Appliances-fixtures should be selected based on their ENERGY STAR® rating and also on the basis that they meet recommended efficiency levels. Components, fixtures, and furnishings should be positioned and located from optimum energy utilization point of view -- for example, grouping similar functions allows localization of special requirements for particular tasks and results in lower first cost and lower operating costs. Equipment that has high heat production should be grouped together -- for example, computer centers or lab areas should have separate, dedicated HVAC equipment.
Energy ConsumptionAccording to U.S. Department of Energy -- A Consumers Guide to Energy Efficiency and Renewable Energy --
Regarding appliances-fixtures ... in a typical U.S. home, the appliances and home electronics are responsible for about 20 percent of the energy bill.
Estimating Appliance and Home Electronics Energy UseIf you're trying to decide whether to invest in more energy efficient appliances-fixtures you'd like to determine your electricity loads and estimate appliance energy consumption.
Formula for Estimating Energy Consumption for your appliances-fixtures ... you can use this formula to estimate an appliance's energy use:
(Wattage × Hours Used Per Day ÷ 1000 = Daily Kilowatt-hour (kWh) consumption
(1 kilowatt (kW) = 1,000 Watts)
Multiply this by the number of days you use the appliance during the year for the annual consumption. You can then calculate the annual cost to run an appliance by multiplying the kWh per year by your local utility's rate per kWh consumed.
Note: To estimate the number of hours that a refrigerator actually operates at its maximum wattage, divide the total time the refrigerator is plugged in by three. Refrigerators, although turned "on" all the time, actually cycle on and off as needed to maintain interior temperatures.
Examples: Window fan:
(200 Watts × 4 hours/day × 120 days/year) ÷ 1000 = 96 kWh × 8.5 cents/kWh = $8.16/year
Personal Computer and Monitor:
(120 + 150 Watts × 4 hours/day × 365 days/year) ÷ 1000 = 394 kWh × 8.5 cents/kWh = $33.51/year
Wattage You can usually find the wattage of most appliances stamped on the bottom or back of the appliance, or on its nameplate. The wattage listed is the maximum power drawn by the appliance. Since many appliances have a range of settings (for example, the volume on a radio), the actual amount of power consumed depends on the setting used at any one time.
If the wattage is not listed on the appliance, you can still estimate it by finding the current draw (in amperes) and multiplying that by the voltage used by the appliance. Most appliances in the United States use 120 volts. Larger appliances, such as clothes dryers and electric cooktops, use 240 volts. The amperes might be stamped on the unit in place of the wattage. If not, find a clamp-on ammeteran electrician's tool that clamps around one of the two wires on the applianceto measure the current flowing through it. You can obtain this type of ammeter in stores that sell electrical and electronic equipment. Take a reading while the device is running; this is the actual amount of current being used at that instant.
When measuring the current drawn by a motor, note that the meter will show about three times more current in the first second that the motor starts than when it is running smoothly.
Many appliances continue to draw a small amount of power when they are switched "off." These "phantom loads" occur in most appliances that use electricity, such as VCRs, televisions, stereos, computers, and kitchen appliances. Most phantom loads will increase the appliance's energy consumption a few watt-hours. These loads can be avoided by unplugging the appliance or using a power strip and using the switch on the power strip to cut all power to the appliance.
Typical Wattages of Various AppliancesHere are some examples of the range of nameplate wattages for various household appliances:
Alphabetical Listing by Appliance Name
Aquarium = 501210 Watts
Clock radio = 10
Coffee maker = 9001200
Clothes washer = 350500
Clothes dryer = 18005000
Dishwasher = 12002400 (using the drying feature greatly increases energy consumption)
Dehumidifier = 785
Electric blanket- Single/Double = 60 / 100
Furnace = 750
Whole house = 240750
Hair dryer = 12001875
Heater (portable) = 7501500
Clothes iron = 10001800
Microwave oven = 7501100
Radio (stereo) = 70400
Refrigerator (frost-free, 16 cubic feet) = 725
Toaster = 8001400
Toaster oven = 1225
VCR/DVD = 1721 / 2025
Vacuum cleaner = 10001440
Water heater (40 gallon) = 45005500
Water pump (deep well) = 2501100
Water bed (with heater, no cover) = 120380
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