10 C.F.R. Appendix B1 to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Freezers
Title 10 - Energy
1. Definitions. 1.1 “HRF–1–1979” means the Association of Home Appliance Manufacturers standard for household refrigerators, combination refrigerators-freezers, and household freezers, also approved as an American National Standard as a revision of ANSI B38.1–1970. 1.2 “Anti-sweat heater” means a device incorporated into the design of a freezer to prevent the accumulation of moisture on exterior surfaces of the cabinet under conditions of high ambient humidity. 1.3 “Cycle” means the period of 24 hours for which the energy use of a freezer is calculated as though the consumer-activated compartment temperature controls were preset so that the desired compartment temperatures were maintained. 1.4 “Cycle type” means the set of test conditions having the calculated effect of operating a freezer for a period of 24 hours with the consumer-activated controls other than the compartment temperature control set to establish various operating characteristics. 1.5 “Standard cycle” means the cycle type in which the anti-sweat heater switch, when provided, is set in the highest energy consuming position. 1.6 “Adjusted total volume” means the product of, (1) the freezer volume as defined in HRF–1–1979 in cubic feet, times (2) an adjustment factor. 1.7 “Automatic Defrost” means a system in which the defrost cycle is automatically initiated and terminated, with resumption of normal refrigeration at the conclusion of defrost operation. The system automatically prevents the permanent formation of frost on all refrigerated surfaces. Nominal refrigerated food temperatures are maintained during the operation of the automatic defrost system. 1.8 “Long-time Automatic Defrost” means an automatic defrost system where successive defrost cycles are separated by 14 hours or more of compressor-operating time. 1.9 “Stabilization Period” means the total period of time during which steady-state conditions are being attained or evaluated. 1.10 “Variable defrost control” means a long-time automatic defrost system (except the 14-hour defrost qualification does not apply) where successive defrost cycles are determined by an operating condition variable or variables other than solely compressor operating time. This includes any electrical or mechanical device. Demand defrost is a type of variable defrost control. 1.11 “Quick freeze” means an optional feature on freezers which is initiated manually and shut off manually. It bypasses the thermostat control and places the compressor in a steady-state operating condition until it is shut off. 2. Test Conditions. 2.1 Ambient temperature. The ambient temperature shall be 90.0±1.0 °F. (32.2±0.6 °C.) during the stabilization period and during the test period. The ambient temperature shall be 80±2 °F dry bulb and 67 °F wet bulb during the stabilization period and during the test period when the unit is tested in accordance with section 3.3. 2.2 Operational conditions. The freezer shall be installed and its operating conditions maintained in accordance with HRF–1–1979, section 7.2 through section 7.4.3.3, except that the vertical ambient gradient at locations 10 inches (25.4 cm) out from the centers of the two sides of the unit being tested is to be maintained during the test. Unless the area is obstructed by shields or baffles, the gradient is to be maintained from 2 inches (5.1 cm) above the floor or supporting platform to a height one foot (30.5 cm) above the unit under test. Defrost controls are to be operative and the anti-sweat heater switch is to be “on” during one test and “off” during a second test. The quick freeze option shall be switched off unless specified. 2.3 Steady State Condition. Steady state conditions exist if the temperature measurements taken at four minute intervals or less during a stabilization period are not changing at a rate greater than 0.042 °F. (0.023 °C.) per hour as determined by the applicable condition of A or B. A—The average of the measurements during a two hour period if no cycling occurs or during a number of complete repetitive compressor cycles through a period of no less than two hours is compared to the average over an equivalent time period with three hours elapsed between the two measurement periods. B—If A above cannot be used, the average of the measurements during a number of complete repetitive compressor cycles through a period of no less than two hours and including the last complete cycle prior to a defrost period, or if no cycling occurs, the average of the measurements during the last two hours prior to a defrost period; are compared to the same averaging period prior to the following defrost period. 3. Test Control Settings. 3.1 Model with no user operable temperature control. A test shall be performed during which the compartment temperature and energy use shall be measured. A second test shall be performed with the temperature control electrically short circuited to cause the compressor to run continuously. If the model has the quick freeze option, it is to be used to bypass the temperature control. 3.2 Model with user operable temperature control. Testing shall be performed in accordance with one of the following sections using the standardized temperature of 0.0 °F. (−17.8 °C.). Variable defrost control models shall achieve 0±2 °F during the steady-state conditions prior to the optional test with no door openings. 