recent National Lab Testing: A Step in the Right Direction We are encouraged that the DOE has investigated the Association of Home Appliance Manufacturer’s (AHAM) 1992 and 2009 laundry test loads. The AHAM 1992 load in particular is composed of 100% cotton clothing articles with a diversity of fabric thicknesses, creating a test load in which clothing articles dry at significantly different rates. Production of this load has been discontinued, but a new order could be made. This is important for automatic termination tests because some dryer models have sensors that are only placed at one location in the drum and may have a biased sample of the moisture of the clothing because real word clothing tends to have greater variability of dryness at the end of the cycle. The investigation of AHAM test loads also assessed dryer performance when drying combined loads and with different temperature settings. Both provided useful insight into dryer performance in more realistic settings. However, our interpretation of the test procedure leads us to believe that the exhaust simulator should have been placed on the natural gas dryer, which was not done in the tests performed by the Pacific Northwest National Laboratory (PNNL). Furthermore, we feel that this investigation could have been improved by assessing dryer performance using a more realistic test procedure as discussed in the next section. We encourage DOE to incorporate these modifications discussed below into additional investigative testing to inform a test procedure revision. Supplemental Tests: Adding More Realism In collaboration with the NEEA, we have developed four supplemental tests to the D2 test procedure (see Appendix for test procedure language). We harmonized the test procedure with the format and language of the D2 procedure in all sections unless we had significant reason to deviate. We created this test procedure with the objective of better matching the test procedure to real-world conditions which allows more accurate differentiation in energy use between dryers (which will also affect the efficiency ranking of models), while also minimizing test procedure burden to the extent possible and providing repeatability. Our test approach also eliminates potential gaming associated with testing clothes dryers using a single cloth composition, dryer setting configuration, and laundry load size.
- 3. 3 Since the D2test procedure only assesses performance when drying a medium-sized laundry load with thin, uniform, and half-synthetic test cloths, we chose a more challenging load for the supplemental tests. Developed with industry input, our supplemental test load is composed of real clothing including socks, underwear, t-shirts, towels, and jeans, resulting in a test load with higher cotton content. We sourced this clothing from Lands’ End, but if the DOE wanted to increase reproducibility, it could explore the potential for having realistic clothing manufactured to tight tolerances like the current test cloths. We created small, medium, and large test loads to mimic the results of NEEA’s 2013 field study4 which suggested that typical users compose laundry loads of many different sizes during everyday dryer use. While the medium size load matches the DOE test load weight of 8.45 pounds, the small test load weighs 4.22 pounds, or half the size of the DOE test load, and is used only in the first supplemental test. The large load weighs 16.9 pounds, twice the size of the DOE load, and is used only in the second supplemental test. These represent reasonable departures from the average load size in the field, which NEEA found to be 7.4 pounds. The first and second supplemental tests specify dryer settings that are similar to those specified by the DOE except we use medium temperature, because that was the most common temperature setting in NEEA field data. Also, if an efficient cycle setting or operating mode (referred to as eco mode) is present in the as-shipped condition, we do not run it in eco-mode, representing the fact that many consumers may easily disable this eco-mode. We would be open to running these tests on eco mode if the dryer automatically defaulted back to eco, perhaps after 2 hours. This is especially true for cases where the eco mode significantly increases drying time, which we measured as being up to three times longer than the time needed to dry clothing using normal dryer settings. To evaluate the savings possible from efficient mode selection, we created supplemental test three and specify a medium-sized load of realistic clothing that is dried using the most efficient setting configuration possible. If there is no eco-mode, we specify the lowest temperature available on a normal program. Our fourth supplemental test specifies a medium-sized clothing load that is dried using a setting configuration that achieves the fastest rate of drying possible, often heavy duty. We developed tests three and four to bound the range of drying speeds. One could argue for a fifth supplemental test that assesses dry performance when loaded with a medium-sized laundry load and configured with the normal settings specified in tests one and two. However, we believe that with proper weighting of the D2 and four supplemental tests, we could closely approximate real-world behavior. We do not believe the added test burden of this fifth supplemental test would provide sufficient additional information-we can already interpolate to it. We derived final remaining moisture content (RMC) targets through laboratory investigation, consumer acceptability testing, and consultations with industry. We specify 4% final moisture content targets for the small, large, and eco-mode runs. However, for the fastest run, we specify a target final moisture content of 2%, representing the fact that many consumers in the field used the more dry setting. We specify an initial moisture content for all supplemental tests of 62%, representing the NEEA field study average. We have used this test procedure to test a variety of dryers, including baseline electric and gas, and a number of ENERGY STAR certified models including two hybrid heat pumps (Emerging Technology Award winners), and a European pure heat pump. Figure 1 shows the D2 combined energy factor (CEF: pounds dried per kWh) and utility combined energy factor (UCEF) of the dryers we tested with all five runs weighted equally. We are open to adjusting these weighting factors based on field data. ENERGY STAR and even the EPA Emerging Technology Award (ETA) (hybrid heat pumps with supplemental electric resistance heating) dryers are only marginally better than conventional dryers by this metric. However, there is significant room for improvement because the European (pure heat pump) dryer test shows significantly better efficiency than any of the other electric dryers tested. When the performance of gas and electric dryers are compared on a site energy basis, a gas dryer does not appear to perform as well as an electric dryer because losses associated with electricity generation for electric dryers are ignored. The general trends are similar to the D2 test, but the rank orders change significantly. This shows that it is not possible to do a simple correction factor from a D2 result to the UCEF. The failed runs (not low enough final RMC) are included in the 4 NEEA, Emerging Technology Research: Clothes Dryers 2013. http://neea.org/docs/default-source/ac-packets/neea-dryers- research-2013.pdf?sfvrsn=2
- 4. 4 average, though theseruns could be given zero values to provide incentive for manufacturers to maintain consumer satisfaction. Figure 1. Utility Combined Energy Factor (UCEF, average of CEF values achieved during supplemental tests one through four and DOE D2) (light purple, green, red, and blue) and D2 CEF values (dark purple, green, red, and blue).5 The number of runs failed per dryer (target remaining moisture content not reached even when drying under maximum dryness settings) is signified by the number of stars to the left of the bar. Figure 2 shows the annual CO2 emissions from the different dryers. These CO2 generation estimates were made using the EPA emission calculator values.6 In this case, the losses of electricity generation are fully accounted for and the gas dryer performs best, significantly better than even the European heat pump. Since the other dryers are all electric, the relative ranking stays the same among them. 5 One test for each of D2, small, large, eco, and fast runs was performed for each dryer – all on a single unit. 6 EPA, Greenhouse Gas Equivalencies Calculator. http://www.epa.gov/cleanenergy/energy-resources/calculator.html#results 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 UCEF (lb/kWh) Utility Combined Energy Factor and D2 Values of all Dryers Tested (Ordered by UCEF Values) European Heat Pump Emerging Tech Dryers ENERGY STAR Dryer Baseline Electric Dryers Baseline Gas Dryer * One failed run ** Two failed runs * * ** * * D2 Value UCEF D2 Value UCEF D2 Value UCEF D2 Value UCEF D2 Value UCEF
- 5. 5 Figure 2. CO2emissions per year for European heat pump, emerging technology, ENERGY STAR, baseline electric, and baseline gas dryers. Figure 3 shows the run-to-run variability between the D2 test and the four supplemental test runs on a single Emerging Technology Award dryer tested. There is a significant difference in both time and CEF between the D2 and supplemental tests, and among supplemental tests (different load sizes and dryer settings). This highlights the need for high efficiency levels across a variety of conditions, instead of just for the D2 test scenario. 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 CO2 Gas Annually (metric tons) CO2 Gas Annually (Metric Tons) European Heat Pump Emerging Tech Dryers ENERGY STAR Dryer Baseline Electric Dryers Baseline Gas Dryer
