Washer Energy regulations & standby power - History and summary
In December 2007, the Congress enacted EISA, setting the first minimum water efficiency requirements for clothes washers. Minimum energy efficiency requirements, however, were left unchanged from the existing levels set by DOE in 2001, which became effective in January 2007. The 2007 standards which went into effect on January 1, 2011, required residential clothes washers to be manufactured with a modified energy factor (MEF) of at least 1.26 and a maximum water factor (WF) of 9.5 or less.
MEF is expressed in cubic feet of washer capacity per kWh per cycle and incorporates the machine electrical energy consumption, the hot water energy consumption, and the energy required to remove the remaining moisture in the clothes.
WF is expressed in gallons per cubic feet of capacity. A higher MEF indicates better energy efficiency while a lower WF indicates better water efficiency.
In May 2012, DOE adopted new clothes washer standards based on a 2010 agreement between manufacturers and efficiency proponents. DOE uses new metrics called IMEF (integrated
modified energy factor) and IWF (integrated water factor) which add standby and off-mode
energy consumption into the formula.
Integrated modified energy factor (IMEF) means the quotient of the cubic foot (or litre) capacity of the clothes container divided by the total clothes washer energy consumption per cycle, with such energy consumption expressed as the sum of:
a) The machine electrical energy consumption; b) The hot water energy consumption;
c) The energy required for removal of the remaining moisture in the wash load; and d) The combined low-power mode energy consumption.
Integrated water factor (IWF) means the quotient of the total weighted per-cycle water consumption for all wash cycles in gallons divided by the cubic foot (or litre) capacity of the clothes washer.
The IMEF/IWF standard levels in the 2012 final rule are equivalent to the MEF/WF levels in the negotiated agreement.
Standards for top-loading washers with capacity equal or greater than 1.6 ft3 (45.3 litres) require:
a minimum IMEF of 1.29 (corresponding to a MEF of 1.72) and a maximum IWF of 8.4 (corresponding to WF of 8.0) effective since March 2015 and
a minimum IMEF of 1.57 IMEF (2.0 as MEF) and a maximum IWF of 6.5 (6.0 as WF) effective since January 2018.
Compared to the current standards, the energy and water savings achievable with the 2018 standards are about 33% and 19%, respectively.
Standards for front-loading washers with capacity equal or greater than 1.6 ft3 (45.3 litres) are
effective since March 2015 and require
a minimum IMEF of 1.84 (2.2 as MEF) and a maximum IWF of 4.7 (4.5 as WF).
Compared to the current standards, the energy and water savings achievable with the 2015 standards are about 15% and 35%, respectively. According to DOE, the standards for top and front loading washers will save about 2 quads of energy, 3 trillion gallons of water and about 113 million metric tons of CO2 emissions over 30 years. DOE estimates total net dollar savings for U.S. consumers over that same period will exceed $31 billion.
Currently, ENERGY STAR-qualified products must meet a minimum MEF of 2.0 and a maximum WF of 6.0.
Front-loaders are generally more efficient than top-loaders, although manufacturers have introduced some new high-efficiency top-loading models that are as efficient as some front-loaders (cf. section 4.3.3.1). Until recently, top-loaders were much more common than front-loaders, but front-loaders now make up about half of annual sales in the US market. Clothes washer efficiency improvements can be achieved through advances in mechanical technology (efficient motors); reductions in the amount of water consumed to clean a given volume of laundry; and higher spin speeds to remove more moisture from the clothes at the end of the cycle (see for instance:
www.appliance-standards.org/product/clothes-washers).
US Federal Energy Conservation Standard for residential clothes washers – amended
Clothes washers manufactured and distributed in commerce, as defined by 42 U.S.C. 6291(16), on or after March 7, 2015, and before January 1, 2018, must meet the energy conservation standards shown in the Table 1.11, as specified in the Code of Federal Regulations, 10 CFR 430.32(g)(3).
Table 1.11: Amended Energy Conservation Standards for Residential Clothes Washers as
of March 7th, 2015
Product Class Integrated Modified Energy Factor IMEF (ft3/kWh/cycle)
(Minimum values)
Integrated Water Factor IWF (gal/cycle/ft3)
(Maximum values) 1. Top-loading, Compact
(less than 1.6 ft3 capacity)
0.86 14.4
2. Top-loading, Standard (1.6 ft3 or greater capacity)
1.29 8.4
3. Front-loading, Compact (less than 1.6 ft3 capacity)
1.13 8.3
4. Front-loading, Standard (1.6 ft3 or greater capacity)
1.84 4.7
Clothes washers manufactured and distributed in commerce on or after January 1, 2018 must meet the energy conservation standards shown in the Table 1.12.
