EGEE 102
Energy Conservation and Environmental Protection

Energy Use of Home Appliances, Page 3

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Locating 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.

toaster with wattage information enlarged
You can find the wattage information on the bottom or back of many appliances.
Credit: absak.com

A refrigerator, although turned "on" all the time, actually cycles on and off at a rate that depends on a number of factors. These factors include how well it is insulated, room temperature, freezer temperature, how often the door is opened, if the coils are clean, if it is defrosted regularly, and the condition of the door seals.

To get an approximate figure for the number of hours that a refrigerator actually operates at its maximum wattage, divide the total time the refrigerator is plugged in by three.

The table below shows wattage of some typical household appliances.

Power consumption (Wattage)
Appliance Wattage (range)
Clock Radio 10
Coffee Maker 900 - 1200
Clothes Washer 350 - 500
Clothes Dryer 1800-5000
Dishwasher 1200-2400
Hair Dryer 1200-1875
Microwave Oven 750-1100
Laptop 50
Refrigerator 725
36" Television 133
Toaster 800-1400
Water Heater 4500-5500
Typical range of power consumption (Wattage) of some commonly used appliances
Appliance Wattage
Aquarium 50 - 1210
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 - ceiling 65 - 175
Fan - window 55 - 250
Fan - furnace 750
Fan - whole house 240 - 750
Hair Dryer 1200 - 1875
Heater (portable) 750 - 1500
Clothes Iron 1000 - 1800
Microwave Oven 750 - 1100
Personal Computer - CPU - awake / asleep 120 / 30 or less
Personal Computer - Monitor - awake / asleep 150 / 30 or less
Laptop 50
Radio (stereo) 70 - 400
Refrigerator (frost free, 16 cubic feet) 725
19" Television 65 - 110
27" Television 113
36" Television 133
53" - 61" Projection TV 170
Flat Screen TV 120
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 (w/heater, no cover) 120 - 380

Amperes and Voltage

Animation showing an ampmeter

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 an ammeter 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.

Phantom Loads

Also note that 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 VCR, televisions, stereos, computers, and kitchen appliances.

Most phantom loads will increase the appliance's energy consumption a few watts per hour. 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.