- 6. 6 Figure 3. CEFversus drying time for all tests run on one of two emerging tech dryers. Figure 4 - Figure 8 show the CEF results as a function of drying time from all dryers tested on each of the five different tests (DOE D2 and supplemental tests one through four). In Figure 3, one conventional dryer appears to meet the applicable ENERGY STAR Version 1.0 CEF requirement. 1 2 3 4 5 0 10 20 30 40 50 60 70 80 90 100 110 120 130 COMBINEDENERGYFACTOR(CEF) DURATION (MIN) Emerging Tech Dryer #1 Run Time vs. CEF Values D2 Small Large "Eco" "Fastest" Emerging Tech Award "Worst Case" Setting CEF ≥ 3.73 Emerging Tech Award Normal Setting CEF ≥ 4.3 EPA ENERGY STAR CEF = 3.93
- 7. 7 Figure 4. CEFversus drying time for all dryers tested using DOE D2 test protocol based on one test per data point. Figure 5 shows small load CEFs versus drying times. The hybrid heat pumps actually had lower efficiency than several of the conventional dryers. This may be due to the fact that a significant amount of electric resistance heating is used in the beginning of the runs, and since the small load runs are shorter, the runs are composed of a greater overall fraction of electric resistance heating. However, this does not have to be the case, because the European heat pump does not have any electric resistance. The European heat pump is more efficient than any of the conventional dryers, but the margin is relatively small. 1 2 3 4 5 6 7 0 10 20 30 40 50 60 70 80 COMBINEDENERGYFACTOR(CEF) DURATION (MIN) D2 Run Time vs. CEF Values European HP Emerging Tech Dryers ENERGY STAR Dryer Baseline Dryers Baseline Gas Dryer Emerging Tech Award "Worst Case" Setting CEF ≥ 3.73 Emerging Tech Award Normal Setting CEF ≥ 4.3 Emerging Tech Award "Best Case" Setting CEF ≥ 5.3 EPA ENERGY STAR CEF = 3.93
- 8. 8 Figure 5. CEFversus duration for all dryers tested using supplemental test one (small, 4.2 lb test load with normal dryer settings). Figure 6 shows the CEFs and drying times for all dryer testing conducted using supplemental test two (large, 16.9 pound supplemental load, normal dryer settings). One Emerging Technology Award dryer did not perform as well as some of the conventional dryers. Drying times are significantly longer, as expected. 1 2 3 4 5 6 7 0 10 20 30 40 50 60 70 80 90 100 COMBINEDENERGYFACTOR(CEF) DURATION (MIN) Small Run Time vs. CEF Values European HP Emerging Tech Dryers ENERGY STAR Dryer Baseline Dryers Baseline Gas Dryer Emerging Tech Award "Worst Case" Setting CEF ≥ 3.73 Emerging Tech Award Normal Setting CEF ≥ 4.3 Emerging Tech Award "Best Case" Setting CEF ≥ 5.3 EPA ENERGY STAR CEF = 3.93
- 9. 9 Figure 6. CEFversus duration values for all dryers tested using supplemental test two (large, 16.9 lb supplemental test load, normal dryer settings). Figure 7 shows the CEFs and drying times for all dryers testing using supplemental test three (medium, 8.45 pound supplemental test load, efficient dryer settings). The Emerging Technology Award and ENERGY STAR dryers were less efficient than several conventional dryers. This finding is particularly concerning and has the potential to lead to significant confusion in the marketplace if energy efficient dryers, tested in the most energy efficient mode, are actually yielding no savings for customers when used with a realistic load. 1 2 3 4 5 6 7 0 20 40 60 80 100 120 140 160 180 COMBINEDENERGYFACTOR(CEF) DURATION (MIN) Large Run Time vs. CEF Values European HP Emerging Tech Dryers ENERGY STAR Dryer Baseline Dryers Baseline Gas Dryer Emerging Tech Award " Worst Case" Setting CEF ≥ 3.73 Emerging Tech Award Normal Setting CEF ≥ 4.3 Emerging Tech Award "Best Case" Setting CEF ≥ 5.3 EPA ENERGY STAR CEF = 3.93
- 10. 10 Figure 7. CEFversus duration values for all dryers tested using supplemental test three (medium, 8.45 lb supplemental test load, efficient dryer settings). Figure 8 shows the CEFs and drying times for supplemental test four (medium, 8.45 pound supplemental test load, fastest drying settings). One of the Emerging Technology Award dryers and the ENERGY STAR certified dryer performed worse than several conventional dryers. 1 2 3 4 5 6 7 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 COMBINEDENERGYFACTOR(CEF) DURATION (MIN) "Eco" Run Time vs. CEF Values European HP Emerging Tech Dryers ENERGY STAR Dryer Baseline Dryers Baseline Gas Dryer Emerging Tech Award "Worst Case" Setting CEF ≥ 3.73 Emerging Tech Award Normal Setting CEF ≥ 4.3 Emerging Tech Award "Best Case" Setting CEF ≥ 5.3 EPA ENERGY STAR CEF = 3.93
- 11. 11 Figure 8. CEFversus drying time for all dryers tested using supplemental test four (medium, 8.45 lb supplemental test load, “fastest” drying settings). Overall, performance on the realistic tests was significantly different than the D2 tests. Not only was the rank order of efficiency changed within a category, but in many cases, supposedly more efficient dryers were actually less efficient than conventional dryers under some test conditions. This demonstrates the critical importance of testing dryers with realistic clothing under a variety of settings and load sizes, all of which are encountered in the field. For most dryers, the difference in CEF and drying time is greater for the different load sizes than for the different settings. However, dryers may behave differently in the future, so we believe it is still important to test different settings. Repeatability We have calculated the variation7 based on a number of repeat tests across all the dryers.8 Table 1 shows the variation for each of the five tests. In three out of the four supplemental tests, the variation is actually less than the D2 test. Table 1. Variation for DOE D2 test and each Supplemental test. Test D2 Small Large Eco Fast Variation 5.1% 5.4% 2.8% 3.0% 2.3% Number of data points 25 6 8 17 5 7 Coefficient of variation, i.e. the standard deviation (SD) divided by the mean. 8 Some of the repeat tests went out of tolerance for environmental controls for a limited amount of time, but the average value over the run was always in tolerance. If anything, this overstates the variability and applies equally to D2 and supplemental tests, so the comparison between D2 and supplemental tests is still valid. 1 2 3 4 5 6 7 0 10 20 30 40 50 60 70 80 90 100 110 120 COMBINEDENERGYFACTOR(CEF) DURATION (MIN) "Fastest" Run Time vs. CEF Values European HP Emerging Tech Dryers ENERGY STAR Dryer Baseline Dryers Baseline Gas Dryer Emerging Tech Award "Worst Case" Setting CEF ≥ 3.73 Emerging Tech Award Normal Setting CEF ≥ 4.3 Emerging Tech Award "Best Case" Setting CEF ≥ 5.3 EPA ENERGY STAR CEF = 3.93
- 12. 12 In order tocalculate the overall variation in the UCEF, we use the conventional method of adding variations.9 Generally, adding more tests reduces the percent variation in the average CEF. Even when starting with the variation of the DOE value, adding the greater variation of the small realistic test still decreases the variation in the average CEF (see Table 2). Then as more realistic tests are added, the uncertainty in the UCEF falls even further. Table 2. Variation for suites of tests. Test suite D2 D2 + 1 realistic D2 + 2 realistic D2 + 3 realistic D2 + 4 realistic Variation in average CEF 5.1% 3.7% 2.6% 2.1% 1.8% This analysis shows that with the four supplemental tests, the overall repeatability is better than with the single DOE D2 test. The current testing burden for dryer manufacturers is a single DOE D2 test per unit.10 Our proposal is to add four supplemental tests, for a total of five tests. While this would increase the overall number of tests, we believe additional testing is both justified and necessary based on laboratory tests that have uncovered significant changes in relative energy use when a clothes dryer is tested with loads that will be more realistic of actual customer use. Additionally, the additional testing would still be significantly less than the test burden required for a clothes washer. We do not yet have data on reproducibility to characterize the variation between test labs. Therefore, we recommend that the DOE repeat some of these tests to assess reproducibility. However, we note that both the D2 and the supplemental tests would have added variation due to differences in test labs and dryer units (within the same model). Even if there is greater variation between batches of clothing associated with realistic clothing, the overall repeatability of the average CEF could be better with realistic clothing because of the better repeatability. Even if overall repeatability with realistic clothing is not as good as the D2 test procedure, the added accuracy (see NEEA comment letter December 15, 2014) of the realistic tests is well worth the small increase in variation. Because this test procedure more closely mimics behavior in the real world, it should also more accurately capture the real-world savings of technologies that have not yet been commercialized, such as exhaust heat exchangers. Additional recommendations We encourage DOE to enable comparison of dryers by incorporating the use of CO2 emissions and TDV as metrics of comparing dryers. Natural gas represents an interim technology step, especially in new construction, that produces similar amounts of CO2 emissions as today’s heat pumps, but is more cost-effective and enables faster drying time. TDV could recognize dryers that move electrical consumption off peak. We encourage the DOE to begin to consider an integrated washer-dryer test procedure. Using the same realistic clothing load we developed for the dryer test procedure would provide additional data on real-world washer performance. Furthermore, manufacturer test burden can actually be reduced because the clothing could go directly from the washer to the dryer, avoiding the labor-intensive step of wetting the clothing for the dryer to tight tolerances. Also, synergies between the washer and dryer in terms of energy efficiency and cycle time could be better understood. 9 SDtot 2 = SD1 2 + … + SDn 2 10 For certification, two or three units of the same basic model must be tested.
