Energy-Efficient Appliances Technology Snapshot & Benefits:
Both immediate and indirect economic savings can come from energy-efficient appliances such as refrigerators, horizontal-axis washing machines, clothes dryers, dishwashers, etc. Immediate and continuing savings accrue from lower utility bills for electricity and/or water. The performance levels of these appliances meet, and generally exceed, those of industry "standard" models. As a case in point, consider household refrigeration. By the late 1970s, refrigerators reached their most inefficient performance by requiring about 1750 kiloWatt-hours per year to operate. Modern energy-efficient refrigerators provide the same or better service at 450-550 kiloWatt-hours per year, and they are much quieter in operation. Estimated Cost Savings:
The direct economic savings achieved by efficient appliances are a function of how much the appliance will be used, the performance level of the equipment being replaced, and local costs for utilities. When you replace older equipment, it is not uncommon for electricity consumption for that appliance to decrease by 50% or more. In general, if the appliance being replaced is more than 15 years old, and it is replaced with a state-of-the-art unit, you may expect utility savings of 20%-60% compared with the energy required by the previous appliance. Horizontal-axis washing machines typically save consumers 50% in both electric and water utilities. Additional savings come from reduced quantities of detergent. Your monthly electrical bill is for all electricity used by all electrical loads in the building, so changing a single appliance will lower the bill, but in proportion to the amount of electricity formerly used by that appliance. If refrigeration represents 15-20% of your electric bill, a new refrigerator that is twice as efficient as the unit being replaced will lower your total bill by about 7-10%. Any increase in initial cost is usually more than made up in monthly savings. See ACEEE Consumer Guide to Home Energy Saving for more detailed information on appliances and savings. Issues:
Availability of the most energy-efficient appliances may be an issue. Sometimes the best equipment is in demand, which can mean that discounts and sale prices are either unavailable or of lower value. Over time, as manufacturers and suppliers clear inventories of less efficient models by offering discounts, expect the price of efficient appliances to come down as well. Regional Issues:
Primarily, regional issues involve supply, delivery, and installation. Installation (Getting It Done):
Be sure to price shop and to get two or three (or more) prices. Inquire about installation and removal of your old unit. For any refrigeration unit, be sure that the refrigerant will be removed and recycled responsibly. Refrigerants are very potent greenhouse gases and must be captured and contained. Shopping for price and availability will give you perspective on the true costs of equipment and installation in your area. More Information on This Topic: U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy: Energy Savers - Appliances U.S. Department of Energy's Building Technologies Program: Dishwasher Tips U.S. Department of Energy's Building Technologies Program: Laundry Tips U.S. Department of Energy's Building Technologies Program: Refrigerator/Freezer Energy Tips Energy Star®: Appliances Energy Star®: Clothes Washers Energy Star®: Dehumidifiers Energy Star®: Dishwashers Energy Star®: Refrigerators Energy Star®: Room Air Conditioners Energy-Efficient Windows
Technology Snapshot & Benefits:
Significant economic savings can come from modern windows. Unless recently upgraded, your windows are likely a major source of heat loss. In cold climates, windows transfer heating energy out of the building through both conduction and radiation. Additionally, depending upon how weather-tight the frame and seals, windows may transfer energy by convection as well. This situation is reversed in hot climates, with windows allowing heat into a building and forcing expensive cooling systems to work overtime. Typical walls in homes are insulated to a level of R-11 to R-19, yet a single pane of standard glass has an insulating value of about R-1. In other words, heat can leak out of, or into, a building about 11 to 19 times more easily through glass than through the wall. This is why your grandparents insisted on installing "storm" windows for the winter in northern climates - to boost window-insulating value to R-2, or perhaps R-2.5 with a good seal and tightly trapped air between the panes. Modern windows using specially developed E-glass are much more effective at keeping heat and cold where you want them. Most progressive window manufacturers offer several lines of energy efficient glass with "R" values in excess of R-4. New designs still in laboratory development promise R-values of 10 or more. Since glass is a fixed part of the building envelope, it performs 24 hours each and every day. With energy efficient glass, less fuel is required for a given level of comfort with corresponding cost savings and pollution savings. Estimated Cost Savings:
Assuming the same or greater level of comfort that you are used to, you can save a lot of energy and money by eliminating heat loss or gain through windows. It is common in Northern climates to save 30-40% of annual heating costs with super-efficient windows. With a monthly heating bill of $200 dollars, this equates to an estimated savings of $60-80 per month. Some large homes cost as much as $600 per month to heat, and the savings for these homes could approach $240 per month. The value of new windows depends upon how much glass area you have in your home and upon local climate. The National Climatic Data Center (NCDC) provides an historical record of departures of average daily temperatures from a reference temperature of 65 degrees F. This information is available as "Heating Degree-Days per Year" and provides a very useful estimate of how much energy can leak through windows. Issues:
For new homes, getting efficient glass is simply a matter of working with a builder or architect to specify performance glass. With older homes, the choice of retrofit is a little more problematic. It is unlikely that the glass in your house will suddenly "conk out" or reach the end of its useful life like a failed furnace or hot water heater. Therefore, you will be faced with the prospect of switching out older intact glass panels for newer glass panels. Nonetheless, this can improve comfort and lower operating expenses. Capital costs can be $5,000 to $10,000 or more, and still make sound economic sense when combined with a program of debt consolidation and/or refinancing. Regional Issues:
Selection of glass may depend on local climates. Windows can be "tuned" by the manufacturer for southern or northern exposures and for different climates. Be sure that you get the right glass for you. Installation (Getting It Done):
In addition to considering new windows throughout, also consider supplementary performance windows that can be treated as storm windows, inaddition to your existing glass. Particularly if your house has period architecture, this option allows you to retain the original glazing and sash while enjoying economic savings and the enhanced comfort of performance windows. Be sure to get bids from two or three (or more) window manufacturers, installers and/or glazing contractors to gain immediate perspective on the true costs of windows and installation in your area. More Information On This Topic:
Energy Recovery - Controlled Ventilation Systems
Technology Snapshot & Benefits:
The growing trend toward "tightening the home" improves a home's energy efficiency by controlling air and moisture movement to and from the home. However, making the home "tight" with poor ventilation can cause the home to retain moisture (which may cause mold) and other factors that compromise indoor air quality. Controlled ventilation systems are a means of increasing the amount of cleaner, fresher air entering the home, without the energy losses associated with simply opening windows. Estimated Cost Savings:
Systems can capture energy in the exiting air and then transfer that energy to the air entering the home. Product manufacturers should be able to provide cost saving estimates for specific properties. Issues:
Not all heating, ventilation, and air conditioning contractors have experience installing controlled ventilation systems. Make sure to work with a qualified, experienced contractor. Installation (Getting It Done):
Systems may cost several thousand dollars. Simplicity is the key to a cost-effective installation. Homeowners should hire a qualified heating, ventilation, and air conditioning contractor with experience installing controlled ventilation systems to get the job done.
Insulating for Energy Efficiency
Technology Snapshot & Benefits:
You can save a lot of money by installing or improving insulation. Insulation retards the flow of heat and is one of the most cost-effective investments that you can make. The effectiveness of insulation is measured by its tested resistance to heat flow and is known by its "R" value. The greater the "R" value, the greater the effectiveness. One of the easiest and most effective places to install insulation is in the attic, since heat rises from the heated rooms below. Insulation comes in many different forms including the familiar fiberglass, Styrofoam, vermiculite, pouring wool, cellulose materials such as shredded newspaper, and numerous "foamed-in-place" types. Particularly within the fiberglass and rigid foamed board types, there are a variety of choices of heat-reflective coatings. Properly installed insulation always improves comfort and reduces heating and cooling costs. Estimated Cost Savings:
Heating buildings is one of the largest expenditures of energy in the nation and one of the greatest opportunities for saving. The average U.S. household spent more than $2,350 in 1999 for energy: $1,200 for home energy and $1,150 for motor gasoline to run vehicles. (AEO2001, p.213) Of the $1,200 spent in the home, nearly half is spent for heating and cooling (AEO2001, p.162) and in aggregate, amounted to more than $50 billion in 1999. (p.159) For new construction, the maximum recommended amounts of insulation yield huge savings compared to no insulation. For existing buildings, upgrading to the recommended amount of insulation will save money. The amount of savings vary widely depending upon your starting point – namely, how much insulation you already have. See Energy Star's Cost-Effective Insulation Values for Existing Homes for recommended insulating values for walls, floors, ceilings, and basements. In general terms, when you double the R value of your insulation, the heat flow through the insulated surface will halve. Your bill, however, may not halve because of other, less well-insulated surfaces in the building. Typical savings for retrofit insulation are on the order of 20-30% of your heating bill. For a monthly heating bill of $200, this can amount to $40-$60 in savings. Issues:
A plan will help you with insulating decisions. In general, you should bring the attic insulation up to currents standards because it is easy to do so. Wall insulation can be problematic, as many walls are little more than the width of a 2x4, which limits the depth of insulation that can be easily installed. Sometimes a second interior wall can be built which provides a deeper cavity for insulation as well as providing an easy opportunity to upgrade electrical wiring and new cable and telephone wiring. This is most economical when done as part of a larger room-remodeling effort. Regional Issues:
The amount of insulation that you need varies upon your climate and exposure to prevailing winds. Northern locations benefit most from insulation during the heating season; southern locations benefit most during the cooling season. Installation (Getting It Done):
Be sure to get bids from two or three (or more) contractors and explore different methods and types of insulation. Multiple bids will allow you to gain immediate perspective on the true costs and value of insulation in your area. More Information on This Topic: U.S. Department of Energy's Building Technologies Program: Insulation Materials U.S. Department of Energy's Building Technologies Program: Insulation Sealing Cost-Effective Insulation Values for Existing Homes Buildings for the 21st Century: Wall Insulation Buildings for the 21st Century: Ceilings and Attics Buildings for the 21st Century: Basement Insulation ColoradoENERGY.org - Calculating Savings: Adding Insulation References: Lawrence Berkeley National Laboratory U.S. Department of Energy Moisture Management for Energy Efficiency and Comfort
Technology Snapshot & Benefits:
You can increase comfort and save money by mindfully managing the moisture content of the air in your home. Humans are most comfortable at a relative humidity of 50%, plus or minus 10%. Relative humidity is the amount of moisture that air contains relative to the maximum amount that it could contain (at any given temperature and pressure). Two separate strategies are required: one for summer and one for winter. In the winter, air inside the house is cycled repeatedly past heating elements in your heating system, where it gets drier and drier. As room air dries, you will increasingly experience dry and itchy skin, dry eyes and mouth, chapped hands, static electricity and a wide range of other discomforts. From an energy efficiency perspective, the dry air increases the rate of evaporation of body moisture from your skin and this evaporation makes you feel chilled. A normal reaction is to turn up the heat as you attempt to keep warm. The net result is that you will burn extra fuel to maintain a higher room temperature and the air will become progressively drier. In the winter, your strategy is to add moisture to the air. In summer, the situation is generally reversed and your strategy is to reduce relative humidity of the room air. As humidity levels increase above about 50%, evaporation from your skin is reduced. Lower evaporation rates deprive your body of its normal cooling mechanism and you feel warm. A typical reaction is to turn down the thermostat of your air conditioning in an attempt to keep cool. The net result is that you will burn extra fuel and money to maintain a lower room temperature than necessary, compared to the amount of cooling that is needed if relative humidity is maintained at comfortable levels. Studies have shown that when humidity is maintained at around 50% in a living space, air conditioner thermostats may be set as much as 5 to 7 degrees (F) warmer while providing the same level of comfort to occupants. Since most air conditioners are electric, and most electricity is produced in central-station power-plants, energy and pollution savings from reduced air conditioning are huge. This is because the electricity that arrives at your electric outlet is produced and delivered at an overall fuel efficiency of about 30%. Turning up the thermostat of your air conditioner has a dramatic and positive effect on your electric bill and on summer pollution levels. To do this and maintain (or improve) comfort, you must control relative humidity of the room air. Estimated Cost Savings:
Economic savings achieved by moisture control are in direct proportion to how much less you run your furnace in the winter and air conditioner in the summer. Costs to achieve moisture control vary with the level of sophistication of the equipment. At the inexpensive end are simple operational changes that cost you nearly nothing. An example is the practice of venting a clothes dryer through a lint filter to the interior of a building rather than the exterior. This technique captures productively both the moisture in the clothing and the heat generated by the clothes dryer. In addition, a new generation of rechargeable desiccant technologies is emerging that provide low-cost means of reducing moisture in buildings during the summer months. Depending upon the level of sophistication of equipment and controls, you may expect savings to your utility bills in the range of 10-30%. Issues:
Moisture control is not fully appreciated by the building industry. Often, equipment is purposefully oversized as a way of providing performance during periods of peak demand. By definition, peaks occur infrequently and the equipment is oversized for the balance of the time, requiring more energy than necessary to operate. A primary issue facing you in your quest to achieve moisture control in buildings is finding an installer or contractor that understands techniques that take into consideration the lifetime operating costs of equipment. An installer or builder is usually sensitive to "first cost" considerations, but seldom appreciates the full cost of operation over the useful lifetime of the equipment. As a homeowner, you see not only the initial cost but the full operating cost as well. Availability of the most energy-efficient equipment may be an issue. Sometimes the best equipment is "in demand" and this can mean that discounts are either unavailable or limited. Regional Issues:
Buildings in northern climates are more likely to benefit from humidification in winter. Buildings in southern climates are more likely to benefit from de-humidification in summer. Some systems can achieve both goals, but traditionally both humidification and de-humidification functions have not been incorporated in the same piece of equipment. Other regional issues involve supply, delivery, and installation of equipment. Installation (Getting It Done):
Be sure to price shop and to get two or three (or more) prices. Inquire about installation and removal of any older equipment that you may have in your building. For any air conditioning or refrigeration unit, be sure that the refrigerant will be removed and recycled responsibly. Refrigerants are very potent greenhouse gases and must be captured and contained. Shopping for price and availability will give you perspective on the true costs of equipment and installation in your area. Natural Daylighting
Technology Snapshot & Benefits:
Both obvious and hidden economic savings come from building designs that rely on natural lighting. Throughout much of the day, owners and occupants can easily benefit from natural lighting and avoid electrical consumption otherwise required by artificial indoor lamps. Not so obviously, considerable economic gain may be achieved through increased productivity of workers and occupants. Studies have repeatedly demonstrated that natural illumination is the "gold standard" by which the efficacy of artificial lighting technologies is gauged. Further, studies show that workers with access to windows and natural light are happier, more productive, and suffer fewer health problems than workers resigned to artificial lighting. Technologies include efficient windows, skylights, light shafts, and many architectural features that allow natural light to penetrate into the building. Newer technologies are used as well. Over the past decade, some Japanese shoppers have benefited from natural light delivered to the interior of shopping malls via fiber optic cables originating on the roof. Estimated Cost Savings:
The direct economic savings achieved by "daylighting" must be balanced against any potential heat loss associated with any window or skylight. For maximum cost effectiveness, only the most efficient windows and skylights should be considered. Actual savings will depend upon how much you rely on artificial lighting, your local climatic conditions, etc. It is a good idea to check with local builders and energy offices to better calculate energy savings. However, it is unlikely that any consultant will be able to quantify the true value of access to daylight – as measured by satisfaction with the building, increased productivity, and improved health. Issues:
Daylighting technologies are relatively easy to incorporate in new construction. Opportunities in existing buildings may require a little creativity or the advice of an architect or builder. For more information, see http://www.daylighting.org/. Regional Issues:
Brighter climates may offer more resource to work with, but consider issues of heat gain and loss in addition to increased illumination. Daylighting in northern climates may provide disproportionately greater benefits to morale and human health because these regions often are subjected to prolonged cloud cover during winter months. Installation (Getting It Done):
Be sure to get bids from two or three (or more) installers and/or building contractors specializing in windows and skylights to gain immediate perspective on the true costs of equipment and installation in your area. More Information On This Topic: National Renewable Energy Laboratory: Passive Solar U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy: Passive Solar Home Design U.S. Department of Energy's Energy Savers: Energy Recovery Ventilation for Residences |