3.2.1 A first test shall be performed with all temperature controls set at their median position midway between their warmest and coldest settings. Knob detents shall be mechanically defeated if necessary to attain a median setting. A second test shall be performed with all controls set at either their warmest or their coldest setting (not electrically or mechanically bypassed), whichever is appropriate, to attempt to achieve compartment temperatures measured during the two tests which bound (i.e., one is above and one is below) the standardized temperature. If the compartment temperatures measured during these two tests bound the standardized temperature, then these test results shall be used to determine energy consumption. If the compartment temperature measured with all controls set at their coldest setting is above the standardized temperature, a third test shall be performed with all controls set at their warmest setting and the result of this test shall be used with the result of the test performed with all controls set at their coldest setting to determine energy consumption. If the compartment temperature measured with all controls set at their warmest setting is below the standardized temperature; then the result of this test alone will be used to determine energy consumption. 3.2.2 Alternatively, a first test may be performed with all temperature controls set at their warmest setting. If the compartment temperature is below the standardized temperature, then the result of this test alone will be used to determine energy consumption. If the above condition is not met, then the unit shall be tested in accordance with 3.2.1 above. 3.2.3 Alternatively, a first test may be performed with all temperature controls set at their coldest setting. If the compartment temperature is above the standardized temperature, a second test shall be performed with all controls set at their warmest setting and the results of these two tests shall be used to determine energy consumption. If the above condition is not met, then the unit shall be tested in accordance with 3.2.1 above. 3.3 Variable defrost control optional test. After a steady-state condition is achieved, the door-opening sequence is initiated with an 18±2 second freezer door-opening occurring every eight hours to obtain three door-openings per 24-hour period. The first freezer door-opening shall occur at the initiation of the test period. The door(s) are to be opened 60 to 90°with an average velocity for the leading edge of the door of approximately two feet per second. Prior to the initiation of the door-opening sequence, the freezer defrost control mechanism may be re-initiated in order to minimize the test duration. 4. Test Period. 4.1 Test Period. Tests shall be performed by establishing the conditions set forth in Section 2 and using control settings as set forth in Section 3 above. 4.1.1 Nonautomatic Defrost. If the model being tested has no automatic defrost system, the test time period shall start after steady state conditions have been achieved, and be of not less than three hours' duration. During the test period the compressor motor shall complete two or more whole cycles (a compressor cycle is a complete “on” and a complete “off” period of the motor). If no “off” cycling will occur, as determined during the stabilization period, the test period shall be three hours. If incomplete cycling (less than two compressor cycles) occurs during a 24 hour period, the results of the 24 hour period shall be used. 4.1.2 Automatic Defrost. If the model being tested has an automatic defrost system, the test time period shall start after steady state conditions have been achieved and be from one point during a defrost period to the same point during the next defrost period. If the model being tested has a long-time automatic defrost system, the alternate provisions of 4.1.2.1 may be used. If the model being tested has a variable defrost control the provisions of 4.1.2.2. shall apply. 4.1.2.1 Long-time Automatic Defrost. If the model being tested has a long-time automatic defrost system, the test time period may consist of two parts. A first part would be the same as the test for a unit having no defrost provisions (section 4.1.1). The second part would start when a defrost period is initiated during a compressor “on” cycle and terminate at the second turn “on” of the compressor motor or after four hours, whichever comes first. 4.1.2.2 Variable defrost control. If the model being tested has a variable defrost control system, the test shall consist of three parts. Two parts shall be the same as the test for long-time automatic defrost in accordance with section 4.1.2.1 above. The third part is the optional test to determine the time between defrosts (5.2.1.3). The third part is used by manufacturers that choose not to accept the default value of F of 0.20, to calculate CT. 4.1.2.3 Variable defrost control optional test. After steady-state conditions with no door-openings are achieved in accordance with section 3.3 above, the test is continued using the above daily door-opening sequence until stabilized operation is achieved. Stabilization is defined as a minimum of three consecutive defrost cycles with times between defrost that will allow the calculation of a Mean Time Between Defrosts (MTBD1) that satisfies the statistical relationship of 90 percent confidence. The test is repeated on at least one more unit of the model and until the Mean Time Between Defrosts for the multiple unit test (MTBD2) satisfies the statistical relationship. If the time between defrosts is greater than 96 hours (compressor “on” time) and this defrost period can be repeated on a second unit, the test may be terminated at 96 hours (CT) and the absolute time value used for MTBD for each unit. 5. Test Measurements. 5.1 Temperature Measurements. Temperature measurements shall be made at the locations prescribed in Figure 7–2 of HRF–1–1979 and shall be accurate to within ±0.5 °F. (0.3 °C.) of true value. 5.1.1 Measured Temperature. The measured temperature is to be the average of all sensor temperature readings taken at a particular time. Measurements shall be taken at regular intervals not to exceed four minutes. 