Appliance Performance beyond ENERGY STAR^®

Emerging standards focus on performance over prescriptive requirements

Peter J. Arsenault, FAIA, NCARB, LEED-AP

Residential construction and renovation has increasingly focused on energy efficiency as a part of good design. Typically, we focus on energy used for heating, cooling, water heating, and lighting, which is appropriate since in a typical house, those systems can account for over 70 percent of the energy consumed. But the other 30 percent of residential energy consumption merits attention as well. According to the U.S. Environmental Protection Agency (EPA), 13 percent of the energy used in a typical home can be attributed to just four common appliances—the refrigerator, dishwasher, clothes washer, and clothes dryer. Furthermore, another 11 percent is consumed by other miscellaneous appliances and equipment in a home such as cooking appliances like ranges, microwaves, etc. The energy efficiency of residential appliances is constantly being improved. Emerging efficiency standards and technology advancement means that manufacturers are offering products which are more resource efficient and cost effective than ever before.

Appliance History and Overview

The time period following World War II produced significant growth and prosperity in the U.S. and elsewhere. The mantra of modern living included chore saving home appliances and they became increasingly standard in new and remodeled homes everywhere. Energy was abundant and inexpensive, so energy efficiency wasn’t a dominant concern rather convenience, performance and style were the focus. When the energy crisis of the 1970’s struck, things changed.

In 1975, the US Congress passed the Energy Policy and Conservation Act with far reaching standards and requirements for the production and conservation of energy in the United States. Part B of Title III of this act included minimum energy conservation standards for appliances and equipment which were mandatory for all appliance manufacturers in order to sell their products in the U.S. This Act of Congress was subsequently amended and updated during the 1980s by the National Energy Conservation Policy Act and the National Appliance Energy Conservation Act (amended further in 1988). The impact of these laws was dramatic. Appliance manufacturers began paying close attention to the energy efficiency of their products and the average amount of energy utilized by residential appliances dropped by 30 to 60 percent depending on the specific appliance between 1975 and 1993. This was only the beginning. Continual efficiency improvements became commonplace and developed momentum as manufacturers recognized energy efficiency as a desirable and marketable feature of their products.

The energy performance of residential appliances has increased notably contributing to more sustainable residential designs. Photo courtesy of Whirlpool Corporation

Renewed interest in energy conservation and CO2 air pollution led to additional Energy Policy Acts (EPACT) being passed by Congress and signed by the President in 1992 and again in 2005. The comprehensive Energy Independence and Security Act of 2007 (EISA) built on the prior two decades of legislated energy advancement with a continued appropriate emphasis on energy efficiency and conservation. (These laws are codified in the United States Code, Title 42, Chapter 77, Subchapter III, Part A—Energy Conservation Program for Consumer Products Other Than Automobiles.) In all, the products regulated by this legislation represent about 90 percent of home energy use. Standards developed in response to this legislation have reportedly saved American consumers $40 billion on their utility bills in 2010, and the annual carbon dioxide reduction will reach 250 million tons by the year 2020. Legislation and the continued efforts of household appliance manufacturers have resulted in further energy efficiency gains through 2010 compared to 1975 levels with a 75 percent average energy use reduction for refrigerators, 80 percent for clothes washers, and 76 percent for dishwashers. These are dramatic improvements, making energy efficient appliances the norm, not the exception.

Since the 1970’s the amount of electricity needed to run common household appliances has decreased dramatically. Courtesy of Whirlpool Corporation

It is worth noting that concurrent with the interest in conserving energy, interest in reducing the use of potable water was also a growing concern during this time period. There are two reasons for this. First, most potable water requires a significant amount of energy to pump, move, treat, process and deliver to consumers. Only a small fraction of this water is actually consumed by people through drinking or cooking. Most residential water is used for washing, showering and flushing which all typically require energy for moving, processing and treating before returning the water back to the environment. Hence, reducing the amount of water required by a household directly reduces the amount of energy used to deliver and recover that water. Second, as populations have increased in certain areas of the U.S., the demand for water has increased to the point where supply is becoming scarce. In some cases, supply is already being disputed for territorial control. The combination of increasing water scarcity and the energy requirements of processing water in aging infrastructure systems have driven the logical inclusion of water conservation in energy legislation.