Table 1.12: Amended Energy Conservation Standards for Residential Clothes Washers as
of January 1st, 2018
Product Class Integrated Modified Energy Factor
Product Class Integrated Modified Energy Factor IMEF (ft3/kWh/cycle)
(Minimum values)
Integrated Water Factor IWF (gal/cycle/ft3)
(Maximum values) 1. Top-loading, Compact
(less than 1.6 ft3 capacity)
1.15 12.0
2. Top-loading, Standard (1.6 ft3 or greater capacity)
1.57 6.5
3. Front-loading, Compact (less than 1.6 ft3 capacity)
1.13 8.3
4. Front-loading, Standard (1.6 ft3 or greater capacity)
1.84 4.7
New Test Procedure for Measuring the Energy Consumption of Clothes Washers
The test methods for domestic and commercial washing machines in force since March 2012 in USA is described in the Federal Register: 10 CFR Section 430.23(j), Appendix J2 to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Automatic and Semi- Automatic Clothes Washers (U.S. Government [n.d.]). This replaces Appendix J1 from 2005 which was already described in Lot 14 Task 1 in 2007. Changes of the current test standard compared to the Appendix J1 can be summarised as follows (see ENER Lot 14, Task 1).
IMEF & IWF calculations: The effects of all power modes and other changes are included. The metrics now ‘integrate’ all of these items.
Annual number of cycles revised from 392 to 295: Based on 2005 surveys, 295 cycles / year have been considered to represent consumer use. This is also needed for the annual cost calculation.
Updates of TUFs (Temperature Use Factors) and DUFs (Dryer Use Factors): All the same TUFs (Temperature Use Factors) have been kept, but warm/warm will be now treated as a complete wash/rinse cycle and warm/cold will be adjusted when warm/warm is available (US machines do not have temperature setting but just warm or cold water inlets). Based on 2005 survey data, the DUF (Dryer Use Factor) has been increased from 0.84 to 0.91 to reflect higher use of spin drying.
Elimination of LAF (Load Adjustment Factor) and replacement of the representative load size with the weighted average load size: The LAF was judged to be duplicative and was eliminated. Representative Load Size used in the drying energy equation will be replaced with an average load size that utilizes the LUFs (Load Usage Factors).
Energy Test Cycle definition changes: Extensive changes and discussion on the new definition took place. The new energy test cycle will require testing of the normal cycle similar to J1 but also requires testing of TUFs that are available in other cycles but not in the normal cycle.
New Capacity Measurement method: To assure consistency among stakeholders, the measurement methods have either been revised or clarified.
Test Cloth: Clarification of ‘lot’ and ‘roll’ definitions, size and weight tolerances and preconditioning requirements. These are detailed in the J2 test procedure.
Detergent: Use of the detergent formula described in the AHAM (Association of Home Appliance Manufacturers) standard test at a dosage of 27.0g + 4.0 g/lb in J1 & J2
Water extractor: J1 specifies tests for extractors up to 500 units of gravitational acceleration (g, or g-force) in order to determine the remaining moisture content (RMC)
correlation curve for test cloth lots. To account for washers that can spin faster, a 650 g extraction test has been added to J2.
Annual operating cost calculation (includes low-power modes & number of cycles): Since new power modes are part of the calculations, these costs must be added to the annual cost.
Low-Power mode inclusion (based on IEC 62301 ed. 2.0): The new test procedure includes energy use in low-power modes in addition to the regular washing mode.
- Active mode: Includes all of the washing functions along with delay start and cycle finished functions.
“… a mode in which the clothes washer is connected to a mains power source, has been activated, and is performing one or more of the main functions of washing, soaking, tumbling, agitating, rinsing, and/or removing water from the clothing, or is involved in functions necessary for these main functions, such as admitting water into the washer or pumping water out of the washer. Active mode also includes delay start and cycle finished modes…”
- Active washing mode: Includes only the washing functions in a test cycle (i.e. not delay start and cycle finish)
“… a mode in which the clothes washer is performing any of the operations included in a complete cycle intended for washing a clothing load, including the main functions of washing, soaking, tumbling, agitating, rinsing, and/or removing water from the clothing…”
- Inactive mode: This is one of two ‘Low-power’ modes and includes the stand-by modes
“… a 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…”
- Off mode: This is one of two ‘Low-power’ modes and can include power for an indicator
“… a mode in which the clothes washer is connected to a mains 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…”
- Standby mode: Included in the ‘Inactive mode’ and includes functions that take place outside of the active washing mode
“… any mode in which the clothes washer is connected to a mains power source and offers one or more of the following user oriented or protective functions that 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…”
Delay Start’ falls within this mode because by definition in J2, it “… is facilitated by a timer.”