5.1.2 Compartment Temperature. The compartment temperature for each test period shall be an average of the measured temperatures taken during a complete cycle or several complete cycles of the compressor motor (one compressor cycle is one complete motor “on” and one complete motor “off” period). For long-time automatic defrost models, compartment temperature shall be that measured in the first part of the test period specified in 4.1.1. For models equipped with variable defrost controls, compartment temperatures shall be those measured in the first part of the test period specified in 4.1.2.2. 5.1.2.1 The number of complete compressor motor cycles over which the measured temperatures in a compartment are to be averaged to determine compartment temperature shall be equal to the number of minutes between measured temperature readings rounded up to the next whole minute or a number of complete cycles over a time period exceeding one hour. One of the cycles shall be the last complete compressor motor cycles during the test period. 5.1.2.2 If no compressor motor cycling occurs, the compartment temperature shall be the average of the measured temperatures taken during the last thirty-two minutes of the test period. 5.1.2.3 If incomplete cycling occurs (less than one cycle) the compartment temperature shall be the average of all readings taken during the last three hours of the last complete “on” period. 5.2 Energy Measurements: 5.2.1 Per-day Energy Consumption. The energy consumption in kilowatt-hours per day for each test period shall be the energy expended during the test period as specified in section 4.1 adjusted to a 24 hour period. The adjustment shall be determined as follows: 5.2.1.1 Nonautomatic and automatic defrost models. The energy consumption in kilowatt-hours per day shall be calculated equivalent to: ET=(EP×1440× K)/T where ET=test cycle energy expended in kilowatt-hours per day, EP=energy expended in kilowatt-hours during the test period. T=length of time of the test period in minutes, 1440=conversion factor to adjust to a 24 hour period in minutes per day, and K=correction factor of 0.7 for chest freezers and 0.85 for upright freezers to adjust for average household usage, dimensionless. 5.2.1.2 Long-time Automatic Defrost. If the two part test method is used, the energy consumption in kilowatt-hours per day shall be calculated equivalent to: ET=(1440× K× EP1/T1) + ((EP2−(EP1× T2/T1))× K×12/CT) where ET, 1440, and K are defined in 5.2.1.1 EP1=energy expended in kilowatt-hours during the first part of the test. EP2=energy expended in kilowatt-hours during the second part of the test, CT=Defrost timer run time in hours required to cause it to go through a complete cycle, to the nearest tenth hour per cycle, 12=conversion factor to adjust for a 50% run time of the compressor in hours per day, and T1 and T2=length of time in minutes of the first and second test parts respectively. 5.2.1.3 Variable defrost control. The energy consumption in kilowatt-hours per day shall be calculated equivalent to: ET=(1440 × EP1/T1) + (EP2 − (EP1 × T2/T1) × (12/CT) where 1440 is defined in 5.2.1.1 and EP1, EP2, T1, T2 and 12 are defined in 5.2.1.2. CT=(CTL × CTM)/(Fx (CTM − CTL) + CTL) where: CTL=least or shortest time between defrost in tenths of an hour (greater than or equal to 6 hours but less than or equal to 12 hours, 6 ≤ L ≤ 12) CTM=maximum time between defrost cycles in tenths of an hour (greater than CTL but not more than 96 hours, CTL ≤ CTM ≤ 96) F=ratio of per day energy consumption in excess of the least energy and the maximum difference in per day energy consumption and is equal to F=(1/CT − 1/CTM)/(1/CTL − 1/CTM) = (ET − ETL)/(ETM − ETL) or 0.20 in lieu of testing to find CT ETL=least electrical energy consumed, in kilowatt hours ETM=maximum electrical energy consumed, in kilowatt hours For demand defrost models with no values for CTL and CTM in the algorithm the default values of 12 and 84 shall be used, respectively. 5.2.1.4 Variable defrost control optional test. Perform the optional test for variable defrost control models to find CT. CT=MTBD × 0.5 MTBD=mean time between defrost X=time between defrost cycles N=number of defrost cycles 5.3 Volume measurements. The total refrigerated volume, VT, shall be measured in accordance with HRF–1–1979, section 3.20 and section 5.1 through 5.3. 6. Calculation of Derived Results From Test Measurements. 6.1 Adjusted Total Volume. The adjusted total volume, VA, for freezers under test shall be defined as: VA=VT× CF where VA=adjusted total volume in cubic feet, VT=total refrigerated volume in cubic feet, and CF=Correction factor of 1.73, dimensionless. 6.2 Average Per Cycle Energy Consumption: 6.2.1 The average per-cycle energy consumption for a cycle type is expressed in kilowatt-hours per cycle to the nearest one hundredth (0.01) kilowatt-hour and shall depend upon the compartment temperature attainable as shown below. 6.2.1.1 If the compartment temperature is always below 0.0 °F. (−17.8 °C.), the average per-cycle energy consumption shall be equivalent to: E=ET1 where E=Total per-cycle energy consumption in kilowatt-hours per day. ET is defined in 5.2.1, and Number 1 indicates the test period during which the highest compartment temperature is measured. 6.2.1.2 If one of the compartment temperatures measured for a test period is greater than 0.0 °F. (17.8 °C.), the average per-cycle energy consumption shall be equivalent to: E=ET1+((ET2−ET1)×(0.0−TF1)/(TF2−TF1)) where E is defined in 6.2.1.1 ET is defined in 5.2.1 TF=compartment temperature determined according to 5.1.2 in degrees F. Numbers 1 and 2 indicate measurements taken during the first and second test period as appropriate, and 0.0=Standardized compartment temperature in degrees F. [47 FR 34528, Aug. 10, 1982; 48 FR 13013, Mar. 29, 1983, as amended at 54 FR 36241, Aug. 31, 1989; 54 FR 38788, Sept. 20, 1989]
Title 10: Energy
PART 430—ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS
Subpart B—Test Procedures
Appendix B1 to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Freezers