- 13. 13 Conclusions To summarize, weencourage DOE to build on its recent work and test dryers with a variety of load sizes, settings, and clothing compositions. Although increased, the energy testing burden would be less than what manufacturers encounter when testing and certifying clothes washers to DOE, and the repeatability may be better than the current D2 test procedure. The rank order of the efficiency of dryers changes significantly when using realistic clothing of different load sizes and settings. Therefore, the supplemental testing is critical to determine real-world energy savings of dryers. With industry vetting and anticipated use for utility rebate programs, supplemental tests one through four of the NEEA / PG&E Utility Test Protocol are well-positioned to supplement the existing D2 procedure. Considering CO2 and TDV would also make for a more fair comparison between dryer technologies and combining the washer and dryer test procedures would enable even more realism. We are grateful for the opportunity to submit these comments and look forward to engaging further with DOE in the effort to improve the energy efficiency of clothes dryers. Sincerely, Patrick Eilert Principal, Codes and Standards Pacific Gas and Electric Company
- 14. 14 APPENDIX: SUPPLEMENTAL TESTPROCEDURE LANGUAGE Utility Test Protocol for Residential Clothes Dryers Combined Supplemental and DOE D2 Test Procedures Developed by ECOVA on behalf of NEEA and PG&E Version 0.05 The Northwest Energy Efficiency Alliance (NEEA) and Pacific Gas and Electric (PG&E) commissioned Ecova to expand on the U.S. Department of Energy’s (DOE) new residential clothes dryer test procedure, Uniform Test Method for Measuring the Energy Consumption of Clothes Dryers - Appendix D2, to include a wider range of drying modes and settings, and a more diverse and challenging test load of mostly 100% cotton garments. This new, expanded group of dryer tests, finalized in August of 2014 and named the Utility Test Protocol, produces a final Utility Combined Energy Factor (UCEF). The UCEF is a weighted average the five combined energy factors (CEF) calculated from the results of the five tests described in this protocol. NEEA and PG&E worked with Ecova to develop the Utility Test Protocol because the DOE’s Appendix D2 only assesses dryer performance in a single mode with a uniform test load composed of thin, half synthetic test cloths. NEEA collected field data showing that real world dryer operation was significantly different, with consumers drying clothing loads of varying size, cotton content, and clothing dimensionality under multiple dryer modes. The supplemental tests more fully account for real world use conditions by testing dryers in a variety of operational modes with a test load composed of realistic test articles. At this point, the supplemental tests are only for full-sized dryers with automatic termination capability. Appendix D2 was designed to assess dryer performance during auto-terminating operation with a uniform test load and was added to Subpart B of Code of Federal Regulations Part 430, Uniform Test Method for Measuring the Energy Consumption of Clothes Dryers on August 13th , 2013. NEEA and PG&E modeled the Utility Test Protocol after Appendix D2 to ensure consistency of approach as much as possible, making it possible for laboratory technicians already familiar with Appendix D2 to carry out the Utility Test Protocol without the need for new equipment or retraining. This protocol remains largely unchanged from Appendix D2 in Sections 1 to 2.5 and Sections 3.5 to 4.8. Sections 2.6, 2.7 and 3.4 were modified with additional language for the new test loads, and Sections 3.3 and 4.9 for additional tests runs and post data processing. These tests shall be performed on an individual unit (unit-to-unit variation does not need to be tested).
- 15. 15 CONTENTS 1. DEFINITIONS........................................................................................................................................16 2. TESTINGCONDITIONS ......................................................................................................................18 2.1 Installation...................................................................................................................................18 2.2 Ambient temperature and humidity. ...........................................................................................18 2.3 Energy supply. ............................................................................................................................19 2.4 Instrumentation. ..........................................................................................................................20 2.5 Lint Trap(s).................................................................................................................................21 2.6 Test Cloths. .................................................................................................................................21 2.7 Test Loads...................................................................................................................................23 2.8 Clothes dryer preconditioning.....................................................................................................24 3. TEST PROCEDURES AND MEASUREMENTS.................................................................................24 3.1 Drum Capacity............................................................................................................................24 3.2 Dryer Loading.............................................................................................................................25 3.3 Test Cycle. ..................................................................................................................................25 3.4 Data recording.............................................................................................................................27 Table 1. Supplemental test clothing dimensions and measurement instructions. ...................................28 3.5 Standby Mode and Off Mode Power. .........................................................................................31 4. CALCULATION OF DERIVED RESULTS FROM TEST MEASUREMENTS.................................31 4.1 DOE Test calculations. ...............................................................................................................31 4.2 Supplemental Test calculations...................................................................................................34 4.3 Utility Combined Energy Factor (UCEF) in pounds per kilowatt-hour......................................37
- 16. 16 1. DEFINITIONS 1.1 Activemode: Mode in which the clothes dryer is connected to a main power source, has been activated and is performing the main function of tumbling the clothing with or without heated or unheated forced air circulation to remove moisture from the clothing, remove wrinkles or prevent wrinkling of the clothing, or both. 1.2 AHAM: Association of Home Appliance Manufacturers. 1.3 AHAM HLD-1:The test standard published by the Association of Home Appliance Manufacturers, titled “Household Tumble Type Clothes Dryers,” (2009), AHAM HLD-1- 2009 (incorporated by reference; see § 430.3). 1.4 Automatic termination control: Dryer control system with a sensor which monitors either the dryer load temperature or its moisture content and with a controller which automatically terminates the drying process. A mark, detent, or other visual indicator which indicates a preferred automatic termination control setting must be present if the dryer is to be classified as having an “automatic termination control.” A mark is a visible single control setting on one or more dryer controls. 1.5 Automatic termination control dryer: Clothes dryer which can be preset to carry out at least one sequence of operations to be terminated by means of a system assessing, directly or indirectly, the moisture content of the load. An automatic termination control dryer with supplementary timer or that may also be manually controlled shall be tested as an automatic termination control dryer. 1.6 Bone dry: Condition of a load of test clothes which has been dried in a dryer at maximum temperature for a minimum of 10 minutes, removed, and weighed before cool down, and then dried again for 10-minute periods until the final weight change of the load is 0.3 percent or less. 1.7 Compact/compact size: Clothes dryer with a drum capacity of less than 4.4 cubic feet. 1.8 Conventional clothes dryer: Clothes dryer that exhausts the evaporated moisture from the cabinet and generates heat by use of an electrical resistance heating element. 1.9 Cool down: Portion of the clothes drying cycle when the added gas or electric heat is terminated and the clothes continue to tumble and dry within the drum. 1.10 Cycle: Sequence of operation of a clothes dryer which performs a clothes drying operation, and may include variations or combinations of the functions of heating, tumbling, and drying. 1.11 Drum capacity: Volume of the drying drum in cubic feet. 1.12 “IEC 62301” (Second Edition) means the test standard published by the International Electrotechnical Commission (“IEC”) titled “Household electrical appliances— Measurement of standby power,” Publication 62301 (Edition 2.0 2011-01) (incorporated by reference; see § 430.3). 1.13 Inactive mode: Standby mode that facilitates the activation of active mode by remote switch (including remote control), internal sensor, or timer, or that provides continuous status display. 1.14 Moisture content: Ratio of the weight of water contained by the test load to the bone-dry weight of the test load, expressed as a percent.