‘Cycle Finish’ falls within this mode because by definition in J2, it “… provides continuous status display …”
- Combined low-power mode: This includes all of the low-power modes
“… the aggregate of available modes other than active washing mode, including inactive mode, off mode, delay start mode, and cycle finished mode.”
- Energy use is accounted for in 2 distinct areas:
1. Active Power – Basically the same as J1. Accounts for power consumed during the energy cycle and includes all energy used in the Active washing mode.
2. Low Power – Accounts for power consumed in all modes other than the Active Washing mode. Modes included are Standby, Off, Delay Start, Cycle Finish
- Low-power energy consumption per cycle is calculated by (section 4.4 in the J2 procedure):
a. measuring and averaging power consumption in each low power mode per IEC 62301
b. multiplying this average power consumption by the annual hours not accounted for by annual use hours (i.e. 8465 hours = 8760 hours per year – 295 hours of use per year)
c. and then divide this total by the annual number of cycles (295 cycles)
Combined Low-Power (ETLP) per cycle = [(Pia x Sia) + (Po x So)] x Kp/295 = Average of
(Inactive power + Off power)/annual cycles Where:
Pia = Washer inactive mode power, in watts, for clothes washers capable of operating in
inactive mode; otherwise, Pia = 0.
Po = Washer off mode power, in watts, for clothes washers capable of operating in off
mode; otherwise, Po=0.
Sia = Annual hours in inactive mode as defined as Soi if no off mode is possible, [Soi/2] if both
inactive mode and off mode are possible, and 0 if no inactive mode is possible.
So = Annual hours in off mode as defined as Soi if no inactive mode is possible, [Soi/2] if both
inactive mode and off mode are possible, and 0 if no off mode is possible. Soi = Combined annual hours for off and inactive mode = 8,465.
Kp = Conversion factor of watt-hours to kilowatt-hours = 0.001.
295 = Representative average number of clothes washer cycles in a year. US Energy Guide label (mandatory)
According to (US EPA [n.d.]b), major home appliances such as clothes washers must meet the Appliance Standards Program set by the US Department of Energy (DOE). Manufacturers must use standard test procedures developed by DOE to prove the energy use and efficiency of their products (cf. section above).
Test results are printed on a yellow Energy Guide label, which manufacturers are required to display on their appliances according to the Appliance Labeling Rule of the Federal Trade Commission (FTC). This label estimates how much energy the appliance uses, compares energy use of similar products,
and lists approximate annual operating costs. The exact costs will depend on local utility rates and the type and source of your energy. Appliances which are ENERGY STAR qualified (cf. next section) must carry the Energy Guide label.
For clothes washers, the Energy Guide label shall provide the following information (FTC 2012): Models for which the Energy Guide label applies
Capacity class; and capacity (tub volume) in cubic feet
Estimated Yearly Energy Cost (US Dollar), when used with an electric water heater (the indication of a cost range of similar models, as for example given for dishwashers, is not available for clothes washers).
Estimated yearly electricity use (kWh).
Estimated Yearly Energy Cost (US Dollar), when used with a natural gas water heater. US Energy Star logo if applicable for the Energy Guide labelled appliance.
The estimated energy cost is based on six wash loads a week and a national average electricity cost of 12 cents per kWh and natural gas cost of $1.09 per therm.
US Energy Star label for Residential Clothes Washers (voluntary)
ENERGY STAR is a U.S. Environmental Protection Agency (EPA) voluntary programme to identify and promote energy–efficient products in order to reduce energy consumption through voluntary labelling of or other forms of communication about products that meet the highest energy efficiency standards.
Specifications for residential clothes washers (status: March, 2015) are reported in Table 1.12. Clothes washers that have earned the ENERGY STAR are about 25% more efficient than non- qualified models and are more efficient than models that simply meet the federal minimum standard for energy efficiency.
Only front and top loading clothes washers meeting the ENERGY STAR definitions for residential clothes washer and commercial clothes washer, with capacities greater than 1.6ft3 (45.3 l) are
eligible to earn the ENERGY STAR certification. Such definitions correspond with the definitions provided for the DOE standards.