Standards and Programs for Appliance Performance

Federal legislation was an appropriate first step to spark change in appliance energy use. However, practical execution of the federal legislation comes about through performance standards and programs that can test and certify those appliances as compliant. Federal standards for appliances were developed to ensure compliance with the legislative mandate. Furthermore, two additional voluntary standards have emerged which offer manufacturers a method to communicate the resource efficiency of their appliances to customers.

Federal Standards

With legislation in place, a federal mechanism is obviously needed to determine if the law is being followed. In this case, the U.S. Department of Energy (DOE) and specifically the Buildings Technologies Office is charged with setting minimum energy efficiency standards for approximately 50 categories of appliances and equipment used in homes, businesses, and other applications. The appliances and equipment covered include, among other things, refrigeration, cooking, dishwashing, clothes washing and drying. In addition, the DOE implements the laws designed to limit the water consumption of several plumbing products. For most of these products and appliances, the laws passed by Congress established time schedules for the DOE to create, review and update standards and test procedures. All manufacturers and importers of covered products must use the DOE test procedures to demonstrate compliance with the standards, unless granted explicit waivers. This means that any appliance which does not meet the standards cannot legally be sold in the United States. Hence, it is fair to assume that any commercially available appliance that is specified, purchased, or installed has met these federal standards or they wouldn’t be on the market.

The DOE regulations or standards governing covered appliances and equipment are established through a rulemaking process that provides opportunities for public review and comment. Manufacturers, product importers and distributors, energy suppliers, efficiency and environmental advocates, and other members of the public are encouraged by the DOE to participate in the rulemakings. The DOE maintains a rulemaking schedule and provides progress reports to Congress every six months.

There are two notable updates underway that apply to certain appliances. In 2014, new federal standards related to refrigerators will take effect requiring roughly 20 to 30 percent more energy use reductions compared to the standard in effect in 2013. Similarly, clothes washers are targeted for updated federal standards in 2015 which will reduce the allowable amount of water and energy used in these appliances.

ENERGY STAR® for Appliances

ENERGY STAR® is a well-known federal program initiated in 1992 by the U.S. Environmental Protection Agency (EPA) in the interest of reducing air pollution by reducing the need for fossil fuel produced electrical energy. The EPA joined with the U.S. DOE to develop this program as a way to encourage and recognize products of many types that excel in their ability to go beyond simply meeting the minimum federal standards for energy efficiency described earlier. The familiar blue and white ENERGY STAR® label has therefore become a recognized symbol for energy efficiency that is earned by demonstrating performance through verifiable testing. It is intended to help consumers save money and protect the environment through the proliferation of energy-efficient buildings, products, and practices over less efficient alternatives. The program is completely voluntary but has been embraced by many companies as a means to distinguish their products and demonstrate their commitment to energy efficiency which has become a requirement of many consumers.

Appliances are a significant category of products within the overall ENERGY STAR® program. To qualify, appliances must use 10 to 50 percent less energy and water (actual percentage depends on the appliance type) than standard models that simply meet the federal standards. This is often accomplished through the incorporation of advanced technology in the products which still allows the appliance to perform its basic or core function but uses less energy in doing so. Just as modern LED light bulbs use less energy to provide just as much or more light than traditional incandescent bulbs, modern ENERGY STAR labeled appliances still provide their full core functional requirements but with demonstrated energy use reductions. In order to qualify to earn and display the ENERGY STAR label, those appliances must be tested at qualified independent labs which report the results back to the manufacturer to submit to the EPA. Once reviewed and accepted that test data is available to be accessed through the ENERGY STAR® web site.

Like the federal standards, ENERGY STAR® testing and requirements are updated periodically in response to trends and improvements in technology. Since this program is based on exceeding the federal minimum standards it becomes more stringent when the federal standards are made more stringent. Hence the new 2014 federal requirements for refrigerators discussed previously means that a 2014 standard refrigerator could now be more energy efficient than a comparable 2013 ENERGY STAR® model.