- 17. 17 1.15 Moisture sensingcontrol: System which utilizes a moisture sensing element within the dryer drum that monitors the amount of moisture in the clothes and automatically terminates the dryer cycle. 1.16 Off mode: Mode in which the clothes dryer is connected to a main power source and is not providing any active or standby mode function, and where the mode may persist for an indefinite time. An indicator that only shows the user that the product is in the off position is included within the classification of an off mode. 1.17 Standard size: Clothes dryer with a drum capacity of 4.4 cubic feet or greater. 1.18 Standby mode: Any product mode where the energy using product is connected to a mains power source and offers one or more of the following user-oriented or protective functions which may persist for an indefinite time: (a) To facilitate the activation of other modes (including activation or deactivation of active mode) by remote switch (including remote control), internal sensor, or timer. (b) Continuous functions, including information or status displays (including clocks) or sensor-based functions. A timer is a continuous clock function (which may or may not be associated with a display) that provides regular scheduled tasks (e.g., switching) and that operates on a continuous basis. (c) To maintain connection to the internet or computer network that enabled external interaction with the dryer. 1.19 Temperature sensing control: System which monitors dryer exhaust air temperature and automatically terminates the dryer cycle. 1.20 Timer dryer: Clothes dryer that can be preset to carry out at least one operation to be terminated by a timer, but may also be manually controlled, and does not include any automatic termination function. 1.21 Ventless clothes dryer: Clothes dryer that uses a closed-loop system with an internal condenser to remove the evaporated moisture from the heated air. The moist air is not discharged from the cabinet. 1.22 Normal Program: Product mode in which the clothes dryer operates using a group of automated settings designated as normal. For dryers that do not have a “normal” program, the cycle recommended by the manufacturer for drying cotton or linen clothes shall be considered as “normal”. 1.23 Eco Program: Eco Program: Product mode in which the clothes dryer operates using a group of automated settings to achieve energy savings above normal operation during the course of the dryer cycle. The eco program is a pre-determined setting advertised on the product by the manufacturer in order to save energy for a typical cotton/poly load (e.g. not “delicates” or other specialty load types). If more than one eco program exists, the test shall be run at the most efficient eco program available as specified by the manufacturer. If no advertised energy savings program exists, the “eco program” will be defined as by selecting a normal cycle setting and the lowest temperature setting available, excluding any no-heat settings. 1.24 Fastest Program: Product mode in which the clothes dryer operates using a group of automated settings to achieve the most rapid rate of drying during the course of the dryer cycle. The fastest program shall be specified by the manufacturer as the product mode in
- 18. 18 which the dryerapplies the fastest drying rate possible to an eight and a half pound load composed of real clothing of varying thickness and cotton content (i.e. shortest cycle time). If the manufacturer does not provide input, the fastest program shall be created manually by selecting a cycle setting that allows the highest temperature and shortest drying time (commonly labeled as heavy-duty), excluding any cycles meant to sanitize clothing. If there are separate energy buttons, the fastest setting should be used, such as “speed.” 2. TESTING CONDITIONS 2.1 INSTALLATION. 2.1.1 All clothes dryers. For both conventional clothes dryers and ventless clothes dryers, as defined in sections 1.8 and 1.21 of this appendix, install the clothes dryer in accordance with manufacturer's instructions as shipped with the unit. If the manufacturer's instructions do not specify the installation requirements for a certain component, it shall be tested in the as-shipped condition. Where the manufacturer gives the option to use the dryer both with and without a duct, the dryer shall be tested without the exhaust simulator described in section 3.3.5.1 of AHAM HLD-1 (incorporated by reference; see § 430.3). All external joints should be taped to avoid air leakage. Control setting indicator lights showing the cycle progression, temperature or dryness settings, or other cycle functions that cannot be turned off during the test cycle shall not be disconnected during the active mode test cycle. For standby and off mode testing, the clothes dryer shall also be installed in accordance with section 5, paragraph 5.2 of IEC 62301 (Second Edition) (incorporated by reference; see § 430.3), disregarding the provisions regarding batteries and the determination, classification, and testing of relevant modes. For standby and off mode testing, all lighting systems shall remain connected. 2.1.2 Conventional clothes dryers. For conventional clothes dryers, as defined in section 1.8 of this appendix, the dryer exhaust shall be restricted by adding the AHAM exhaust simulator described in section 3.3.5.1 of AHAM HLD-1 (incorporated by reference; see § 430.3). 2.1.3 Ventless clothes dryers. For ventless clothes dryers, as defined in section 1.21, the dryer shall be tested without the AHAM exhaust simulator. If the manufacturer gives the option to use a ventless clothes dryer, with or without a condensation box, the dryer shall be tested with the condensation box installed. 2.2 AMBIENT TEMPERATURE AND HUMIDITY. 2.2.1 For drying testing, maintain the room ambient air temperature at 75 ± 3 ºF and the room relative humidity at 50 ±10 percent.
- 19. 19 2.2.2 For standbyand off mode testing, maintain room ambient air temperature conditions as specified in section 4, paragraph 4.2 of IEC 62301 (Second Edition) (incorporated by reference; see § 430.3). 2.3 ENERGY SUPPLY. 2.3.1 Electrical supply. Maintain the electrical supply at the clothes dryer terminal block within 1 percent of 120/240 or 120/208Y or 120 volts as applicable to the particular terminal block wiring system and within 1 percent of the nameplate frequency as specified by the manufacturer. If the dryer has a dual voltage conversion capability, conduct the test at the highest voltage specified by the manufacturer. 2.3.1.1 Supply voltage waveform. For the clothes dryer standby mode and off mode testing, maintain the electrical supply voltage waveform indicated in section 4, paragraph 4.3.2 of IEC 62301 (Second Edition) (incorporated by reference; see § 430.3). If the power measuring instrument used for testing is unable to measure and record the total harmonic content during the test measurement period, it is acceptable to measure and record the total harmonic content immediately before and after the test measurement period. 2.3.2 Gas supply. 2.3.2.1 Natural gas. Maintain the gas supply to the clothes dryer immediately ahead of all controls at a pressure of 7 to 10 inches of water column. If the clothes dryer is equipped with a gas appliance pressure regulator for which the manufacturer specifies an outlet pressure, the regulator outlet pressure shall be within ±10 percent of the value recommended by the manufacturer in the installation manual, on the nameplate sticker, or wherever the manufacturer makes such a recommendation for the basic model. The hourly Btu rating of the burner shall be maintained within ±5 percent of the rating specified by the manufacturer. If the requirement to maintain the hourly Btu rating of the burner within ± 5 percent of the rating specified by the manufacturer cannot be achieved under the allowable range in gas inlet test pressure, the orifice of the gas burner should be modified as necessary to achieve the required Btu rating. The natural gas supplied should have a heating value of approximately 1,025 Btus per standard cubic foot. The actual heating value, H n 2, in Btus per standard cubic foot, for the natural gas to be used in the test shall be obtained either from measurements made by the manufacturer conducting the test using a standard continuous flow calorimeter as described in section 2.4.6 or by the purchase of bottled natural gas whose Btu rating is certified to be at least as accurate a rating as could be obtained from measurements with a standard continuous flow calorimeter as described in section 2.4.6. 2.3.2.2 Propane gas. Maintain the gas supply to the clothes dryer immediately ahead of all controls at a pressure of 11 to 13 inches of water column. If the clothes dryer is equipped with a gas appliance pressure regulator for which the manufacturer specifies an outlet pressure, the regulator outlet pressure shall be within ±10 percent of the value recommended by the manufacturer in the installation manual, on the nameplate sticker, or wherever the manufacturer makes such a recommendation for the basic model. The hourly Btu rating of the burner shall be maintained within ±5 percent of the rating specified by the manufacturer. If the requirement to maintain the hourly Btu rating of the
- 20. 20 burner within ±5 percent of the rating specified by the manufacturer cannot be achieved under the allowable range in gas inlet test pressure, the orifice of the gas burner should be modified as necessary to achieve the required Btu rating. The propane gas supplied should have a heating value of approximately 2,500 Btus per standard cubic foot. The actual heating value, H p, in Btus per standard cubic foot, for the propane gas to be used in the test shall be obtained either from measurements made by the manufacturer conducting the test using a standard continuous flow calorimeter as described in section 2.4.6 or by the purchase of bottled gas whose Btu rating is certified to be at least as accurate a rating as could be obtained from measurement with a standard continuous calorimeter as described in section 2.4.6. 2.4 INSTRUMENTATION. Perform all test measurements using the following instruments as appropriate. 2.4.1 Weighing scale for test cloth. The scale shall have a range of 0 to a maximum of at least 30 pounds with a resolution of at least 0.2 ounces and a maximum error no greater than 0.3 percent of any measured value within the range of 3 to 15 pounds. 2.4.1.2 Weighing scale for drum capacity measurements. The scale should have a range of 0 to a maximum of at least 600 pounds with resolution of 0.50 pounds and a maximum error no greater than 0.5 percent of the measured value. 2.4.2 Kilowatt-hour meter. The kilowatt-hour meter shall have a resolution of 0.001 kilowatt- hours and a maximum error no greater than 0.5 percent of the measured value. 2.4.3 Gas meter. The gas meter shall have a resolution of 0.001 cubic feet and a maximum error no greater than 0.5 percent of the measured value. 2.4.4 Dry and wet bulb psychrometer. The dry and wet bulb psychrometer shall have an error no greater than ±1 °F. A relative humidity meter with a maximum error tolerance expressed in °F equivalent to the requirements for the dry and wet bulb psychrometer or with a maximum error tolerance of ± 2 percent relative humidity would be acceptable for measuring the ambient humidity. 2.4.5 Temperature. The temperature sensor shall have an error no greater than ±1 °F. 2.4.6 Standard Continuous Flow Calorimeter. The calorimeter shall have an operating range of 750 to 3,500 Btu per cubic foot. The maximum error of the basic calorimeter shall be no greater than 0.2 percent of the actual heating value of the gas used in the test. The indicator readout shall have a maximum error no greater than 0.5 percent of the measured value within the operating range and a resolution of 0.2 percent of the full-scale reading of the indicator instrument. 2.4.7 Standby mode and off mode watt meter. The watt meter used to measure standby mode and off mode power consumption shall meet the requirements specified in section 4, paragraph 4.4 of IEC 62301 (Second Edition) (incorporated by reference; see § 430.3). If the power measuring instrument used for testing is unable to measure and record the crest factor, power factor, or maximum current ratio during the test measurement period, it is acceptable to measure the crest factor, power factor, and maximum current ratio immediately before and after the test measurement period.