ENERGY STAR allowance for connected appliances
Energy Star has published new eligibility criteria and partner commitments which are effective since March 2015 to qualify a product for the ENERGY STAR label. These include some 5% allowance on the Integrated Modified Energy Factor (IMEF) if the washing machine fulfils some ‘connected criteria’. With this allowance it will be easier to qualify for the ENERGY STAR or any of the established tiers of the Consortium for Energy Efficiency (CEE) (cf. next section and Table 1.13 further below).
The following criteria are required for being a ‘connected appliance’ (extracted from ENERGY STAR® Program Requirements Product Specification for Clothes Washers Eligibility Criteria Version 7.0) (US EPA [n.d.]a):
Connected Clothes Washer System
To be recognized as ‘connected’ and to be eligible for the connected allowance, a “connected clothes washer system” as shown in Figure 1.4 shall include the base appliance plus all elements (hardware, software) required to enable communication in response to consumer-authorized energy related commands.
Figure 1.4: Connected Clothes Washer System Boundary – Illustrative Example
Communications
1. Open Standards – Communication with entities outside the Connected Clothes Washer System that enables connected functionality must use, for all communication layers, standards.
2. Communications Hardware Architecture – Communication with entities outside the Connected Clothes Washer System that enables connected functionality shall be enabled by any of the following means, according to the manufacturer’s preference:
a. Built-in communication technology
b. Manufacturer-specific external communication module(s) and/or device(s)
c. Open standards-based communication port on the appliance combined with open standards- based communications module
d. Open standards-based communication port(s) on the appliance in addition to a, b or c, above
Open Access
To enable interconnection with the product, in addition to the section above that requires open- standards, an interface specification, Application Programming Interface (API) or similar documentation shall be made available to interested parties that at a minimum, allows transmission, reception and interpretation of the following information:
1. Energy Consumption Reporting specified (must include accuracy, units and measurement interval);
2. Operational Status, User Settings & Messages (if transmitted via a communication link); 3. Demand Response
Energy Consumption Reporting
In order to enable simple, actionable energy use feedback to consumers and consumer authorized energy use reporting to 3rd parties, the product shall be capable of transmitting energy
consumption data via a communication link to energy management systems and other consumer authorized devices, services, or applications. This data shall be representative of the product’s interval energy consumption. It is recommended that data be reported in watt-hours for intervals of 15 minutes or less, however, representative data may also be reported in alternate units and intervals.
The product may also provide energy use feedback to the consumer on the product itself. On- product feedback, if provided, may be in units and format chosen by the manufacturer (e.g., $/month).
Remote Management
The product shall be capable of receiving and responding to consumer authorized remote requests (not including third-party remote management which may be made available solely at the discretion of the manufacturer), via a communication link, similar to consumer controllable functions on the product. The product is not required to respond to remote requests that would compromise performance and/or product safety as determined by the product manufacturer.
Operational Status, User Settings & Messages
1. The product shall be capable of providing the following information to energy management systems and other consumer authorized devices, services or applications via a communication link:
Operational / Demand Response (DR) status (e.g., off/standby, cycle in process, delay appliance load, temporary appliance load reduction).
2. The product shall be capable of providing the following information on the product and/or to energy management systems and other consumer authorized devices, services or applications via a communication link:
At least two types of messages relevant to the energy consumption of the product. For example, messages for clothes washers might address performance issues or report of energy consumption that is outside the product’s normal range.
Demand Response
A connected clothes washer shall have the capability to receive, interpret and act upon consumer- authorized signals by automatically adjusting its operation depending on both the signal’s contents and settings from consumers. At a minimum, the product shall be capable of providing the following:
Delay Appliance Load Capability: The capability of the product to respond to a signal in accordance with consumer settings, except as permitted below, by delaying the start of an operating cycle beyond the delay period.
a. Default settings –The product shall ship with default settings that enable a response for at least 4 hours.
b. Consumer override – The consumer shall be able to override the product’s Delay Appliance Load response before or during a delay period.
c. The product shall be able to provide at least one Delay Appliance Load response per consumer initiated operating cycle.
Temporary Appliance Load Reduction Capability: TBD
Information to Consumers
If additional modules, devices, services and/or infrastructure are part of the configuration required to activate the product’s communications capabilities, prominent labels or other forms of consumer
literature. These shall provide specific information on what consumers must do to activate these capabilities (e.g. “This product has Wi-Fi capability and requires Internet connectivity and a wireless router to enable interconnection with an Energy Management System, and/or with other external devices, systems or applications.”). Compliance with Connected functionality shall be through examination of product and/or product documentation. In addition, demand response functionality shall be evaluated using the TBD ENERGY STAR Clothes Washers Test Method to Validate Demand Response in order to be eligible for the connected allowance.