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 Use

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 ammeter—an electrician's tool that clamps around one of the two wires on the appliance—to 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 Appliances

Alphabetical Listing by Appliance Name

Aquarium = 50–1210 Watts

Clock radio = 10

Coffee maker = 900–1200

Clothes washer = 350–500

Clothes dryer = 1800–5000

Dishwasher = 1200–2400 (using the drying feature greatly increases energy consumption)

Dehumidifier = 785

Electric blanket- Single/Double = 60 / 100

FAN --

Furnace = 750

Whole house = 240–750

Hair dryer = 1200–1875

Heater (portable) = 750–1500

Clothes iron = 1000–1800

Microwave oven = 750–1100

PERSONAL COMPUTER --

Radio (stereo) = 70–400

Refrigerator (frost-free, 16 cubic feet) = 725

TELEVISION --(COLOR)

Toaster = 800–1400

Toaster oven = 1225

VCR/DVD = 17–21 / 20–25

Vacuum cleaner = 1000–1440

Water heater (40 gallon) = 4500–5500

Water pump (deep well) = 250–1100

Water bed (with heater, no cover) = 120–380