- 21. 21 2.5 LINT TRAP(S). Cleanthe lint trap(s) thoroughly before each test run. 2.6 TEST CLOTHS. 2.6.1 Energy test cloth for DOE test. The energy test cloth shall be clean and consist of the following: (a) Pure finished bleached cloth, made with a momie or granite weave, which is a blended fabric of 50-percent cotton and 50-percent polyester and weighs within ±10 percent of 5.75 ounces per square yard after test cloth preconditioning, and has 65 ends on the warp and 57 picks on the fill. The individual warp and fill yarns are a blend of 50-percent cotton and 50-percent polyester fibers. (b) Cloth material that is 24 inches by 36 inches and has been hemmed to 22 inches by 34 inches before washing. The maximum shrinkage after five washes shall not be more than 4 percent on the length and width. (c) The number of test runs on the same energy test cloth shall not exceed 25 runs. 2.6.2 Energy stuffer cloths for DOE test. The energy stuffer cloths shall be made from energy test cloth material, and shall consist of pieces of material that are 12 inches by 12 inches and have been hemmed to 10 inches by 10 inches before washing. The maximum shrinkage after five washes shall not be more than 4 percent on the length and width. The number of test runs on the same energy stuffer cloth shall not exceed 25 runs after test cloth preconditioning. 2.6.3.1 Supplemental test clothes. The following supplemental test clothing shall be purchased from Lands’ End Clothing catalog. Clothing dimension measurements shall be measured as described in section 3.4.9 of this test procedure using a standard scale (in pounds). (a) Article: V-neck T-shirt (Model # 411453-AH2) Specifications: Regular fit, Short Sleeve, Relaxed Size: Medium Color: Black Cotton content: 100% Dimensions: 24”x 20” ±8% Bone dry weight after conditioning: 0.318lbs ±0.032 lbs (b) Article: Dress Socks (pair) (Model #: 412010-AH5) Size: Medium Color: Navy Cotton content: 70% Dimensions (per sock):16.5”x 2.5” ±8% Bone dry weight after conditioning (per pair) 0.116lbs ±0.012 lbs (c) Article: Boxer Shorts (Model #: 385086-AH0) Size: 42 Color: Pearl gray Cotton content: 100% Dimensions: 16”x 17” ±8% Bone dry weight after conditioning: 0.294lbs ±0.029 lbs
- 22. 22 (d) Article: CorduroyLeggings (Model #: 420127-AH0) Specifications: Regular Fit 2 Sport Size: Medium Color: Deep Black Cotton content: 73% Dimensions: 34”x 15” ±8%. Bone dry weight after conditioning: 0.642lbs ±0.064 lbs (e) Article: Bath Towel (Model #: 400365-AHX) Size: Bath Towel Color: Orchid Petal Cotton content: 100% Dimensions: 53”x 28” ±8% Bone dry weight after conditioning: 1.498lbs ±0.15 lbs (f) Article: Blue Jeans (Model #: 307460-AH3) Specifications: Medium, Uncuffed Size: 30” x 30” (length x inseam) Color: Indigo Cotton content: 100% Dimensions: 39”x 16” ±8% Bone dry weight after conditioning: 1.422lbs ±0.14 lbs 2.6.3.2 Test clothing life. The number of test runs on the same article of clothing shall not exceed 25 runs. 2.6.4 DOE Test Cloth Preconditioning. All new test cloth load and energy stuffer cloths shall be treated as follows: (1) Bone dry the load to a weight change of ± 1 percent, or less, as prescribed in section 1.6 of this appendix. (2) Place the test cloth load in a standard clothes washer set at the maximum water fill level. Wash the load for 10 minutes in soft water (17 parts per million hardness or less), using 60.8 grams of AHAM standard test detergent Formula 3. Wash water temperature should be maintained at 140 °F ±5 °F (60 °C ±2.7 °C). Rinse water temperature is to be controlled at 100 °F ±5 °F (37.7 °C ±2.7 °C). (3) Rinse the load again at the same water temperature. (4) Bone dry the load as prescribed in section 1.6 of this appendix and weigh the load. (5) Steps (2)-(4) are repeated until there is a weight change of 1 percent or less. (6) A final cycle is to be a hot water wash with no detergent, followed by two warm water rinses. (7) Bone dry the load once again, as prescribed in section 1.6 of this appendix, and weigh the load before using the load for testing. 2.6.5 Supplemental Test Clothes Preconditioning. All new test clothing loads shall be treated as follows: (1) Bone dry the load to a weight change of ± 0.3 percent, or less, as prescribed in section 1.6 of this appendix. (2) Place the test cloth load in a standard clothes washer set at the maximum water fill level. Wash the load for 10 minutes in soft water (17 parts per million
- 23. 23 hardness or less),using 60.8 grams of AHAM standard test detergent Formula 3. Wash water temperature should be maintained at 140 °F ±5 °F (60 °C ±2.7 °C). Rinse water temperature is to be controlled at 100 °F ±5 °F (37.7 °C ±2.7 °C). (3) Rinse the load again at the same water temperature. (4) Bone dry the load as prescribed in section 1.6 of this appendix and weigh the load. (5) Steps (2)-(4) are repeated until there is a weight change of 0.5 percent or less. (6) A final cycle is to be a hot water wash with no detergent, followed by two warm water rinses. (7) Bone dry the load once again, as prescribed in section 1.6 of this appendix, and weigh the load before using the load for testing. 2.7 TEST LOADS. 2.7.1 DOE Test Cloths - Compact size dryer load. Prepare a bone-dry test load of energy cloths that weighs 3.00 pounds ± .03 pounds. The test load can be adjusted to achieve proper weight by adding energy stuffer cloths, but no more than five stuffer cloths may be added per load. Dampen the load by agitating it in water whose temperature is 60 °F ± 5 °F and consists of 0 to 17 parts per million hardness for approximately 2 minutes to saturate the fabric. Then, extract water from the wet test load by spinning the load until the moisture content of the load is between 52.5 and 57.5 percent of the bone-dry weight of the test load. Make a final mass adjustment, such that the moisture content is 57.5 percent ± 0.33 percent by adding water uniformly distributed among all of the test clothes in a very fine spray using a spray bottle. 2.7.2 DOE Test Cloths - Standard size dryer load. Prepare a bone-dry test load of energy cloths that weighs 8.45 pounds ± .085 pounds. The test load can be adjusted to achieve proper weight by adding stuffer cloths, but no more than five stuffer cloths may be added per load. Dampen the load by agitating it in water whose temperature is 60 °F ± 5 °F and consists of 0 to 17 parts per million hardness for approximately 2 minutes to saturate the fabric. Then, extract water from the wet test load by spinning the load until the moisture content of the load is between 52.5 and 57.5 percent of the bone-dry weight of the test load. Make a final mass adjustment, such that the moisture content is 57.5 percent ± 0.33 percent by adding water uniformly distributed among all of the test clothes in a very fine spray using a spray bottle. 2.7.3 Supplemental Test Loads. 2.7.3.1 Small Supplemental Test Load. Prepare a bone-dry test load of the supplemental test clothes, composed of one of each article of supplemental test clothes (a pair of socks constitutes one article), referenced in section 2.6.3 a-f of this appendix, for a total weight of 4.22 lbs ±0.085 lbs. If, through use, the bone dry weight of the load falls below 4.16 lbs, the load shall be discarded. 2.7.3.2 Medium Supplemental Test Load. Prepare a bone-dry test load of the supplemental test clothes, composed of two of each article of supplemental test clothes, referenced in section 2.6.3 a-f of this appendix (a pair of socks constitutes one article), for a total weight of 8.45 lbs ±0.17 lbs. If, through use, the bone dry weight of the load falls below 8.28 lbs, the load shall be discarded.