Updates to federal standards for refrigerators mean that for 2014 appliance manufacturers must effectively improve their models 20 to 30 percent over 2013 standards which is equal to or more efficient than 2013 ENERGY STAR® levels. To qualify for a 2014 ENERGY STAR® label, refrigerators will need to be 10 percent more efficient than the 2014 standards or 40 to 45 percent more than the 2013 federal standards. Courtesy of Whirlpool Corporation

This is because a 2013 ENERGY STAR® refrigerator needed to be 20% more efficient than the federal standard in effect in 2013 to qualify. The new 2014 federal standard meets or exceeds the prior (2013) ENERGY STAR® threshold at 20 to 30 percent more efficient than the previous 2013 federal standard. While this sounds like large gains, the absolute energy use (measured in terms of kilowatt hours) has been reduced dramatically since the 1970s. The 2014 ENERGY STAR® update could amount to a calculated average of only $6 per year difference in energy use between a 2014 ENERGY STAR® refrigerator and a comparable 2014 federal standard refrigerator. Recognizing this diminishing absolute amount of energy available to be saved, the 2014 ENERGY STAR® label (Version 5.0 for Residential Refrigerators and Freezers) can now be earned for a refrigerator that uses only 10 percent less energy than the 2014 federal standard.

In addition to product category updates in the ENERGY STAR® program, new product categories have also been added over time while some products still remain outside the purview of the program. For example, refrigerators, clothes washers and dishwashers are some of the appliance categories that have been eligible to apply for an ENERGY STAR® label, but cooking appliances and clothes dryers are not currently covered under the program. A clothes dryer standard is under development and may be available in 2015.

AHAM Sustainability Standards

The Association of Home Appliance Manufacturers (AHAM) is an appliance industry trade association representing manufacturers of major, portable and floor care home appliances, and suppliers to the industry throughout the U.S. and Canada. Altogether, AHAM boasts a membership of over 150 companies located throughout the world. In addition, AHAM is also a standards development organization, accredited by the American National Standards Institute (ANSI). In that role, it has authored numerous appliance performance testing standards used by manufacturers, consumer organizations and governmental bodies to rate and compare appliances.

In recent years, AHAM has embarked on a broad Product Sustainability Initiative with the overall goal to provide meaningful product sustainability information to consumers, their member companies, and other stakeholders. Their stated intention for this initiative is to drive innovation and continual improvement in the sustainability performance of home appliances by empowering consumers with information and knowledge. To date, they have produced first editions of two completely voluntary, consensus based Sustainability Standards – one for refrigerators and one for clothes washers with others planned or in the works.

A summary of the updated and changing nature of standards related to different household appliances between 2013 and 2015. Image courtesy of Whirlpool Corporation

Refrigerators. The Sustainability Standard for Household Refrigeration Appliances was first published in June of 2012 and was produced as a joint effort between AHAM, Canadian Standards Association (operating as CSA Group), and Underwriters Laboratories (UL). Because of this tri-party development and publication, the standard is cited as AHAM 7001-2012/ CSA SPE-7001.12/ UL 7001. It recognizes that the environmental performance of refrigeration home appliances has commonly been evaluated on the single environmental attribute of electricity consumption during use. This Standard was intentionally developed using life cycle thinking with a broader, multi-attribute, and more holistic approach to assess the environmental impacts of refrigeration home appliances using life-cycle assessment (LCA) data along with other key factors. Eligible refrigeration products can be evaluated for their sustainability under this standard based on six attributes each of which provides points that can be awarded through a combination of prerequisite and optional point items as follows: (note that the first five attributes are required; Item (f), innovation, is a bonus attribute, and is therefore not required):

 

For refrigeration appliances to be considered as having some level of recognized environmental performance under this Standard, such appliances shall

(a.) Receive a minimum total of 60 points.

(b.) Meet ENERGY STAR® performance criteria within the attribute of “energy consumption during use”.

(c.) Meet the requirements of the product performance attribute.

(d.) Show a balanced manner of reaching the 60 point level such that some points are attained in each of the 5 required attributes (i.e. items (a.) – (e.) above).

Full details of all aspects of the definitions, prerequisites, requirements, and testing of household refrigeration appliances is included in the full publication of the standard.

The Association of Home Appliance Manufacturers (AHAM) has teamed with the CSA Group and UL to create a series of voluntary sustainability standards for appliances that address the full life cycle of those appliances. Courtesy of Whirlpool Corporation and AHAM

Clothes Washers. The Sustainability Standard for Household Clothes Washing Appliances was developed in a manner similar to the refrigeration standard development. It was also a joint effort of AHAM, CSA, and UL and is referred to as AHAM-7003-2013/ CSA SPE-7003/ UL 7003. First published in May of 2013, it also recognizes that there is more to a sustainable clothes washing appliance than just water use and energy consumption. Eligible products can be evaluated for their sustainability under this Standard based on six attributes each of which provides points that can be awarded through a combination of prerequisite and optional point items as follows: (note that the first five attributes are required; Item (f), innovation, is a bonus attribute, and is therefore not required):

 

For clothes washing appliances to be considered as having some level of recognized environmental performance under this Standard, such appliances shall

(a.) Receive a minimum total of 60 points.