- 24. 24 2.7.3.3 Large SupplementalTest Load. Prepare a bone-dry test load of the supplemental test clothes, composed of four of each article of supplemental test clothes (a pair of socks constitutes one article), referenced in section 2.6.3 a-f of this appendix, for a total weight of 16.90 lbs ±0.34 lbs. If, through use, the bone dry weight of the load falls below 16.56 lbs, the load shall be discarded. 2.7.4 Method of wetting clothing. Dampen the load by agitating it in water whose temperature is 60 °F ± 5 °F and consists of 0 to 17 parts per million hardness for approximately 2 minutes to saturate the fabric. Then, extract water from the wet test load by spinning the load in a top-load washer until the moisture content of the load is between 60% and 64% of the bone dry weight of the test load. If moisture target is not reached by the end of the damping process, DO NOT make any adjustments. Restart the damping process in washer from the start until desired moisture is reached. 2.7.5 Method of loading. Load the energy test cloths by grasping them in the center, shaking them to hang loosely, and then dropping them in the dryer at random. 2.8 CLOTHES DRYER PRECONDITIONING. 2.8.1 Conventional non-heat pump clothes dryers. For conventional clothes dryers, before any test cycle, operate the dryer without a test load in the non-heat mode for 15 minutes or until the discharge air temperature is varying less than 1 °F for 10 minutes—whichever is longer—in the test installation location with the ambient conditions within the specified test condition tolerances of section 2.2 in the appendix. 2.8.2 Ventless and heat pump clothes dryers. For ventless and heat pump clothes dryers, before any test cycle, the steady-state temperature measured at the compressor inlet and outlet must be within the ambient room temperature range described in section 2.2.1 of the appendix for a minimum of ten minutes. The machine may be left at ambient room conditions for at least 6 hours between tests as an alternative to measuring compressor inlet and outlet temperature. 3. TEST PROCEDURES AND MEASUREMENTS 3.1 DRUM CAPACITY. Measure the drum capacity by sealing all openings in the drum except the loading port with a plastic bag, and ensuring that all corners and depressions are filled and that there are no extrusions of the plastic bag through any openings in the interior of the drum. Fill the drum with water to a level determined by the intersection of the door plane and the loading port (i.e., the uppermost edge of the drum that is in contact with the door seal). Record the temperature of the water and then the weight of the dryer with the added water and then determine the mass of the water in pounds. Add the appropriate volume to account for any space in the drum interior not measured by water fill (e.g., the space above the uppermost edge of the drum within a curved door) and subtract the appropriate volume to account for the space that is measured by water fill but cannot be used when the door is closed (e.g., space occupied by the door when closed). The drum capacity is calculated as follows:
- 25. 25 C= w/d +/−volume adjustment C= capacity in cubic feet. w= mass of water in pounds. d= density of water at the measured temperature in pounds per cubic foot. 3.2 DRYER LOADING. Load the dryer as specified in 2.7. 3.3 TEST CYCLE. 3.3.1. Test Cycle Dryer Settings. 3.3.1.1 DOE Test. For timer dryers, as defined in section 1.20 of this appendix, operate the clothes dryer at the maximum temperature setting and, if equipped with a timer, at the maximum time setting. Any other optional cycle settings that do not affect the temperature or time settings shall be tested in the as-shipped position. If the clothes dryer does not have a separate temperature setting selection on the control panel, the maximum time setting should be used for the drying test cycle. For automatic termination control dryers, as defined in section 1.5 of this appendix, a “normal” program shall be selected for the test cycle using the DOE Medium Test Load defined in section 2.7.2 a. For dryers that do not have a “normal” program, the cycle recommended by the manufacturer for drying cotton or linen clothes shall be selected. Where the drying temperature setting can be chosen independently of the program, it shall be set to the maximum. Where the dryness level setting can be chosen independently of the program, it shall be set to the “normal” or “medium” dryness level setting. If such designation is not provided, then the dryness level shall be set at the mid-point between the minimum and maximum settings. Any other optional cycle settings that do not affect the program, temperature or dryness settings shall be tested in the as-shipped position. If the final moisture content is greater than the target RMC value of 2%, the test shall be invalid and a new run shall be conducted using the highest dryness level setting. If the final RMC is still above 2%, the test will be considered invalid. 3.3.1.2 Supplemental Test One. The purpose of this test condition is to evaluate dryer performance with a small supplemental test load operating in the dryer’s “normal” setting for cotton/linen loads. A “normal” mode, as defined in section 1.22, shall be selected for the test cycle using the Small Supplemental Test Load (4.22 lb) defined in section 2.7.2.1. For dryers that do not have a “normal” program, the cycle recommended by the manufacturer for drying cotton or linen clothes shall be selected. Where the drying temperature setting can be chosen independently of the program, it shall be set to medium. Where the dryness level setting can be chosen independently of the program, it shall be set to the “normal” or “medium” dryness level setting. If such designation is not provided, then the dryness level shall be set at the mid-point between the minimum and maximum settings. Any other optional cycle settings that do not affect the program,
- 26. 26 temperature or drynesssettings shall be tested in the as-shipped position. If the final moisture content is greater than the targeted RMC value of 4%, the test shall be invalid and a new run shall be conducted using the highest dryness level setting. If the final RMC is still above 4%, the test will be considered invalid. 3.3.1.3 Supplemental Test Two. The purpose of this test condition is to evaluate dryer performance with a large supplemental test load operating in the dryer’s “normal” setting for cotton/linen loads. A “normal” program, as defined in section 1.22, shall be selected for the test cycle using the Large Supplemental Test Load (16.90 lbs) defined in section 2.7.2.3. For dryers that do not have a “normal” program, the cycle recommended by the manufacturer for drying cotton or linen clothes shall be selected. Where the drying temperature setting can be chosen independently of the program, it shall be set to medium. Where the dryness level setting can be chosen independently of the program, it shall be set to the “normal” or “medium” dryness level setting. If such designation is not provided, then the dryness level shall be set at the mid-point between the minimum and maximum settings. Any other optional cycle settings that do not affect the program, temperature or dryness settings shall be tested in the as-shipped position. If the final moisture content is greater than the targeted RMC value of 4%, the test shall be invalid and a new run shall be conducted using the highest dryness level setting. If the final RMC is still above 4%, the test will be considered invalid. 3.3.1.4 Supplemental Test Three. The purpose of this test is to evaluate dryer performance with a medium supplemental test load operated in the dyer’s most efficient operating setting for cotton/linen loads. In addition to evaluating a dryer’s most efficient mode of operation, this test will also become the basis for any utility-imposed drying cycle time limit. An “Eco program”, as defined in section 1.23 of this test procedure, shall be selected for the test cycle using the Medium Supplemental Test Load (8.45 lbs) defined in section 2.7.2.2. For dryers that do not have a “Eco” program efficient setting, the test shall be run by selecting a normal cycle setting and the lowest temperature setting available, excluding any no-heat settings. Where the dryness level setting can be chosen independently of the program, it shall be set to the “normal” or “medium” dryness level setting. If such designation is not provided, then the dryness level shall be set at the mid-point between the minimum and maximum settings. Any other optional cycle settings that do not affect the program, temperature or dryness settings, shall be tested in the most efficient setting position. If the final moisture content is greater than the targeted RMC value of 4%, the test shall be invalid and a new run shall be conducted using the highest dryness level setting. If the final RMC is still above 4%, the test will be considered invalid. 3.3.1.5 Supplemental Test Four. The purpose of this test is to evaluate dryer performance with a medium supplemental test load operated in the dyer’s most rapid drying rate for cotton/linen loads. The “Fastest” program, as defined in section 1.24 of this test procedure, shall be selected for the test cycle using the Medium Supplemental Test Load (8.45 lbs) defined in section 2.7.2.2.
- 27. 27 Where the dryingtemperature setting can be chosen independently of the program, it shall be set to the maximum. Where the dryness level setting can be chosen independently of the program, it shall be set to the “normal” or “medium” dryness level setting. If such designation is not provided, then the dryness level shall be set at the mid- point between the minimum and maximum settings. Any other optional cycle settings that do not affect the program, such as temperature or dryness settings, shall be tested in the as-shipped position. If the final moisture content is greater than the targeted RMC value of 2%, the test shall be invalid and a new run shall be conducted using the highest dryness level setting. If the final RMC is still above 2%, the test will be considered invalid. 3.3.2 Timer dryers (DOE cloth test only). Dry the load until the moisture content of the test load is between 1 and 2.5 percent of the bone-dry weight of the test load, at which point the test cycle is stopped, but do not permit the dryer to advance into cool down. If required, reset the timer to increase the length of the drying cycle. After stopping the test cycle, remove and weigh the test load. The clothes dryer shall not be stopped intermittently in the middle of the test cycle for any reason. Record the data specified by section 3.4 of this appendix. If the dryer automatically stops during a cycle because the condensation box is full of water, the test is stopped, and the test run is invalid, in which case the condensation box shall be emptied and the test re-run from the beginning. For ventless dryers, as defined in section 1.21 of this appendix, during the time between two cycles, the door of the dryer shall be closed except for loading (and unloading). 3.3.3 Automatic termination control dryers. Operate the clothes dryer until the completion of the programmed cycle, including the cool down period. The cycle shall be considered complete when the dryer indicates to the user that the cycle has finished (by means of a display, indicator light, audible signal, or other signal) and the heater and drum/fan motor shuts off for the final time. If the clothes dryer is equipped with a wrinkle prevention mode (i.e., that continuously or intermittently tumbles the clothes dryer drum after the clothes dryer indicates to the user that the cycle has finished) that is activated by default in the as-shipped position or if manufacturers' instructions specify that the feature is recommended to be activated for normal use, the cycle shall be considered complete after the end of the wrinkle prevention mode. After the completion of the test cycle, remove and weigh the test load. Record the data specified in section 3.4 of this appendix. If the final moisture content is greater than the target RMC value for the test, the test shall be invalid and a new run shall be conducted using the highest dryness level setting. The technician should empty the condensation box before running a test. If the dryer automatically stops during a cycle because the condensation box is full of water, the test is stopped, and the test run is invalid, in which case the condensation box shall be emptied and the test re-run from the beginning. During the time between two cycles, the door of the dryer shall be closed except for loading (and unloading). 3.4 DATA RECORDING. Record for each test cycle: 3.4.1 Bone-dry weight of the test load described in section 2.7. 3.4.2 Moisture content of the wet test load before the test, as described in section 2.7.
- 28. 28 3.4.3 Moisture contentof the dry test load obtained after the test described in section 3.3. 3.4.4 Test room conditions, temperature, and percent relative humidity described in section 2.2.1. 3.4.5 For electric dryers — the total kilowatt-hours of electric energy, E t, consumed during the test described in section 3.3. 3.4.6 For gas dryers — 3.4.6.1 Total kilowatt-hours of electrical energy, E te, consumed during the test described in section 3.3. 3.4.6.2 Cubic feet of gas per cycle, E tg, consumed during the test described in section 3.3. 3.4.6.3 Correct the gas heating value, GEF, as measured in sections 2.3.2.1 and 2.3.2.2, to standard pressure and temperature conditions in accordance with U.S. Bureau of Standards, circular C417, 1938. 3.4.7 Cycle settings. Select clothing settings in accordance with section 3.3.2 for the automatic termination control dryer test. 3.4.8 Test duration. Record the total duration of the test, T A, described in section 3.3 from the start of the cycle to cycle completion. 3.4.9. Clothing Dimensions. To obtain the clothing dimensions, first shake and lay the articles flat, then measure the length by the width of all test articles as shown below in Table 1: TABLE 3. SUPPLEMENTAL TEST CLOTHING DIMENSIONS AND MEASUREMENT INSTRUCTIONS. Clothing Article Measurement Instructions V-Neck T-shirt X Measurement: along bottom edge of shirt Y Measurement: from bottom edge to bottom seam of sleeve Boxer Shorts X Measurement: along waistband
- 29. 29 Y Measurement: fromtop of waistband to bottom corner of leg ‘sleeve’ Blue Jeans X Measurement: along waistband Y Measurement: top of waistband to bottom of pants sleeve
- 30. 30 Table 1 continued. CorduroyLeggings X Measurement: along waistband Y Measurement: top of waistband to bottom of pants ‘sleeve’ Dress Socks X Measurement: from edge of heel to top of tip Y Measurement: from bottom of sock tip to top of sock band Bath Towel X Measurement: along bottom edge of towel Y Measurement: along left edge of towel Individual articles must remain within a ±8% range of specified article length and width, as referenced in the supplemental test clothes section 2.6.3 of this appendix.
- 31. 31 3.5 STANDBY MODEAND OFF MODE POWER. Establish the testing conditions set forth in Section 2 “Testing Conditions” of this appendix. For clothes dryers that take some time to enter a stable state from a higher power state as discussed in Section 5, Paragraph 5.1, Note 1 of IEC 62301 (Second Edition ) (incorporated by reference; see § 430.3), allow sufficient time for the clothes dryer to reach the lower power state before proceeding with the test measurement. Follow the test procedure specified in section 5, paragraph 5.3.2 of IEC 62301 (Second Edition) for testing in each possible mode as described in sections 3.5.1 and 3.5.2 of this appendix. 3.5.1 If a clothes dryer has an inactive mode, as defined in section 1.13 of this appendix, measure and record the average inactive mode power of the clothes dryer, P IA, in watts. 3.5.2 If a clothes dryer has an off mode, as defined in section 1.16 of this appendix, measure and record the average off mode power of the clothes dryer, P OFF, in watts. 4. CALCULATION OF DERIVED RESULTS FROM TEST MEASUREMENTS 4.1 DOE TEST CALCULATIONS. Calculation of derived results for measurements gathered during the DOE Test as described in section 3.3.1.1. 4.1.1 Total per-cycle electric dryer energy consumption for DOE. Calculate the total electric dryer energy consumption per cycle, E ce, expressed in kilowatt-hours per cycle and defined as: E ce= E t, for automatic termination control dryers, and, E ce= [55.5/(W w− W d)] × E t× field use, for timer dryers Where: 55.5 = an experimentally established value for the percent reduction in the moisture content of the test load during a laboratory test cycle expressed as a percent. E t= the energy recorded in section 3.4.5 of this appendix field use = 1.18, the field use factor for clothes dryers with time termination control systems only without any automatic termination control functions. W w= the moisture content of the wet test load in percent as recorded in section 3.4.2 of this appendix. W d= the moisture content of the dry test load in percent as recorded in section 3.4.3 of this appendix. 4.1.2 Per-cycle gas dryer electrical energy consumption for DOE. Calculate the gas dryer electrical energy consumption per cycle, E ge, expressed in kilowatt-hours per cycle and defined as: E ge= E te,
- 32. 32 for automatic terminationcontrol dryers, and, E ge= [55.5/(W w−W d)] × E te× field use, for timer dryers Where: E te= the energy recorded in section 3.4.6.1 of this appendix. field use, 55.5, W w, W d as defined in section 4.1.1 of this appendix. 4.1.3 Per-cycle gas dryer gas energy consumption for DOE. Calculate the gas dryer gas energy consumption per cycle, E ge, expressed in Btus per cycle and defined as: E gg= E tg× GEF for automatic termination control dryers, and, E gg= [55.5/(W w−W d)] × E tg× field use × GEF for timer dryers Where: E tg= the energy recorded in section 3.4.6.2 of this appendix. GEF = corrected gas heat value (Btu per cubic foot) as defined in section 3.4.6.3 of this appendix, field use, 55.5, W w, W d as defined in section 4.1.1 of this appendix. 4.1.4 Total per-cycle gas dryer energy consumption expressed in kilowatt-hours for DOE. Calculate the total gas dryer energy consumption per cycle, E cg, expressed in kilowatt- hours per cycle and defined as: E cg= E ge+ (E gg/3412 Btu/kWh) Where: E ge= the energy calculated in section 4.1.2 of this appendix E gg= the energy calculated in section 4.1.3 of this appendix 4.1.5 Per-cycle standby mode and off mode energy consumption for DOE. Calculate the dryer inactive mode and off mode energy consumption per cycle, E TSO, expressed in kWh per cycle and defined as: E TSO= [(P IA× S IA) + (P OFF× S OFF)] × K/283 Where: P IA= dryer inactive mode power, in watts, as measured in section 3.5.1; P OFF= dryer off mode power, in watts, as measured in section 3.5.2. If the clothes dryer has both inactive mode and off mode, S IA and S OFF both equal 8,620 ÷ 2 = 4,310, where 8,620 is the total inactive and off mode annual hours; If the clothes dryer has an inactive mode but no off mode, the inactive mode annual hours, S IA, is equal to 8,620 and the off mode annual hours, S OFF, is equal to 0; If the clothes dryer has an off mode but no inactive mode, S IA is equal to 0 and S OFF is equal to 8,620 Where: K = 0.001 kWh/Wh conversion factor for watt-hours to kilowatt-hours; and
- 33. 33 283 = representativeaverage number of clothes dryer cycles in a year. 4.1.6 Per-cycle combined total energy consumption expressed in kilowatt-hours for DOE. Calculate the per-cycle combined total energy consumption, E CC, expressed in kilowatt- hours per cycle and defined for an electric clothes dryer as: E CC= E ce+ E TSO Where: E ce= the energy calculated in section 4.1.1 of this appendix, and E TSO= the energy calculated in section 4.1.5 of this appendix, and defined for a gas clothes dryer as: E CC= E cg+ E TSO Where: E cg= the energy calculated in section 4.1.4 of this appendix, and E TSO= the energy calculated in section 4.1.5 of this appendix. 4.1.7 Per-cycle Energy Factor in pounds per kilowatt-hour for DOE. Calculate the energy factor, EF, expressed in pounds per kilowatt-hour and defined for an electric clothes dryer as: EF = W bonedry/E ce Where: W bonedry= the bone dry test load weight recorded in section 3.4.1 of this appendix, and E ce= the energy calculated in section 4.1.1 of this appendix, and defined for a gas clothes dryer as: EF = W bonedry/E cg Where: W bonedry= the bone dry test load weight recorded in section 3.4.1 of this appendix, and E cg= the energy calculated in section 4.1.4 of this appendix. 4.1.8 Per-cycle Combined Energy Factor in pounds per kilowatt-hour for DOE. Calculate the combined energy factor, CEF, expressed in pounds per kilowatt-hour and defined as follows: CEF = W bonedry/E CC Where: W bonedry= the bone dry test load weight recorded in section 3.4.1 of this appendix, and E CC= the energy calculated in section 4.1.6 of this appendix. If the test run was invalid, the CEF shall be given a value of 0. 4.1.9 Per-cycle Test Duration in minutes. Calculate the per-cycle test duration, T A, expressed in minutes and defined as follows: T A = T D For automatic termination dryers and