(b.) Meet ENERGY STAR® performance criteria within the attribute of “energy and water consumption during use”.

(c.) Meet the requirements of the product performance prerequisite.

(d.) Show a balanced manner of reaching the 60 point level such that some points are attained in each of the 5 required attributes (i.e. items (a.) – (e.) above).

(e.) Under the Materials attribute, meet the prerequisite and receive at least one point in certain evaluation subsections.

(f.) Under the Manufacturing and operations attribute, meet the prerequisite and receive at least one point in certain evaluation subsections.

(g.) Under the End of life attribute, meet the prerequisite and receive at least one point in certain evaluation subsections.

The published clothes washing standard goes on to provide the details of all of the attributes, testing and documentation required similar to the refrigeration standard. It is anticipated that AHAM will continue to develop similar voluntary standards for other types of appliances. In fact, they have pending standards for dishwashers and cooking appliances that may be released during 2014.

Emerging Technology in Appliances

All of the advances in the energy efficiency of appliances come directly from advances in the technology used in the design, fabrication, and operation of those appliances. Each of the 5 major appliance categories have seen real energy savings benefits due to the research, development, and field engineering efforts of appliance manufacturers. Some of these advances are discussed in more detail in the following sections.

Technological advances in the design and manufacture of appliances have created a new generation of very energy and water efficient products. Photo courtesy of Whirlpool Corporation

Refrigeration

Refrigerators have typically been cited as the most energy intensive household appliance because they operate 24 hours a day, every day, all year. Improvements in the mechanical portion of the refrigerator, the insulation used, and the ability to control when it is used all have helped to reduce the amount of energy used and the associated cost.

Refrigerator compressor technology is one of the notable advancements made in recent years. Many of today's compressors can operate at variable capacity as opposed to older compressors which operated either at 100 percent on or 100 percent off. The variability allows them to adjust to work only as hard as conditions warrant. These compressors are generally more efficient in terms of the energy required for work provided compared to older models. Some refrigerators also include multiple evaporators—one for the fresh food compartment and one for the freezer. A dual evaporator system increases the efficiency of the appliance because air is cooled only to the temperature required by each compartment (instead of pulling very cold air from the freezer for use in the fresh food compartment). From a usage standpoint, this has additional consumer benefits such as more even temperature distributions, higher humidity level in the fresh food compartment which generally leads to food staying fresher longer, less freezing potential of fresh food, and no odor transfer between the freezer and fresh food compartment.

The insulation used in refrigerators is being updated in many cases and becoming more environmentally benign. Blowing agents are used in the insulation foaming process of the refrigerator doors and cabinet. Old blowing agents had very high global warming potentials while newer ones are being adopted by appliance manufacturers, which have reduced this global warming potential by more than 99 percent.

In terms of refrigerator control, some manufacturers are offering “smart refrigerators” with internet connectivity that supports remote control functionality. By connecting to the “smart grid” of a public utility company, these refrigerators are able to automatically understand (in time of use pricing zones) when the price of electricity is higher than other hours and delay certain energy intensive functions (such as defrosting, or ice harvesting) to periods when the energy is cheapest. While this approach does not lower the overall energy usage, it does lower the cost to operate. In addition, this connectivity allows the owners to change temperature settings from their smart phone or even be notified if a door was left open. The smart refrigerator can also send an alert of a power outage which can help in identifying food or medicine that may have spoiled during that time.

Dishwashers

Overall energy and water use are key drivers in dishwasher performance. A significant portion of the energy used by a dishwasher is the energy required for heating the water they utilize, since many dishwashers on the market use internal booster heaters. That is actually a good thing, because it allows domestic hot water heater temperatures to be turned down to around 120°F instead of the higher temperatures desired for dish washing (sanitizing). The lower water heater temperatures mean less energy is used on an ongoing basis with the higher temperature created only for the intermittent needs of the dishwasher.

Many new dishwashers today include sensors which detect how dirty the specific load is and can adjust the wash cycle parameters to optimize energy and water use for the level of soiling, thus conserving resources. Even without this sensor, many new models can be programmed manually to match the level of washing or drying desired. This can include a simple rinse option which can actually use much less water than rinsing dishes by hand. New technology has just been launched which allows the dishwasher to save the last rinse of water for reuse in the prewash of the next cycle. This cuts water use by a further 33 percent over a comparable product today. When it comes to drying dishes, controls become important. Dishwashers that have a no-heat drying option typically provide good drying results with less energy since electricity is the source of the drying heat.

Just like refrigerators, dishwashers are starting to be offered in “smart” models. By connecting to the smart grid, they offer consumers the option to delay the start of the cleaning cycle until electricity prices are lowest (in time of use zones). They can also change any energy intensive drying settings based on the price of electricity. Furthermore, through internet connectivity these smart appliances can notify customers when their dishes are clean or when there are issues to address.

Cooking Appliances

As mentioned previously, there are limited U.S. federal standards that apply to appliances or other products used for cooking which regulate standby power and prohibit a constantly operating pilot light for gas appliances. As a practical matter there are many variables that make developing meaningful standards a difficult process at best. For example, consider the variable amount of time that any given cooking appliance may actually be used during an average day. Nonetheless, appliance manufacturers have forged ahead with new technology which results in products that are achieving new levels of efficiency and performance.

Double oven ranges provide smaller oven chambers requiring less energy to heat them up to temperature. Photo courtesy of Whirlpool Corporation

One notable example is the use of electric induction cooking elements as an alternative to either traditional electric resistance or natural gas cooking. Induction elements are the newest and most innovative types of cook-tops since the induction elements transfer electromagnetic energy directly to the pan, where heat is needed, and not to the surrounding area. As a result, this type of cooking appliance is very energy efficient, using significantly less energy than radiant electric systems and has been calculated to provide even greater savings when compared to natural gas.

When it comes to ovens, certain free standing ranges are being built today with two oven cavities. This provides convenience in cases where two separate dishes are being cooked at the same time but which require different temperatures. However, it is also more energy efficient because the oven cavities are smaller than a comparable free standing range with just one oven cavity so each cavity requires less energy to heat up to temperature while heating up faster in the process. Models that provide a smaller top oven cavity, where a vast majority of meals could be cooked, use less energy than the traditional larger single cavities. Some self-cleaning ovens also have innovative coatings on the cavity wall which make it harder for soils to stick. That is coupled with temperature cleaning options at lower temperatures than the traditional self-clean cycle which essentially heats the oven up to such a high temperature that it burns all the soils off. Lower self cleaning temperatures translate to less energy used in the process.

Clothes Washers

On average, hot water heating accounts for about 90 percent of the energy consumed by a clothes washer – only about 10 percent of the energy goes to run the washer motor. Hence, clothes washer efficiency clearly needs to address both energy and hot water usage. One emergent trend for greater efficiency is to use horizontal axis (H-axis) or front loading washing machines which have been shown to use about half to a third of the energy of conventional vertical-axis top-loaders. The horizontal wash drum orientation fundamentally requires less energy and water to get the same load just as clean in part because the whole tub does not need to fill up to do the washing. They also use a faster spin speed than vertical axis machines allowing more water to drain out of the wet clothes such that they will require less drying energy as a result.

Front loading, horizontal axis washers have demonstrated lower energy and water usage and can be readily paired with front loading dryers. Photo courtesy of Whirlpool Corporation

Independent of machine style, selecting a model with many choices to control wash cycles and water temperature gives the owner more ability to reduce operational energy use. Generally, washing a full load is most efficient and capable of saving thousands of gallons of water each year. Nonetheless, controls should allow the option of using a smaller amount of water for small loads when needed.

Just like dishwashers and refrigerators, “smart” clothes washers that can connect to the smart grid are commercially available today. They offer the option to delay the start of the cleaning cycle to when prices are lowest (in time of use pricing zones) and can send notifications on when a load is complete, etc. Like dishwashers, certain clothes washers also sense the size and soiling level of the clothing load and adjust cycle parameters automatically to optimize resource efficiency. Some front loaders have a bulk dosing option, where the user will add a large amount of detergent into a special cartridge in the machine. The machine will then determine how much detergent is required based on the load conditions sensor thus avoiding human error in overdosing the load.

Clothes Dryers

The fundamental energy choice in clothes dryers is to select between electric and gas-fired models. In terms of comparative energy use, gas dryers are generally less expensive to operate however there is not a lot of variation in actual energy use between models for identical loads run for identical times. The main variables for determining the amount of energy used in dryers become the frequency of usage and the running time selected when they are used.