- 34. 34 T A =[55.5/(W w – W d)] × T D for timer dryers. Where: T D = the duration of the dryer test case in minutes as measured in section 3.4.9 55.5, W w, W d as defined in section 4.1.1 of this appendix. 4.2 SUPPLEMENTAL TEST CALCULATIONS. Repeat sections 4.2.1 through 4.2.9 a total of four times, once for each supplemental test (sections 3.3.1.2 through 3.3.1.5). 4.2.1 Total per-cycle electric dryer energy consumption. Calculate the total electric dryer energy consumption per cycle, E ce, expressed in kilowatt-hours per cycle and defined as: E ce = [PD/(W w− W dt)] × E t, Where: PD = 58% for tests conducted during sections 3.3.1.2 through 3.3.1.4; PD = 60% for the test conducted during section 3.3.1.5; E t = the energy recorded in section 3.4.5 of this appendix; W w = the moisture content of the wet test load in percent as recorded in section 3.4.2 of this appendix; W dt = target dry weight of 4% for tests conducted during sections 3.3.1.2 through 3.3.1.4; and W dt = target dry weight of 2% for the test conducted during section 3.3.1.5 4.2.2 Per-cycle gas dryer electrical energy consumption. Calculate the gas dryer electrical energy consumption per cycle, E ge, expressed in kilowatt-hours per cycle and defined as: E ge= [PD/(W w−W dt)] × E te, Where: E te= the energy recorded in section 3.4.6.1 of this appendix. PD, W w, W dt as defined in section 4.2.1 of this appendix. 4.2.3 Per-cycle gas dryer gas energy consumption. Calculate the gas dryer gas energy consumption per cycle, E ge, expressed in Btus per cycle and defined as: E gg= [PD/(W w−W dt)] × E tg × GEF Where: E tg= the energy recorded in section 3.4.6.2 of this appendix. GEF = corrected gas heat value (Btu per cubic foot) as defined in section 3.4.6.3 of this appendix, PD, W w, W dt as defined in section 4.2.1 of this appendix. 4.2.4 Total per-cycle gas dryer energy consumption expressed in kilowatt-hours. Calculate the total gas dryer energy consumption per cycle, E cg, expressed in kilowatt- hours per cycle and defined as:
- 35. 35 E cg= Ege+ (E gg/3412 Btu/kWh) Where: E ge= the energy calculated in section 4.2.2 of this appendix E gg= the energy calculated in section 4.2.3 of this appendix 4.2.5 Per-cycle standby mode and off mode energy consumption. Calculate the dryer inactive mode and off mode energy consumption per cycle, E TSO, expressed in kWh per cycle and defined as: E TSO= [(P IA× S IA) + (P OFF× S OFF)] × K/283 Where: P IA= dryer inactive mode power, in watts, as measured in section 3.5.1; P OFF= dryer off mode power, in watts, as measured in section 3.5.2. If the clothes dryer has both inactive mode and off mode, S IA and S OFF both equal 8,620 ÷ 2 = 4,310, where 8,620 is the total inactive and off mode annual hours; If the clothes dryer has an inactive mode but no off mode, the inactive mode annual hours, S IA, is equal to 8,620 and the off mode annual hours, S OFF, is equal to 0; If the clothes dryer has an off mode but no inactive mode, S IA is equal to 0 and S OFF is equal to 8,620 Where: K = 0.001 kWh/Wh conversion factor for watt-hours to kilowatt-hours; and 283 = representative average number of clothes dryer cycles in a year. 4.2.6 Per-cycle combined total energy consumption expressed in kilowatt-hours. Calculate the per-cycle combined total energy consumption, E CC, expressed in kilowatt- hours per cycle and defined for an electric clothes dryer as: E CC= E ce+ E TSO Where: E ce= the energy calculated in section 4.2.1 of this appendix, and E TSO= the energy calculated in section 4.2.5 of this appendix, and defined for a gas clothes dryer as: E CC= E cg+ E TSO Where: E cg= the energy calculated in section 4.2.4 of this appendix, and E TSO= the energy calculated in section 4.2.5 of this appendix. 4.2.7 Per-cycle Energy Factor in pounds per kilowatt-hour. Calculate the energy factor, EF, expressed in pounds per kilowatt-hour and defined for an electric clothes dryer as: EF = W bonedry/E ce Where: W bonedry= the bone dry test load weight recorded in section 3.4.1 of this appendix, and
- 36. 36 E ce= theenergy calculated in section 4.2.1 of this appendix, and defined for a gas clothes dryer as: EF = W bonedry/E cg Where: W bonedry= the bone dry test load weight recorded in section 3.4.1 of this appendix, and E cg= the energy calculated in section 4.2.4 of this appendix. 4.2.8 Per-cycle Combined Energy Factor in pounds per kilowatt-hour. Calculate the combined energy factor, CEF, expressed in pounds per kilowatt-hour and defined as follows: CEF = W bonedry/E CC Where: W bonedry= the bone dry test load weight recorded in section 3.4.1 of this appendix, and E CC= the energy calculated in section 4.2.6 of this appendix. If the test run was invalid, the CEF shall be given a value of 0. 4.2.9 Per-cycle Test Duration in minutes. Calculate the per-cycle test duration, T A, expressed in minutes and defined as follows: T A = [PD/(W w – W dt)] × T D Where: T D = the duration of the dryer test case as measured in section 3.4.9 PD, W w, W dt as defined in section 4.2.1 of this appendix.
- 37. 37 4.3 UTILITY COMBINEDENERGY FACTOR (UCEF) IN POUNDS PER KILOWATT-HOUR. [NOTE – This section is provided herein for general reference and is not specifically related to dryer testing. The UCEF value is calculated from the test results of the test protocol. The weighting factors and UCEF credit values shown here may have changed. ] Calculate the Utility Combined Energy Factor, UCEF, expressed in pounds per kilowatt-hour and defined as: UCEF = α × CEF 1 + β × CEF 2 + γ × CEF 3 + δ × CEF 4 + ε × CEF 5 + UCEF CREDIT Where: UCEF = the Utility Combined Energy Factor, a weighted average of the CEF calculated for the four supplemental tests and DOE D2 CEFs α = the Supplemental Test One weighting factor, see table below CEF 1 = the calculated combined energy factor for Supplemental Test One, calculated in section 4.2.8 for the test case described in section 3.3.1.2 β = the Supplemental Test Two weighting factor, see table below CEF 2 = the calculated combined energy factor for Supplemental Test Two, calculated in section 4.2.8 for the test case described in section 3.3.1.3 γ = the Supplemental Test Three weighting factor, see table below CEF 3 = the calculated combined energy factor for Supplemental Test Three, calculated in section 4.2.8 for the test case described in section 3.3.1.4 δ = the Supplemental Test Four weighting factor, see table below CEF 4 = the calculated combined energy factor for Supplemental Test Four, calculated in section 4.2.8 for the test case described in section 3.3.1.5 ε = the DOE D2 weighting factor, see table below CEF 5 = the calculated combined energy factor for DOE D2, calculated in 4.1.8 for the test case described in section 3.3.1.1 UCEF CREDIT = Functionality credits as defined by utility programs Weighting Factors Table Weighting factors were set to reflect results most consistent settings used in various field testing. Because no direct correlation exists between the 5 utility tests and all possible combinations of all possible dryers designs, the weighting factors are representative, not specific setttings. Weighting factors are divided into two different product categories, “non-ENERGYSTAR dryers” and “efficient dryers”. This is done because efficient dryers have settings that are designed provide energy savings, whereas non- ENERGYSTAR dryers do not typically have such consumer options. Efficient dryers will be more likely used in
- 38. 38 their efficient mode(because they have them, and because consumers presumably purchased them at least in part because they wanted that feature). Table 2 below provides weighting factors for both dryer categories. Table 2. Weighting factors by dryer category. D2 Cloths Supplemental Test Small Large Eco Fast D2 Performance Tier α β γ δ ε Total Non-ENERGY STAR 29% 14% 5% 24% 29% 100% Designed to be Efficient 21% 11% 30% 18% 21% 100% REAL CLOTHING