The operational energy use of a dryer is largely dictated by whether or not the dryer employs sensors to automatically turn off the dryer once clothes are dry. The alternative is timed drying which leaves the running time, and corresponding energy use, to the guesswork of the user. The best dryers have moisture sensors inside the drum for sensing clothing dryness and automatically shut the machine off when the clothes have dried. Most others only infer dryness by using temperature sensors in the exhaust air portion of the dryer, which may result in running the dryer longer than needed. Compared with timed drying, savings of about 10 percent with temperature-sensing controls and 15 percent with moisture-sensing controls are possible.

Like clothes washers there are “smart” grid compatible clothes dryers commercially available today. They offer the option to delay the start of the drying cycle to when prices are lowest and can also send consumers notification to their mobile device when their load is complete among other things. Almost all such connected appliances can report the real-time energy usage of the appliances as they are being used.

Currently, the ENERGY STAR® program does not rate clothes dryers, but that may be changing in the near future. Measurement tests and standards are being worked on to define a reliable means to measure and differentiate performance of clothes dryers.

Efficient Appliances in Green Homes

With an understanding of the energy efficiency of each of these major appliances, what is their impact on the design of green homes? Different green home rating systems look at this a little differently, so let’s take a brief look at each.

Home Energy Rating System (HERS) by RESNET

The Residential Energy Services Network (RESNET) is an independent, not-for-profit member based organization primarily made up of certified home energy raters serving builders, contractors, and federal government agencies. The primary tool used for establishing an energy rating by this organization is the HERS Index which is a modeled estimation of total home energy use and cost compared to a baseline value. A certified RESNET HERS home rater assesses on site the many variables of a subject home including the size of the home, number of bedrooms, insulation levels, window types and sizes, climate region, and home orientation, as well as information on all the appliances, lighting, etc. To calculate the home’s HERS Index Score, the rater compares the data against a 'reference home'– a designed-model home of the same size and shape as the actual home, so the score is always relative to the size, shape and type of house being rated. A typical new, energy code compliant (based on 2006 version of the International Energy Conservation Code (IECC)) home is assigned a baseline value of 100 while a typical existing home today would have a baseline score a 130. So for example, a new home with a HERS Index score of 70 would be deemed to be 30 percent more efficient than a comparable baseline new home while a score of 130 in this case would be deemed 30 percnet less efficient.

The HERS Index is used to establish a comparative score on energy efficiency for homes. Image courtesy of Whirlpool Corporation and RESNET

Keep in mind that this index is all based on modeling, not actual performance - actual results will vary depending on the number of occupants, behavior, weather, etc. Nonetheless, the HERS Index has become an accepted methodology to estimate and communicate the energy efficiency of a home to prospective homebuyers. In terms of addressing appliances, there are baseline assumptions for old appliances in the model that are compared to the actual appliances installed in the house. Updating the old refrigerator, cooking appliance, dishwasher, washing machine, and dryer could reduce the HERS Index by 2 to 4 or more points, which would indicate a 2 to 4 percent more efficient home overall. HERS raters are also equipped to make recommendations on selecting the most appropriate energy efficient appliances for a particular home.

ICC700-2012: National Green Building Standard (formerly NAHB Green)

In 2007, the National Association of Home Builders (NAHB) and the International Code Council (ICC) partnered to create the 2008 NAHB Green Building Standard. The 2012 version referred to as the ICC700-2012 National Green Building Standard (NGBS) incorporates enhancements gleaned from its first four years of use. It also updates its baseline for energy performance to the 2009 version of the International Energy Conservation Construction Code (IECC). In January 2013, the NGBS was approved by the American National Standards Institute (ANSI) as an American National Standard.

The NGBS is a multi-attribute, point-based green standard specifically intended for residential buildings. It is broken down into 6 basic rating categories which include Lot Design, Resource Efficiency, Energy Efficiency, Water Efficiency, Indoor Environmental Quality, Operation, and Maintenance/ Building Owner Education. The seventh category of “Other” is an opportunity to earn additional points by acquiring points in any of the previous six by exceeding the minimum requirements in each category. Under this standard, a building can strive to achieve one of four rating levels based on the number of points earned:

Bronze level: 231 points needed

Silver level: 349 points needed

Gold level: 509 points needed

Emerald level: 641 points needed.

The National Green Building Standard is broken down by 7 categories and is based on earning points within each of those categories to demonstrate a level of performance. Courtesy of Whirlpool Corporation

Appliances are specifically covered under the Energy Efficiency category in Chapter 7 of the NGBS. This category allows for two different options to show compliance. If the “Performance Path” is selected, then the entire building needs to be modeled or rated similar to the HERS Index or other computer-modeling software. Then points are assigned based on the percentage of reduction compared to the 2009 IECC baseline. The other option is to use the “Prescriptive Path” whereby a checklist is used to show points being earned for specific items. In the case of appliances, if those installed are ENERGY STAR® rated then they can earn up to 3 points for a refrigerator (depending on climate zone location), 1 point for a dishwasher, 4 points for a washing machine, and 1 point for an induction cooktop. Under innovative practices, an additional point can be earned for using between three to five Smart Appliances and 2 points when six or more Smart Appliances are installed. Water conserving appliances are addressed in Chapter 8 under the Water Efficiency category. If the dishwasher and clothes washer are ENERGY STAR® rated then they can earn 2 and 13 points respectively since water usage, in addition to energy usage, is accounted for on those machines. If the clothes washer demonstrates a water factor of 6.0 or less, then the NGBS points jump from 13 to 24.

All told, appliances can contribute up to 37 possible points toward a final Prescriptive Path building rating – more than 10% of the Silver level requirement. A Performance Path model may achieve a different number of points, potentially more than the Prescriptive Path, and should be compared accordingly.

LEED® for Homes

The U.S. Green Building Council (USGBC) is well known for its popular Leadership in Energy and Environmental Design (LEED) program. This family of green building rating systems includes one specifically for homes updated in 2013 and referred to as LEED for Homes version 4. This comprehensive rating system has six fundamental categories: Location and Transportation, Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, and Indoor Environmental Quality. In addition, there are two optional categories of Innovation and Regional Priority credits that can earn a green home ten points beyond the 100 points available in the first six categories. Within both the Energy and Atmosphere and Water Efficiency categories, the choice is given to follow either a Performance Path option by using a computer-modeled level of energy performance or a Prescriptive Path option by following a checklist of specific items.

A green home under the USGBC LEED for Homes program will benefit from looking at the kitchen and laundry design as part of the overall green basis for the home. Photo courtesy of Whirlpool Corporation

High efficiency appliances are specifically addressed in the prescriptive path for Energy and Atmosphere with up to 2 points available out of the 38 total in this category. Although they are not specifically addressed in the Water Efficiency category, appliances can certainly play into the calculation of total water use in a building. Therefore, in many cases, both the Performance Path and Prescriptive Path should be looked at to determine which yields the more favorable results towards certification.

The Materials & Resources category is where LEED commonly addresses recycled content and other characteristics of building materials. In LEED for Homes v.4, this section has been updated to take a broader look at the life cycle of building products, but still focuses on the permanent components of a building. Since appliances are not considered permanent parts of the structure, they typically do not get recognized for their contributions in this area.

Conclusion

There are many choices when it comes to specifying and selecting appliances. Appliances manufactured today have higher levels of energy and water efficiency and core product performance than ever before, even those products without an ENERGY STAR® label. On one hand, these advances are being driven by evolving standards and regulations, but also by improvements in the technology that goes into the appliances and improvements in the process of appliance manufacturing. . When highly efficient and properly controlled appliances are included in the design of a green home they can contribute notably to the overall green rating of that home, no matter which certification is used. Architects that make informed choices regarding the appliances used in the homes that they design can take advantage of this latest technology and achieve even higher levels of green residential performance.

Peter J. Arsenault, FAIA, NCARB, LEED AP is a nationally known architect, sustainability consultant, technical writer and continuing education presenter. www.linkedin.com/in/pjaarch

Additional Resources:

Commentary on standards from DOE website: http://www1.eere.energy.gov/buildings/appliance_standards/about_appliance_and_equipment.html

American Council for an Energy-Efficient Economy (ACEEE)

Appliance Standards Awareness Project

Association of Home Appliance Manufacturers

NAHB and the ICC 700 National Green Building Standard

US Green Building Council and the LEED rating system

 

Whirlpool Corporation, the leading manufacturer of major home appliances, brings you Inside Advantage® – innovative products providing efficiency and performance; market insights helping you to create more appealing designs; and targeted services that make doing business with us easier and more profitable. www.insideadvantage.com